RP-1455 Advanced HVAC Control Sequences for Airside Equipment

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems %A&'E () C(*%E*%S 1+1

A. #. ). *. . 1+

'"st of Hard ,"red Po"nts ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 

VAV Terminal Unit (Reheat !tional" ........................................................................................................ 2 $an Po%ere& Terminal Unit ('erie or Parallel, )ontant or Variable '!ee& $an" .................. ........................... .................. ........... .. 2 *+al *+t Terminal Unit %ith -nlet 'enor ('na! Ating or )ol& *+t inim+m )ontrol" .................. ..................... ... 3 *+al *+t Terminal Unit %ith *iharge 'enor ('na! Ating or i/ing )ontrol"............ )ontrol"..................... .................. ............... ...... 4 +lti!le one VAV Air an&ling Unit ........................................................................................................ 4 Control #"a.rams ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ /

A. VAV Terminal Unit %ith Reheat ..................................................................................................................  #. Parallel $anPo%ere& Terminal Unit, )ontant Vol+me $an .......................................................................  ). Parallel $anPo%ere& Terminal Unit, Variable Vol+me $an ........................................................................  *. 'erie $anPo%ere& Terminal Unit ...............................................................................................................  . *+al *+t Terminal Unit %ith -nlet 'enor ................................................................................................ 6 $. *+al *+t Terminal Unit %ith *iharge 'enor ......................................................................................... 6 7. +lti!le one VAV Air an&ling Unit %ith Ret+rn $an an& A ea+rement 'tation ............. ...................... ............... ...... 8 . +lti!le one VAV Air an&ling Unit %ith Relief $an an& *ifferential Pre+re A ea+rement...... 10 1+0

Sequences of (erat"on ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 11

A. 7eneral ........................................................................................................................................................ 11 #. 7eneri Thermal one ............................................................................................................................... 22 ). one 7ro+!................................................................................................................................................ 28 *. VAV )oolingnl9 Terminal Unit ............................................................................................................. 31 . VAV Reheat Terminal Unit ........................................................................................................................ 35 $. Parallel $anPo%ere& Terminal Unit, )ontant Vol+me $an ..................................................................... 38 7. Parallel $anPo%ere& Terminal Unit, Variable Vol+me $an ...................................................................... 45 . 'erie $anPo%ere& Terminal Unit, )ontant Vol+me $an ........................................................................ 50 -. *+al *+t VAV Terminal Unit : 'na! Ating )ontrol .............................................................................. 55 ;. *+al *+t VAV Terminal Unit : i/ing )ontrol %ith -nlet Airflo% 'enor ............. ....................... ................... .................. ........... 0 <. *+al *+t VAV Terminal Unit : i/ing )ontrol %ith *iharge Airflo% 'enor ................... ............................ ................ ....... 5 =. *+al *+t VAV Terminal Unit : )ol& *+t inim+m )ontrol ................................................................ 0 . +lti!le one VAV Air an&ling Unit ...................................................................................................... 4 1+4

A. #. ). *. . $. 7. . -. ;. <. =.

Pro.ramm"n. Parameters! Sett"n.s 2 Var"a$les++++++++++++++++++++++++++++++++++ ++++++++++++++++ ++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++ ++++++++++++ 133

7eneri Thermal one ............................................................................................................................. 100 VAV Terminal Unit, %> Reheat ................................................................................................................ 100 Parallel $anPo%ere& Terminal Unit, )ontant Vol+me $an ................................................................... 101 Parallel $anPo%ere& Terminal Unit, Variable Vol+me $an .................................................................... 101 'erie $anPo%ere& Terminal Unit, )ontant Vol+me $an ...................................................................... 101 *+al *+t VAV Terminal Unit, 'na! Ating )ontrol, *+al -nlet 'enor .................... ............................. .................. ................. ........ 101 *+al *+t VAV Terminal Unit, 'na! Ating )ontrol, *iharge 'enor.................. ............................ ................... .................. ........... .. 102 *+al *+t VAV Terminal Unit, i/ing )ontrol, *+al -nlet 'enor ...................................................... 102 *+al *+t VAV Terminal Unit, i/ing )ontrol, *iharge 'enor ........................................................ 102 *+al *+t VAV Terminal Unit, )ol& *+t inim+m )ontrol ................................................................ 102 +lti!le one VAV Air an&ling Unit .................................................................................................... 103 Alarm =evel in A=) -m!lementation ..................................................................................................... 105

November 30, 2014

Page 1 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems 1+1 A+

'"st of Hard ,"red Po"nts Po" nts VAV %erm"nal n"t Reheat (t"onal6 #escr"t"on

%ye

A VAV #o/ *am!er Poition

&+

OR

t%o * an& one A-

#ev"ce

o&+lating at+ator OR

$loating at+ator %>!oition fee&ba? o&+lating valve

eating 'ignal (reheat bo/e onl9"

A

*iharge Airflo%

A-

*iharge Air Tem!erat+re one Tem!erat+re =oal verri&e (if a!!liable" +!an9 'enor (if a!!liable"

AA**-

o&+lating eletri heating oil *ifferential !re+re tran&+er onnete& to flo% enor *+t tem!erat+re enor Room tem!erat+re enor one thermotat overri&e %ith +!an9 enor

@in&o% '%ith (if a!!liable" one Tem!erat+re 'et!oint A&+tment (if a!!liable" one )2 =evel (if a!!liable"

*-

@in&o% %ith

A-

one thermotat a&+tment

A-

Room )2 enor

OR

)an Po7ered %erm"nal n"t Ser"es or Parallel! Constant or Var"a$le Seed )an6 #escr"t"on

%ye

#ev"ce

$an '!ee& )omman& (if a!!liable" $an 'tart>'to! (if e!arate from fan !ee& !oint" $an 'tat+

A

)onnet to )

*


*-

)onnet to +rrent %ith

OR

OR

OR

$an '!ee& $ee&ba?

AA


VAV #o/ *am!er Poition

OR



$loating at+ator %>!oition fee&ba? o&+lating valve

eating 'ignal

A

Primar9 Airflo%

A-

Total Airflo% (if a!!liable"

A-

November 30, 2014

OR

o&+lating eletri heating oil *ifferential !re+re tran&+er onnete& to flo% enor *ifferential !re+re tran&+er onnete& to flo% enor

Page 2 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems #escr"t"on

#ev"ce

*iharge Air Tem!erat+re one Tem!erat+re =oal verri&e (if a!!liable"

AA*-

*+t tem!erat+re enor Room tem!erat+re enor one thermotat overri&e %ith

+!an9 'enor (if a!!liable" @in&o% '%ith (if a!!liable" one Tem!erat+re 'et!oint A&+tment (if a!!liable"

**-

+!an9 enor @in&o% %ith

A-


A-


one )2 =evel (if a!!liable"

C+

%ye

#ual #uct %erm"nal n"t 7"th nlet Sensors Sna Act"n. or Cold #uct 8"n"mum Control6 #escr"t"on

%ye

#ev"ce

)ooling *am!er Poition

A (R t%o * an& one A-

o&+lating at+ator (R $loating at+ator %>!oition fee&ba?

eating *am!er Poition

A (R t%o * an& one A-

o&+lating at+ator (R $loating at+ator %>!oition fee&ba?

)ooling Airflo%

A-

eating Airflo%

A-

*iharge Air Tem!erat+re one Tem!erat+re =oal verri&e (if a!!liable" +!an9 'enor (if a!!liable"

AA**-

*ifferential !re+re tran&+er onnete& to flo% enor *ifferential !re+re tran&+er onnete& to flo% enor *+t tem!erat+re enor Room tem!erat+re enor one thermotat overri&e %ith +!an9 enor

@in&o% '%ith (if a!!liable" one Tem!erat+re 'et!oint A&+tment (if a!!liable" one )2 =evel (if a!!liable, ol& &+t minim+m ontrol onl9"

*-

@in&o% %ith

A-


A-


November 30, 2014

Page 3 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems #+

#ual #uct %erm"nal n"t 7"th #"schar.e Sensor Sna Act"n. or 8"9"n. Control6 #escr"t"on

%ye

A OR

)ooling *am!er Poition

t%o * an& one AA OR

eating *am!er Poition

E+


#ev"ce


$loating at+ator %>!oition fee&ba? o&+lating at+ator OR

$loating at+ator %>!oition fee&ba?

*iharge Airflo%

A-

*ifferential !re+re tran&+er onnete& to flo% enor

*iharge Air Tem!erat+re one Tem!erat+re =oal verri&e (if a!!liable"

AA*-

*+t tem!erat+re enor Room tem!erat+re enor one thermotat overri&e %ith

+!an9 'enor (if a!!liable" @in&o% '%ith (if a!!liable" one Tem!erat+re 'et!oint A&+tment (if a!!liable" one )2 =evel (if a!!liable, mi/ing ontrol onl9"

**-

+!an9 enor @in&o% %ith

A-


A-


8ult"le one VAV A"r Handl"n. n"t #escr"t"on

%ye

#ev"ce

'+!!l9 $an 'tart>'to! '+!!l9 $an igh 'tati Alarm Reet '+!!l9 $an '!ee& '+!!l9 Airflo% (if a!!liable" '+!!l9 Air Tem!erat+re

* * A AA-

)onnet to V$* R+n *r9 ontat to 120V or 24V ontrol ir+it )onnet to V$* '!ee& Airflo% mea+rement tation at +!!l9 fan *+t tem!erat+re enor

*+t 'tati Pre+re $ilter Pre+re *ro! onomiBer +t&oor Air *am!er Ret+rn Air *am!er +t&oor Air Tem!erat+re (o!tional" i/e& Air Tem!erat+re Ret+rn Air Tem!erat+re )ooling 'ignal

AAA A AAAA

*ifferential !re+re tran&+er &o%n &+t *ifferential !re+re tran&+er aro filter o&+lating at+ator o&+lating at+ator Tem!erat+re enor at o+t&oor air inta?e Averaging tem!erat+re enor *+t tem!erat+re enor o&+lating )@ valve o&+lating @ valve

eating 'ignal

A

OR

o&+lating eletri heating oil

November 30, 2014

Page 4 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems #escr"t"on

%ye

#ev"ce

)or un"ts 7"th a common econom";er
+t&oor Airflo%

A-

Airflo% mea+rement tation

)or un"ts 7"th a searate m"n"mum outdoor a"r damer! "nclude the follo7"n. o"nts

inim+m +t&oor Air *am!er !en>)loe inim+m +t&oor Air *am!er *ifferential Pre+re OR

*

T%o !oition at+ator *ifferential !re+re tran&+er

A-

OR

Airflo% mea+rement tation

inim+m +t&oor Airflo%

)or un"ts 7"th actuated rel"ef damers $ut no rel"ef fan! "nclude the follo7"n. o"nts

Relief *am!er !en>)loe

A

#+il&ing 'tati Pre+re

A-

o&+lating a+tator *ifferential !re+re tran&+er bet%een re!reentative !ae an& o+t&oor

)or un"ts 7"th a rel"ef fan! "nclude the follo7"n. o"nts

Relief $an 'tart>'to! Relief $an '!ee& Relief *am!er !en>)loe

* A *


A-

)onnet to V$* R+n )onnet to V$* '!ee& T%o !oition at+ator *ifferential !re+re tran&+er bet%een re!reentative !ae an& o+t&oor

)or un"ts 7"th a return fan! "nclude the follo7"n. o"nts

Ret+rn $an 'tart>'to! Ret+rn $an igh 'tati Alarm Reet

* *

)onnet to V$* R+n *r9 ontat to 120V or 24V ontrol ir+it

Ret+rn $an '!ee& Ret+rn Airflo% (if a!!liable" Ret+rn $an 'tati Pre+re /ha+t *am!er

A AAA


A-

)onnet to V$* '!ee& Airflo% mea+rement tation at ret+rn fan *ifferential !re+re tran&+er at fan o&+lating at+ator *ifferential !re+re tran&+er bet%een re!reentative !ae an& o+t&oor

November 30, 2014

Page 5 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems 1+

Control #"a.rams

A+

VAV %erm"nal n"t 7"th Reheat

&+

Parallel )an-Po7ered %erm"nal n"t! Constant Volume )an

November 30, 2014

Page  of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems C+

Parallel )an-Po7ered %erm"nal n"t! Var"a$le Volume )an

#+

Ser"es )an-Po7ered %erm"nal n"t

November 30, 2014

Page  of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems E+

#ual #uct %erm"nal n"t 7"th nlet Sensors

)+

#ual #uct %erm"nal n"t 7"th #"schar.e Sensor

November 30, 2014

Page 6 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems =+

8ult"le one VAV A"r Handl"n. n"t 7"th Return )an and (A 8easurement Stat"on

November 30, 2014

Page 8 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems H+

8ult"le one VAV A"r Handl"n. n"t 7"th Rel"ef )an and #"fferent"al Pressure (A 8easurement

November 30, 2014

Page 10 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems 1+0 A+

Sequences of (erat"on =eneral 1.

Unle other%ie in&iate&, ontrol loo! hall be enable& an& &iable& bae& on the tat+ of the 9tem being ontrolle& to !revent %in&+!.

2.

@hen a ontrol loo! i enable&, it a n& all it ontit+ent (+h a the !ro!ortional an& integral term" hall be et to a Ne+tral val+e.

3.

A ontrol loo! in Ne+tral hall orre!on& to a on&ition %hih a!!lie the minim+m ontrol effet, i.e. valve>&am!er loe&, V$* at minim+m !ee&, et.

4.

@hen there are m+lti!le o+t&oor air tem!erat+re enor, the 9tem hall +e the vali& enor %hih i !h9iall9 loet to the eC+i!ment being ontrolle&.. a.

+t&oor air tem!erat+re enor at air han&ler o+t&oor air inta?e hall be oni&ere& vali& onl9 %hen the +!!l9 fan i !roven on an& +nit i in +!ie& o&e (!ro&+ing airflo% aro the enor".

b.

The general T'4 o+t&oor air tem!erat+re enor hall be vali& onl9 if all o+t&oor air inta?e enor are invali&.

.

The o+t&oor air tem!erat+re +e& for gra!hi &i!la9, o!tim+m tart, !lant AT lo?o+t, an& other global eC+ene hall be the average of all vali& enor rea&ing.

5.

The term D!rovenE (i.e. D!roven onE> D!roven offE" hall mean that the eC+i!mentF *- tat+ !oint mathe the tate et b9 the eC+i!mentF * omman& !oint.

.

The term Dontrol loo!E or Dloo!E i +e& generiall9 for all ontrol loo!. Thee %ill t9!iall9 be P-* loo!, b+t !ro!ortional !l+ integral !l+ &erivative gain are not reC+ire& on all loo!. Unle !eifiall9 in&iate& other%ie, the follo%ing g+i&eline hall be follo%e&G Use of proportional-only prevents integral windup. a.

Ue !ro!ortional onl9 (Ponl9" loo! for limiting loo! (+h a Bone ) 2 ontrol loo!, et.".

Derivative terms make loop tuning difficult in practice. b.

*o not +e the &erivative term on an9 loo! +nle fiel& t+ning i not !oible %itho+t it.

.

To avoi& abr+!t hange in eC+i!ment o!eration, the o+t!+t of ever9  ontrol loo! hall be limite& to a ma/im+m rate of hange of 25H !er min+te +nle other%ie note&.

6.

All et!oint, timer, &ea&ban&, P-* gain, et. lite& in eC+ene hall be a!able of being a&+te& b9 the o!erator thro+gh the normal )' +er interfae %hether in&iate& a a&+table in eC+ene or not. 'oft%are (virt+al" !oint hall be +e& for thee variable. $i/e& alar n+mber hall not be embe&&e& in !rogram e/e!t for !h9ial ontant (e.g. onverion fator".

November 30, 2014

Page 11 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems All hardware points, not just inputs, should be capable of being overridden for purposes of testing and commissioning. For eample, the commissioning agent should be able to command damper positions, valve positions, fan speeds, etc directly through !"#$ overrides. %he following re&uirement to e&uate hardware points to software points is necessary for systems that do not allow overriding real input points. Application $pecific #ontrollers 'A$#( are e cepted because, in our eperience, it may not be cost effective or feasible for all points due to limitations of A$# hardware. )owever, some critical points 'e.g. *A* bo damper position( may need to have this capability+ these are specifically addressed in subse&uent se&uences. 8.

Val+e for all !oint, inl+&ing real (har&%are" !oint +e& in ontrol eC+ene hall be a!able of being overri&&en b9 the +er (e.g. for teting an& ommiioning". -f har&%are &eign !revent thi for har&%are !oint, the9 hall be eC+ate& to a oft%are !oint an& the oft%are !oint hall be +e& in all eC+ene. /e!tionG Not reC+ire& for all A') har&%are !oint.

10.

V$* inim+m '!ee& 'et!oint %here needs to be corresponding instructions in the %A specifications. For eample • $tart the fan or pump. • "anually set speed to  )/ '012( unless otherwise indicated in control se&uences. For cooling towers with gear boes, use 312 or whatever minimum speed is recommended by tower manufacturer. • 4bserve fan5pump in field to ensure it is visibly rotating. 6f not, gradually increase speed until it is. • %he speed at this point shall be the minimum speed setpoint for this piece of e&uipment. a.

inim+m !ee& et!oint for all V$*&riven eC+i!ment hall be &etermine& in aor&ane %ith the tet an& balane !eifiation.

%he following prevents separate, potentially conflicting minimum speed setpoints from eisting in the !"#$ software and the drive firmware. b.

$or eah !iee of eC+i!ment, the minim+m !ee& hall be tore& in a ingle oft%are !oint. Thi val+e hall be ma!!e& to the V$*F minim+m !ee& et!oint via the &riveF net%or? interfaeI in the ae of a har&%ire& V$* interfae, the minim+m !ee& hall be the lo%et !ee& omman& ent to the &rive b9 the )'.

%he following prohibits the practice of e&uating the minimum speed of a piece of e&uipment to a 7/ero8 speed in the !"#$, which creates confusion during subse&uent building recommissioning. .

November 30, 2014

The minim+m !ee& et!oint hall be tore& a a !oitive !erentage of f+ll range. -.e. 0H !ee& hall orre!on& to f+ll9 to!!e& eC+i!ment, an& the minim+m !ee& hall be a val+e greater than 0H.

Page 12 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems A %rim 9 :espond loop controls a setpoint for pressure, temperature, or other variables at an air handler or plant. 6t reduces the setpoint at a fied rate, until a downstream /one is no longer satisfied and generates a re&uest. ;hen a sufficient number of re&uests are present, the setpoint is increased in response. %he importance of each /one
Trim J Re!on& 'et!oint Reet =ogi a.

Trim J Re!on& et!oint reet logi an& Bone>9tem reet ReC+et %here referene& in eC+ene hall be im!lemente& a &eribe& belo%.

b.

A DReC+etE i a all to reet a tati !re+re or tem!erat+re et!oint, generate& b9 &o%ntream Bone or air han&ling 9tem. Thee ReC+et are ent +!tream to the !lant or 9tem that erve the Bone or air han&ler %hih generate& the ReC+et. 1"

$or eah &o%ntream Bone or 9tem, an& for eah t9!e of et!oint reet ReC+et lite& for the Bone>9tem, !rovi&e the follo%ing oft%are !ointG 6mportance "ultiplier is used to scale the number of re&uests the /one5system is generating. A value of /ero causes the re&uests from that /one or system to be ignored. A value greater than one can be used to effectively increase the number of re&uests from the /one5system based on the critical nature of the spaces served. a"

-m!ortane +lti!lier (&efa+lt K 1"

:e&uest-)ours accumulates the integral of re&uests 'prior to adjustment of 6mportance "ultiplier( to help identify /ones5systems that are driving the reset logic. :ogue /one identification is particularly critical in this contet, since a single rogue /one can keep the %rim 9 :esponse loop at maimum, and prevent it from saving any energy.

November 30, 2014

b"

ReC+eto+r. ver9 / min+te (&efa+lt 5 min+te", a&& />0 time the +rrent n+mber of ReC+et to thi reC+etho+r a+m+lator !oint. The reC+etho+r !oint i reet to Bero +!on a global omman& from the 9tem>!lant erving the Bone>9tem : thi global !oint im+ltaneo+l9 reet the reC+etho+r !oint for all Bone>9tem erve& b9 thi 9tem>!lant.

"

)+m+lativeHReC+eto+r. Thi i the Bone>9tem ReC+eto+r &ivi&e& b9 the Bone>9tem r+nho+r (the ho+r in an9 o&e other than Uno+!ie& o&e" ine the lat reet, e/!ree& a a !erentage.

&"

A =evel 4 alarm i generate& if the Bone -m!ortane +lti!lier i greater than Bero, the Bone>9tem )+m+lativeHReC+eto+r e/ee& 0H, an& the total n+mber of Bone>9tem r+nho+r e/ee& 40.

2"

'ee Bone an& air han&ling 9tem ontrol eC+ene for logi to generate ReC+et.

3"

+lti!l9 the n+mber of ReC+et &etermine& from Bone>9tem logi time the -m!ortane +lti!lier an& en& to the 9tem>!lant that erve the Bone>9tem. 'ee 9tem>!lant logi to ee ho% ReC+et are +e& in Trim J Re!on& logi. Page 13 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems .

$or eah +!tream 9tem or !lant et!oint being ontrolle& b9 a TJR loo!, &efine the follo%ing variable. All variable belo% hall be a&+table from a reet gra!hi aeible from a h9!erlin? on the aoiate& 9tem>!lant gra!hi. -nitial val+e are &efine& in 9tem>!lant eC+ene belo%. Val+e for trim, re!on&, time te!, et. hall be t+ne& to !rovi&e table ontrol. Var"a$le

'P0

&.

#ef"n"t"on

-nitial et!oint

'P

in

inim+m et!oint

'P

a/

a/im+m et!oint

T&

*ela9 timer

T

Time te!

-

N+mber of ignore& ReC+et

R

N+mber of ReC+et from Bone>9tem

'P rim

Trim amo+nt

'Pre

Re!on& amo+nt (m+t be o!!oite in ign to 'P rim"

'Prema/

a/im+m re!one !er time interval (m+t be ame ign a 'P e"

Trim J Re!on& logi hall reet et!oint %ithin the range 'P min to 'P ma/. @hen the aoiate& &evie (e.g. fan, !+m!" i off, the et!oint hall be 'P 0. The reet logi hall be ative %hile the aoiate& &evie i !roven on, tarting T & after initial &evie tart omman&. @hen ative, ever9 time te! T, trim the et!oint b9 'P trim. -f there are more than - ReC+et, re!on& b9 hanging the et!oint b9 'Pre L (R-", (i.e. the n+mber of ReC+et min+ the n+mber of -gnore& ReC+et", b+t no more than 'Prema/. -n other %or&, ever9 time te! TG )hange et!oint b9 'Ptrim -f RM-, alo hange et!oint b9 (R-"L'P re b+t no larger than 'P rema/

November 30, 2014

Page 14 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems %he following is an eample of a se&uence which uses %rim 9 :espond to control the static pressure setpoint of a *A* A)U serving multiple downstream /ones 'tati !re+re et!oint hall be reet +ing trim an& re!on& logi %ithin the range 0.15 inhe to 1.5 inhe. @hen fan tart, et!oint i 0.5 inhe. After fan i !roven on for 5 min+te, ever9 2 min+te, &ereae the et!oint b9 0.04 inhe. -f there are more than t%o !re+re reC+et, inreae the et!oint b9 0.0 for eah reC+et in e/e of t%o, +! to a ma/im+m of 0.15. A !re+re reC+et i generate& %hen an9 VAV &am!er erve& b9 the 9tem i more than 85H o!en.

=ote that it is recommended that > $? res > @ > $? trim > so that one does not get stuck at a value, as can happen if $? res and $? trim are e&ual in absolute value. %his se&uence defines the %9: variables as follows SP3

SPm"n

SPma9

%d

%



SPtr"m

SPres

SPres-ma9

0.5

0.15

1.50

5

2

2

-0.04

0.06

0.15

'All /ones are e&ual, e.g. an open plan office, so the 6mportance factor is not used.( Description of general operation %he se&uence will slowly reduce the A)U
November 30, 2014

Page 15 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems %his is a trend graph of the eample above, continued for a period of an hour R M - K et!oint rie

R K 5  'Prema/K 0.15E R K   'Prema/K 0.15E

R K   'Prema/K 0.15E

R O - K et!oint fall

R O - K et!oint fall tea&il9

%he system will tend towards minimum static pressure 'thus saving energy( but respond rapidly to increasing demand from the terminal units. %his cyclic pattern is characteristic of a robust %rim 9 :espond loop G the setpoint is not epected to remain static ecept at its minimum and maimum values.

12.

C+i!ment 'taging an& Rotation %he automatic even wear rotation presented in the following section is written using the basis of e&uipment run time to determine position in the &ueue for staging and is triggered only during a stage up or stage down event. %hese se&uences will provide the most even run time across multiple pieces of e&uipment. %he engineer may consider modifying this se&uence to achieve other effects, such as • ?roviding a minimum run time before a piece of e&uipment is staged off to prevent the e&uipment from short cycling. • ?roviding a maimum run time before a piece of e&uipment is staged off 'this is useful for systems that operate continuously(. a.

A+tomati ven @ear Rotation 1"

November 30, 2014

=ea&>lagG Unle other%ie note&, !arallel tage& &evie (+h a !+m!, to%er" that are not re&+n&ant hall be lea&>lag alternate& %hen more than one i off or more than one i on o that the &evie %ith the mot o!erating ho+r i ma&e the later tage &evie an& the one %ith the leat n+mber of ho+r i ma&e the earlier tage &evie. $or e/am!le, a+ming there are three &evie, if all three are off or all are on, the taging or&er %ill im!l9 be bae& on r+n ho+r from lo%et to highet. -f t%o &evie are on, the one %ith the mot ho+r %ill be et to be tage 2 %hile the other i et to tage 1I thi ma9 be the revere of the o!erating or&er %hen the &evie %ere tarte&. -f t%o &evie are off, the one %ith the mot ho+r %ill be et to be tage 3 %hile the other i et to tage 2I thi ma9 be the revere of the o!erating or&er %hen the &evie %ere to!!e&.

Page 1 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems 2"

b.

=ea&>tan&b9G Unle other%ie note&, !arallel &evie (+h a !+m!, to%er" that are 100H re&+n&ant hall be lea&>tan&b9 alternate& %hen more than one i off o that the &evie %ith the mot o!erating ho+r i ma&e the later tage &evie an& the one %ith the leat n+mber of ho+r i ma&e the earlier tage &evie. $or e/am!le, a+ming there are three &evie, if all three are off, the taging or&er %ill be bae& on r+n ho+r from lo%et to highet. -f &evie r+n ontin+o+l9, lea&>tan&b9 hall %ith at an o!erator!eifie& r+ntimeI tan&b9 &evie hall firt be tarte& an& !roven on before former lea& &evie i hange& to tan&b9 an& h+t off.

/e!tion 1"

!erator hall be able to man+all9 fi/ taging or&er via oft%are !oint on gra!hi overri&ing the ven @ear or Perio&i Rotation logi above, b+t not overri&ing the -n Alarm or an& !eration logi belo%.

%he following se&uence does not lock out a device that is in alarm. 6t moves all devices in alarm to the end of the rotation se&uence such that they will be the last devices c alled to run. %he se&uence will only called for these devices in alarm if all of the devices not in alarm are already enabled and there is a call for a stage-up 'e.g. due to loss of control(.A device in alarm will respond if called to run, only if it is capable of doing so 'e.g. not locked out on internal safety, locked out on an )4A switch at the starter or otherwise disabled(. 6t is important to note that this staging does not override the devices internal safeties so it will not damage e &uipment. =ote some alarm conditions could be triggered when the underlying e&uipment is fully operable. For eample a status point not matching the on5off command could be triggered by a faulty status signal. %he same is true for a supervised )4A at a control panel, the operator might have been testing the e&uipment and simply forgot to turn the )4A back to AU%4. 2"

-n AlarmG -f the lea& &evie ha a fa+lt on&ition or ha been man+all9 %ithe& off, a =evel 2 alarm hall be generate& an& the &evie hall be et to the lat tage !oition in the lea&>lag or&er +ntil alarm i reet b9 o!erator. 'taging !oition of remaining &evie hall follo% the !revailing (ven @ear or Perio&i Rotation" logi. A &evie in alarm an onl9 a+tomatiall9 move +! in the taging or&er if another &evie goe into alarm. $a+lt on&ition inl+&e the follo%ingG ;e are including pumps, chillers and boilers even though they are beyond the scope of :?0CC in anticipation of %#-0. etending this work to such devices. a"

b"

November 30, 2014

Variable '!ee& $an an& P+m! (1"

V$* ritial fa+lt i N

(2"

'tat+ !oint not mathing it on>off !oint for 15 eon& %hile the &evie i omman&e& on

(3"

'+!ervie& A at ontrol !anel in $$ !oition

(4"

=o of !o%er (e.g. V$* *) #+ voltage K Bero"

)ontant '!ee& $an an& P+m! (1"

'tat+ !oint not mathing it on>off !oint for 15 eon& %hile the &evie i omman&e& on

(2"

'+!ervie& A at ontrol !anel in $$ !oition

Page 1 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems "

&"

)hiller (1"

)hiller alarm ontat

(2"

)hiller i man+all9 h+t off a in&iate& b9 the tat+ of the =oal>A+to %ith from hiller gate%a9

(3"

)hiller tat+ remain off 5 min+te after omman& to tart

#oiler (1"

#oiler alarm !oint i N

(2"

-f it leaving %ater tem!erat+re remain 15 °$ belo% et!oint for 30 min+te.

Any condition in which a device appears to continue to run after being commanded off is considered a case of 7hand operation8+ in practice this condition may arise due to other circumstances 'e.g. a bad current transducer(. 3"

an& !erationG -f a &evie i on in an& (e.g. via an A %ith or loal ontrol of V$*", the &evie hall be et to the lea& &evie an& a =evel 4 alarm hall be generate&. The &evie %ill remain a lea& +ntil the alarm i reet b9 the o!erator. an& o!eration i &etermine& b9 a"

b"

"

November 30, 2014

Variable '!ee& $an an& P+m! (1"

'tat+ !oint not mathing it on>off !oint for 15 eon& %hile the &evie i omman&e& off

(2"

V$* in loal Dhan&E mo&e

(3"

'+!ervie& A at ontrol !anel in N !oition

)ontant '!ee& $an an& P+m! (1"

'tat+ !oint not mathing it on>off !oint for 15 eon& %hile the &evie i omman&e& off

(2"

'+!ervie& A at ontrol !anel in N !oition

)hillerG )hiller i man+all9 t+rne& on a in&iate& b9 the tat+ of the loal>a+to %ith from hiller gate%a9.

Page 16 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems Defining the operator
Alarm a.

There hall be 5 level of alarm 1"

=evel 1G )ritial>life afet9

2"

=evel 2G 'ignifiant eC+i!ment fail+re

3"

=evel 3G Nonritial eC+i!ment fail+re>o!eration

4"

=evel 4G nerg9 onervation monitor

5"

=evel 5G aintenane in&iation, notifiation

)ierarchical alarm suppression is described in a paper by Meff $chein and $teve ushby, published in )*A#9: :esearch Manuary, 311. 6t is a techni&ue for suppressing etraneous or nuisance alarms, based on the principle that if a fault occurs both at a source 'e.g. A)U( and a load 'e.g. *A* bo(, then the fault at the load is likely caused by the fault at the source and is at any rate of a lower priority than the source fault+ as such, the alarm for the load fault is suppressed in favor of the alarm for the source fault, so that the operator
ierarhial Alarm '+!!reion a.

November 30, 2014

$or eah !iee of eC+i!ment or !ae ontrolle& b9 the )', &efine it relationhi! (if an9" to other eC+i!ment in term of Do+reE, Dloa&E, or D9temE.

Page 18 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems For e&uipment that participates in a %rim 9 :esponse loop, the e&uipment generating the re&uests will always be the load component, and the e&uipment receiving and responding to the re&uests will be a source component. 1"

A om!onent i a Do+reE if it !rovi&e reo+re to a &o%ntream om!onent, +h a a hiller !rovi&ing hille& %ater to an AU.

2"

A om!onent i a Dloa&E if it reeive reo+re from an +!tream om!onent, +h a an AU that reeive hille& %ater from a hiller.

3"

The ame om!onent ma9 be both a loa& (reeiving reo+re from an +!tream o+re" an& a o+re (!rovi&ing reo+re to a &o%ntream loa&".

4"

A et of om!onent i a D9temE if the9 hare a loa& in ommon (i.e. olletivel9 at a a o+re to &o%ntream eC+i!ment, +h a a et of hiller in a lea&>lag relationhi! erving air han&ler". a"

-f a ingle om!onent at a a o+re for &o%ntream loa& (e.g. an AU a a o+re for it VAV bo/e", then that ingle o+re om!onent hall be &efine& a a D9temE of one element.

b"

$or eC+i!ment %ith aoiate& !+m! (hiller, boiler, ooling to%er"G (1"

-f the !+m! are in a onetoone relationhi! %ith eC+i!ment the9 erve, the !+m! hall be treate& a !art of the 9tem to %hih the9 are aoiate& (i.e. the9 are not oni&ere& loa&" ine a !+m! fail+re %ill neearil9 &iable it aoiate& eC+i!ment.

(2"

-f the !+m! are hea&ere& to the eC+i!ment the9 erve, then the !+m! ma9 be treate& a a 9tem, %hih i a loa& relative to the +!tream eC+i!ment (e.g. hiller" an& a o+re relative to &o%ntream eC+i!ment (e.g. air han&ler".

!ample #onsider a building with four cooling tower cells, each with its own pump, two chillers with two #); pumps in a headered arrangement, three air handlers, and 01 *A* boes on each A)U, with each *A* bo serving multiple rooms. • %he cooling towers together constitute a system, which is a source to the chillers. • %he chillers together constitute a system, which is a load to the cooling tower system and a source to the #); pump system. • %he #); pumps together constitute a system, which is a load to the chillers and a source to the air handlers. • !ach air handler constitutes its own separate system because they do not share a load in common. !ach A)U is a load to the #); pump system, and a source to its own *A* boes. • !ach *A* bo constitutes its own system because they do not share a load in common. !ach *A* bo is a load to its A)U 'only+ no relationship to the other A)Us(, and a source to the rooms that it serves. • !ach interior space is a load to its associated *A* bo. b.

$or eah 9tem a &efine& above, there hall be a '9tem< flag, %hih i either tr+e or fale.

.

'9tem< hall be tr+e %hen all of the follo%ing are tr+eG

November 30, 2014

1"

The 9tem i !roven on.

2"

The 9tem i ahieving it tem!erat+re an&>or !re+re et!oint(" for at leat five min+te

Page 20 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems 3" &.

The 9tem i rea&9 an& able to erve it loa&

'9tem< hall be fale %hile the 9tem i tarting +! (i.e. before reahing et!oint" or %hen eno+gh of the 9temF om!onent are +navailable (in alarm, &iable&, or t+rne& off" to &ir+!t the abilit9 of the 9tem to erve it loa&. Thi threhol& hall be &efine& b9 the &eign engineer for eah 9tem. 1"

#9 &efa+lt, =evel 1 thro+gh =evel 3 om!onent alarm (in&iating eC+i!ment fail+re" hall inhibit '9tem<. =evel 4 an& =evel 5 om!onent alarm (maintenane an& energ9 effiien9 alarm" hall not affet '9tem<.

2"

The o!erator hall have the abilit9 to in&ivi&+all9 &etermine %hih om!onent alarm ma9 or ma9 not inhibit '9tem<. !amples 6f a boiler system consists of a pair of boilers si/ed for 0112 of the design load, in a lead-standby relationship, then $ystem4N is true if at least one boiler is operational and achieving setpoint. 6f a chiller system consists of three chillers each si/ed for C12 of the design load, then $ystem4N is true if at least two chillers are available to run. 6f only one chiller is available to run, then $ystem4N will be false 'even though the one remaining chiller may be sufficient to serve off-peak loads(.

e.

f.

November 30, 2014

The )' hall eletivel9 +!!re (i.e. fail to re!ort" alarm for loa& om!onent if '9tem< i fale for the o+re 9tem %hih erve that loa&. 1"

-f '9tem< i fale for a ooling %ater 9tem (i.e. hiller, ooling to%er, or aoiate& !+m!" then onl9 high tem!erat+re alarm from the loa& hall be +!!ree&.

2"

-f '9tem< i fale for a heating %ater 9tem (i.e. boiler or aoiate& !+m!" then onl9 lo% tem!erat+re alarm from the loa& hall be +!!ree&.

3"

-f '9tem< i fale for an airi&e 9tem (air han&ler, fan oil, VAV bo/, et" then all alarm from the loa& hall be +!!ree&.

Thi hierarhial +!!reion hall aa&e thro+gh m+lti!le level of loa&o+re relationhi!, +h that alarm at &o%ntream loa& hall alo be +!!ree&.

Page 21 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems !ample A building has a cooling tower system 'towers and #D; pumps(, a chiller system 'chillers and #); pumps(, a boiler system 'boilers and )); pumps(. %hese systems serve several air handlers 'each considered its own system(, and each air handler serves a series of *A* boes. 6f $ystem4N is false for the cooling tower system, then high temperature alarms are suppressed for the chillers, the air handlers, the *A* boes and /ones, but not for the boilers. Low temperature alarms are not suppressed. '=ote that in actuality, the hardwired interlock between cooling tower and c hiller would inhibit chiller operation if the cooling towers are off or locked out. %he eample is retained for illustrative purposes.( 6f $ystem4N is false for the chiller system, then high temperature alarms are suppressed for the air handlers and the *A* boes, but not for the cooling towers or boilers. Low temperature alarms are not suppressed. 6f $ystem4N is false for the boiler system, then low temperature alarms are suppressed for the air handlers and the *A* boes, but not for the cooling towers or chillers. )igh temperature alarms are not suppressed. 6f $ystem4N is false for one of the air handlers, then all alarms 'low temperature, high temperature, and airflow( are suppressed for all *A* boes served by that air handler only. Alarms are not suppressed for the cooling towers, chillers, boilers, or the other A)U or its *A* boes. 6f one *A* bo is in alarm, then all alarms 'e.g. /one temperature, #43 ( are suppressed for all spaces served by that *A* bo only. =o other alarms are suppressed. g.

&+

The follo%ing t9!e of alarm %ill never be +!!ree& b9 thi logiG 1"

=ife>afet9 an& =evel 1 alarm

2"

$ail+retotart alarm (i.e. eC+i!ment i omman&e& on, b+t tat+ !oint ho% eC+i!ment to be off"

3"

$ail+retoto!>han& alarm (i.e. eC+i!ment i omman&e& off, b+t tat+ !oint ho% eC+i!ment to be on"

=ener"c %hermal ones 1.

Thi etion a!!lie to all ingle Bone 9tem an& +bBone of air han&ling 9tem, +h a VAV bo/e, fan!o%ere& bo/e, et.

2.

inim+m +t&oor Air a.

$or ever9 Bone that reC+ire mehanial ventilation, the Bone minim+m o+t&oor airflo% an& et!oint hall be al+late& &e!en&ing on the governing tan&ar& or o&e for o+t&oor air reC+irement. one that &o not reC+ire mehanial ventilation ma9 &iregar& thi etion.

%he following section describes ventilation logic which complies with #alifornia %itle 3. 6f the project is to comply with $tandard 3 ventilation re&uirements, delete subsection 7b8 and skip to subsection 7c8. b.

November 30, 2014

$or om!liane %ith )alifornia Title 24, o+t&oor air et!oint hall be al+late& a follo%G

Page 22 of 105


The follo%ing information hall be a he&+le& on the !lan or !rovi&e& b9 the engineer of reor& for eah ventilation BoneG a"

VominG one minim+m o+t&oor airflo% for o+!ant, !er Title 24 !reribe& )$!ero+!ant reC+irement.

b"

VareaminG one minim+m o+t&oor airflo% for b+il&ing area, !er Title 24 !reribe& 2 )$!erft reC+irement.

=ote that *occ-min and *area-min for %itle 3 ventilation should not be confused with the area component and occupant component of minimum outdoor air as defined in $tandard 3.0. For %itle 3 compliance, *occ-min and *area-min should not be summed to establish the /one outdoor airflow. 2"

$or eah Bone, al+late the Bone minim+m o+t&oor air et!oint, %hih are +e& at the AU level for minim+m o+t&oor air ontrol a"

b" 3"

oneAbAmin i eC+al to (1"

Vareamin if the Bone ha a )2 enor.

(2"

Vareamin if the Bone ha an o+!an9 enor an& i +n!o!+late&

(3"

ero if the Bone ha a %in&o% %ith an& the %in&o% i o!en

(4"

one*eAmin other%ie.

one*eAmin i eC+al to the larger of Varea min an& Vomin.

Vomin, Vareamin, oneAbAmin, an& one*eAmin hall be a fi/e& val+e for eah Bone.

%he following section describes ventilation logic which complies with A$):A! $tandard 3. 6f the project is to comply with #alifornia %itle 3 ventilation re&uirements, delete subsection 7c8 and use subsection 7b8, above. .

$or om!liane %ith the Ventilation Rate Proe&+re of A'RA 'tan&ar& 2.1, o+t&oor air et!oint hall be al+late& a follo%G 1"

The follo%ing information hall be a he&+le& on the !lan or !rovi&e& b9 the engineer of reor& for eah ventilation BoneG a"

b"

"

November 30, 2014

The area om!onent of the breathing Bone o+t&oor airflo% V bBA (1"

Thi i the Bone floor area time the o+t&oor airflo% rate !er +nit area, a given in Table 1 of 'tan&ar& 2.1

(2"

i.e. V bBA K AB L R a

The !o!+lation om!onent of the breathing Bone o+t&oor airflo% V bBP (1"

Thi i the Bone &eign !o!+lation (%itho+t &iverit9" time the o+t&oor airflo% rate !er o+!ant, a given in Table 1 of 'tan&ar& 2.1

(2"

i.e. V bBP K PB L R !

one air &itrib+tion effetivene B in eating

Page 23 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems &"

one air &itrib+tion effetivene B) in )ooling

$trictly speaking, $tandard 3.0 re&uires only a single occupant diversity ratio D for the entire system. 6f individual /one diversities are provided on plans, they may be used 'see A)U se&uences(. 4therwise, a single system-wide diversity ratio should be used in calculations. e"

+!ant &iverit9 ratio *i for eah Bone that i !art of a m+ltiBone ventilation 9tem. (one erve& b9 a &e&iate& ingleBone +nit &o not reC+ire thi val+e."

2"

$or eah Bone, the breathing Bone o+t&oor airflo% hall be the +m of the area an& the !o!+lation om!onentI i.e. V bB K V bBA  V bBP

3"

$or eah Bone in +!ie& o&e, the reC+ire& Bone o+t&oor airflo% VoB hall be al+late& a follo%G a"

b"

4"

-f the Bone i !o!+late&, or if there i no o+!an9 enorG (1"

-f &iharge air tem!erat+re at the terminal +nit i le than Bone !ae tem!erat+reG VoB K V bB > B)

(2"

-f &iharge air tem!erat+re at the terminal +nit i greater than Bone !ae tem!erat+reG VoB K V bB > B

-f the Bone ha an o+!an9 enor an& i +n!o!+late&G (1"

-f &iharge air tem!erat+re at the terminal +nit i le than Bone !ae tem!erat+reG VoB K V bBA > B)

(2"

-f &iharge air tem!erat+re at the terminal +nit i greater than Bone !ae tem!erat+reG VoB K V bBA > B

$or eah Bone in +!ie& o&e that i !art of a m+ltiBone ventilation 9tem, the Bone !rimar9 o+t&oor air fration  !B hall be real+late& ever9 5 min+te a follo%. (one erve& b9 a &e&iate& ingleBone +nit ma9 &iregar& thi al+lation."G a"

 !B K VoB > V !B

b"

@here V !B i the average Bone !rimar9 airflo% ine the lat real+lation of  !B, a mea+re& b9 the Bone airflo% enor

"

-f a Bone ha an o+!an9 enor an& i +n!o!+late&, et  !B to Bero. O p/ is overridden to /ero for an unpopulated /one in order to avoid the situation where an unpopulated /one 'which has a low ventilation minimum, for area only( bec omes the critical /one and drives up the outside air re&uirements for the entire system. $etting O p/ to /ero effectively drops that /one out of the system level outdoor air calculation. %he 7right8 way to avoid this issue is to dynamically reset the /one and system outdoor air setpoints by continuously recalculating the multiple spaces e&uation. 6f that function is added in the future, this clause should be removed.

&"

November 30, 2014

Thi al+lation i not reC+ire& for Bone that r eeive all their o+t&oor air from a ingleBone air han&ler.

Page 24 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems 3.

'et!oint a.

ah Bone hall have e!arate o+!ie& an& +no+!ie& heating an& ooling et!oint.

b.

The ative et!oint hall be &etermine& b9 the o!erating o&e of the one 7ro+! Qee 1.3)..

.

&.

e.

1"

The et!oint hall be the o+!ie& et!oint &+ring +!ie& o&e, @arm+! o&e, an& )ool&o%n o&e.

2"

The et!oint hall be +no+!ie& et!oint &+ring Uno+!ie& o&e, 'etba? o&e, an& 'et+! o&e.

*efa+lt et !oint hall be bae& on Bone t9!eG (ccu"ed one %ye Heat"n. Cool"n. VAV  Perimeter 0S$ 4S$ VAV  -nterior 0S$ (or N>A" 3S$ eh>le Room 5S$ 65S$ Net%or?ing>)om!+ter 5S$ 5S$

noccu"ed Heat"n. Cool"n. 0S$ 80S$ 0S$ (or N>A" 80S$ 5S$ 65S$ 5S$ 5S$

The oft%are hall !revent 1"

The heating et!oint from e/ee&ing the ooling et!oint min+ 1S$ (i.e. the minim+m &ifferene bet%een heating an& ooling et!oint hall be 1S$"

2"

The +no+!ie& heating et!oint from e/ee &ing the o+!ie& heating et!ointI an&

3"

The +no+!ie& ooling et!oint from being le than the o+!ie& ooling et!oint.

@here the Bone ha a loal et!oint a&+tment ?nob>b+tton 1"

The a&+tment hall be a!able of being limite& in oft%are. %hese are absolute limits imposed by programming, which are in addition to the range limits 'e.g. PQF( of the thermostat adjustment device.

2"

a"

A a &efa+lt, the ative o+!ie& ooling et!oint hall be limite& bet%een 2S$ an& 60S$.

b"

A a &efa+lt, the ative o+!ie& heating et!oint hall be limite& bet%een 5S$ an& 2S$.

The ative heating an& ooling et!oint hall be in&e!en&entl9 a&+table, re!eting the limit an& antioverla! logi &eribe& above. 6f /one thermostat provides only a single setpoint adjustment, then the adjustment shall move both the active heating and cooling setpoinst upwards or downwards by the same amount, within the limits described above.

November 30, 2014

3"

The a&+tment hall onl9 be effetive in +!ie& o&e, an& hall be Bero in all other mo&e.

4"

At the onet of &eman& limiting, the loal et!oint a&+tment val+e hall be froBen. $+rther a&+tment of the et!oint b9 loal ontrol hall be +!en&e& for the &+ration of the &eman& limit event.

Page 25 of 105


-f the %in&o% %ith in&iate the %in&o% i o!en, the loal et!oint a&+tment a&+tment hall be et to Bero. The loal et!oint a&+tment hall re+me it !revio+ val+e %hen the %in&o% %ith in&iate the %in&o% i loe&.

Demand limits can be triggered triggered for different different reasons including including utility utility shed events+ eceeding eceeding of a predefined threshold+ threshold+ or to prevent ecessive rates rates in a ratchet schedule. Additional Additional logic 'not 'not provided here( is needed to define the Demand Limit Levels. For eample function shall utili/e a sliding window window method selectable in • $liding ;indow %he demand control function increments of one minute, up to 1 minutes, 0C minute default. utility rate schedule. For each 4n-?eak • Demand Levels Demand time periods shall be set up as per utility or ?artial-?eak period, three demand level limits can be defined. ;hen the measured demand eceeds the limit, the Demand Limit Level switch for that level shall be set+ when demand is less than 012 below the limit, the switch shall be reset. %hese levels are used at the /one level 'see Oone #ontrol se&uences( to shed demand. An override for critical /ones /ones like data centers centers or e&uipment e&uipment rooms should should be provided through the RU6. RU6. %his override feature should re&uire some level of supervision so that all /ones don
)ooling *eman& =imit =imit 'et!oint A&+tmentG The ative ooling et!oint for all Bone hall be inreae& %hen a &eman& limit i im!oe& on the aoiate& aoiate& one 7ro+!. The o!erator hall have the abilit9 to e/em!t e /em!t in&ivi&+al Bone from thi a&+tment thro+gh the normal )' +er interfae. )hange &+e to &eman& &eman& limit are not +m+lative. +m+lative. 1"

At *eman& =imit =evel 1, inreae et!oint b9 1S$.

2"


3"


)eating Demand Limits Limits may be desirable desirable in buildings buildings with electric heat or heatpumps, heatpumps, or in regions regions with limited gas distribution infrastructure. infrastructure. g.

eating *eman& =imit =imit 'et!oint A&+tmentG The ative heating et!oint for all Bone hall be &ereae& %hen a &eman& limit i im!oe& on the aoiate& one 7ro+!. 7ro+!. The o!erator hall have the abilit9 to e/em!t e /em!t in&ivi&+al Bone from thi a&+tment thro+gh the normal )' +er interfae. )hange &+e to &eman& &eman& limit are not +m+lative. +m+lative. 1"

At *eman& =imit =evel 1, &ereae et!oint b9 1S$.

2"


3"


h.

@in&o% %ithe. $or Bone that have o!erable %in&o% %ith in&iator %ithe, %hen the %in&o% %ith in&iate the %in&o% i o!en, the heating et!oint hall be tem!oraril9 et to 40S$ an& the ooling et!oint hall be tem!oraril9 et to 120S$.

i.

+!an9 enor. $or Bone that have an o+!an9 %ith 1"

November 30, 2014

@hen the %ith in&iate the !ae ha been +n!o!+late& for one min+te ontin+o+l9 &+ring the +!ie& o&e, the ative heating et!oint hall be &ereae& b9 2S$ an& the ooling et!oint hall be inreae& b9 2S$. Page 2 of 105


.

@hen the %ith in&iate that the !ae ha been !o!+late& for one min+te ontin+o+l9, the ative heating an& ooling et!oint hall be retore& to their !revio+ val+e.

ierarh9 of 'et!oint A&+tmentG A&+tmentG The follo%ing a&+tment retrition retrition hall !revail in or&er from highet to lo%et !riorit9G 1"

'et!oint overla! retrition ('etion 1.3#.3.&.1"

2"

Abol+te limit on loal et!oint a&+tment ('etion 1.3#.3.e.1"

3"

@in&o% %ithe

4"

*eman& limit

5"

a"

+!an9 enorG )hange of et!oint b9 o+!an9 enor i a&&e& to hange of et!oint b9 an9 &eman& limit in effet.

b"

=oal et!oint a&+tmentG An9 hange to et!oint b9 loal a&+tment are froBen at the onet of the &eman& limiting event an& r emain fi/e& for the &+ration of the event. A&&itional loal a&+tment a&+tment are ignore& for the &+ration of the &eman& limiting event.

'he&+le& et!oint bae& on one 7ro+! mo&e

%he following will cause all /ones in the Oone Rroup to operate in 4ccupied "ode to ensure that the system has ade&uate load to operate stably. 4.

=oal overri&eG @hen thermotat overri&e b+tton b+tton are &e!ree&, the all for +!ie& o&e o!eration hall be ent +! to the one 7ro+! ontrol for 0 min+te.

5.

)ontrol =oo! a.

T%o e!arate ontrol loo! hall o!erate to maintain !ae tem!erat+re at et!oint, the )ooling =oo! an& the eating =oo!. 1"

The eating =oo! hall be enable& %henever the !ae tem!erat+re i belo% the +rrent Bone tem!erat+re heating et!oint, an& &iable& other%ie.

2"

The )ooling =oo! hall be enable& %henever the !ae tem!erat+re i above the +rrent Bone tem!erat+re ooling et!oint, an& &iable& other%ie.

b.

The )ooling =oo! hall maintain the !ae tem!erat+re at the ative  ooling et!oint. The o+t!+t of the loo! hall be a virt+al !oint ranging from 0H (no ooling" to 100H (f+ll ooling".

.

The eating =oo! hall maintain the !ae tem!erat+re at the ative heating et!oint. The o+t!+t of the loo! hall be a virt+al !oint ranging from 0H (no heating" to 100H (f+ll heating".

&.

=oo! hall be +e !ro!ortional  integral logi or f +BB9 logi. Pro!ortionalonl9 Pro!ortionalonl9 ontrol i not ae!table, altho+gh the integral integral gain hall be mall relative to the !ro!ortional gain. P an& - gain hall be a&+table b9 the o!erator.

e.

'ee other etion for ho% the o+t!+t from thee loo! are +e&.

November 30, 2014

Page 2 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems .

.

one 'tate a.

eatingG %hen the o+t!+t of the !ae heating ontrol loo! i nonBero an& the o+t!+t of the ooling loo! i eC+al to Bero.

b.

)oolingG %hen the o+t!+t of the !ae ooling ontrol loo! i nonBero a n& the o+t!+t of the heating loo! i eC+al to Bero.

.

*ea&ban&G %hen not in either eating or )ooling.

one Alarm a.

one tem!erat+re alarm Default time delay delay for /one temperature alarm '01 minutes( is is intentionally long, to minimi/e minimi/e nuisance alarms. For critical /ones such as 6% closets, consider consider reducing time delay or setting delay to /ero. 1"

-f the Bone i 3S$ above ooling or belo% heating et!oint for 10 min+te, generate =evel 3 alarm.

2"

-f the Bone i 5S$ above ooling or belo% heating et!oint for 10 min+te, generate =evel 2 alarm.

3"

'+!!re Bone tem!erat+re alarm a follo%G a"

After Bone et!oint i hange& for a !erio& of 10 min+te !er &egree of &ifferene bet%een the Bone tem!erat+re tem!erat+re at the time of the hange hange an& the ne% ne% et!oint. Thi Thi +!!reion !erio& a!!lie an9 time that the Bone et!oint i hange&. For eample if setpoint changes changes from JQF JQF to K1QF and and the /one temperature is J.CQF at the time of the change, inhibit alarm for 0.CQFE01 minutes5QF 0C minutes after the change. =ote that this this includes automatic automatic changes changes in setpoint setpoint e.g. due to a window switch or occupancy status.

b.

November 30, 2014

b"

@hile one 7ro+! i in @arm+! or )ool&o%n o&e. Oone alarms are not suppressed suppressed in $etup, $etback, or Unoccupied Unoccupied "odes so that you detect heating or cooling e&uipment or control failures which could result in ecessive pull down or pick up loads and even free/ing of pipes if left undetected.

"

$or Bone %ith an -m!ortane m+lti!lier Qee 1.3A.11.b.1"a" of Bero for it tati !re+re reet, 'AT 'AT reet, or @'T @'T reet Trim Trim J Re!one loo!.

$or Bone %ith ) 2 enorG 1"

)2 enorG -f the ) 2 onentration i le than 300 !!m, or the Bone i in Uno+!ie& o&e for more than 2 ho+r an& Bone )2 onentration e/ee& 00 !!m, generate a =evel 3 alarm. The alarm te/t hall i&entif9 the enor an& in&iate that it ma9 be o+t of alibration.

2"

-f the )2 onentration e/ee& et!oint !l+ 10H for more than 10 min+te generate a =evel 3 alarm.

Page 26 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems Oone $cheduling Rroups, or Oone Rroups, are sets of /ones on a single floor, served by a single air handler, which operate together for ease of scheduling and5or in order to ensure sufficient load to maintain stable operation in the upstream e&uipment. A Oone Rroup is e&uivalent an 6solation Area as defined in $ection ..H.H. of A$):A! B1.0-3101. ';e chose to use a different term because 76solation Area8 seemed to cause c onfusion, or suggest isolation e.g. as one would find in a hospital setting.(

C+

one =rous 1.

ah 9tem hall be bro?en into e!arate one 7ro+! om!oe& of a olletion of one or more Bone erve& b9 a ingle air han&ler.

2.

one hall be aigne& to one 7ro+! a follo%G a.

ah Bone erve& b9 a fanoil or ingleBone air han&ler hall be it o%n one 7ro+!.

b.

$or air han&ler erving m+lti!le Bone, Bone hall be aigne& to one 7ro+! a !eifie& b9 the &eigner, or a follo%G

.

1"

All om!+ter room, net%or?ing loet, mehanial an& eletrial room erve& b9 the air han&ler hall be a ingle one 7ro+!.

2"

A one 7ro+! hall not !an floor.

3"

A one 7ro+! hall not e/ee& 25,000 C+are feet.

4"

-f f+t+re o+!an9 !attern are ?no%n, a ingle one 7ro+! hall not inl+&e !ae belonging to more than one tenant.

Aignment of Bone to one 7ro+! an be hange& at the o!eratorF %or?tation.

3.

ah one 7ro+! hall have e!arate o+!an9 he&+le an& o!erating mo&e from other one 7ro+!. =ote that, from the user
4.

All Bone in eah one 7ro+! hall be in the ame o!erating mo&e at all time. -f one Bone in a one 7ro+! i !lae& in an9 mo&e other than Uno+!ie& o&e (&+e to overri&e, eC+ene logi, or  he&+le& o+!an9" all Bone in that one 7ro+! hall enter that mo&e.

5.

A one 7ro+! ma9 be in onl9 one mo&e at an9 given time.

%he %esting and #ommissioning 4verrides will be specified for each type of terminal unit and system in subse&uent se&uences. %hese overrides allow a commissioning agent to e.g. force a /one into cooling, or drive a valve all the way open or closed. Oone Rroup override switches allow a commissioning agent to apply a /one-level override to all /ones in a Oone Rroup simultaneously. %his greatly accelerates the testing and commissioning process. .

$or eah one 7ro+!, !rovi&e a et of teting>ommiioning oft%are %ithe that overri&e all Bone erve& b9 the one 7ro+!. Provi&e a e!arate oft%are %ith for eah of the Bonelevel overri&e %ithe lite& +n&er DTeting an& )ommiioning verri&eE in terminal +nit eC+ene. @hen the val+e of a one 7ro+!F overri&e %ith i hange&, the orre!on&ing overri&e %ith for ever9 Bone in the

November 30, 2014

Page 28 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems one 7ro+! hall hange to the ame val+e. '+beC+entl9, the Bonelevel overri&e %ith at ma9 be hange& to a &ifferent val+e. The val+e of the Bonelevel %ith ha no effet on the val+e of the one 7ro+! %ith, an& the val+e of the one 7ro+! %ith onl9 affet the Bonelevel %ithe %hen the one 7ro+! %ith i hange&. %he modes presented in the following section are to enable different setpoints and ventilation re&uirements to be applied to Oone Rroups based on their operating schedule, occupancy status, and deviation from current setpoint. .

one 7ro+! !erating o&eG ah one 7ro+! hall have the follo%ing mo&eG a.

+!ie& o&eG A one 7ro+! i in the +!ie& o&e %hen an9 of the follo%ing i tr+eG 1"

The time of &a9 i bet%een the one 7ro+!F he&+le& o+!ie& tart an& to! time.

2"

The he&+le have been overri&&en b9 the +!ant verri&e '9tem. 4ccupant 4verride $ystem is a web-based system to allow individuals to modify the schedule of their /one. %his is a best-in-class feature that will not be available on all projects.

3"

An9 Bone loal overri&e timer (initiate& b9 loal overri&e b+tton" i nonBero.

;arm-Up and #ool-Down "odes are used to bring the Oone Rroups up to temperature based on their scheduled occupancy period. %he algorithms used in these modes 'often referred to as 74ptimal $tart8( predict the shortest time to achieve occupied setpoint to reduce the central system energy use based on past performance. ;e recommend using a global outdoor air temperature, not associated with any A)U, to determine ;arm-up start time. %his is because unit-mounted 4A sensors, which are usually placed in the outdoor air intake stream, are often inaccurate 'reading high( when the unit is off due to air leakage from the space through the 4A damper. b.

@armU! o&eG $or eah Bone, the )' hall al+late the reC+ire& %arm+! time bae& on the BoneF o+!ie& heating et!oint, the +rrent Bone tem!erat+re, the o+t&oor air tem!erat+re, an& a ma>a!ait9 fator for eah Bone. one %here the %in&o% %ith in&iate that a %in&o% i o!en hall be ignore&. The ma fator hall be man+all9 a&+te& or elft+ne& b9 the )'. -f a+tomati, the t+ning !roe hall be t+rne& on or off b9 a oft%are %ith, to allo% t+ning to be to!!e& after the 9tem ha been traine&. @arm+! o&e hall tart bae& on the Bone %ith the longet al+late& %arm+! time reC+irement, b+t no earlier than 3 ho+r before the tart of the he&+le& o+!ie& !erio&, an& hall en& at the he&+le& +!ie& tart ho+r.

.

)ool*o%n o&eG $or eah Bone, the )' hall al+late the reC+ire& ool&o%n time bae& on the BoneF o+!ie& ooling et!oint, the +rrent Bone tem!erat+re, the o+t&oor air tem!erat+re, an& a ma>a!ait9 fator for eah Bone. one %here the %in&o% %ith in&iate that a %in&o% i o!en hall be ignore&. The ma fator hall be man+all9 a&+te& or elft+ne& b9 the )'. -f a+tomati, the t+ning !roe hall be t+rne& on or off b9 a oft%are %ith, to allo% t+ning to be to!!e& after the 9tem ha been traine&. )ool&o%n o&e hall tart bae& on the Bone %ith the longet al+late& ool&o%n time reC+irement, b+t no earlier than 3 ho+r before the tart of the he&+le& o+!ie& !erio&, an& hall en& at the he&+le& +!ie& tart ho+r.

November 30, 2014

Page 30 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems $etback and $etup "odes are used to keep /one temperatures 'and mass( from getting ecessively far from occupied setpoints so that the #ool-Down and ;arm-Up "odes can achieve setpoint when initiated. %he minimum number of /ones 'set at C here( are to ensure that the central systems 'fans, pumps, heating sources or cooling sources( can operate stably. 4bviously the si/e of the /ones and the characteristics of the central systems are a factor in choosing the correct number of /ones in each group. &.

'etba? o&eG *+ring Uno+!ie& o&e, if an9 5 Bone (or all Bone, if fe%er than 5" in the one 7ro+! fall belo% their +no+!ie& heating et!oint, the one 7ro+! hall enter 'etba? o&e +ntil all !ae in the one 7ro+! are 2°$ above their +no+!ie& et!oint.

e.

$reeBe Protetion 'etba? o&eG *+ring Uno+!ie& o&e, if an9 ingle Bone fall belo% 36 °$, the one 7ro+! hall enter 'etba? o&e +ntil all Bone are above 42 °$, an& a =evel 3 alarm hall be et.

f.

'et+! o&eG *+ring Uno+!ie& o&e, if an9 5 Bone (or all Bone, if fe%er than 5" in the one rie above their +no+!ie& ooling et!oint, the one 7ro+! hall enter 'et+! o&e +ntil all !ae in the one 7ro+! are 2°$ belo% their +no+!ie& et!oint. one %here the %in&o% %ith in&iate that a %in&o% i o!en hall be ignore&.

g.

Uno+!ie& o&eG @hen the one 7ro+! i not in an9 other mo&e.

6f the minimum ventilation rate is more than 3C2 or so of the cooling maimum, or demand control ventilation is used, a reheat bo is recommended to avoid overcooling. Demand control ventilation logic is not provided for cooling-only boes.

#+

VAV Cool"n.-(nly %erm"nal n"t 1.

'ee 7eneri Thermal one for et!oint, loo!, ontrol mo&e, alarm, et.

2.

*eign airflo% rate hall be a he&+le& on !lanG a.

one ma/im+m ooling airflo% et!oint (Voolma/"

b.

one minim+m airflo% et!oint (Vmin"

3.

'ee 1.3#.2 for al+lation of Bone minim+m o+t&oor airflo%.

4.

The o+!ie& minim+m airflo% VminL hall be eC+al to Vmin e/e!t a follo%G a.

-f the Bone ha an o+!an9 enor, VminL hall be eC+al to Vareamin (if ventilation i aor&ing to )alifornia Title 24" or V oB (if ventilation i aor&ing to A'RA 'tan&ar& 2.1" %hen the room i +n!o!+late&.

b.

-f the Bone ha a %in&o% %ith, VminL hall be Bero %hen the %in&o% i o!en.

.

-f Vmin i nonBero an& le than the lo%et !oible airflo% et!oint allo%e& b9 the ontrol (Vm", VminL hall be et eC+al to Vm. The minim+m et!oint Vm hall be &etermine& a follo%G 1"

November 30, 2014

*etermine the veloit9 !re+re enor rea&ing *? m in inhe 2 that %ill give a reliable flo% in&iation. -f thi information i not !rovi&e& b9 the enor man+fat+rer, &etermine the veloit9 !re+re that %ill re+lt in a &igital rea&ing from the tran&+er an& A>*

Page 31 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems onverter of 12 bit or o+nt (a+ming a 10 bit A>* onverter". Thi i oni&ere& +ffiient reol+tion for table ontrol. 2"

*etermine the minim+m veloit9 vmfor eah VAV bo/ iBe an& mo&el. -f the VAV bo/ man+fat+rer !rovi&e an am!lifiation fator F for the flo% !i?+!, al+late the minim+m veloit9 vm a

vm

= 4005

*? m F

@here $ i not ?no%n it an be al+late& from the mea+re& )$ at 1 inh ignal from the VP enor

 4005 A   F =   #F"  1   

2

%here A i the nominal &+t area (ft2", eC+al to

 D  A = π    24 

2

%here * i the nominal &+t &iameter (inhe". 3"

)al+late the minim+m airflo% et!oint allo%e& b9 the ontrol (*m" for eah VAV bo/ iBe a

*m = vm A 5.

Ative ma/im+m an& minim+m et!oint hall var9 &e!en&ing on the o&e of the one 7ro+! the Bone i a !art ofG Seto"nt

(ccu"ed

Cool-do7n

Setu

,arm-u

Set$ac>

noccu"ed

)ooling ma/im+m

Voolma/

Voolma/

Voolma/

0

0

0

inim+m

VminL

0

0

0

0

0

eating ma/im+m

VminL

0

0

0

0

0

November 30, 2014

Page 32 of 105


)ontrol logi i &e!ite& hematiall9 in the fig+re belo% an& &eribe& in the follo%ing etion. Relative level of vario+ et!oint are &e!ite& for +!ie& o&e o!eration. )ooling a/im+m

Ative Airflo% 'et!oint

inim+m Airflo% 'et!oint

eating =oo! 'ignal

a.

.

)ooling =oo! 'ignal

@hen the Bone i in )ooling, the )ooling =oo! o+t!+t hall be ma!!e& to the ative airflo% et!oint from the minim+m to the ooling ma/im+m airflo% et!oint. 1"

b.

*ea&ban&

-f +!!l9 air tem!erat+re from air han&ler i greater than room tem!erat+re, )ooling hall be lo?e& o+t.

@hen the Bone i in *ea&ban& or eating, the ative airflo% et!oint hall be the minim+m airflo% et!oint.

The VAV &am!er hall be mo&+late& b9 a ontrol loo! to maintain the mea+re& airflo% at the ative et!oint.

%he following se&uence applies to rooms with both *A* boes and fan-coils where the *A* system was not designed to handle the 6DF room loads G to save costs. *A* acts as primary while fan-coil asks as backup. %he 6mportance multiplier is set to /ero to prevent this /one from becoming a rogue /one and driving the resets. 6.

$or Bone erving %or?room an& -*$ et. that are alo erve& b9 fanoilG a.

-f the tati !re+re et!oint of the 9tem erving the VAV bo/ i at the ma/im+m of the reet range, limit the airflo% to 15H of the Bone ma/im+m +ntil the et!oint i 0.15E belo% the ma/im+m et!oint.

b.

Thi Bone hall have an -m!ortane +lti!lier of 0 o that it &oe not generate an9 '9tem ReC+et.

November 30, 2014

Page 33 of 105


Alarm a.

b.

=o% airflo% 1"

-f the mea+re& airflo% i le than 0H of et!oint for 5 min+te, generate a =evel 3 alarm.

2"

-f the mea+re& airflo% i le than 50H of et!oint for 5 min+te, generate a =evel 2 alarm.

3"

-f a Bone ha an -m!ortane m+lti!lier of 0 Qee 1.3A.11.b.1"a" for it tati !re+re reet Trim J Re!on& ontrol loo!, lo% airflo% alarm hall be +!!ree& for that Bone.

Airflo% enor alibration. -f the fan erving the Bone ha been off for 10 min+te an& airflo% enor rea&ing i above 20 )$, generate a =evel 3 alarm.

?er 0.HA.B, all hardware points can be overridden through the !"#$. !ach of the following points is interlocked so that they can be overridden together at a Oone Rroup level, per 0.H#.. !.g. %he #A can check for leaking dampers by forcing all *A* boes in a Oone Rroup closed and then recording airflow at the A)U. 10.

11.

Teting>)ommiioning verri&eG Provi&e oft%are !oint that interlo? to a 9tem level !oint to a.

$ore Bone airflo% et!oint to Bero

b.

$ore Bone airflo% et!oint to Voolma/.

.

$ore Bone airflo% et!oint to Vmin

&.

$ore &am!er f+ll loe&>o!en

e.

Reet reC+etho+r a+m+lator !oint to Bero (!rovi&e one !oint for eah reet t9!e lite& belo%"

'9tem ReC+et a.

b.

November 30, 2014

)ooling 'AT Reet ReC+et 1"

-f the )ooling =oo! i le than 65H, en& 0 ReC+et.

2"

-f the )ooling =oo! i greater than 85H, en& 1 ReC+et.

3"

-f the Bone tem!erat+re e/ee& the BoneF ooling et!oint b9 3S$ for 2 min+te, en& 2 ReC+et.

4"


'tati Pre+re Reet ReC+et 1"

-f the *am!er =oo! i le than 65H, en& 0 ReC+et.

2"

-f the *am!er =oo! i greater than 85H, en& 1 ReC+et.

3"

-f the mea+re& airflo% i le than 0H of et!oint for 1 min+te, en& 2 ReC+et.

4"

-f the mea+re& airflo% i le than 50H of et!oint for 1 min+te, en& 3 ReC+et.

Page 34 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems 6f the minimum ventilation rate is more than 3C2 or so of the cooling maimum, or demand controlled ventilation is used, a reheat bo is recommended to avoid overcooling.

E+

VAV Reheat %erm"nal n"t 1.


2.



b.


.

one ma/im+m heating airflo% et!oint (Vheatma/"

3.


4.

The o+!ie& minim+m airflo% VminL hall be eC+al to Vmin e/e!t a follo%G a.


b.


.

-f Vmin i nonBero an& le than the lo%et !oible airflo% et!oint allo%e& b9 the ontrol (Vm", VminL hall be et eC+al to Vm. The minim+m et!oint Vm hall be &etermine& in aor&ane %ith 1.3*.4. above.

November 30, 2014

Page 35 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems &.

-f the Bone ha a ) 2 enor 1"

*+ring +!ie& o&e, a Ponl9 loo! hall maintain )2 onentration at 1000 PPI reet 0H at 600 PP an& 100H at 1,000 PP of ) 2. The loo! o+t!+t from 0 to 50H hall reet the o+!ie& minim+m airflo% et!oint (VminL" from the Bone minim+m airflo% et!oint Vmin +! to ma/im+m ooling airflo% et!oint Voolma/, a ho%n belo%.

Vool ma/

VminL

Vmin

0H

50H )2 )ontrol =oo!

100H

2"

-f ventilation o+t&oor airflo% i ontrolle& in aor&ane %ith )alifornia Title 24, the loo! o+t!+t from 50H to 100H %ill be +e& at the 9tem level to reet o+t&oor air minim+mI ee AU ontrol.

3"

-f ventilation o+t&oor airflo% i ontrolle& in aor&ane %ith A'RA 'tan&ar& 2.1, the loo! o+t!+t from 50H to 100H hall be ignore&.

4"

=oo! i &iable& an& o+t!+t et to Bero %hen the Bone i not in +!ie& o&e.

%hese se&uences use different maimum airflow setpoints for heating and cooling. %his 7dual ma8 logic allows the minimum airflow setpoint to be lower than in a conventional se&uence where the minimum airflow e&uals the heating airflow. )eating is non-/ero in #ool-down to allow for individual /ones within a Oone Rroup which may need heating while the Oone Rroup is in #ool-down. 5.


(ccu"ed

Cool-do7n

Setu

,arm-u

Set$ac>

noccu"ed

)ooling ma/im+m

Voolma/

Voolma/

Voolma/

0

0

0

inim+m

VminL

0

0

0

0

0

eating ma/im+m

a/(Vheat ma/, VminL"

Vheatma/

0

Voolma/

Voolma/

0

November 30, 2014

Page 3 of 105


)ontrol logi i &e!ite& hematiall9 in the fig+re belo% an& &eribe& in the follo%ing etion. Relative level of vario+ et!oint are &e!ite& for +!ie& o&e o!eration. )ooling a/im+m Airflo%

80S$ *AT eating a/ Airflo%

*iharge Air Tem!erat+re 'et!oint Ative Airflo% 'et!oint

inim+m Airflo% *AT K AU 'AT eating =oo! 'ignal *ea&ban&

a.

)ooling =oo! 'ignal

@hen the Bone i in )ooling, the )ooling =oo! o+t!+t hall be ma!!e& to the airflo% et!oint from the minim+m to the ooling ma/im+m airflo% et!oint. ot %ater valve i loe& +nle the +!!l9 air tem!erat+re i belo% the minim+m et!oint Qee 1.3..e belo%. 1"


b.

@hen the Bone i in *ea&ban&, the ative airflo% et!oint hall be the minim+m airflo% et!oint. ot %ater valve i loe& +nle the +!!l9 air tem!erat+re i belo% the minim+m et!oint Qee 1.3..e belo%.

.

@hen the Bone i in eating, the eating =oo! hall maintain !ae tem!erat+re at the heating et!oint a follo%G %he purpose of the following heating se&uence is to minimi/e the reheat energy consumption by first increasing the $A% while maintaining minimum flow, and only increasing the total airflow if needed to satisfy the /one. %he design engineer should set *heat-ma such that the design heating load is met by *heat-ma #F" at B1QF.

November 30, 2014

1"

$rom 050H, the eating =oo! o+t!+t hall reet the &iharge tem!erat+re from the +rrent AU 'AT et!oint to the leer of 80S$ or 20S$ above !ae tem!erat+re.

2"

$rom 51H100H, if heating i available (i.e. lea& hot %ater !+m!, or eletri heating oil, i enable&" the eating =oo! o+t!+t hall reet the a tive airflo% et!oint from the minim+m airflo% et!oint to the ma/im+m heating airflo% et!oint.

Page 3 of 105


The hot %ater valve (or mo&+lating eletri heating oil" hall be mo&+late& to maintain the &iharge tem!erat+re at et!oint. (*iretl9 ontrolling heating off the Bone tem!erat+re ontrol loo! i not ae!table."

%his prevents ecessively cold supply air temperatures if the A)U is providing high outdoor airflows and does not have a heating coil.

.

e.

-n an9 o&e e/e!t Uno+!ie&, the hot %ater valve (or mo&+lating eletri heating oil" hall be mo&+late& to maintain a +!!l9 air tem!erat+re no lo%er than 50S$.

f.

The VAV &am!er hall be mo&+late& b9 a ontrol loo! to maintain the mea+re& airflo% at the ative et!oint.

Alarm a.

b.

.

=o% airflo% 1"


2"


3"


=o% +!!l9 air tem!erat+re 1"

-f boiler !lant i !roven on an& the +!!l9 air tem!erat+re i 15S$ le than et!oint for 10 min+te, generate a =evel 3 alarm.

2"


3"

-f a Bone ha an -m!ortane m+lti!lier of 0 Qee 1.3A.11.b.1"a" for it @'T reet Trim J Re!on& ontrol loo!, lo% +!!l9 air tem!erat+re alarm hall be +!!ree& for that Bone.





b.

$ore Bone airflo% et!oint to Voolma/

.


&.

$ore Bone airflo% et!oint to Vheatma/

e.


November 30, 2014

Page 36 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems

8.

f.

$ore heating to off>loe&

g.



b.

.

&.

)+



2"


3"


4"




2"


3"


4"


-f there i a hot %ater oil, heating @'T Reet ReC+et 1"

-f the @ valve i le than 65H, en& 0 ReC+et.

2"

-f the @ valve i greater than 85H, en& 1 ReC+et.

3"

-f the +!!l9 air tem!erat+re i 15S$ le than et!oint for 5 min+te, en& 2 ReC+et.

4"


-f there i a hot %ater oil an& a boiler !lant, boiler Plant ReC+et. 'en& the boiler !lant that erve the Bone a #oiler Plant ReC+et a follo%G 1"


2"


Parallel )an-Po7ered %erm"nal n"t! Constant Volume )an 1.


2.


November 30, 2014

one ma/im+m ooling (!rimar9" airflo% et!oint (Voolma/"

Page 38 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems b. one minim+m !rimar9 airflo% et!oint (Vmin" 6f ventilation is controlled in accordance with #alifornia %itle 3, *min may be less than 4A-min, or even /ero, if there is enough plenum air available for transfer from adjacent /ones to provide minimum ventilation. 6f, on the other hand, each /one

4.

The o+!ie& !rimar9 airflo% minim+m VminL hall be eC+al to Vmin e/e!t a f ollo%G a.

-f the Bone ha an o+!an9 enor, VminL hall be eC+al to Vareamin (if ventilation i aor&ing to )alifornia Title 24" or V oB (if ventilation i aor&ing to A'RA 'tan&ar& 2.1" %hen the room i +n!o!+late&. Oone minimum outside air * o/ is divided by system ventilation efficiency ! v to avoid a situation where the unpopulated /one drives the system outdoor air fraction to 0112. %he 7right8 way to avoid this issue is to dynamically reset the system outdoor air setpoint by continuously recalculating the multiple spaces e&uation. 6f that function is added in the future, the ! v factor should be removed from this calculation.

b.


.

-f Vmin i nonBero an& le than the lo%et !oible airflo% et!oint allo%e& b9 the ontrol (Vm", VminL hall be et eC+al to Vm. The minim+m et!oint Vm hall be &etermine& in aor&ane %ith 1.3*.4..

&.


*+ring +!ie& o&e, a Ponl9 loo! hall maintain )2 onentration at 1000 PPI reet 0H at 600 PP an& 100H at 1,000 PP of ) 2. The loo! o+t!+t from 0 to 50H hall reet the o+!ie& minim+m airflo% et!oint (VminL" from the Bone minim+m airflo% et!oint Vmin +! to ma/im+m *)V airflo% et!oint V)2ma/, a ho%n belo%. a"

@hen the Bone i in )ooling, V)2ma/ i eC+al to the ma/im+m ooling airflo% et!oint Voolma/.

%he following logic prevents the total supply airflow from eceeding *cool-ma, which could create diffuser noise problems. b"

November 30, 2014

@hen the Bone i in eating or *ea&ban&, V)2ma/ i eC+al to Voolma/ min+ the !arallel fan airflo%.

Page 40 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems V)2 ma/

VminL

Vmin

0H

5.


100H

2"


3"


4"


Ative ma/im+m an& minim+m !rimar9 air et!oint hall var9 &e!en&ing on the o&e of the one 7ro+! the Bone i a !art ofG Seto"nt

(ccu"ed

Cool-do7n

Setu

,arm-u

Set$ac>

noccu"ed

)ooling ma/im+m

Voolma/

Voolma/

Voolma/

0

0

0

inim+m

VminL

0

0

0

0

0

November 30, 2014

Page 41 of 105


)ontrol logi i &e!ite& hematiall9 in the fig+re belo% an& &eribe& in the follo%ing etion.

-f Amin M Vmin (a+ming )alifornia Title 24 ventilation r+le"G )ooling a/im+m *iharge Air Tem!erat+re 'et!oint

Ative Primar9 Airflo% 'et!oint

Parallel $an Amin (Title 24 ventilation"

inim+m Primar9 Airflo% 'et!oint


*ea&ban&

)ooling =oo! 'ignal

-f Amin  Vmin, or if 'tan&ar& 2.1ventilation r+le are +e&G )ooling a/im+m *iharge Air Tem!erat+re 'et!oint


Parallel $an

inim+m Primar9 Airflo% 'et!oint Amin (Title 24 ventilation"


a.

November 30, 2014

*ea&ban&

)ooling =oo! 'ignal

@hen the Bone i in )ooling, the )ooling =oo! o+t!+t hall be ma!!e& to the !rimar9 airflo% et!oint from the ooling ma/im+m to the minim+m airflo% et!oint. eating oil i off.

Page 42 of 105


.


b.

@hen the Bone i in *ea&ban&, the !rimar9 airflo% et!oint hall be the minim+m airflo% et!oint. eating oil i off.

.

@hen Bone i in eating 1"

A the eating =oo! o+t!+t inreae from 0 to 100H, it hall reet the &iharge tem!erat+re from the +rrent AU 'AT et!oint to 80S$.

2"

The hot %ater valve (or mo&+lating eletri heating oil" hall be mo&+late& to maintain the &iharge tem!erat+re at et!oint. (*iretl9 ontrolling heat off Bone tem!erat+re ontrol loo! i not ae!table."

&.

The VAV &am!er hall be mo&+late& to maintain the mea+re& !rimar9 airflo% at et!oint.

e.

$an )ontrolG 1"

$an hall r+n %henever Bone i in eating.

2"

-f ventilation i aor&ing to )alifornia Title 24, fan hall r+n in *ea&ban& an& )ooling %hen the !rimar9 +!!l9 air vol+me i le than Amin for one min+te, an& hall h+t off %hen !rimar9 air vol+me i above Amin b9 10H for 3 min+te.

3"

-f ventilation i aor&ing to A'RA 'tan&ar& 2.1, the fan hall be off in *ea&ban& an& )ooling.

Alarm a.

b.

.

=o% Airflo% 1"


2"


3"


=o% '+!!l9 Air Tem!erat+re 1"


2"


3"


$an alarm i in&iate& b9 the tat+ in!+t being &ifferent from the o+t!+t omman& after a !erio& of 15 eon& after a hange in o+t!+t tat+. 1"

November 30, 2014

)omman&e& on, tat+ offG =evel 2

Page 43 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems 2" &.

)omman&e& off, tat+ onG =evel 4



8.



b.


.


&.


e.


f.

T+rn fan on>off

g.



b.

.



2"


3"


4"




2"


3"


4"



November 30, 2014


Page 44 of 105


&.

=+

2"


3"


4"




2"


Parallel )an-Po7ered %erm"nal n"t! Var"a$le Volume )an 1.


2.


one ma/im+m ooling (!rimar9" airflo% et!oint (Voolma/"

b. one minim+m !rimar9 airflo% et!oint (Vmin" 6f ventilation is controlled in accordance with #alifornia %itle 3, *min may be less than 4A-min, or even /ero, if there is enough plenum air available for transfer from adjacent /ones to provide minimum ventilation. 6f, on the other hand, each /one
Parallel fan ma/im+m airflo% (Pfanma/"

!#" fan must be programmed with relationship between speed signal and airflow. !#"s can be programmed either for #F" 'with fan curve mapped into logic( or tor&ue 'pressure dependent airflow(. %his is outdoor the scope of these se&uences, but should be addressed by the design engineer. 3.

PfanB i the lo%et rate the fan %ill o!erate at %hen it i t+rne& on b+t ha the lo%et !oible !ee& ignal from the )'.

4.


5.

The o+!ie& ooling minim+m VminL hall be eC+al to Vmin e/e!t a f ollo%G a.


b.


.


November 30, 2014

Page 45 of 105



*+ring +!ie& o&e, a Ponl9 loo! hall maintain )2 onentration at 1000 PPI reet 0H at 600 PP an& 100H at 1,000 PP of ) 2. The loo! o+t!+t from 0 to 50H hall reet the o+!ie& minim+m airflo% et!oint (VminL" from the Bone minim+m airflo% et!oint Vmin +! to ma/im+m *)V airflo% et!oint V)2ma/, a ho%n belo%. a"

@hen the Bone i in )ooling, V)2ma/ i eC+al to the ma/im+m ooling airflo% et!oint Voolma/.

%he following logic prevents the total supply airflow from eceeding *cool-ma, which could create diffuser noise problems. b"

@hen the Bone i in eating or *ea&ban&, V)2ma/ i eC+al to Voolma/ min+ the !arallel fan airflo%.

V)2 ma/

VminL

Vmin

0H

.


100H

2"


3"


4"


Ative ma/im+m an& minim+m !rimar9 air et!oint hall var9 &e!en&ing on the o&e of the one 7ro+! the Bone i a !art ofG Seto"nt

(ccu"ed

Cool-do7n

Setu

,arm-u

Set$ac>

noccu"ed

)ooling ma/im+m

Voolma/

Voolma/

Voolma/

0

0

0

inim+m

VminL

0

0

0

0

0

November 30, 2014

Page 4 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems .

)ontrol logi i &e!ite& hematiall9 in the fig+re belo% an& &eribe& in the follo%ing etion. Relative level of vario+ et!oint are &e!ite& for +!ie& o&e o!eration. )ooling a/im+m

*iharge Air Tem!erat+re 'et!oint Total )$ Pfanma/

Amin (Title 24 ventilation"

Parallel fan )$ Ative Primar9 Airflo% 'et!oint


PfanB eating =oo! 'ignal *ea&ban&

a.

@hen the Bone i in )ooling 1"

The )ooling =oo! o+t!+t hall be ma!!e& to the airflo% et!oint from the ooling ma/im+m to the minim+m airflo% et!oint. a"

b.

November 30, 2014

)ooling =oo! 'ignal


2"

eating oil i off

3"

-f ventilation i aor&ing to )alifornia Title 24G -n +!ie& o&e onl9, !arallel fan tart %hen !rimar9 airflo% &ro! belo% minim+m o+t&oor airflo% (Amin" min+ one half of PfanB an& h+t off %hen !rimar9 airflo% rie above Amin. $an airflo% rate et!oint i eC+al to Amin min+ the +rrent !rimar9 airflo% et!oint.

4"

-f ventilation i aor&ing to A'RA 'tan&ar& 2.1, !arallel fan hall be off in )ooling.

@hen the Bone i in *ea&ban& 1"

The airflo% et!oint hall be the minim+m airflo% et!oint.

2"

eating oil i off.

3"

-f ventilation i aor&ing to )alifornia Title 24G -n +!ie& o&e onl9, !arallel fan r+n if !rimar9 airflo% et!oint i belo% minim+m o+t&oor airflo% (Amin". $an airflo% rate et!oint i eC+al to Amin min+ the +rrent !rimar9 airflo% et!oint.

Page 4 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems 4" .

&.

6.

-f ventilation i aor&ing to A'RA 'tan&ar& 2.1, !arallel fan hall be off in *ea&ban&.


Parallel fan hall r+n.

2"

$rom 050H, the eating =oo! o+t!+t hall reet the &iharge tem!erat+re from the +rrent AU 'AT et!oint to 80S$.

3"

$rom 50H100H, the eating =oo! o+t!+t hall reet the !arallel fan airflo% et!oint from the airflo% et!oint reC+ire& in *ea&ban& (ee aboveI thi i PfanB if *ea&ban& et!oint i le than PfanB" !ro!ortionall9 +! to the ma/im+m airflo% et!oint (Pfanma/".

4"

The hot %ater valve (or mo&+lating eletri heating oil" hall be mo&+late& to maintain the &iharge tem!erat+re at et!oint. (*iretl9 ontrolling heating off Bone tem!erat+re ontrol loo! i not ae!table."

The VAV &am!er hall be mo&+late& to maintain the mea+re& !rimar9 airflo% at the !rimar9 airflo% et!oint.

Alarm a.

b.

.

&.

November 30, 2014

=o% Airflo% 1"


2"


3"




2"


3"




2"



Page 46 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems ?er 0.HA.B, all hardware points can be overridden through the !"#$. !ach of the following points is interlocked so that they can be overridden together at a Oone Rroup level, per 0.H#.. !.g. %he #A can check for leaking dampers by forcing all *A* boes in a Oone Rroup closed and then recording airflow at the A)U. 8.

10.



b.


.


&.


e.


f.

T+rn fan on>off

g.



b.

.

November 30, 2014



2"


3"


4"




2"


3"


4"




2"


3"


4"


Page 48 of 105


H+



2"


Ser"es )an-Po7ered %erm"nal n"t! Constant Volume )an 1.


2.



b.


3.


4.



b.


.


=ote that D#* with series fan-powered boes usually will not save energy since transfer air will almost always keep #43 levels low anyway. &.


November 30, 2014


Page 50 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems Vool ma/

VminL

Vmin

0H

5.


100H

2"


3"


4"



(ccu"ed

Cool-do7n

Setu

,arm-u

Set$ac>

noccu"ed

)ooling ma/im+m

Voolma/

Voolma/

Voolma/

0

0

0

inim+m

VminL

0

0

0

0

0

November 30, 2014

Page 51 of 105


)ontrol logi i &e!ite& hematiall9 in the fig+re belo% an& &eribe& in the follo%ing etion. )ooling a/im+m 'erie $an *iharge Air Tem!erat+re 'et!oint



eating =oo! 'ignal *ea&ban&

a.

)ooling =oo! 'ignal

@hen the Bone i in )ooling, the )ooling =oo! o+t!+t hall be ma!!e& to the !rimar9 airflo% et!oint from the ooling ma/im+m to the minim+m airflo% et!oint. eating oil i off. 1"


b.

@hen the Bone i in *ea&ban&, the !rimar9 airflo% et!oint hall be the minim+m airflo% et!oint. eating oil i off.

.


The eating =oo! hall reet the &iharge tem!erat+re from the +rrent AU 'AT et!oint to 80S$. igher tem!erat+re ten& to a+e air to tratif9 an& b9!a into the ret+rn air.

2"

The hot %ater valve (or mo&+lating eletri heating oil" hall be mo&+late& to maintain the &iharge tem!erat+re at et!oint. (*iretl9 ontrolling heating off Bone tem!erat+re ontrol loo! i not ae!table."

&.

The VAV &am!er hall be mo&+late& to maintain the mea+re& airflo% at et!oint.

e.

$an )ontrolG $an hall r+n %henever Bone i in +!ie& o&e. Prior to tarting the fan, the &am!er i firt &riven f+ll9 loe& to en+re that the fan i not rotating ba?%ar&. ne the fan i !roven on for a fi/e& time &ela9 (15 eon&", the &am!er overri&e i releae&.

November 30, 2014

Page 52 of 105


Alarm a.

b.

.

&.

6.

8.

=o% Airflo% 1"


2"


3"




2"


3"




2"





b.


.


&.


e.


f.

T+rn fan on>off

g.




November 30, 2014


Page 53 of 105


b.

.

&.

November 30, 2014

2"


3"


4"




2"


3"


4"




2"


3"


4"




2"


Page 54 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems $nap Acting #ontrol logic is the first choice among the various DD control schemes G it is the most efficient and does not re&uire DD boes with miing sections which have a high pressure drop. 6t allows use of dual standard airflow sensors, one at each inlet, with standard pressure independent logic blocks+ alternatively, a single discharge airflow sensor may be used. )owever, snap acting logic is not ideal for #43 control because it can cause the /one to oscillate between #ooling and )eating. %his occurs when the #43 control pushes the *minE up to *cool-ma+ at that point temperature control is lost and if the space is overcooled, it will be pushed into )eating, where it will be overheated, then back again. 6f #4 3 demand controlled ventilation is re&uired, the miing logic described in the net section should be used. %his logic assumes no ability to mi hot and c old air to prevent overly low supply air temperatures which may occur on systems with high outdoor airflows and no preheat coil. $o a preheat coil is likely to be re&uired on such systems if mied air temperature can fall below CQF or so in winter. =ote that snap acting logic can also be problematic for /ones with high minimums, since the room itself is acting as the miing bo. ecause no cold duct air is supplied during heating mode, the heating system must include ventilation air either with direct outdoor air intake or indirectly via transfer air from over-ventilated spaces on the same system. :efer to $tandard 3.0 and the $tandard 3.0 User
+

#ual #uct VAV %erm"nal n"t ? Sna Act"n. Control 1.


2.



b.


.


3.


4.

The o+!ie& ooling minim+m VminL hall be eC+al to Vmin e/e!t a f ollo%G

5.

a.


b.


.


Ative ma/im+m an& minim+m et!oint hall var9 &e!en&ing on the o&e of the one 7ro+! the Bone i a !art ofG

November 30, 2014

Page 55 of 105


.

Seto"nt

(ccu"ed

Cool-do7n

Setu

,arm-u

Set$ac>

noccu"ed

)ooling ma/im+m

Voolma/

Voolma/

Voolma/

0

0

0

inim+m

VminL

0

0

0

0

0

eating ma/im+m

Vheatma/

0

0

Vheatma/

Vheatma/

0

)ontrol logi i &e!ite& hematiall9 in the fig+re belo% an& &eribe& in the follo%ing etion. Relative level of vario+ et!oint are &e!ite& for +!ie& o&e o!eration. )ooling a/im+m

Tranition from )ooling to%ar& eating

eating a/im+m ot *+t Airflo%

)ol& *+t Airflo% inim+m Airflo% 'et!oint eating =oo! 'ignal

November 30, 2014

*ea&ban&

)ooling =oo! 'ignal

Page 5 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems Tranition from eating to%ar& )ooling

)ooling a/im+m


)ol& *+t Airflo% inim+m Airflo% 'et!oint eating =oo! 'ignal

*ea&ban&

)ooling =oo! 'ignal

6f the terminal unit is e&uipped with airflow sensors at both inlets, use paragraph a and delete paragraph b. a.

Tem!erat+re an& *am!er )ontrol %ith &+al inlet airflo% enorG 1"

@hen the Bone i in )ooling, the )ooling =oo! o+t!+t hall reet the ooling +!!l9 airflo% et!oint from the minim+m to ooling ma/im+m et!oint. The ooling &am!er hall be mo&+late& b9 a ontrol loo! to maintain the mea+re& ooling airflo% at et!oint. The heating &am!er hall be loe&. a"

2"

@hen the Bone i in eating, the eating =oo! o+t!+t hall reet the heating +!!l9 airflo% et!oint from the minim+m to heating ma/im+m et!oint. The heating &am!er hall be mo&+late& b9 a ontrol loo! to maintain the mea+re& heating airflo% at et!oint. The ooling &am!er hall be loe&. a"

3"

November 30, 2014

-f ol& &e? +!!l9 air tem!erat+re from air han&ler i greater than room tem!erat+re, )ooling hall be lo?e& o+t.

-f hot &e? +!!l9 air tem!erat+re from air han&ler i le than room tem!erat+re, eating hall be lo?e& o+t.

@hen the Bone i in *ea&ban&, the ooling an& heating airflo% et!oint hall be their lat et!oint +t before entering *ea&ban&. -n other %or&, %hen going from )ooling to *ea&ban&, the ooling airflo% et!oint i eC+al to the Bone minim+m an& the heating et!oint i Bero. @hen going from eating to *ea&ban&, the heating airflo% et!oint i eC+al to the Bone minim+m an& the ooling et!oint i Bero. Thi re+lt in a na!ation %ith in the &am!er et!oint a in&iate& in the fig+re above.

Page 5 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems 6f the terminal unit is e&uipped with airflow sensors at both inlets, use paragraph b and delete paragraph a above. b.

.

Tem!erat+re an& *am!er )ontrol %ith a ingle &iharge airflo% enorG 1"

@hen the Bone i in )ooling, the )ooling =oo! o+t!+t hall reet the &iharge airflo% et!oint from the minim+m to ooling ma/im+m et!oint. The ooling &am!er hall be mo&+late& b9 a ontrol loo! to maintain the mea+re& &iharge airflo% at et!oint. The heating &am!er hall be loe&.

2"

@hen the Bone i in eating, the eating =oo! o+t!+t hall reet the &iharge airflo% et!oint from the minim+m to heating ma/im+m et!oint. The heating &am!er hall be mo&+late& b9 a ontrol loo! to maintain the mea+re& &iharge airflo% at et!oint. The ooling &am!er hall be loe&.

3"

@hen the Bone i in *ea&ban&, the &iharge airflo% et!oint hall be the Bone minim+m, maintaine& b9 the &am!er that %a o!erative +t before entering *ea&ban&. The other &am!er hall remain loe&. -n other %or&, %hen going from )ooling to *ea&ban&, the ooling &am!er hall maintain the &iharge airflo% at the Bone minim+m et!oint an& the heating &am!er hall be loe&. @hen going from eating to *ea&ban&, the heating &am!er hall maintain the &iharge airflo% at the Bone minim+m et!oint an& the ooling &am!er hall be loe&. Thi re+lt in a na!ation %ith in the &am!er et!oint a in&iate& in the fig+re above.

Alarm a.

b.

=o% Airflo% 1"


2"


3"






b.


.


&.


e.

$ore ooling &am!er f+ll loe&>o!en

November 30, 2014

Page 56 of 105


8.

f.

$ore heating &am!er f+ll loe&>o!en

g.



b.

.

&.

e.



2"


3"


4"


)ooling 'tati Pre+re Reet ReC+et 1"


2"


3"


4"


eating 'AT Reet ReC+et 1"

-f the eating =oo! i le than 65H, en& 0 ReC+et.

2"

-f the eating =oo! i greater than 85H, en& 1 ReC+et.

3"

-f the Bone tem!erat+re fall belo% the BoneF heating et!oint b9 3S$ for 2 min+te, en& 2 ReC+et.

4"


eating 'tati Pre+re Reet ReC+et 1"


2"


3"


4"


eating $an ReC+et. 'en& the heating fan that erve the Bone a eating $an ReC+et a follo%G 1"

November 30, 2014

-f the Bone eating =oo! i le than 1H, en& 0 ReC+et.

Page 58 of 105


-f the Bone eating =oo! i greater than 15H, en& 1 ReC+et.

"iing #ontrol logic is the preferred option for use with demand control ventilation. 6f the bo serves more than one room, it re&uires a DD bo with miing capability G a pair of single-duct boes strapped together with a common plenum will not work because the discharge air will stratify rather than mi. )owever, if only a single room is served G as is typical for a /one using D#* G then the room becomes the miing bo and this issue can be disregarded. %his se&uence utili/es two airflow sensors, one at each inlet. %his eliminates the need for a restriction at the discharge to facilitate flow measurement 'and its associated pressure drop(. A discharge restriction may still be re&uired for miing+ see previous paragraph. ;hen the majority of the airflow is through one duct, the airflow velocity in the other duct may be too low to read and result in hunting at that damper. %his is not a problem, because the absolute airflow in that duct will be too low for minor fluctuations to be detectable, while the airflow in the dominant duct is sufficient to provide a clear velocity signal. ecause no cold duct air is supplied during heating mode, the heating system must include ventilation air either with direct outdoor air intake or indirectly via transfer air from over-ventilated spaces on the same system. :efer to $tandard 3.0 and the $tandard 3.0 User
@+

#ual #uct VAV %erm"nal n"t ? 8"9"n. Control 7"th nlet A"rflo7 Sensors 1.


2.



b.


.


3.


4.



b.


.


&.


November 30, 2014


Page 0 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems Vool ma/

VminL

Vmin

0H

5.


100H

2"


3"


4"



(ccu"ed

Cool-do7n

Setu

,arm-u

Set$ac>

noccu"ed

)ooling ma/im+m

Voolma/

Voolma/

Voolma/

0

0

0

inim+m

VminL

0

0

0

0

0

eating ma/im+m

Vheatma/

0

0

Vheatma/

Vheatma/

0

November 30, 2014

Page 1 of 105


)ontrol logi i &e!ite& hematiall9 in the fig+re belo% an& &eribe& in the follo%ing etion. Relative level of vario+ et!oint are &e!ite& for +!ie& o&e o!eration.


)ooling a/im+m


)ol& *+t Airflo%

inim+m Airflo% 'et!oint eating =oo! 'ignal

*ea&ban&

)ooling =oo! 'ignal

Tranition from eating to%ar& )ooling

)ooling a/im+m


)ol& *+t Airflo%


November 30, 2014

*ea&ban&

)ooling =oo! 'ignal

Page 2 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems a.

Tem!erat+re )ontrol 1"

@hen the Bone i in eating, the eating =oo! o+t!+t hall reet the heating +!!l9 airflo% et!oint from Bero to the ma/im+m heating et!oint. The heating &am!er hall be mo&+late& b9 a ontrol loo! to maintain the mea+re& heating airflo% at et!oint. The ooling &am!er hall be ontrolle& to maintain minim+m airflo%, a &eribe& belo%. a"

2"

@hen the Bone i in )ooling, the )ooling =oo! o+t!+t hall reet the ooling +!!l9 airflo% et!oint from Bero to the ma/im+m ooling et!oint. The ooling &am!er hall be mo&+late& b9 a ontrol loo! to maintain the mea+re& ooling airflo% at et!oint. The heating &am!er hall be ontrolle& to maintain minim+m airflo%, a &eribe& belo%. a"

3"

b.

.



@hen the Bone i in *ea&ban&, the ooling an& heating &am!er are ontrolle& to maintain minim+m airflo%, a &eribe& belo%.

inim+m Vol+me )ontrol 1"

-n eating, the ooling &am!er i mo&+late& to maintain the +m of the mea+re& inlet airflo% at the minim+m airflo% et!oint.

2"

-n )ooling, the heating &am!er i mo&+late& to maintain the +m of the mea+re& inlet airflo% at the minim+m airflo% et!oint.

3"

-n *ea&ban&, the lat &am!er that %a +e& to maintain minim+m airflo% ontin+e to &o o (for e/am!le in tranitioning from eating into *ea&ban&, the ooling &am!er %o+l& ontin+e to maintain minim+m airflo%".

Alarm a.

b.

November 30, 2014

=o% Airflo% 1"


2"


3"



Page 3 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems ?er 0.HA.B, all hardware points can be overridden through the !"#$. !ach of the following points is interlocked so that they can be overridden together at a Oone Rroup level, per 0.H#.. !.g. %he #A can check for leaking dampers by forcing all *A* boes in a Oone Rroup closed and then recording airflow at the A)U. 6.

8.



b.


.


&.


e.


f.


g.



b.

.

November 30, 2014



2"


3"


4"




2"


3"


4"




2"


3"


Page 4 of 105


&.

e.




2"


3"


4"




2"


"iing #ontrol logic is the preferred option for use with demand control ventilation. 6f the bo serves more than one room, it re&uires a DD bo with miing capability G a pair of single-duct boes strapped together with a common plenum will not work because the discharge air will stratify rather than mi. )owever, if only a single room is served G as is typical for a /one using D#* G then the room becomes the miing bo and this issue can be disregarded. %his se&uence utili/es a single airflow sensor at the discharge outlet. %his re&uires a restriction at the outlet to ensure that airflow velocity is high enough to measure, which adds etra pressure drop. 6t is somewhat a legacy approach, from when adding a second airflow sensor was much more epensive. As dual-airflow-sensor controllers are now more common, the net se&uence 'miing control with inlet airflow sensors( is generally preferred. ecause no cold duct air is supplied during heating mode, the heating system must include ventilation air either with direct outdoor air intake or indirectly via transfer air from over-ventilated spaces on the same system. :efer to $tandard 3.0 and the $tandard 3.0 User
+

#ual #uct VAV %erm"nal n"t ? 8"9"n. Control 7"th #"schar.e A"rflo7 Sensor 1.


2.



b.


.


3.


4.



November 30, 2014

Page 5 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems b.


.


&.



Vool ma/

VminL

Vmin

0H

5.


100H

2"


3"


4"



(ccu"ed

Cool-do7n

Setu

,arm-u

Set$ac>

noccu"ed

)ooling ma/im+m

Voolma/

Voolma/

Voolma/

0

0

0

inim+m

VminL

0

0

0

0

0

eating ma/im+m

Vheatma/

0

0

Vheatma/

Vheatma/

0

November 30, 2014

Page  of 105


)ontrol logi i &e!ite& hematiall9 in the fig+re belo% an& &eribe& in the follo%ing etion. Relative level of vario+ et!oint are &e!ite& for +!ie& o&e o!eration.


)ooling a/im+m


)ol& *+t Airflo%


*ea&ban&

)ooling =oo! 'ignal

Tranition from eating to%ar& )ooling

)ooling a/im+m


)ol& *+t Airflo%


November 30, 2014

*ea&ban&

)ooling =oo! 'ignal

Page  of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems ecause there is only only a single airflow sensor sensor on the combined combined discharge, discharge, typical pressure-independent pressure-independent control will not work. 6nstead, the active ')eating or #ooling( #ooling( damper position e&uals the active loop signal 'i.e. pressure pressure dependent control(, with with additional additional logic to ensure ensure that minimum minimum and maimum maimum airflow volumes are met. a.

Tem!erat+re )ontrol 1"

@hen the Bone i in eating, the eating =oo! o+t!+t hall be ma!!e& to the heating &am!er !oition. a"

2"

@hen the Bone i in )ooling, the )ooling =oo! o+t!+t hall be ma!!e& to the ooling &am!er !oition. a"

3"

b.

.

.



@hen the Bone i in *ea&ban&, the ooling an& heating &am!er are ontrolle& to maintain minim+m airflo%, a &eribe& belo%.

inim+m Vol+me )ontrol 1"

-n eating, the ooling &am!er i mo&+late& to maintain mea+re& &iharge airflo% at the minim+m airflo% et!oint.

2"

-n )ooling, the heating &am!er i mo&+late& to maintain mea+re& &iharge airflo% at the minim+m airflo% et!oint.

3"

-n *ea&ban&, the lat &am!er that %a +e& to maintain minim+m airflo% ontin+e to &o o (for e/am!le in tranitioning from eating into *ea&ban&, the ooling &am!er %o+l& ontin+e to maintain minim+m airflo%".

a/im+m Vol+me )ontrol 1"

There hall be a a/im+m Vol+me )ontrol loo! %hih %hih i a revereating Ponl9 loo!. The loo!F et!oint hall be the +rrent ma/im+m airflo% vol+me, i.e. either Voolma/ or Vheatma/ &e!en&ing on %hether the Bone i in )ooling or eating.

2"

The o+t!+t of the a/im+m Vol+me )ontrol loo! hall be a &am!er !oition from 0H to 100H. Thi val+e hall be the ma/im+m &am!er &am!er !oition of the +rrentl9ative &am!er, i.e. the ma/im+m ooling &am!er !oition in )oolingI the ma/im+m heating &am!er !oition in eating.

Alarm a.

November 30, 2014

=o% Airflo% 1"


2"


Page 6 of 105


b.

-f a Bone ha an -m!ortane m+lti!lier of 0 Qee 1.3A.11.b.1"a" 1.3A.11.b.1"a" for it tati tati !re+re !re+re reet Trim J Re!on& ontrol loo!, lo% airflo% alarm hall be +!!ree& for that Bone.


?er 0.HA.B, all hardware points can be overridden through the !"#$. !ach of the following points is interlocked so that they can be overridden together at a Oone Rroup level, per 0.H#.. !.g. %he #A can check for leaking leaking dampers by forcing all *A* *A* boes in a Oon Oonee Rroup closed and then recording airflow at the A)U. 6.

8.

Teting>)ommiioning Teting>)ommiioning verri&eG Provi&e oft%are !oint !oint that interlo? to a 9tem level !oint to a.


b.


.


&.


e.


f.


g.



b.

.



2"


3"


4"




2"


3"


4"



November 30, 2014


Page 8 of 105


&.

e.

2"


3"


4"




2"


3"


4"




2"


#old Duct "inimum #ontrol #ontrol logic is the most conventional but least efficient dual dual duct control strategy. 6t assures ventilation rates without $tandard 3.0 7generali/ed multiple spaces8 considerations since only the cold duct has ventilation air with DFDD systems. %his strategy utili/es dual dual airflow sensors, one at each inlet. 6t may be used with or without demand control ventilation. %he designer must ensure that the cooling minimum and heating maimum sum to less than the cooling maimum to avoid over-supplying the diffusers.

'+

#ual #uct VAV %erm"nal n"t ? Cold #uct 8"n"mum Control 1.


2.



b.


.


3.


4.



November 30, 2014

Page 0 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems b.


.


&.



Vool ma/

VminL

Vmin

0H

5.


100H

2"


3"


4"



(ccu"ed

Cool-do7n

Setu

,arm-u

Set$ac>

noccu"ed

)ooling ma/im+m

Voolma/

Voolma/

Voolma/

0

0

0

inim+m

VminL

0

0

0

0

0

eating ma/im+m

Vheatma/

0

0

Vheatma/

Vheatma/

0

November 30, 2014

Page 1 of 105


)ontrol logi i &e!ite& hematiall9 in the fig+re belo% an& &eribe& in the follo%ing etion. Relative level of vario+ et!oint are &e!ite& for +!ie& o&e o!eration. )ooling a/im+m


)ol& *+t Airflo%


a.

)ooling =oo! 'ignal

Tem!erat+re an& *am!er )ontrolG 1"

@hen the Bone i in )ooling, the )ooling =oo! o+t!+t hall reet the ooling +!!l9 airflo% et!oint from the minim+m to ooling ma/im+m et!oint. The ooling &am!er hall be mo&+late& b9 a ontrol loo! to maintain the mea+re& ooling airflo% at et!oint. The heating &am!er hall be loe&. a"

November 30, 2014

*ea&ban&


2"

@hen the Bone i in *ea&ban&, the ooling airflo% et!oint hall be the minim+m et!oint. The ooling &am!er hall be mo&+late& b9 a ontrol loo! to maintain the mea+re& ooling airflo% at et!oint. The heating &am!er hall be loe&.

3"

@hen the Bone i in eating, a"

The eating =oo! o+t!+t hall reet the heating +!!l9 airflo% et!oint from Bero to heating ma/im+m et!oint. The heating &am!er hall be mo&+late& b9 a ontrol loo! to maintain the mea+re& heating airflo% at et!oint.

b"

The ooling airflo% et!oint hall be the minim+m et!oint. The ooling &am!er hall be mo&+late& b9 a ontrol loo! to maintain the mea+re& ooling airflo% at et!oint.

"


Page 2 of 105


Alarm a.

b.

=o% Airflo% 1"


2"


3"




8.



b.


.


&.


e.


f.


g.



b.

November 30, 2014



2"


3"


4"




2"


Page 3 of 105


.


4"


eating 'AT Reet ReC+et

&.

1"


2"


3"


4"


eating 'tati Pre+re Reet ReC+et

e.

8+

3"

1"


2"


3"


4"




2"


8ult"le one VAV A"r Handl"n. n"t 1.

AU 9tem o&e are the ame a the o&e of the one 7ro+! erve& b9 the 9tem. @hen one 7ro+! erve& b9 an air han&ling 9tem are in &ifferent mo&e, the follo%ing hierarh9 a!!lie (highet one et AU mo&e". a.

+!ie& o&e

b.

)ool&o%n o&e

.

'et+! o&e

&.

@arm+! o&e

e.

'etba? o&e

f.

Uno+!ie& o&e

November 30, 2014

Page 4 of 105


'+!!l9 $an )ontrol a.

b.

'+!!l9 $an 'tart>'to! 1"

'+!!l9 fan hall r+n %hen 9tem i in the )ool&o%n o&e, 'et+! o&e, or +!ie& o&e.

2"

-f there are an9 VAVreheat bo/e on !erimeter Bone, +!!l9 fan hall alo r+n %hen 9tem i in 'etba? o&e or @arm+! o&e (i.e. all o&e e/e!t Uno+!ie&".

3"

TotaliBe +rrent airflo% rate from VAV bo/e an& &i!la9 on AU gra!hi at &iharge &+t. -f the AU ha an airflo% mea+rement tation, &i!la9 the A$' airflo% rate a&aent to the +mofBone airflo% rate.

'tati Pre+re 'et!oint Reet 1"

'tati !re+re et!ointG 'et!oint hall be reet +ing Trim J Re!on& logi Qee 1.3A.11. The follo%ing !arameter are +ggete& a a tarting !lae, b+t the9 %ill reC+ire a&+tment &+ring the ommiioning>t+ning !haeG Var"a$le

Value

'P0 'P in 'P a/ T& T R

0.5 inhe 0.1 inhe Per TA# re!ort 10 min+te 2 min+te 2 one 'tati Pre+re Reet ReC+et 0.05 inhe 0.0 inhe 0.13 inhe

'P rim 'P e 'P e a/

.

'tati Pre+re )ontrol )igh pressure trips may occur if all *A* boes are closed 'as in Unoccupied "ode( or if fire5smoke dampers are closed 'in some F$D designs, the dampers are interlocked to the fan status rather than being controlled by smoke detectors(. 1"

November 30, 2014

'+!!l9 fan !ee& i ontrolle& to maintain &+t tati !re+re at et!oint %hen the fan i !roven on. 'ee 1.3A.10 for minim+m !ee& et!oint. @here the one 7ro+! erve& b9 the 9tem are mall, !rovi&e m+lti!le et of gain that are +e& in the ontrol loo! a a f+ntion of a loa& in&iator (+h a +!!l9 fan airflo% rate, the area of the one 7ro+! that are o+!ie&, et.".

Page 5 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems Delete the net paragraph if there is only one supply fan or if fan isolation is by barometric dampers. %he delay is to ensure fan is on before damper opens to prevent backflow from the other fan from back-wheeling the fan prior to startup. #ontractor should adjust rate of isolation damper closing and opening to prevent damage to plenum. 2"

3.

=oo! o+t!+t hall be ma!!e& to the V$* !ee& f rom minim+m V$* !ee& to 100H !ee&. 'tart to o!en iolation &am!er (inlet one" %hen fan reahe minim+m !ee&. )loe the &am!er %hen the fan tat+ in&iate fan i off.

'+!!l9 Air Tem!erat+re )ontrol a.

)ontrol loo! i enable& %hen the +!!l9 air f an i !roven on, an& &iable& an& o+t!+t et to *ea&ban& (no heating, minim+m eonomiBer" other%ie.

%he default range of outdoor air temperatures 'K1QF G 1QF( used to reset the 4ccupied "ode $A% setpoint was chosen to maimi/e economi/er hours. 6t may be preferable to use a lower range of 4A%s 'e.g. CQF G CCQF( to minimi/e fan energy if • %here is a 35K chiller plant that is running anyway • :eheat is minimi/ed, as in a *A* dual-fan, dual-duct system %he climate severely limits the number of available economi/er hours • 6f using this logic, the engineer should oversi/e interior /ones and rooms with high cooling loads 'design them to be satisfied by the warmest $A%( so these /ones don
'+!!l9 Air Tem!erat+re 'et!oint 1"

*+ring +!ie& o&eG 'et!oint hall be reet from Tmin %hen the o+t&oor air tem!erat+re i 0°$ an& above, !ro!ortionall9 +! to Tma/ %hen the o+t&oor air tem!erat+re i 0°$ an& belo%. a"

Tmin hall be the &eign ooling oil leaving air tem!erat+re !er oil he&+le.

b"

Tma/ hall be reet +ing Trim J Re!on& logi Q ee 1.3A.11 bet%een 'Pmin (the &eign +!!l9 air tem!erat+re !er the AU he&+le" an& 'Pma/. The follo%ing !arameter are +ggete& a a tarting !lae, b+t the9 %ill reC+ire a&+tment &+ring the ommiioning>t+ning !haeG $?min should e&ual the design supply air temperature. $?ma may need to be less than CQF for dehumidification in humid climates. 6t should not normally be greater than CQF, as this may lead to ecessive fan energy use. Var"a$le 'P0 'Pmin

'Pma/ T& T R

November 30, 2014

Value 'P a/ *eign 'AT (55W$ t9!" 5W$ (or le for &eh+mi&ifiation" 10 min+te 2 min+te 2 one )ooling 'AT ReC+et

Page  of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems Var"a$le 'P rim 'P e 'P e a/

Value 0.2W$ 0.3W$ 1.0W$

The net re+lt of thi 'AT reet trateg9 i &e!ite& in the hart belo%G Tma/ %ith no ReC+et 5S$ t n i o ! t e ' T A '

Tma/ %ith man9 ReC+et

55S$ Tmin 53S$ 0S$

2"

+t&oor Air Tem!erat+re

0S$

*+ring 'et+! or )ool*o%n o&eG 'et!oint hall be Tmin.

%he following will effectively lock out the economi/er and cooling coil, which is desirable for warmup even if there is no heating coil at the A)U to meet the higher $A%. %his does not apply in the case of a DFDD A)U, or if all the /ones are e&uipped with fan-powered boes such that the A)U is off in warmup and setback. 3"

November 30, 2014

*+ring @armU! an& 'etba? o&eG 'et!oint hall be 85S$.

Page  of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems %he following paragraph applies when the unit has a separate minimum outdoor air damper. 4utdoor air and return air dampers are se&uenced rather than complementary 'as per most standard se&uences( to reduce fan power at part loads. .

$or +nit %ith a e!arate minim+m o+t&oor air &am!erG '+!!l9 air tem!erat+re hall be ontrolle& to et!oint +ing a ontrol loo! %hoe o+t!+t i ma!!e& to eC+ene the hot %ater valve or mo&+lating eletri heating oil (if a!!liable", eonomiBer o+t&oor &am!er, ret+rn air &am!er, an& hille& %ater valve a ho%n in the &iagram belo%. +t&oor air an& ret+rn air &am!er are eC+ene& rather than om!lementar9 (a !er mot tan&ar& eC+ene" to re&+e fan !o%er at !art loa& 1"

The !oint of tranition along the /a/i ho%n an& &eribe& belo% a re re!reentative. 'e!arate gain hall be +e& for eah etion of the ontrol ma! (hot %ater, eonomiBer, hille& %ater", %hih are &etermine& b9 the )ontrator to !rovi&e table ontrol. -f thi i not !oible, )ontrator hall a&+t the !reie val+e of the /a/i threhol& ho%n in the fig+re to !rovi&e table ontrol.

100H onomiBer +t&oor Air *am!er Poition

Ret+rn Air *am!er Poition n e ! o H , n o i t i ( o P e v l a v > r e ! m a *

@ Valve>)oil (if a!!liable"

Ret+rn Air *am!er Poition

onomiBer +t&oor Air *am!er Poition

)@ Valve

0H '+!!l9 Air Tem!erat+re )ontrol =oo! 'ignal

November 30, 2014

Page 6 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems %he following paragraph applies when the unit has a common damper for minimum outdoor air and economi/er function 'i.e. no separate minimum outdoor air damper(. 4utdoor air and return air dampers are se&uenced rather than complementary 'as per most standard se&uences( to reduce fan power at part loads. &.

$or +nit %ith a ombine& minim+m o+t&oor air an& eonomiBer &am!erG '+!!l9 air tem!erat+re hall be ontrolle& to et!oint +ing a ontrol loo! %hoe o+t!+t i ma!!e& to eC+ene the hot %ater valve or mo&+lating eletri heating oil (if a!!liable", o+t&oor air &am!er, ret+rn air &am!er, an& hille& %ater valve a ho%n in the &iagram belo%. +t&oor air an& ret+rn air &am!er are eC+ene& rather than om!lementar9 (a !er mot tan&ar& eC+ene" to re&+e fan !o%er at !art loa&. +t&oor air &am!er minim+m (inAP" an& ma/im+m (a/AP" !oition an& ret+rn air &am!er ma/im+m !oition (a/RAP" are limite& for eonomiBer lo?o+t an& to maintain minim+m o+t&oor airflo% rate a &eribe& in !aragra!h 1.3..& an& 1.3..& belo%. 1"

The !oint of tranition along the /a/i ho%n an& &eribe& belo% a re re!reentative. 'e!arate gain hall be +e& for eah etion of the ontrol ma! (hot %ater, eonomiBer, hille& %ater", %hih are &etermine& b9 the )ontrator to !rovi&e table ontrol. -f thi i not !oible, )ontrator hall a&+t the !reie val+e of the /a/i threhol& ho%n in the fig+re to !rovi&e table ontrol. a/AP 100H

a/RAP +t&oor Air *am!er Poition

n e ! o H , n o i t i ( o P e v l a v > r e ! m a *

Ret+rn Air *am!er Poition @ Valve>)oil (if a!!liable"

Ret+rn Air *am!er Poition +t&oor Air *am!er Poition )@ Valve

inAP 0H '+!!l9 Air Tem!erat+re )ontrol =oo! 'ignal

%he following section applies to air handlers with a separate minimum 4A damper, S? sensor5fied orifice control, and D#*. 6t should be deleted if the unit has a common minimum 4A and economi/er damper. 4.

inim+m +t&oor Air )ontrol %ith a e!arate minim+m o+t&oor air &am!er an& &ifferential !re+re ontrol a.

November 30, 2014


Page 8 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems %he following section describes ventilation logic which complies with #alifornia %itle 3. 6f the project is to comply with $tandard 3 ventilation re&uirements, delete subsection 7b8 and skip to subsection 7c8. b.

+t&oor airflo% et!oint, for )alifornia Title 24 ventilationG 1"

'ee Bone )2 ontrol logi +n&er terminal +nit eC+ene.

2"

+t&oor air abol+te minim+m an& &eign minim+m et!oint are real+late& ontin+o+l9 bae& on the o&e of the Bone being erve&. a"

AbinAL i the +m of oneAbAmin for all Bone in all one 7ro+! that are in +!ie& o&e, b+t hall be no larger than the abol+te minim+m o+t&oor airflo%, AbinA he&+le& on *ra%ing.

b"

*einAL i the +m of one*eAmin for all Bone in all one 7ro+! that are in +!ie& o&e, b+t hall be no larger than the &eign minim+m o+t&oor airflo%, *einA he&+le& on *ra%ing.

6nstructions for establishing "inD? are given in the %est And alance $pecification. For eample 0( 4pen the minimum outdoor air damper and return air damper fully+ close the e conomi/er outdoor air damper. 3( "easure outdoor airflow. H( 6f outdoor airflow rate is above design minimum, adjust damper linkage on minimum outdoor air damper so that intake is at minimum with damper fully stroked. ( 6f outdoor airflow rate is below design minimum, temporarily adjust return air damper position via the !"#$ until design outdoor airflow is achieved. %his position shall be used for testing only and shall not limit the return air damper position during normal operation. C( =ote differential pressure across the outdoor air damper. %his value becomes the design minimum outdoor air differential pressure setpoint in the !"#$. #onvey this setpoint to !"#$ installer and note on air balance report. ( ;ith the system at the minimum outdoor air position, reduce supply air fan speed until the outdoor airflow is e&ual to the absolute minimum outdoor airflow on A)U schedule. K( =ote differential pressure across the outdoor air damper. %his value becomes the absolute minimum outdoor air differential pressure setpoint in the !"#$. #onvey this setpoint to !"#$ installer and note on air balance report. 3"

November 30, 2014

*P 'et!oint a"

*etermine in on+ntion %ith air balaner the abol+te minim+m o+t&oor air &am!er &ifferential !re+re, Abin*P, that !rovi&e an o+t&oor airflo% eC+al to the abol+te minim+m o+t&oor airflo%, AbinA, he&+le& on &ra%ing.

b"

*etermine in on+ntion %ith air balaner the &eign minim+m o+t&oor air &am!er &ifferential !re+re, *ein*P, that !rovi&e the &eign minim+m o+t&oor airflo%, *einA, he&+le& on &ra%ing.

Page 60 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems %he following e&uation prevents ecess outdoor air from being supplied during periods of partial occupancy. 4"

The ative minim+m &ifferential !re+re et!oint, Ab*P!L an& *e*P!L, hall be &etermine& b9 the eC+ation belo%G

 AbsMinOA* AbsDPsp* = AbsMinDP  AbsMinOA   DesMinOA* DesDPsp* = DesMinDP  DesMinOA  5"

A *P 'et!oint (in*P!". The minim+m o+t&oor air *P et!oint (in*P!" hall be reet bae& on the highet Bone )2 P-* loo! ignal from Ab*P!L at 50H ignal to *e*P!L at 100H ignal.


+t&oor airflo% et!oint, for A'RA 'tan&ar& 2.1 ventilationG 1"

)2 ignal from Bone are &iregar&e& at the air han&ler level.

2"

ver9 5 min+te, the )' hall al+late the +norrete& o+t&oor air inta?e V o+, bae& on the Bone &iverit9 *i (or 9tem &iverit9 *" an& the area an& !o!+lation om!onent of V bB for all Bone in +!ie& o&e, a follo%G $trictly speaking, $tandard 3.0 re&uires only a single occupant diversity ratio D for the entire system. 6f individual /one diversities are provided on plans, they may be used. 4therwise, a single system-wide diversity ratio should be used in this calculation.

V =  (D ∗ V) '  V ! "##$% &%

a"

3"

4"

! "##$% &%

$or an9 Bone %ith an o+!an9 enor, *i hall be et to Bero %hen the o+!an9 enor ho% that the Bone i +n!o!+late&.

ver9 5 min+te, the )' hall al+late the +rrent 9tem ventilation effiien9  v. Thi i the mallet val+e of the Bone ventilation effiien9 vB for an9 Bone in +!ie& o&e, al+late& in aor&ane %ith A!!en&i/ A of 'tan&ar& 2.1. a"

$or ingle+!!l9 9temG vB K 1  (V o+ > V !"   !B

b"

@here  !B i the Bone !rimar9 o+t&oor air fration Qee 1.3#.2..3" an& V ! i the 9tem !rimar9 airflo% at the air han&ler.

ver9 5 min+te, the )' hall al+late the minim+m o+t&oor air et!oint inA!. Thi hall be the +norrete& o+t&oor air inta?e Vo+, &ivi&e& b9 the 9tem ventilation effiien9 v, b+t hall be not be greater than D*e in AE a he&+le& on the &ra%ingG

MinOAsp = MM+M, V-. / DesMinOA0

November 30, 2014

Page 61 of 105


*eign A *P 'et!ointG *etermine in on+ntion %ith air balaner the &eign minim+m o+t&oor air &am!er &ifferential !re+re, *ein*P, that !rovi&e the &eign minim+m o+t&oor airflo%, *einA, he&+le& on &ra%ing.

"

A *P 'et!oint (in*P!"G The minim+m o+t&oor air *P et!oint in*P! hall be al+late&

 MinOAsp MinDPsp = DesMinDPDesMinOA &.

!en minim+m o+t&oor air &am!er %hen the +!!l9 air fan i !roven on an& the 9tem i in +!ie& o&e. *am!er hall be loe& other%ie.

e.

Ret+rn Air *am!erG @hen the +!!l9 fan i !roven on, the +nit i in +!ie& o&e, an& eonomiBer o+t&oor air &am!er i &iable& &+e to the high tem!erat+re lo?o+t, or the eonomiBer o+t&oor air &am!er i le than 3H o!en for 5 min+te +ntil it i above 5H o!en, the RA &am!er ignal i mo&+late& to maintain &ifferential !re+re aro the minim+m o+t&oor air &am!er at et!oint, in*P!.

%he following section applies to air handlers with a separate minimum 4A damper, an airflow measurement station, and D#*. 6t should be deleted if the unit has a common minimum 4A and economi/er damper. 5.

inim+m +t&oor Air )ontrol %ith a e!arate minim+m o+t&oor air &am!er an& airflo% mea+rement a.





2"

+t&oor air abol+te minim+m an& &eign minim+m et!oint are real+late& ontin+o+l9 bae& on the o&e of the Bone being erve&.

3"

a"

AbinAL i the +m of oneAbAmin for all Bone in all one 7ro+! that are in +!ie& o&e, b+t hall be no larger than the abol+te minim+m o+t&oor airflo%, DAb in AE he&+le& on *ra%ing.

b"

*einAL i the +m of one*eAmin for all Bone in all one 7ro+! that are in +!ie& o&e, b+t hall be no larger than the &eign minim+m o+t&oor airflo%, D*e in AE he&+le& on *ra%ing.

A 'et!oint (inA!" a"

November 30, 2014

The minim+m o+t&oor air et!oint inA! hall be reet bae& on the highet Bone )2 ontrol loo! ignal from AbinAL at 50H ignal to *einAL at 100H ignal.

Page 62 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems %he following section describes ventilation logic which complies with A$):A! $tandard 3. 6f the project is to comply with #alifornia %itle 3 ventilation re&uirements, delete subsection 7c8 and use subsection 7b8, above. .



2"

ver9 5 min+te, the )' hall al+late the +norrete& o+t&oor air inta?e V o+, bae& on the 9tem &iverit9 * an& the area an& !o!+lation om!onent of V bB for all Bone in +!ie& o&e, a follo%G $trictly speaking, $tandard 3.0 re&uires only a single occupant diversity ratio D for the entire system. 6f individual /one diversities are provided on plans, they may be used. 4therwise, a single system-wide diversity ratio should be used in this calculation.

V =  (D ∗ V) '  V ! "##$% &%

a"

3"

4"

! "##$% &%




b"




&.

inim+m +t&oor Air )ontrol =oo! 1"

inim+m o+t&oor air ontrol loo! i enable& %hen the AU i in +!ie& o&e an& &iable& an& o+t!+t et to Bero other%ie.

2"

The o+t&oor airflo% rate hall be maintaine& at the minim+m o+t&oor air et!oint inA! b9 a revereating ontrol loo! %hoe o+t!+t i ma!!e& to the minim+m o+t&oor air &am!er ignal.

e.

Ret+rn Air *am!erG @hen the +!!l9 fan i !roven on, the +nit i in +!ie& o&e, an& eonomiBer o+t&oor air &am!er i &iable& &+e to the high tem!erat+re lo?o+t, or the eonomiBer o+t&oor air &am!er i le than 3H o!en for 5 min+te +ntil it i above 5H o!en, an& the minim+m o+t&oor air &am!er i f+ll9 o!en, the RA &am!er ignal i mo&+late& to maintain minim+m o+t&oor airflo% at et!oint, inA!, &etermine& above.

November 30, 2014

Page 63 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems %he following section applies to air handlers with a common minimum 4A and economi/er damper 'i.e. no separate minimum 4A damper(, an airflow measurement station, and D#*. 6t should be deleted if the unit has a separate minimum 4A damper. .

inim+m +t&oor Air )ontrol %ith a ingle ommon &am!er for minim+m o+t&oor air an& eonomiBer f+ntion, an& airflo% mea+rement a.





2"

+t&oor air abol+te minim+m an& &eign minim+m et!oint are real+late& ontin+o+l9 bae& on the o&e of the Bone being erve&.

3"

a"

AbinAL i the +m of oneAbAmin for all Bone in all one 7ro+! that are in +!ie& o&e, b+t hall be no larger than the abol+te minim+m o+t&oor airflo%, DAb in AE he&+le& on *ra%ing.

b"

*einAL i the +m of one*eAmin for all Bone in all one 7ro+! that are in +!ie& o&e, b+t hall be no larger than the &eign minim+m o+t&oor airflo%, D*e in AE he&+le& on *ra%ing.

A 'et!oint (inA!" a"

The minim+m o+t&oor air et!oint inA! hall be reet bae& on the highet Bone )2 ontrol loo! ignal from AbinAL at 50H ignal to *einAL at 100H ignal.




2"

ver9 5 min+te, the )' hall al+late the +norrete& o+t&oor air inta?e V o+, bae& on the 9tem &iverit9 * an& the area an& !o!+lation om!onent of V bB for all Bone in +!ie& o&e, a follo%G $trictly speaking, $tandard 3.0 re&uires only a single occupant diversity ratio D for the entire system. 6f individual /one diversities are provided on plans, they may be used. 4therwise, a single system-wide diversity ratio should be used in this calculation.

V =  (D ∗ V) '  V ! "##$% &%

November 30, 2014

! "##$% &%

Page 64 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems a"

3"

4"




b"




&.

inim+m +t&oor Air )ontrol =oo! 1"

inim+m o+t&oor air ontrol loo! i enable& %hen the AU i in +!ie& o&e an& &iable& an& o+t!+t et to Bero other%ie.

2"

The o+t&oor airflo% rate hall be maintaine& at the minim+m o+t&oor air et!oint inA! b9 a revereating ontrol loo! %hoe o+t!+t i ma!!e& to eonomiBer &am!er minim+m !oition, inAP, an& ma/im+m ret+rn air &am!er !oition, a/RAP, a in&iate& in the fig+re belo%. 100H a/RAP

inAP

n e ! o H , n o i t i ( o P r e ! m a *

0H

inAP

a/RAP

0H

50H

100H

+t&oor Airflo% )ontrol =oo! +t!+t 'ignal

November 30, 2014

Page 65 of 105


onomiBer =o?o+t a.

The normal eC+ening of the eonomiBer &am!er (above" hall be &iable& %henever the o+t&oor air tem!erat+re e/ee& the eonomiBer lo?o+t tem!erat+re a !eifie& in the follo%ing table, %hih varie b9 limate Bone an& e onomiBer ontrol &evie t9!eG *evie T9!e

$i/e& *r9 #+lb

*ifferential *r9 #+lb $i/e& nthal!9  $i/e& *r9b+lb b.

A'RA )limate one

onomiBer =o?o+t Tem!erat+re

1#, 2#, 3#, 3), 4#, 4), 5#, 5), #, , 6 5A, A 1A, 2A, 3A, 4A 1#, 2#, 3#, 3), 4#, 4), 5A, 5#, 5), A, #, , 6

TA M 0S$ TA M 5S$

All

hA M 26 #t+>lb or TA M 5S$

TA M 5S$

TA M TRA

ne the eonomiBer i &iable&, it hall not be reenable& %ithin 10 min+te, an& vie vera.

%he following paragraph applies to air handlers with a separate minimum 4A damper. 6t should be deleted if the unit has a common minimum 4A and economi/er damper. %he three minute delay is because the minimum 4A damper may be pressure controlled. 6n that case, delay allows time for the plenum pressure to stabili/e, so that the return damper loop doesn
-f the +nit ha a e!arate minim+m o+t&oor air &am!erG @hen eonomiBer i &iable&, the ret+rn air &am!er hall be f+ll9 o!ene&, %ait 15 eon&, then the eonomiBer o+t&oor air &am!er hall be h+t. After 3 min+te time &ela9, ret+rn air &am!er hall be releae& for inim+m +t&oor Air )ontrol (ee above".

%he following paragraph applies to air handlers with a common minimum 4A and economi/er damper 'i.e. no separate minimum 4A damper(. 6t should be deleted if the unit has a separate minimum 4A damper. &.

November 30, 2014

-f the +nit ha a ommon &am!er for minim+m o+t&oor air an& eonomiBer f+ntionG @hen eonomiBer i enable&, a/AP K 100H. @hen eonomiBer i firt &iable&, the ret+rn air &am!er hall be f+ll9 o!ene&, %ait 15 eon&, then et a/AP eC+al to inAP an& releae ret+rn air &am!er for minim+m o+t&oor air ontrol. 'ee inim+m +t&oor Air )ontrol above for minim+m o+t&oor air an& ma/im+m ret+rn air &am!er et!oint.

Page 6 of 105


At+ate& Relief *am!er @itho+t $an, if a!!liable 6f net minimum outdoor air 'minimum outdoor air less fied ehaust such as toilet ehaust( is less than about 1.01 #F"5ft 3 , a building of typical tightness will efiltrate the outdoor air and avoid overpressuri/ation. 6n this case, use paragraph 'a( below and delete paragraph 'b(, so that relief system is enabled only when economi/er is active. 6f net minimum outdoor air is greater than 1.01 #F"5ft 3 , or if building envelope is unusually tight, relief will be re&uired regardless of economi/er status. 6n this case, use paragraph 'b( below and delete paragraph 'a(.

8.

a.

Relief &am!er hall be enable& %hen the a oiate& +!!l9 fan i !roven on in +!ie& o&e an& the aoiate& eonomiBer i enable&, an& &iable& other%ie.

b.

Relief &am!er hall be enable& %hen the a oiate& +!!l9 fan i !roven on in +!ie& o&e, an& &iable& other%ie.

.

@hen enable&, mo&+late relief &am!er to maintain 0.05E b+il&ing tati !re+re. )loe &am!er %hen &iable&.

Relief $an, if a!!liable :elief fans are enabled and disabled with their associated supply fans, but all relief fans that are running, and serve a common volume of space, run at the same speed. %his prevents relief fans from fighting each other, which can lead to flow reversal or space pressuri/ation problems. %he appropriate boundaries between relief systems, establishing which relief fans run together, will need to be determined by the engineer based on building geometry. a.

All o!erating relief fan that erve a ommon>hare& air vol+me hall be ontrolle& a if the9 %ere one 9tem, r+nning at the ame !ee& an& +ing the ame ontrol loo!, even if the9 are aoiate& %ith &ifferent air han&ling +nit.

6f net minimum outdoor air 'minimum outdoor air less fied ehaust such as toilet ehaust( is less than about 1.01 #F"5ft 3 , a building of typical tightness will efiltrate the outdoor air and avoid overpressuri/ation. 6n this case, use paragraph 'b( below and delete paragraph 'c(, so that relief system is enabled only when economi/er is active. b.

A relief fan hall be enable& %hen it aoiate& +!!l9 fan i enable& in +!ie& o&e an& the +!!l9 fanF eonomiBer i enable&, an& hall be &iable& other%ie. 3

6f net minimum outdoor air is greater than 1.01 #F"5ft , or if building envelope is unusually tight, relief will be re&uired regardless of economi/er status. 6n this case, use paragraph 'c( below and delete paragraph 'b( above. .

A relief fan hall be enable& %hen it aoiate& +!!l9 fan i enable& in +!ie& o&e, an& hall be &iable& other%ie.

&.

#+il&ing tati !re+re hall be time average& %ith a li&ing 5 min+te %in&o% (to &am!en fl+t+ation". The average& val+e hall be that &i!la9e& an& +e& for ontrol.

November 30, 2014

Page 6 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems %he following is intended to use barometric relief as the first stage, and then maintain many fans on at low speed to minimi/e noise and reduce losses through discharge dampers and louvers. For this strategy to be effective, fan speed minimums must be set as low as possible. e.

f. 10.

A ontrol loo! maintain the b+il&ing !re+re at a et!oint of 0.05 inhe %ith an o+t!+t ranging from 0 to 100H. The loo! i &iable& an& o+t!+t et to Bero %hen relief 9tem i &iable&. 1"

#arometri reliefG @hen relief 9tem i enable& an& the ontrol loo! o+t!+t i above 5H, o!en the motoriBe& &am!er to all relief fan erving the b+il&ing that are enable&I loe the &am!er %hen the loo! o+t!+t &ro! to 0H for 5 min+te.

2"

Po%ere& reliefG @hen ontrol loo! i above minim+m !ee& !l+ 10H for 1 min+te, relief fan hall tart. $an !ee& ignal to all enable& relief fan hall be the ame an& hall be eC+al to the ontrol loo! ignal b+t no le than the minim+m !ee&. @hen ontrol loo! ignal &ro! to minim+m !ee& for 1 min+te, fan hall to! b+t relief &am!er hall remain o!en for barometri relief !er !revio+ !aragra!h.

$or fan in a =evel 2 alarm, &iharge &am!er hall be loe&.

Ret+rn $an, if a!!liable a.

Ret+rn fan o!erate %henever aoiate& +!!l9 fan i !roven on.

b.

Ret+rn fan !ee& hall be ontrolle& to maintain ret+rn fan &iharge tati !re+re at et!oint. The et!oint hall be reet from R$'Pmin to R$'Pma/. 'et!oint are &etermine& in on+ntion %ith the air balaner a follo%G 1"

R$'PminG That reC+ire& to &eliver the &eign ret+rn air vol+me aro the ret+rn air &am!er %hen the +!!l9 air fan i at &eign airflo% an& on minim+m o+t&oor air. Thi et!oint hall be no le than 0.01 inhe, to maintain !oitive &iharge flo%.

2"

R$'Pma/. That reC+ire& to e/ha+t eno+gh air to maintain b+il&ing tati !re+re at et!oint (0.05 inhe" %hen the +!!l9 air fan i at &eign airflo% an& on 100H o+t&oor air.

%he designer should choose one static pressure setpoint reset scheme below, and delete the other one, depending on availability of total outdoor airflow information. .

Ret+rn fan &iharge tati !re+re et!oint hall be reet a follo% 1"

-f there i an A$' aro the entire o+t&oor air inta?e (i.e. both the eonomiBer inta?e an& the minim+m o+t&oor air inta?e"G The et!oint hall be reet linearl9 from R$'Pmin at the minim+m o+t&oor airflo% to R$'Pma/ at 100H of &eign o+t&oor airflo%.

2"

-f there i not an A$' at the o+t&oor air inta?eG The et!oint hall be reet +ing Trim J Re!on& logi Qee 1.3A.11 %ith the follo%ing !arameterG Var"a$le 'P0 'P in 'P a/ T& T R

November 30, 2014

Value R$'P in R$'P in R$'P in 5 min+te 2 min+te 0 #+il&ing 'tati ReC+et Page 66 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems 'P rim 'P e 'P e a/ a"

0.03E 0.05E 0.05E

A #+il&ing 'tati ReC+et i generate& %hen the b+il&ing tati !re+re ontrol loo! o+t!+t i above 85H +ntil it fall belo% 60H.

&.

/ha+t &am!er hall onl9 be enable& %hen the aoiate& +!!l9 an& r et+rn fan are !roven on an& the minim+m o+t&oor air &am!er i o!en. The e/ha+t &am!er hall be loe& %hen &iable&.

e.

#+il&ing tati !re+re hall be time average& %ith a li&ing 5min+te %in&o% (to &am!en fl+t+ation". The average& val+e hall be that &i!la9e& an& +e& for ontrol. Due the potential for interaction between the building pressuri/ation and return fan control loops, etra care must be taken in selecting the control loop gains. %o prevent ecessive control loop interaction, the closed loop response time of the building pressuri/ation loop should not eceed 05C the closed loop response time of the return fan control loop. %his can be accomplished by decreasing the gain of the building pressuri/ation controller.

f.

11.

@hen e/ha+t &am!er are enable&, a ontrol loo! hall mo&+late e/ha+t &am!er to maintain the b+il&ing !re+re at a et!oint of 0.05 inhe.

$reeBe Protetion 6f a free/estat is present, it may be hardwired to perform some or all of these functions. 6n that case, eliminate those functions from se&uence logic, but maintain the alarm.

12.

a.

U!on ignal from the freeBetat (if intalle&" or if mi/e& air tem!erat+re &ro! belo% 40S$ for 5 min+te, h+t &o%n +!!l9 an& ret+rn fan(", loe o+t&oor air &am!er, ma?e the minim+m heating oil valve !oition 50H an& the minim+m ooling oil valve !oition 20H, en& a #oiler Plant ReC+et, an& et a =evel 2 alarm in&iating the +nit i h+t &o%n b9 freeBe !rotetion.

b.

-f freeBe !rotetion i triggere& b9 oft%are, it hall remain in effet +ntil it i reet b9 a oft%are %ith from the o!eratorF %or?tation. -f a freeBe tat %ith a !h9ial reet %ith i +e& intea&, there hall be no oft%are reet %ith.

Alarm a.

aintenane interval alarm %hen fan ha o!erate& for more than 1500 ho+rG =evel 5. Reet interval o+nter %hen alarm i a?no%le&ge&.

b.

$an alarm i in&iate& b9 the tat+ being &ifferent from the omman& for a !erio& of 15 eon&.

.

1"


2"


$ilter !re+re &ro! e/ee& alarm limitG =evel 5. The alarm limit hall var9 %ith total airflo% (if availableI +e fan !ee& if total airflo% i not ?no%n" a follo%G D? 

November 30, 2014

= D? 100

(  )1.4

Page 68 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems %here *P100 i the high limit !re+re &ro! at &eign airflo% (&etermine limit from filter man+fat+rer" an& *P/ i the high limit at airflo% rate (or !ee& ignal" / (e/!ree& a a fration". $or intane, the et!oint at 50H of &eign airflo% %o+l& be (.5"1.4 or 36H of the &eign high limit !re+re &ro!. &.

igh b+il&ing !re+re (more than 0.10E"G =evel 3

e.

=o% b+il&ing !re+re (le than 0.0E"G =evel 4

%he Automatic Fault Detection and Diagnostics 'AFDD( routines for A)Us continually assesses A)U performance by comparing the values of !"#$ inputs and outputs to a subset of potential fault conditions. %he subset of potential fault conditions that is assessed at any point depends on the 4perating $tate of the A)U, as determined by the position of the cooling and heating valves and the economi/er damper. %ime delays are applied to the evaluation and reporting of fault conditions, to suppress false alarms. Fault conditions which pass these filters are reported to the building operator along with a series of possible causes. %hese e&uations assume that the air handler is e&uipped with hydronic heating and cooling coils, as well as a fully integrated economi/er. 6f any of these components are not present, the associated tests, and variables, should be omitted from the programming. =ote that these alarms rely on reasonably accurate measurement of mied air temperature. An "A% sensor is re&uired for many of these alarms to work, and an averaging sensor is strongly recommended for best accuracy. 13.

A+tomati $a+lt *etetion an& *iagnoti a.

A$** on&ition are eval+ate& ontin+o+l9 an& e!aratel9 f or eah o!erating air han&ling +nit.

b.

The !erating 'tate ('" of eah AU hall be &efine& b9 the omman&e& !oition of the heating oil ontrol valve, ooling oil ontrol valve, an& eonomiBer &am!er in aor&ane %ith the follo%ing table an& orre!on&ing gra!hi. The !erating 'tate ('" of eah AU hall be &efine& b9 the omman&e& !oition of the heating oil ontrol valve, ooling oil ontrol valve, an& eonomiBer &am!er in aor&ane %ith the follo%ing table an& orre!on&ing gra!hi.

November 30, 2014

Page 80 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems %he 4perating $tate is distinct from and should not be confused with the Oone $tatus '#ooling, )eating, Deadband( or Oone Rroup "ode '4ccupied, ;arm-up, etc(. 4$T0 G 4$T represent normal operation during which a fault may nevertheless occur, if so determined by the fault condition tests in section e below. y contrast, 4$TC typically represents an abnormal or incorrect condition 'such as simultaneous heating and cooling( arising from a controller failure or programming error, but it may also occur normally, e.g. when dehumidification is active. Heat"n. Valve Pos"t"on

Cool"n. Valve Pos"t"on

(utdoor A"r #amer Pos"t"on

1G eating

M0

K0

K -N

2G $ree )ooling, o&+lating A

K0

K0

-N  X  100H

3G ehanial  onomiBer )ooling 4G ehanial )ooling, in A

K0 K0

M0 M0

K 100H K -N

(erat"n. State

5G Un?no%n or *eh+mi&ifiation

'1

'2

No other ' a!!lie

'3

'4

100H

n e !  H , n o i t i ( o P e v l a V > r e ! m a *

)@ Valve +t&oor Air *am!er @ Valve

0H

.

The follo%ing !oint m+t be available to the A$** ro+tine for eah AUG For the AFDD routines to be effective, an averaging sensor is recommended for supply air temperature. An averaging sensor is essential for mied air temperature, as the environment of the miing bo will be subject to non-uniform and fluctuating air temperatures. 6t is recommended that the 4A% sensor be located at the A)U, so that it accurately represents the temperature of the incoming air.

November 30, 2014

1"

'+!!l9 air tem!erat+re

2"

i/e& air tem!erat+re Page 81 of 105


&.

3"

Ret+rn air tem!erat+re

4"

+t&oor air tem!erat+re

5"

*+t tati !re+re

"

'AT'P K +!!l9 air tem!erat+re et!oint

"

*'P'P K &+t tati !re+re et!oint

6"

) K heating oil valve !oition omman&I 0H O ) O 100H

8"

)) K ooling oil valve !oition omman&I 0H O )) O 100H

10"

$' K fan !ee& omman&I 0H O $' O 100H

The follo%ing val+e m+t be ontin+o+l9 al+late& b9 the A$** ro+tine for eah AUG 1"

2"

$ive min+te (&efa+lt" rolling average of the follo%ing !oint val+eI o!erator hall have the abilit9 to a&+t the averaging %in&o% for eah !oint in&e!en&entl9 a"

'ATAV7 K rolling average of +!!l9 air tem!erat+re

b"

ATAV7 K rolling average of mi/e& air tem!erat+re

"

RATAV7 K rolling average of ret+rn air tem!erat+re

&"

ATAV7 K rolling average of o+t&oor air tem!erat+re

e"

*'PAV7 K rolling average of &+t tati !re+re

HA K at+al o+t&oor air fration a a !erentage K tation if available.

e.

November 30, 2014

&1 2 31 or !er airflo% mea+rement "1 2 31

3"

HA-N K Ative minim+m A et!oint (inA!" &ivi&e& b9 at+al total airflo% (from +m of VAV bo/ flo%, or b9 airflo% mea+rement tation" a a !erentage.

4"

∆'

K n+mber of hange in !erating 'tate &+ring the !revio+ 0 min+te (moving %in&o%"

The follo%ing internal variable hall be &efine& for eah AU. All !arameter are a&+table b9 the o!erator, %ith initial val+e a given belo%G

Page 82 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems Default values are derived from =6$%6: KHC 'Meffery $chein, 4ctober 311( and have been validated in field trials. %hey are epected to be appropriate for most circumstances, but individual installations may benefit from tuning to improve sensitivity and reduce false alarms. %he default values have been intentionally biased towards minimi/ing false alarms, if necessary at the epense of missing real alarms. %his avoids ecessive false alarms that will erode user confidence and responsiveness. )owever, if the goal is to achieve the best possible energy performance and system operation, these values should be adjusted based on field measurement and operational eperience. *alues for physical factors such as fan heat, duct heat gain, and sensor error can be measured in the field or derived from trendlogs. Likewise the occupancy delay and switch delays can be refined by observing in trend data the time re&uired to achieve &uasi steady state operation. 4ther factors can be tuned by observing false positives and false negatives 'i.e. unreported faults(. 6f transient conditions or noise cause false errors, increase the alarm delay. Likewise, failure to report real faults can be addressed by adjusting the heating coil, cooling coil, temperature, or flow thresholds. Var"a$le *ame

#escr"t"on

#efault Value

Tem!erat+re rie aro +!!l9 fan

2S $

inim+m &ifferene bet%een AT an& RAT to eval+ate eonomiBer error on&ition ($)"

10S $

Y'AT

Tem!erat+re error threhol& for 'AT enor

2S $

YRAT

Tem!erat+re error threhol& for RAT enor

2S $

YAT

Tem!erat+re error threhol& for AT enor

5S $

∆T'$ ∆T-N

2S $ if loal enor  +nit. YAT

Y$ YV$*'P* Y*'P

Tem!erat+re error threhol& for AT enor 5S $ if global enor. Airflo% error threhol&

30H

V$* !ee& error threhol&

5H

*+t tati !re+re error threhol&

0.1E

a/im+m n+mber of hange in !erating 'tate



o&e*ela9

Time in min+te to +!en& $a+lt )on&ition eval+ation after a hange in o&e

80

Alarm*ela9

Time in min+te to that a $a+lt )on&ition m+t !erit before triggering an alarm

0

∆'AX

%he purpose of ∆% "6= is to ensure that the miing bo5economi/er damper tests are meaningful. %hese tests are based on the relationship between supply, return, and outdoor air. 6f :A%  "A%, these tests will not be accurate and will produce false alarms.

f.

November 30, 2014

There are 13 !otential $a+lt )on&ition that an be eval+ate& b9 the A$** ro+tine. -f the eC+ation tatement i tr+e, then the !eifie& fa+lt on&ition e/it. The $a+lt )on&ition to be eval+ate& at an9 given time %ill &e!en& on the !erating 'tate of the AU.

Page 83 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems %hese e&uations assume that the $A% sensor is located downstream of the supply fan, and the :A% sensor is located downstream of the return fan. 6f actual sensor locations differ from these assumptions, it may be necessary to add or delete fan heat correction factors. *'P  *'P'P  Y*'P

Equat"on

an& V$*'P* Z 88H  Y V$*'P*

)C B1

#escr"t"on Poss"$le #"a.nos"s Equat"on

)C B

)C B0

#escr"t"on

Problem %ith V$* ehanial !roblem %ith fan $an +n&eriBe& 'AT 'et!oint too high (too m+h Bone &eman&" ATAV7  YAT  minQ(RATAV7  YRAT", (ATAV7  YAT" AT too lo%I ho+l& be bet%een AT an& RAT

Poss"$le #"a.nos"s

RAT enor error AT enor error AT enor error

Equat"on

ATAV7  YAT M ma/Q(RATAV7  YRAT", (ATAV7  YAT"

#escr"t"on Poss"$le #"a.nos"s Equat"on

)C B4

*+t tati !re+re i too lo% %ith fan at f+ll !ee&

#escr"t"on Poss"$le #"a.nos"s Equat"on #escr"t"on

)C B5 Poss"$le #"a.nos"s

Al"es to (S B1 ? B5


AT too highI ho+l& be bet%een AT an& RAT

RAT enor error AT enor error AT enor error


∆'

M ∆'AX

Too man9 hange in !erating 'tate

Untable ontrol &+e to !oorl9 t+ne& loo! or mehanial !roblem


'ATAV7  Y'AT O ATAV7  YAT  ∆T'$ 'AT too lo%I ho+l& be higher than AT

'AT enor error AT enor error )ooling oil valve lea?ing or t+? o!en eating oil valve t+? loe& or at+ator f ail+re $o+le& or +n&eriBe& heating oil @ tem!erat+re too lo% or @ +navailable

Al"es to (S B1

[ RATAV7  ATAV7 [ Z ∆T-N

Equat"on

an& [ HA  HA-N [ M Y$

)C B/

#escr"t"on Poss"$le #"a.nos"s

November 30, 2014

A fration i too lo% or too highI ho+l& eC+al HA -N

RAT enor error AT enor error AT enor error =ea?ing or t+? eonomiBer &am!er or at+ator

Al"es to (S B1! B4

Page 84 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems 'ATAV7  'AT'P  Y'AT

Equat"on

an& ) Z 88H

)C B

#escr"t"on

Poss"$le #"a.nos"s

Equat"on

)C BD

)C B

)C B13

'AT enor error )ooling oil valve lea?ing or t+? o!en eating oil valve t+? loe& or at+ator f ail+re $o+le& or +n&eriBe& heating oil @ tem!erat+re too lo% or @ +navailable [ 'ATAV7  ∆T'$  ATAV7 [ M

4 56789:5;789

#escr"t"on

'AT too high or too lo%I ho+l& eC+al AT

Poss"$le #"a.nos"s

'AT enor error AT enor error )ooling oil valve lea?ing or t+? o!en eating oil valve lea?ing or t+? o!en

Equat"on

ATAV7  YAT M 'AT'P  ∆T'$  Y 'AT

#escr"t"on

AT i too high for free ooling %itho+t a&&itional mehanial ooling

Poss"$le #"a.nos"s

'AT enor error AT enor error )ooling oil valve lea?ing or t+? o!en

Equat"on

[ ATAV7  ATAV7 [ M

#escr"t"on Poss"$le #"a.nos"s Equat"on #escr"t"on

)C B11 Poss"$le #"a.nos"s Equat"on #escr"t"on )C B1 Poss"$le #"a.nos"s

November 30, 2014

'AT too lo% in f+ll heating (oil i at+rate&"

4 5;789: 5OA 9

AT i too high or too lo%I ho+l& eC+al AT

AT enor error AT enor error =ea?ing or t+? eonomiBer &am!er or at+ator


Al"es to (S B

Al"es to (S B


ATAV7  YAT  'AT'P  ∆T'$  Y'AT AT i too lo% for 100H A ooling

'AT enor error AT enor error eating oil valve lea?ing or t+? o!en =ea?ing or t+? eonomiBer &am!er or at+ator


'ATAV7  Y'AT  ∆T'$ Z ATAV7  YAT 'AT too highI ho+l& be le than AT

'AT enor error AT enor error )ooling oil valve t+? loe& or at+ator fail+re $o+le& or +n&eriBe& ooling oil )@ tem!erat+re too high or )@ +navailable eating oil valve lea?ing or t+? o!en


Page 85 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems 'ATAV7 M 'AT'P  Y'AT

Equat"on

an& )) Z 88H

)C B10

#escr"t"on

Poss"$le #"a.nos"s

g.

'AT enor error )ooling oil valve t+? loe& or at+ator fail+re $o+le& or +n&eriBe& ooling oil )@ tem!erat+re too lo% or )@ +navailable eating oil valve lea?ing or t+? o!en


A +bet of all !otential fa+lt on&ition i eval+ate& b9 the A$** ro+tine. The et of a!!liable fa+lt on&ition &e!en& on the !erating 'tate of the AUG 1"

2"

3"

November 30, 2014

'AT too high in f+ll ooling (oil i at+rate&"

-n ' 1 (eating", the follo%ing $a+lt )on&ition hall be eval+ate&G a"

$)1G *+t tati !re+re i too lo% %ith fan at f+ll !ee&

b"

$)2G AT too lo%I ho+l& be bet%een RAT an& AT

"

$)3G AT too highI ho+l& be bet%een RAT an& AT

&"

$)4G Too man9 hange in !erating 'tate

e"

$)5G 'AT too lo%I ho+l& be higher than AT

f"

$)G A fration i too lo% or too highI ho+l& eC+al HA-N

g"

$)G 'AT too lo% in f+ll heating (oil i at+rate&"

-n '2 (o&+lating onomiBer", the follo%ing $a+lt )on&ition hall be eval+ate&G a"


b"


"


&"


e"

$)6G 'AT too high or too lo%I ho+l& eC+al AT

f"

$)8G AT i too high for free ooling %itho+t mehanial ooling

-n '3 (ehanial  100H onomiBer )ooling", the follo%ing $a+lt )on&ition hall be eval+ate&G a"


b"


"


&"


e"

$)10G AT i too high or too lo%I ho+l& eC+al AT

f"

$)11G AT too lo% for 100H A

g"

$)12G 'AT too highI ho+l& be le than AT

h"

$)13G 'AT too high in f+ll ooling (oil i at+rate&"

Page 8 of 105


5"

-n '4 (ehanial )ooling, in A", the follo%ing $a+lt )on&ition hall be eval+ate&G a"


b"


"


&"


e"

$)G A fration i too lo% or too highI ho+l& eC+al HA-N

f"

$)12G 'AT too highI ho+l& be le than AT

g"

$)13G 'AT too high in f+ll ooling (oil i at+rate&"

-n '5 (ther", the follo%ing $a+lt )on&ition hall be eval+ate&G a"


b"


"


&"


h.

$or eah air han&ler, the o!erator hall be able to +!!re the alarm for an9 $a+lt )on&ition.

i.

val+ation of $a+lt )on&ition hall be +!en&e& +n&er the follo%ing on&itionG 1"

@hen AU i not o!erating.

2"

$or a !erio& of o&e*ela9 min+te follo%ing a hange in o&e (e.g. from @arm+! to +!ie&" of an9 one 7ro+! erve& b9 the AU.

.

$a+lt )on&ition %hih are not a!!liable to the +rrent !erating 'tate hall not be eval+ate&.

?.

A $a+lt )on&ition that eval+ate a tr+e m+t &o o ontin+o+l9 for Alarm*ela9 min+te before it i re!orte& to the o!erator.

l.

@hen a $a+lt )on&ition i re!orte& to the o!erator, it hall be a =evel 3 alarm an& hall inl+&e the &eri!tion of the fa+lt an& the lit of !oible &iagnoe from the table in 1.3.13.f.


Teting>)ommiioning verri&eG Provi&e oft%are !oint that interlo? to a hille& %ater an& hot %ater !lant level to a.

-f there i a hot %ater oil, fore hot %ater valve f+ll o!en

b.

-f there i a hot %ater oil, fore hot %ater valve f+ll loe&

.

$ore hille& %ater valve f+ll o!en

&.

$ore hille& %ater valve f+ll loe&

November 30, 2014

Page 8 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems #entral plant se&uences are not part of the initial scope of :?-0CC, but they are being preserved for future use, when central plant se&uences are added. %ypically, the chiller or boiler plant will start when there is at least one re&uest for C minutes, and stop when there are no re&uests for C minutes, after a minimum run-time has elapsed. #);$% and );$% reset re&uests are used in %rim 9 :espond loops to control supply water temperature based on /one and A)U demands. 15.

Plant ReC+et a.

b.

.

&.

)ooling )@'T Reet ReC+et 1"

-f the )@ valve i le than 65H, en& 0 ReC+et.

2"

-f the )@ valve i greater than 85H, en& 1 ReC+et.

3"

-f the +!!l9 air tem!erat+re e/ee& the +!!l9 air tem!erat+re et!oint b9 3S$ for 2 min+te, en& 2 ReC+et.

4"

-f the +!!l9 air tem!erat+re e/ee& the +!!l9 air tem!erat+re et!oint b9 5S$ for 2 min+te, en& 3 ReC+et.

)hiller Plant ReC+et. 'en& the hiller !lant that erve the 9tem a )hiller Plant ReC+et a follo%G 1"

-f the )@ valve i le than 10H, en& 0 ReC+et.

2"

-f the )@ valve i greater than 85H, en& 1 ReC+et.

-f there i a hot %ater oil, eating @'T Reet ReC+et 1"


2"


3"


4"


-f there i a hot %ater oil an& a boiler !lant, en& the boiler !lant that erve the 9tem a #oiler Plant ReC+et a follo%G 1"


2"


%he alarms described in the net section were removed from the main se&uences as they have been superseded by the AFDD alarms above. )owever, if the AFDD alarms are not installed or used for whatever reason, then these alarms should be included to replace their functionality. 1.

Alternate Alarm (&o not +e if A$** i intalle&" a.

=o% tati !re+re (more than 0.25 inhe belo% et!oint" %hen fan ontrol loo! i ative for longer than 5 min+teG =evel 3.

b.

+t&oor airflo% le than et!oint b9 10H for 10 min+te %hen loo! i ativeG =evel 3.

November 30, 2014

Page 86 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems .

igh +!!l9 air tem!erat+re (more than 5S$ above et!oint" off ooling oil %hen oil ontrol loo! i ative for longer than 15 min+te an& hiller !lant i !roven onG =evel 3.

&.

-f there i a hot %ater oilG

e.

November 30, 2014

1"

=o% +!!l9 air tem!erat+re (more than 15S$ belo% et!oint" off heating oil %hen oil ontrol loo! i ative for longer than 15 min+te an& boiler !lant i !roven onG =evel 3.

2"

@hile heating valve i loe&, if the tem!erat+re rie aro the heating oil e/ee& 2S$ ontin+o+l9 for 30 min+teI or if the &iharge tem!erat+re i more than 5S$ above et!oint for more than 30 min+te ontin+o+l9G =evel 4 in&iating !oibl9 lea?ing valve.

-f there i a mi/e& air tem!erat+re enorG 1"

@hile ooling valve i loe&, if the tem!erat+re &ro! aro the ooling oil e/ee& 2S$ ontin+o+l9 for 30 min+teI or if the &iharge tem!erat+re i more than 5S$ belo% et!oint for more than 30 min+te ontin+o+l9G =evel 4 in&iating !oibl9 lea?ing valve.

2"

-f the o+t&oor air tem!erat+re i above the +!!l9 air tem!erat+re et!oint an& the eonomiBer i enable& an& the mi/e& air tem!erat+re i more than 2°$ &ifferent from the o+t&oor air tem!erat+re for more than 30 min+te ontin+o+l9I R if the o+t&oor air tem!erat+re i more than 5°$ belo% the +!!l9 air tem!erat+re et!oint an& the  hille& %ater valve i o!en (or om!reor are on"G =evel 4 in&iating eonomiBer &am!er ontrol !roblem.

Page 88 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems 1+4

Pro.ramm"n. Parameters! Sett"n.s 2 Var"a$les

%he following pages list the parameters5variables which must be programmed when setting up control se&uences for various types of e&uipment. *ariable names are those used in the !6N4= implementation of these se&uences, which was produced by Automated Logic #orp in the course of this research. '"any terminal unit types re&uire the same parameters, but are described separately because the demo system variable names are different for historical reasons.(

A+

=ener"c %hermal ones Parameter

Units

Description

Hints/Comments

Variable Name in Demo System

Title 24 Ventilation Varea-min

CFM

Minimum OA for building area

min_oa_bldg

Vocc-min

CFM

Minimum OA for occupants

min_oa_occ

Standard 62.1 Ventilation Z

-

Zone occupant diversity ratio

zone_d

VbzP

CFM

reat!ing zone population OA

"#p $ Pz% in &'()

oa_people

VbzA

CFM

reat!ing zone area OA

"#a $ Az% in &'()

oa_area

*z+

-

Zone !eating air distribution effectiveness

ez!

*zC

-

Zone cooling air distribution effectiveness

ezc

Tnin! Prestart ,uning

OnOff

Automatic prestart tuning

+eat .mportance Factor

-

+eat re/uest scalar

0et to 1 to disable re/uests from a zone

!eat_re/uest_2

Cool .mportance Factor

-

Cool re/uest scalar


cool_re/uest_2

0tatic .mportance Factor

-

0tatic pressure re/uest scalar


static_re/uest_2

Hints/Comments


&+

auto_prestart_tuning

VAV %erm"nal n"t! 7< Reheat

(in a&&ition to 7eneri one !arameter" Parameter

Units

Description

Vm

CFM

Minimum airflo3 allo3ed by controls

min_CFM

Vmin

CFM

Minimum zone airflo3 3!en occupied

occ_min

Vcool-ma2

CFM

Zone airflo3 at )114 cooling

air_flo3 5 6Cooling Ma2 Airflo37

V!eat-ma2

CFM

Zone airflo3 at )114 !eating

air_flo3 5 6+eating Ma2 Airflo37

November 30, 2014

Page 100 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems C+

Parallel )an-Po7ered %erm"nal n"t! Constant Volume )an

(in a&&ition to 7eneri one !arameter"

#+

Hints/Comments


Parameter

Units

Description

Vm

CFM


min_CFM

Vmin

CFM


occ_min

Vcool-ma2

CFM


vcool_ma2

CV Fan Flo3

CFM

#ated flo3 of CV fan

fan_flo3rate

Parallel )an-Po7ered %erm"nal n"t! Var"a$le Volume )an


E+

Hints/Comments


Parameter

Units

Description

Vm

CFM


min_CFM

Vmin

CFM


occ_min

Vcool-ma2

CFM


vcool_ma2

Pfan-z

CFM

Parallel fan airflo3 at minimum speed

pfanz

Pfan-ma2

CFM

Parallel fan ma2imum airflo3

pfanma2

Ser"es )an-Po7ered %erm"nal n"t! Constant Volume )an


)+

Hints/Comments


Parameter

Units

Description

Vm

CFM


min_CFM

Vmin

CFM


occ_min

Vcool-ma2

CFM


vcool_ma2

#ual #uct VAV %erm"nal n"t! Sna Act"n. Control! #ual nlet Sensors

(in a&&ition to 7eneri one !arameter" Units

Description

Vm

CFM


min_CFM

Vmin

CFM


occ_min

Vcool-ma2

CFM



V!eat-ma2

CFM


!d_air_flo3 5 6+eating Ma2 Airflo37

November 30, 2014

Hints/Comments


Parameter

Page 101 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems =+

#ual #uct VAV %erm"nal n"t! Sna Act"n. Control! #"schar.e Sensor


H+

Hints/Comments


Parameter

Units

Description

Vm

CFM


min_CFM

Vmin

CFM


occ_min

Vcool-ma2

CFM



V!eat-ma2

CFM


air_flo3 5 6+eating Ma2 Airflo37

#ual #uct VAV %erm"nal n"t! 8"9"n. Control! #ual nlet Sensors


+

Hints/Comments


Parameter

Units

Description

Vm

CFM


min_CFM

Vmin

CFM


occ_min

Vcool-ma2

CFM



V!eat-ma2

CFM



#ual #uct VAV %erm"nal n"t! 8"9"n. Control! #"schar.e Sensor


@+

Hints/Comments


Parameter

Units

Description

Vm

CFM


min_CFM

Vmin

CFM


occ_min

Vcool-ma2

CFM


vcool_ma2

V!eat-ma2

CFM


v!eat_ma2

#ual #uct VAV %erm"nal n"t! Cold #uct 8"n"mum Control

(in a&&ition to 7eneri one !arameter" Units

Description

Vm

CFM


min_CFM

Vmin

CFM


occ_min

Vcool-ma2

CFM



V!eat-ma2

CFM



November 30, 2014

Hints/Comments


Parameter

Page 102 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems +

8ult"le one VAV A"r Handl"n. n"t Parameter

Units

Description

Hints/Comments


S"T and #an Control 0upply Fan Minimum 0peed

4

Minimum allo3ed supply fan VF8 speed

vfd_min

Ma2 #eset OA,

9F

OA, for ma2imum 0A, reset

oat_ma2_reset

:o #eset OA,

9F

OA, for no 0A, reset

oat_no_reset

,min

9F

Cooling coil setpoint at ma2imum reset

t_min

+;-OA ,!res!old

4

Control loop 4 for +;-OA c!angeover

!3_oa_t!res!old

OA-#A ,!res!old

4

Control loop 4 for OA-#A c!angeover

oa_ra_t!res!old

#A-C+; ,!res!old

4

Control loop 4 for #A-C+; c!angeover

ra_c!3_t!res!old

Static Pressre SP $eset 0P1

in+'O

.nitial setpoint

sa_static_stpt 5 6.nitial7

0Pmin

in+'O

Minimum setpoint

sa_static_stpt 5 6Minimum7

0Pma2

in+'O

Ma2imum setpoint

sa_static_stpt 5 6Ma2imum7

,d

mins

,<# delay after fan proven on

sp_tr_delay

,

mins

,ime bet3een ,<# output updates

sa_static_stpt 5 6*very7

.

-

+o3 many reset re/uests to ignore

ignore_air_re/

0Ptrim

in+'O

0etpoint trim amount

sa_static_stpt 5 ,rim by

0res

in+'O

#espond amount

sa_static_stpt 5 6and respond by7

0res-ma2

in+'O

Ma2 response amount per update

sa_static_stpt 5 6 (( respond by more t!an7

S"T Setpoint $eset 0P1

in+'O

.nitial setpoint

sat_stpt_cool 5 6.nitial7

0Pmin

in+'O

Minimum setpoint

sat_stpt_cool 5 6Minimum7

0Pma2

in+'O

Ma2imum setpoint

sat_stpt_cool 5 6Ma2imum7

,d

mins


sat_tr_delay

,

mins


sat_stpt_cool 5 6*very7

.

-


ignore_cool_re/

0Ptrim

in+'O


sat_stpt_cool 5 ,rim by

0res

in+'O

#espond amount

sat_stpt_cool 5 6and respond by7

0res-ma2

in+'O


sat_stpt_cool 5 6 (( respond by more t!an7

%isc A+= 8esign Flo3

CFM

=sed for dirty filter detection

8irty Filter Alarm >imit

in+'O

Ma2 allo3ed filter pressure at )114 flo3

0etbac?;armup Fan

@:

#un 0upply Fan in =noccupied +eat

November 30, 2014

0et to t!e design CFM for t!e A+=(

design_flo3 filter_dp)11

*nable if VAV re!eat bo2es on perimeter(

fa_unocc_!eat

Page 103 of 105

ASHRAE RP-1455: Advanced Control Sequences for HVAC Systems Phase ! A"r #"str"$ut"on and %erm"nal Systems Parameter

Units

Description

Hints/Comments


&tside "ir/'conomi(er Control A0+#A* Climate Zone

-

A0+#A* Climate Zone for OA loc?out

as!rae_climate_zone

*conomizer Control ,ype

-

Control met!od for OA loc?out

econ_control_type

Probe ain

-

0tatic pressure probe gain

oa_probe_gain

A0+#A* &'() Compliance

@:

=se A0+#A* 0td &' ventilation

Absolute Minimum OA

CFM

Absolute Min OA sc!eduled on dra3ings

abs_min_oa

8esign Minimum OA

CFM

8esign Min OA sc!eduled on dra3ings

des_min_oa

Absolute Minimum DP

in+'O

DP E Absolute Min OA sc!eduled on dra3ings

Only applicable if OA DP sensor used

abs_min_dp

8esign Minimum DP

in+'O

dpE 8esign Min OA sc!eduled on dra3ings

Only applicable if OA DP sensor used

des_min_dp

#elief Fan Minimum 0peed

4

Minimum allo3ed relief fan VF8 speed

Only applicable if #elief Fan installed

rf_vfd_min

*nable for 0td &'B disable for ,itle'

as!rae_ventilation

$etrn #an Control )&nly applicable *or $etrn #an +it, &" -P 0P1

in+'O

.nitial setpoint

na

#F0Pmin

in+'O

Minimum return fan pressure setpoint

na

#F0Pma2

in+'O

Ma2imum return fan pressure setpoint

na

,d

mins


na

,

mins


na

.

-


na

0Ptrim

in+'O


na

0res

in+'O

#espond amount

na

0res-ma2

in+'O


na

"tomatic #alt Detection  Dia!nostics Mode 03itc! 8elay

mins

#ule evaluation delay after mode s3itc!

modes3_delay

Alarm 8elay

mins

Fault persistence time before alarm

alarm_delay

Mode C!ange Ma2

-

Ma2 mode s3itc!es per !our

mode_s3_ma2

0upply Fan d,

9F

*2pected supply fan !eat rise

dt_sf

OA,-#A, d, Min

9F

Min OA,-#A, d, for OA fraction test

oatrat_dt_min

,emperature *rror

9F

*2pected temp sensor error "per sensor%

e_satB e_ratB e_matB e_oat

OACFM *rror

4

*2pected OA CFM sensor error

e_oaCFM

VF8 0peed *rror

4

*2pected VF8 speed error

e_vfd

8uct 0tatic Pressure *rror

in+'O

*2pected static pressure sensor error

e_sp

0ensor Average  Factor

-

;eig!ted average  factor "per sensor%

sat_avg_?B mat_avg_?B rat_avg_?B oat_avg_?B sp_avg_?

0ensor Average ;indo3

mins

;eig!ted average 3indo3 "per sensor%

sat_avg_3indo3B mat_avg_3indo3B rat_avg_3indo3B oat_avg_3indo3B sp_avg_3indo3

Fault 8etect *nable

@:

*nable F88 fault detection "per FC%

rp)GG_fc)_enaB (( B rp)GG_fc)H_ena

November 30, 2014

Page 104 of 105

RP-1455 Advanced HVAC Control Sequences for Airside Equipment

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