APPENDIX D.12 Ventilation Calculations and Data 1. Hydration Pump Station Electrical Room Ventilation Calculations 2. Inflow Pump Station Engine Room Ventilation Calculations 3. JennFan Data
APPENDIX D.12 item 1 Calculation - Hydration Pump Station Purpose: Ventilation for electrical room. System Description: The electrical room shall house the electrical, instrumentation and control, and the communication equipment. The ventilation system shall consist of an exhaust fan that will exhaust the heated air from the room with an intake louver to permit the cooler outside air to enter the room. The exhaust fan shall be thermostatically controlled. Design Criteria: 1. 2. 3. 4.
Allowable free air velocity for a intake louver = 700 fpm Maximum 104 degrees F temperature in pump station. Add 16 percent additional free area for bug screen. The Outdoor design conditions shall be based on those of Fort Lauderdale, Florida.
Assumptions: 1. 2. 3. 4.
Lighting heat gain ~ 2W/ft^2 Fan heat gain ~ 80 Btu/hr/fan Ignore operating floor cooling effect Assume box-like structure fully exposed. The building will have no windows and be constructed of cast-in-place concrete and 8” fully grouted masonry units. The roof shall be 10” hollow core slabs. The solar heating loads shall be addressed by a 10 percent increase in the ventilation air supply. At 30% design the solar heat load will be calculated due to the large openings required for detailing the building design. Other building heat loads shall be assumed to be negligible.
Calculations: Determine ventilation supply fan sizing: Lighting heat load = 16 x 21 x 2 = 672 W = 38.2 btu/min Fan heat load = 80 Btu/hr = 1.33 Btu/min Heat Gain Equipment Electrical Room (preliminary estimate) ≈5 kW = 285 Btu/min Total heat load = 285 + 38.2 + 1.33 = 325 Btu/min + 10% envelop heat load + 15% heat load contingency = 406 Btu/min q = 1.08 x Q x (Ti – to) = (40.6) x (60) = 1.08Q (Δ9 deg F) Q = 2,500 CFM
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Determine louver size: 2,500 CFm/700 = 3.6 sq. ft. Add 16% for bug screen = 3.6 + 16% = 4.2 sq. ft. Required fan rating: 2,500 CFM JennFan model 203A: rating of 1,800 CFM, 1/3 Hp motor, requiring a 24” x 24” wall opening. ( Reference – JennFan data Appendix D.12 item 3)
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APPENDIX D.12 item 2 Calculation - Inflow Pump Station Purpose: Ventilation for engine pump room at the Inflow Pump Station. System Description: A forced air ventilation system will be provided for the operating floor area of the pump station. The ventilation system will be available during all times of the year to remove space heat gains and will utilize wall mounted fans for supply and for exhaust.
INFLOW PUMP STATION VENTILATION REQUIREMENT Design Assumption:
Remarks:
1. The equipment enclosure (pump room) is not air conditioned 2. The operating floor inside station temperature is 100 deg.F, dry
District Standard “Ventilation”
bulb 3. The outdoor air temperature is 95 deg.F dry bulb 4. The safety factor is 5%. 5. 500 fpm ventilation air velocity
Min. 400 fpm by District
6. Diversity Factor is .75
Part I. Heat Gain Calculation A. Electrical Pump Motor
Qty of 2 of 200 Hp Electrical motors Usage factor (UF) is .5 and Load Factor (LF) is .9 And assuming the efficiency is 85%.
P*
1 − Eff
qep
=
qep
= 101070
Qep
= 101070
Eff
* UF * LF Per pump motor sensible heat gain
BTU hr
Heat Gain of 2 pumps
BTU hr
B. Diesel Pump Engines
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INFLOW PUMP STATION VENTILATION REQUIREMENT Design Assumption:
Remarks:
1. Qty of 3, 800 Hp Diesel Engine
Caterpillar C27DITA
q dp = 7,166
Btu
Heat Rejection to Atmosphere per
min .
Product specification at 90% load.
Q dp = 1,289,880
Btu
Total Heat Rejection by three 800
Hr ..
Hp Diesel pumps(90% load)
C. Diesel Generators
Qty of two 600 KW Diesel Generators and lead/lag operated
Cummins Genset 600KW
Usage Factor = .5 Load Factor = 1
q
=
g
Qg
=
Per manufacturer product
BTU
7790
Min
q g * LF * UF * Qty
specification =
467400
BTU hr
D. Total Heat Gain
Q = (Qep + Qdp + Qg)*(1+SF)*.D.F.
Q dp = 1,463,450
Total Heat Gain
Btu
Heat Gain after applying safety
Hr .
factor and diversity factor
Total heat gain including solar heating load is addressed in Part II.A. by 10% increase in the Make up air supply Part II. Ventilation Requirement ( H.I.) A. Make up Air
CFM int ake
=
Q
1.08 * Δt
=
1,463,450 1.08 * (100 − 95)
=
271,009cfm
Refer to design assumption (6) Greenheck SBCS-3H72-150
Intake air velocity = 500 fpm
A =
271,009 500
=
Free area of intake louvers opening
542 ft 2
(Gravity intake)
B. Exhaust Air
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INFLOW PUMP STATION VENTILATION REQUIREMENT Design Assumption:
Remarks:
-
Generator 2,280 cfm
Standby
-
800hp engine 1650cfm
90%
-
Total combustion air 7,230cfm
90%
Total exhaust air 290,880cfm
(6) Greenheck SBCE-3H72-150
Part II. Ventilation Requirement ( USACE) A. Make up Air
CFM int ake
=
Q
1.08 * Δt
=
1,463,450 1.08 * (104 − 95)
= 150,560cfm
Refer to design assumption (4) Greenheck SBCS-3L54-75
Intake air velocity = 500 fpm
A =
150,560 500
=
Free area of intake louvers opening
301 ft 2
(Gravity intake)
B. Exhaust Air -
Generator 2,280 cfm
Standby
-
800hp engine 1650cfm
90%
-
Total combustion air 7,230cfm
90%
Total exhaust air 158,386cfm
(4) Greenheck SBCS-3L48-75
Part II. Ventilation Requirement ( USACE-Ft. Lauderdale) A. Make up Air
CFM int ake
=
Q
1.08 * Δt
=
1,463,450 1.08 * (104 − 92.3)
= 115,815cfm
Using USACE req. and Ft Laud. climatic design ASHRAE info. (4) Greenheck SBCS-3H54-75
Intake air velocity = 500 fpm
A =
115,815 500
=
Free area of intake louvers opening
2
232 ft
(Gravity intake)
B. Exhaust Air -
Generator 2,280 cfm
Standby
-
800hp engine 1650cfm
90%
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INFLOW PUMP STATION VENTILATION REQUIREMENT Design Assumption: -
2000hp engine 5455cfm
-
Total combustion air 7,230cfm
Remarks:
90%
Total exhaust air 153,750cfm
(4) Greenheck SBCE-3H48-75
Note: At 30% design the solar heat load will be calculated
due to the large openings required for detailing the building design. Reference – fan and filter data (see Appendix D.12 item 3)
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