Lighti n g for the Workplace
3
CONTENTS
Foreword by Paul Morrell,
4–5
President of the British Council for Offices 6–7
INTRODUCTION
The Chan ging Cor Corpora pora te Pers pect ive
6–7
WORKPLACE LIGHTING – PAST, PRESENT AND FUTURE
Lighting Research versus the Codes
10–11
– T h e Les s o ns o f Li g ht i n g R es ea rch
1 2– 15
– C ur re nt Gu i d an ce an d i t s L i mi t at i o ns
1 6– 23
Key Issues in Work Workplace place Lighting
24–29
Natural Light, Active Light & Balanced Light
30–37
Further Considerations in Work Workplace place Lighting
38–47
Lighting Techniques – Comparing the Options
48–51
W O R K P L A C E L I G H T I N G – A P P L I C A T I ON ON A R E A S
O p e n P l a n O ff i c e s
5 6–6 7
C e l l u l a r O ff i c e s
6 8– 71
De al er R oo m s
7 2–7 5
Co n t rol R oo m s
7 6–7 9
Ca l l Ce nt re s
8 0–8 3
Co m mu ni ca t i on A rea s /Me et i ng R oo m s
8 4– 87
B rea k- Ou t Z o ne s
8 8–9 1
S t or ag e
9 2–9 3
Co m mo n P ar t s
9 4–9 7
IMPRINT Publisher: Zumtobel Staff GmbH, Dornbirn/A Design: Marketing Communication Reprints, even in part, require the permission of the publishers © 2005 Zumtobel Staff GmbH, Dornbirn/A
52–97
98–135
WORKPLACE LIGHTING – LIGHTING DESIGN
P rod u ct Se le ct o r
1 0 0 –13 3
Advi sor soryy S ervi ces
134–135 134 –135
R ef ere nc es & Us e fu l We b si t e s
8–51
1 35
Paul Morrell President of the British Council for Offices (BCO)
London aims to continue being Europe’s leading financial centre and will need more, higher quality office space in the future (photo: Piper’s model of the future City of London, shown at MIPIM 2005)
FOREWORD
The UK offi ce mark et, in particular in London, is changing , dri ven by a numb er of long -ter m tren ds in international banking and finance. Informed forecasts, such as the recent Radley Report*, point, firstly, to a shift towards our capital city, at the expense of Paris and Frankfurt, as Europe’s leading financial centre, with a commensurate pressure on office space. Secondly, we can see a medium-to-long term growth in the number of highly educated, mathematically literate graduates required to run these complex, sophisticated financial operations. This shift from low skill to high skill staff puts a premium Paul Morrell BSc FRICS Hon FRIBA President of British Council for Offices
on worker satisfaction, as they become ever more demanding of their company and working conditions. The lesson is clear – nothing is more important in a service economy like ours than the efficiency of the working environment.
In today’s fast-moving marketplace, successful companies must invest in improved design and specification, to attract and retain an increasingly valuable and demanding workforce. People, not technology, must become the driving force of future office design. If one looks at the ratio of long-term costs of any business, including building design, construction, maintenance and personnel, design is a tiny fraction of the total – about 0.05 % of the cost of your workers. Yet that very small investment in good design has been proven to have a huge impact on staff satisfaction, efficiency and profitability. To put it anot her way, if a building can increase the prod uctivity of its occu pant s by 10 per cent , you essentially get it free.
For all these reasons, improved design and specification – and especially lighting, the subject of this timely brochure from Zumtobel Staff Lighting – can make a significant contribution to long-term success.
* The Outlook for Banks Operating in the City of London (Radley & Associates, March 2004)
5
People & The Workplace As Organisations change, so does the Role of the Workplace
Historical Perspective
a n
rces s o u
R e
M a n
a g
e m e n
m u
H
t
WORKFORCE “the wages grow exponentially”
Lower qualified Less Aspirational Resistant to Change Traditional division between Human Resources and Facilities Management
FM driven Desk/task area focus Functional
“a cost centre to be controlled”
WORKSTATION F a
c i l i t i
Contemporary Best Practice
a t e M a n a g e m
o r
p o r
C
t
e n
e s m a n a g e m
e n
t
wellness war for talent gymnasia esprit de corps brand in the workplace very aspirational management culture attraction, retention, motivation
WORKFORCE Living at Work
WORKPLACE lifestyle in the workplace added value break out zones open change agenda common parts differentiation flexiworking best practice lighting
Productivity factors influenced by lighting: Speed Persistence Accu racy Attr acti on Retention Motivation Satisfaction Happiness Potential Untapped Lighting Dividend
The Untapped Lighting Dividend
Single Path – Physiological
Generic practice lighting (Louvred Downlights)
Best practice lighting (Direct/Indirect)
Visual Capabilities
Visual Capabilities
Task Performance
Conventional Productivity Result
Task Performance
"Lighting and task conditions that improve visibility lead to better task performance"
Enhanced Productivity Dividend
Dual Path – Physiological & Psychological Physiological Path
Visual Capabilities
Personal Control Best practice lighting (Direct/Indirect and controls)
Task Performance
Task Performance
Motivation
“Lighting and task conditions that improve visibility lead to better task performance”
“People with dimming control showed more sustained motivation, and improved performance on a measure of attention”
Productivity factors influenced by lighting: Speed Persistence Accu racy Attr action Retention
Personal Control
Health & Wellbeing
“People with dimming control reported higher ratings of lighting quality, overall environmental satisfaction, and self-rated productivity”
Motivation Satisfaction Happiness The Unta pped
Appraisal Preference
Health & Wellbeing
Mood Psychological Path*
“People who are more satisfied with their lighting, rate the space as more attractive, are happier, and more satisfied with their environment and their work”
Lighting Dividend
*”This is the first time that this complete path has been demonstrated”
“Light is the key to well-being.” – Le Corbusier
lighting design should be based
workplaces – gymnasia, break-
cal, rather than purely visual,
on the latest scientific research
out zones, thoughtfully designed
aspects of lighting.
into lighting and visual comfort –
common parts.
most of which is ignored in
The lead ing fina ncial h ouses in
Constructing and operating a
current advisory codes. As we
The advantag es gain ed by such
the City of London and other
building can cost a lot of money
demonstrate on pages 12–15,
hygiene factors are only just
financial capitals have long
– but not nearly as much as the
this research points towards a
beginning to be fully appreciated
realised the importance of light-
cost of the people who occupy
number of significant conclu-
– easier change management,
ing – share dealer rooms, which
the building. In the same equa-
sions that are embodied in our
sense of belonging, mirroring
produce the most spectacular
tion the cost of the lighting is
whole approach to workplace
the employees own personal
profits, are always equipped
insignificant. Comparatively
lighting.
aspirations – being just some.
with state-of-the-art direct/indi-
So, far from being a cost to be
rect lighting systems. Most have
small investment in better design and better lighting can have a
Thes e p ages illu strate how good
controlled, the workplace is
sophisticated controls. Banks
huge, positive knock-on effect
lighting can pay dividends. The
increasingly being viewed as an
and share traders know that
for many years to come. Con-
historical management perspec-
asset to be managed. But all
such systems create the most
versely bad design can push up
tive of the workplace – a cost to
the investment in hygiene fac-
stimulating and visually comfort-
long-term costs – while hitting
be controlled – has lead to the
tors and company culture can
able working environments.
the bottom line.
adoption of a standardised, and
be stifled if we follow the con-
flawed, lighting approach for
ventional, flawed lighting design
However at Zumtobel Staff we
In a world where the pace of
offices. But there are signs of
path. As business management
don’t believe that the best light-
change in work patterns, com-
change. Exceptional businesses
changes so must lighting begin
ing should be confined only to
pany practices and technology
are beginning to incorporate a
to reap the untapped dividends
high profile bond traders and
is accelerating, we believe that
range of hygiene factors in their
associated with the psychologi-
the like – ordinary administrative staff and other grades should not have to compromise with inferior, direct downlighter sys-
Integrated Model of Lighting Quality*
l d u a
i
v d i
I n
– “Lighting is for more than visibility” – “Comfort is more than glare control”
– – – – – –
tems, which surveys show are
W e l l -
B e i n
g
visibility activity social & communication mood, comfort health & safety aesthetic judgement
universally disliked. For the sake of job satisfaction, visual comfort and general well-being, they also deserve the best lighting – and that means direct/indirect systems. These central principles, derived from the findings of lighting science – direct/indi-
* Jennifer A. Veitch, Ph.D. National Research Council of Canada www.irc.nrc-cnrc.gc.ca/ie/light
rect lighting and dynamic, vari-
The Untapped Lighting Dividend – installation – maintenance – operation – energy – environment
E c o
able light levels – lie at the core of this guide to office lighting. In combination they correspond to Zumtobel Staff’s central lighting – – – –
s * *
n o m i c
A r c h
form composition style codes & standards
e u r i t e c t
design philosophy, which can be summed up in the phrase “lighting for people”.
** see Chart page 7
Economics
THE CHANGING CORPORATE PERSPECTIVE
4 0 0 2 s g n i d l i u B t n e g i l l e t n I / l l e K n a l l A : o t o h P
Extra for Best Practice Potential Untapped Lighting Dividend
Lighting Cost
7
M&E Fitout
Construction Costs
Shell & Core
Rent 15 Years
People Costs 15 Years
Business Operating Costs
“I’m not saying you can walk on light: it doesn’t have structure, but it is part of the structure of the thinking of the architecture.” Richard Meier
WORKPLACE LIGHTING – PAST, PRESENT AND FUTURE
9
Workplace Lighting – Past, Present and Future s r e n t r a P & r e t s o F : t c e t i h c r A
Lighting Research versus the Codes
WORKPLACE LIGHTING – PAST, PRESENT AND FUTURE
11
“Light has a great influence on
Office lighting design is in-
Unfortunately our misguided
lighting is a much more signifi-
huma n s ensi tiv ity. It reaches
creasingly bound by a whole
codes have now come to pass
cant factor in workplace health
the depths of one’s heart and
raft of recommendations and
as good practice, because too
and efficiency than is generally
awak ens somethi ng asle ep
standards emanating from the
few skilled lighting designers
recognised – and should be left
there.”
UK and the EC. A minority of
get the opportunity to design
to the real lighting professionals.
– Motoko Ishii
these standards and recommen-
genuinely creative workplace
The best , healthie st and most
dations are useful – others, as
lighting – as opposed to the
effective lighting schemes result
we shall see, are either out-of-
reception area, the boardroom
from qualified, experienced
date, due to the fast-moving
or the presentation suite, where
designers thinking “outside the
nature of office technology, or
they are most often employed.
box” – basing their designs not
run contrary to the findings of
Developers don’t see good,
on outdated codes and recom-
the most recent lighting research
innovative office lighting as im-
mendations, but on the latest
in both Europe and the USA.
portant, preferring instead to
findings of lighting science.
Take th e o ffici al codi fication of
allow non-lighting specialists to
“dark light” louvred downlights
design and install humdrum,
On pages 12–15 we summarise
in the 1980s, triggered by
and even harmful, lighting,
the conclusions of the most
increased VDT use in the work-
according to a crude distillation
important pieces of recent
place. As a result of that single
of the Codes – an approach we
research in the area of work-
recommendation, office lighting
sum up as “working inside the
place lighting. Then on pages
undoubtedly went downhil, as
box”. As the introduction to the
16–23 we analyse current office
we were plunged into a new
DIAL research (see page 13)
lighting standards and recom-
“Dark Age”. The main problem
pessimistically reports, “good
mendations, to see how they
was the Code’s concentration
lighting designs are rare”.
measure up to these research findings.
on luminaire selection in isola-
In 1992 Royal Life Holdings opened their highly innovative new Headquarters in Peterborough in the UK, designed by Arup Associates. There was already recognition, re-inforced by the success of this building, that direct/indirect lighting provided a preferable airy, attractive workplace. Especially when considering the alternative gloom, so well illustrated here, of the lower height spaces alongside, fitted with the standard solution at the time – Category 2 downlighters.
tion, rather than considering the
At Zumt obel Staf f w e quest ion
entire office environment in a
this approach. We would argue
holistic way.
that research indicates that
The Lessons of Lighting Research
Light Right test site – In the most comprehensive study of its type researchers found overwhelming user preference for direct/indirect lighting systems.
1. Getting the Light Right The “Lig ht Righ t” Cons ort ium
In probably the most compre-
space as more attractive, are
To qu ote Ron Lewis, chairp erson
hensive study of its type con-
happier, and are more com-
of the Light Right Consortium,
ducted in Albany, New York,
fortable and satisfied with their
“Lighting does matter. We have
researchers found that:
environment and work.”
samp led majo r U S corp orat ions
• “This is the first time that
and foun d a s trong conn ecti on
is an independent authoritative research body in the USA, managed by the Pacific Northwest National Laboratory and
• Good lighting improves productivity* • 29–31 % of people under
supported by the Illuminating
downlight only systems rated
Engineering Society of North
them as uncomfortable
Amer ica, the Int ern atio nal Asso -
• 91 % of people were comfort-
ciation of Lighting Designers,
able with a system of direct/
the International Facility Man-
indirect, wall washing and
agers Association, the US
dimming control
Department of Energy and the
• Dimming control over work-
US Environmental Protection
station lighting “increased
Agen cy, amo ngst others.
motivation” and allowed users to “sustain their persistence and vigilance over time”, and be “more accurate” • “People who are more satisfied with their lighting rate the
this complete path has been
betw een lightin g, product ivity
demonstrated”
and its over all valu e to busi nes ses. ” * The Light Right website (www.lightright.org) reproduces the research and results. Co-author of the Light Right research: J.A. Veitch. She is much respected for this and other work done with the Institute for Research in Construction, Ottawa.
WORKPLACE LIGHTING – PAST, PRESENT AND FUTURE
13
DIAL research test site showing two examples below where accent lighting materially improved user perception of the space, compared with the conventional scenarios above.
2. Accent on Interest
pictures and also onto desks, using spotlights or other point sources, were preferred over
DIAL, the German Institute of
all other scenarios. This finding
Appl ied Ligh ting , is an extremel y
fits well with one of the central
reputable and influential re-
principles of Zumtobel Staff’s
search body, which also produ-
approach – that the best results
ces DIALUX, one of the leading
are obtained by a combination
lighting industry software pro-
of different types of luminaire,
grammes. In 1999 it carried out
which might include accent
research into user preferences
lighting (see Products and
for a number of office lighting
Resources).
scenarios, using a variety of luminaire types (see photos). Subjects’ assessments were made in terms of functionality, impression of brightness and the overall attractiveness of the space. One of the central findings was that office scenes which contained additional accent lighting, particularly onto
The Lessons of Lighting Research
The Fleischer research found that our preference for quantity and type of light varies according to task.
3. Dynamic Lighting for Stimulation Susanne Fleischer is a promi-
Fleischer found a clear relationship between lighting conditions outside and inside. People prefer warm direct lighting when the sky is overcast, and indirect cool lighting when sunny.
that “cool” colour temperature
Fleischer concludes: “… It is
lighting was more stimulating
poss ible t o d raw up vari able
than “warm” colour tempera-
ligh ting situati ons … which pro-
tures.
vide an appropriate response
The fina l b ody of research with
to the requirements for type of
important implications for office
nent German researcher who
4. “Cool” Light for the “Third Eye”
until recently worked at the
The impl ication is that a s tati c
acti vity, act ivat ion and well -
lighting has recently emerged
Institute for Hygiene and Occu-
lighting scene throughout the
bein g”. And again “It is therefore
from a number of research cen-
pational Physiology in Zurich.
day, is not the best way to moti- possi ble to c reate light ing scena-
tres, including Brown University
She is the former head of the
vate and enhance performance.
rios for offi ce applications whic h
in the USA. The main findings
“Lighting Harmony” research
More desirable is a lighting sys-
are ergonomical ly appr opriate
are that, firstly, light does not
project, which has found that
tem that can vary not just the
and, moreover, whi ch have a
simply affect the human body
people’s mood, motivation, per-
level, but also the ratio of
posi tive effec t on peop le’s sub-
through our sense of vision. It
formance and feelings of satis-
uplight to downlight, as well as
ject ive well -being.”
appears that we also possess a
faction vary throughout the day,
varying the colour temperature.
so-called “third eye”, a unique
depending on interior and ex-
Thes e f unct ions are possibl e
non-visual photo-receptor cell in
terior light levels and their own
with Zumtobel Staff lighting
the retina directly linked to the
internal circadian rhythms. In
systems and are covered in
pineal gland, which in turn regu-
particular she found that people
our pages on Active Light and
lates our bodily cycles.
preferred direct lighting when
Balanced Light starting on
the sky was overcast and indi-
pages 34 and 35.
What is particularly interesting is
rect lighting when the sky was
that this cell is especially res-
clear and sunny. She also found
ponsive to certain types of light,
WORKPLACE LIGHTING – PAST, PRESENT AND FUTURE
Research shows that the “third eye” receptor is far more responsive to light at the blue end of the spectrum as shown.
at the blue end of the spectrum
York s ugge sts that 18 lux of
(410–460 nm). Exposure to
blue light is more effective at
blue, or “cool” blue-tinted light,
lowering melatonin levels than
seems to encourage the pineal
450 lux of white light.
15
Levels of attentiveness vary over a 24 hour cycle.
Where the Research Takes Us
• Should have forms of control that allow for varying light levels and distribution patterns
gland to suppress the produc-
The impli cation s of this body
according to time of day and
tion of melatonin (which makes
of research for office lighting
outside conditions
us sleep) and therefore impro-
design are clear:
ves alertness. And the light
• Offices should ideally have
doesn’t have to be very bright –
direct/indirect lighting systems
recent discoveries at the Light-
and wall washing
ing Research Centre in New
• Lighting should always be
• A degree of local control is desirable • “Cool” colour temperature lamps are best for maintaining alertness and performance.
achieved with a mix of luminaires
visual pathway (images) photobiological pathway blue light (especially) suppresses melatonin
Current Guidance and its Limitations
Pentland International plc’s new North London headquarters – this 2003 British Council for Office’s Best of the Best Award winner features considerable lighting ingenuity. Archi tect: GHM Roc k Town send, Buil ding Serv ices: Fulc rum
Unfortunately, as we will see, most of the current codes
1. The BCO Fit-Out Guide
(CAT A) and Category B (CAT B) fit-outs for speculative office buildings – a distinction we
are either in conflict with one another – or d on’t measure
The Bri tish Coun cil for Offic es
refer to throughout this publica-
up to the findings of current
is a hugely influential body that
tion. The box at right summaris-
research, being founded more
represents the main players in
es this distinction. Lighting is
on outdated prejudices and
office development. Its Fit-Out
included in the CAT A fit-out
half-understood ideas.
Guide*, which is regularly up-
provision, as part of “basic
dated in the light of new evi-
mechanical and electrical servi-
dence and changing market
ces”, despite the fact that it is
conditions, is written by people
impossible to know the final
who are both pragmatic and
users’ needs and furniture confi-
market-led. Due to the growing
guration at that stage. It is,
influence of the BCO, its guides
however, again mentioned
are rapidly pushing other
under CAT B as part of “Mecha-
Codes, such as those generat-
nical and electrical services
ed by CIBSE, to the margins.
tailoring and upgrades”.
One of the important distinc-
* The BCO also publish a Best Practice Guide, the 2005 edition to which
tions the BCO makes in the latest Fit-Out Guide (October 2003) is between Category A
Zumtob el S taff has contributed.
CAT A and CAT B Fit-outs Explained A C AT A fit -out is the most basic fit-out (including floor coverings, ceilings, floors, M&E, WCs and most importantly, lighting) undertaken by the developer and/or letting agent to sell the space in a speculative development. It is based on an open-plan working scenario but is usually potentially sub-divisible, if necessary. As soon as a client has been found, he will take on the open-plan specification – or will commission a different fit-out.
WORKPLACE LIGHTING – PAST, PRESENT AND FUTURE
17
Wessex Water, near Bath, U.K. This building is one of very few ever to have achieved an “Excellent” rating under the BRE Environmental Assessment Method. Wessex Water was the first ever to achieve the highest possible rating of 10. Arch itect : B ennett s A ssoci ates, Buil ding Serv ices: Buro Happ old
A C AT B fit-out is a b espoke fit-out commissioned if the client comes on board at an early stage – or after the CAT A f it- out has already been installed. It may include a new lighting scheme, blinds, partitions, IT systems, telephones, wall finishes etc. Often, but not always, the CAT A scheme, including the lighting, will be ripped out and everything re-specified from scratch. For obvious reasons, a CAT B fit-out will usually cost more than a CAT A scheme.
In fact, as yet, lighting is not a
no added value in appointing
lighting schemes, to cope with
major priority for the BCO –
specialist lighting designers for
future change, with addressable
there is no specific mention of
the lighting fit-out of the areas
lighting controls and modular
lighting on the Contents page of where most ordinary staff work
lighting systems. In its summary
the current Fit-Out Guide – it is
for most of the day. When they
of the different types of lighting
instead lumped in with “Building
do appoint them, they do so
system available, it does give
Services”, so advice is difficult
only for the specialist areas of
suspended, or freestanding,
to find. When you do find the
the shell-and-core, such as the
direct/indirect systems the high-
small section on lighting, the
entrance area and the atrium.
est recommendation.
mences with the following
For the rest the BCO Guide is
Daylight use and control is
important observation:
the only UK advisory document
briefly mentioned – and there is
that refers to VDT screen testing
an awareness of the issue of
“Design guidance is no longer
and the recommendations of
glare. The Guide states “use of
presc ripti ve and a llows consid er-
EN29241-7 (see page 26). It
blinds … should be considered
able freed om for a su itabl y quali -
also proposes varied lighting
early on in the design process”.
fied and experienced designer
levels between 500 and 300 lux
Zumtobel Staff would take this
to produce certified, compliant
with provision for task lighting
further – in fact, on page 32 we
scheme s of the qualit y requir ed.”
for the visually impaired and
make a strong case for blinds
energy use targets for lighting in
being included as part of the
Unfortunately, as we have alrea-
CAT A fit-outs of 12 W/m .
CAT A fit-out.
dy discussed, developers see
There is an emph asis on flex ible
message is mixed, but it com-
2
Current Guidance and its Limitations
Part L encourages the use of direct-indirect luminaires. Video Arts. Building Services: Downie Consulting
2. Building Regulations (Part L) for Commercial Buildings
The firs t thin g t o say is that the advent of Part L has made many professionals concentrate
The BRE “Ideal office” is their own signature office and makes full use of indirect-direct lighting, even being incorporated under the downstand areas. The wave-form ceiling provides a very even fall-off of ceiling luminance.
3. BRE Environmental Assessment Method (BREEAM)
exclusively on designing for
Credits are awarded against the criteria and an overall score rates the building as “Pass”, “Good”, “Very Good” and
The Buil ding Regul ation s (Part L)
energy savings at the expense
For over a decade, the BRE’s
“Excellent”. On the BREEAM
for Commercial Buildings, 2001,
of other criteria. Lighting design
Environmental Assessment
for offices checklist, the salient
as applied to lighting, are the
driven solely by energy use is
Method (BREEAM) has been
criteria related to workplace
British government’s latest rather
not necessarily good design.
used to assess the environ-
lighting and visual conditions are
blunt instrument for cutting
For example a scheme using
mental performance of both
included in the section “Health
energy use in buildings, to com-
only direct downlighters may
new and existing buildings. It is
and Well-being”. Some of these
ply with the Kyoto agreement on
well comply with Part L, but it
regarded by the UK’s construc-
are already standard practice,
climate change. In summary, for
will not create visually comfor-
tion and property sectors as
but some are not so well known:
commercial buildings (with some
table working conditions for
the measure of best practice
minor exceptions) Part L speci-
people who work there. Good
in environmental design and
fies a maximum energy use of
lighting design is lighting desig-
management. The building
able floor area should be ade-
40 luminaire lumens per watt
ned for people, who in the long
types covered by BREEAM are
quately daylit.
averaged across the entire buil-
term are much more important
offices, homes, industrial units
ding (and according to recent
than energy savings – but there
and retail units and the pro-
controlled system of glare
government statements, this
is no reason why good, visually
gramme’s main criteria concern
control (e.g. internal or exter-
may be increased by 25 % in
comfortable lighting designs
energy use and health and well-
nal blinds).
the near future).
can’t easily comply with Part L.
being, amongst other things.
• At least 80 % of the net lett-
• There should be an occupant-
• High frequency ballasts should be installed in office luminaires.
WORKPLACE LIGHTING – PAST, PRESENT AND FUTURE
19
n o s s ∂ r u g i S n f a R T R
: o t o h P
This European installation would undoubtedly score “very good” or better under the BREEAM rating system.
The LIGHT FIELDS suspended direct/indirect range incorporates the MPO (micro-pyramidal optic) to ensure glare-free lighting whilst having a very high LOR (up to 86 %).
• Maintained lighting levels
• The provision of high frequency
Under the Energy section, there
should be between 350–400 lux
is no specific reference to the
dimming ballasts as a mini-
and the louvre design should
traditional measure of power
mum in perimeter zones.
comply with the LG3 Adden-
usage (W/m ) nor to Part L’s term,
dum 2001.
Luminaire Lumens per Circuit
• Control systems for lighting in
2
• Localised task area lighting instead of uniform lighting.
Watt. Rather, BREEAM predicts
• Mandatory daylight dimming
open-plan office spaces,
energy use and measures these
controls where the Daylight
where there is circulation
in CO2 emissions (see page 45).
Factor exceeds 2 %.
space and daylighting, should
• Lighting systems that have
be zoned into groups, with
BREEAM’s programme is an
gained high user preference in
any one lighting group cover-
important and worthy initiative
recent research surveys.
ing no more than four work-
in the push to improve our
places.
commercial building stock.
on louvre fittings, which
However, if BREEAM is indeed
seems to mitigate against
a view outside (open air or
promoting Best Practice, it
other lighting solutions, such
atrium) with a maximum dis-
should incorporate the following
as direct/indirect systems,
tance of seven metres (approxi-
design measures in its checklist:
which the BRE has installed in
• All workstations should have
mately two office desk spaces) to the nearest window.
• Amendment of the emphasis
its own signature building! In • The installation of blinds as
any case LG3 expressly exclu-
part of the Cat A fit out,
des compliance by luminaire
because they are expensive
selection only.
additions at the Cat B stage.
Current Guidance and its Limitations
g n i K s e n o J : s e c i v r e S g n i d l i u B
The latest generation of MELLOW LIGHT (IV) showing excellent wall and ceiling luminance.
4. SLL (CIBSE) Code for Lighting The CIBSE SLL Code for Ligh t-
This Highly Commended installation was designed by Pinniger & Partners in 1993, predating the LG3 Addendum by 8 years. This is simply a Category 3 luminaire modified by a dropped defractor to put light on walls and ceilings.
5. SLL (CIBSE) Lighting Guide 3 (LG3) – The Visual Environment for Display Screen Use
ing is one of the best, most
rating system for luminaires and instead introduced a “Certificate of Conformity”, which addressed all the relevant issues, and required the room, not the lighting equipment, to Comply with LG3.
comprehensive textbooks avail-
LG3 is probably the most used
able on the lighting of interiors.
document over the last decade
It includes not only detailed
in terms of lighting specification
While retaining some of the use-
schedules of illuminance for
for offices. The document com-
ful design tenets of the earlier
different types of space, it offers
prises an erudite dissertation on
LG3, including the need to put
a welter of good lighting design
the issues, problems and solu-
light onto walls and ceilings, the
advice, a survey of various
tions of lighting spaces for
Adde ndum adop ted very odd
visual effects and an extensive
VDTs. T he docu ment has, how-
criteria for ceiling lighting – and
glossary of terms.
ever, been generally misapplied
missed an opportunity to up-
in that users ignored the objec-
date its advice on VDT screens:
tives of lighting the room but rather defaulted to compliance
A. The latest LG3 put s t oo
by luminaire selection only.
much emphasis on lighting the walls by prescribing a task/wall/
To coun ter this prob lem the SLL
ceiling illuminance ratio of
issued an Addendum in 2001
100/50/30. However, wall illumi-
that dropped the “Category”
nance really only has significance
WORKPLACE LIGHTING – PAST, PRESENT AND FUTURE
Arup Asso ciate s o wn offic es i llust rate the benef it of direc t-ind irect light ing despite the low ceiling height.
With no view to the exterior this training centre is saved by the direct-indirect lighting solution.
for the visual appearance of
up to the ceiling?). And the best As long ago as 1997 BS
cellular offices (where much of
way to ensure a bright ceiling is
EN 29241-7 (Ergonomic Requi-
the wall area is likely to be gl-
by using direct/indirect lighting
rements for Office Work with
azed in any case). In the vast
systems. Situations where a
Visu al Disp lay Termi nals ) recom-
majority of offices, which are
direct/indirect approach is not
mended screen testing, to dis-
open-plan, the walls are gene-
possible, due to low ceiling
cover the actual glare limits of
rally too far away to make much
heights, are discussed on page
individual types of screen, but
of a contribution to the visual
50–51.
LG3, written four y ears later,
scene.
does not recommend this course B. More importantly, LG3 is
We would argue that in terms of still fixated on lighting for VDT
21
of action – instead it has arbitrarily chosen a fixed upper
the visual appearance of most
screens rather than people,
luminance limit on fittings of
office spaces, getting light onto
whereas recent advances in flat
1500 cd/m2. This figure was not
the ceiling is far more important
screen VDT technology threaten
chosen on the basis of any
as the large area of the ceiling
to make this issue a dead duck
genuine research and is already
dominates the peripheral vision.
within two years. Most modern
massively out-of-date, as the
However, ceiling brightness is a
positive (black on white) flat
real figures for different VDT
luminance issue, not a question
screen VDT terminals are not
screens in the Table on page 25
of illuminance (is LG3 compliance
susceptible to luminaire reflec-
show. Some modern screens
really going to be tested by
tions – but in any case they can
can now tolerate luminances
engineers standing on desks,
be easily tested to determine
above 5000 cd/m2 without cau-
holding their illuminance meters
their actual susceptibility.
sing visual discomfort.
Current Guidance and its Limitations
To avoid gloom, increase the percentage of light on the ceiling far beyond the recommended levels.
6. SLL (CIBSE) Lighting Guide 7 (LG7) Office Lighting Guide
the illuminance ratio of the
Pillars and air-conditioning are two more considerations when designing “task area” lighting.
7. BS EN 12464-1
ceiling to the working plane
One major development embodied in BS EN 12464-1 is that
should be 20 % – another 10 %
BS EN 12464-1 has recently
the concept of “maintained illu-
lower than even LG3 and the
been published as a British
minance” and the UGR glare
The draft copy of this d ocument
BCO Guide – which would
Standard in an endeavour to
index system have been intro-
is fairly extensive, but few people
de-prioritise the lighting of the
harmonise lighting standards in
duced to Europe for the first
will find the document of great
ceiling even further.
Europe – an effort that has
time, although the UK has been
interest. In fact it is unclear why
taken many years. EN 12464
familiar with these for years.
it has been produced at all,
does not give detailed design
EN 12464-1 also contains an
except as a fund-raising mea-
advice and in this regard the
extremely low (1000 Cd/m2 ) V DT
sure. LG7 has all the hallmarks
SLL Code for Lighting (see
luminance limit which is clearly
of being written by a committee
page 22) seems set to remain
nonsensical today, but probably
over an extensive period of time
the “bible” of applied interior
reflects the time the document
– for example, all the criteria
lighting.
took to prepare and produce.
relating to VDT lighting remain the same as LG3 Addendum 2001. However, there is no mention of EN 12464-1 or EN 29241 and most of the commentary is very basic and elementary. Most worryingly, it makes a recommendation, that
height = 0.75 m
t a sk a re a
u s e r f l o o r - a r e a
1.00 m
WORKPLACE LIGHTING – PAST, PRESENT AND FUTURE
23
Lighting for People: MELLOW LIGHT IV Balanced offers the opportunity to alter the colour temperature throughout the day in response to user preference.
BS EN 12464-1 strongly encourages designers to adopt “task
8. The Disability Discrimination Act
area” lighting (known in the UK as localised lighting) which is the While it is not possible to dispositioning of luminaires over, or cuss all the measures pertaining close to, the main working area. to lighting and the interior en This is defi ned as the desk area, vironment embodied in this Act, plus the notional chair zone, as
we firmly believe that lighting
depicted in the diagram oppo-
that has been well designed,
site. It proposes lighting to
according to the approach spelt
500 lux within the task zone,
out in this brochure, should
reducing to 300 lux elsewhere.
meet all the necessary requirements. However, it should be
Localised lighting systems have
stressed that designers should
long been considered in the UK.
take cognisance of the Act,
Reduced power density and
and the needs of the visually
energy usage make them attrac-
impaired, when proposing a re-
tive but they do require the
duction in workplace light levels,
designers to know the space-
for energy-saving or other pur-
planning at early concept stage.
poses.
This is n ot likely in the s peculative developer led UK market.
9. Conclusion
the findings of the most advanced lighting research offer a
Many of the current lighting
more solid starting point for
codes and recommendations,
lighting excellence, than out-of-
most notably LG3, LG7 and
date codes and confused and
Part L, are way behind con-
contradictory recommendations.
temporary lighting research –
In the following Section, we out-
and on the whole, do not offer
line our distinctive approach to
effective guidance to produc-
some of the central issues.
ing quality lighting design for the workplace. Others, such as the BCO Fit-out Guide and the BREEAM proposals, are flawed but also have much to commend them. On the whole, Zumtobel Staff prefers to base its approach to lighting design on the principle of lighting for people and their visual comfort. We believe that
Key Issues in Workplace Lighting
WORKPLACE LIGHTING – PAST, PRESENT AND FUTURE
“We find beauty not in the thing
When thinking about office light-
rather than within the confines
its elf but in the pattern s of
ing design, there are a number
of the orthodox, but misguided,
shad ows, t he lig ht and the
of key issues that need to be
recommendations embodied in
darkness, that one thing
considered. In this section we
the codes, we will demonstrate
agai nst anot her creates.”
look at these issues in the light
that more pleasant, visually
– Jun’ichiro Tanizaki, In Praise
of the most recent research out-
comfortable and stimulating
of Shadows
lined above – and put forward
office spaces can be created as
our considered design recom-
a result, while at the same time
mendations and solutions. By
achieving a Certificate of Con-
designing “outside the box”,
formity.
Blurred Image
Increasing tolerance to reflections Reducing tolerance to reflections
Lmax (cd/m 2 ) positive
Type
Make and Model
Date of manufacture
Class
9500 4900 4400 3800 3700 3700 3500 3500 3200 3100 3000
CRT FPD FPD FPD FPD CRT FPD FPD FPD CRT FPD
LG Flatron 915 FT Plus Nokia 500Xa 15" FPD Compaq TFT 5005 15" FPD LG Flatron LCD 575 MS 15" FPD NEC Multisync LCD1760NX Samsung Syncmaster 700 IFT 17" CRT NEC Multisync 1810X Nokia Pro 800+ 18" FPD Dell Ultrashop 1504FP Ilyama LS902UT Visionmaster 1451 NEC 208UX+
Dec-02 Jun-99 Oct-00 Nov-00 Apr-03 Nov-99 Nov-01 Oct-99 Nov-02 Feb-02 Nov-03
I I I I I I I I I I I
2700 2500 2200 2000 2000 1900 1800 1700 1700
FPD FPD CRT FPD LAPTOP FPD FPD FPD FPD
Ilyama TXA 3813MT 15" FPD NEC 1980X Compaq 7500 PE1163T LG 560LS Toshiba Tecra 8000 LAPTOP Samsung Syncmaster 700 TFT 17" FPD LG Studioworks 500 LC 15" FPD LG 1510S Samsung 15" FPD
Not Known Jan-04 Feb-02 Jun-01 Jun-98 Not Known Feb-99 Aug-02 Not Known
I I I I I I I I I
Dec-99 Dec-97 Oct-01 Not Known
I II I I
Jan-95
I
LG3:2001 B2.1 1500 cd/m
1400 1400 1300 1200 Sharp Image
FPD CRT CRT CRT
2
CRT
AOC 4NLR 14" CRT
Please visit our website for further details: http://www.zumtob elstaff.co.uk/screentesting
“Standards and Regulations are out of step with C urrent
1. Taking the Screen Test Results
Research” – Bob Venning, Director of Arup The luminance l imit atio ns given Lighting, LEN April 2004
Luminaire types with enhanced brightness
Brighter luminaires = Light, airy, upbeat environment Darker luminaires = Gloomy, oppressive downbeat environment
limit
LG Studioworks 880 LC 18" FPD Dell D828L 14" CRT Samsung Syncmaster 753s Samsung Syncmaster 550s 15" CRT LG3:2001 B2.1 1000 cd/m 2 limit
900
25
Abov e is a t able of actu al measured data for many types of screen. The screens were originally tested following Lloyd,
in LG3 are not emphatically
Mizukami, Boyce, A prel imin ary
derived and bear no resem-
mode l of ligh ting display interac-
blance to actual fact.
tion 1995 and more recently BS EN 29241-7. Ergonomic requi reme nts for offi ce work with visual display terminals.
Typical “Cat 2” modular downlight
Key Issues in Workplace Lighting
Layout of Zumtobel Staff’s screen test laboratory.
1. Taking the Screen Test – Conclusion
office lighting scheme around mere supposition. So we offer a
Since time immemorial luminaires with a sidelight component (opal diffusers in this case) have contributed to the appearance of ceiling brightness.
2. Putting Light on the Ceiling
service to all our clients to have
“Ceiling Brightness Impression” or CBI for short, which takes into account the visual bright-
As we have already demonstrat-
a sample VDT screen tested at
On previous pages we discussed
ness of the fittings themselves
ed, the correct procedure for
our state-of-the-art facility.
the importance of putting light
as contributors to the overall
on the ceiling, in terms of the
brightness of the ceiling.
determining the glare limits of VDT scree ns is not to set an
More recently ISO BS EN 13406:
overall visual brightness of the
Erroneously, this is something
arbitrary figure but actually to
2002 entitled Ergonomic requi-
space. This is best done with
that CIBSE and SLL have pre-
test them, as recommended in
rem ents for visual display unit s
direct/indirect luminaires, offering
cluded in LG3.
BS EN 29241-7 Ergonomic
based on flat panels has been
variable ratios of lighting distri-
Requirements for Office Work
introduced. BS EN 13406:2002
bution, which can be digitally
So let’s examine a user’s real
with Visual Display Terminals,
is based on the same basic prin-
controlled for different condi-
visual impression of two office
1997. Some of the latest results
ciples as BS EN 29241 but with
tions and times of day.
spaces. In this visual test, there
for modern screens are shown
additional measurements and cal-
in the table on page 25. In fact
culations required. These are
However, as we have already
equipped, firstly, with recessed
in the UK only Zumtobel Staff
included in the Zumtobel Staff
discussed, this is not always
louvre light fittings and, secondly,
currently undertakes screen
testing of such screens.
possible, due to low ceiling
with recessed dual component
heights or the requirement to
fittings, both seen from normal
brightness tests, according
are two vistas of the same office
to the recommendations of
Contact our Technical Depart-
maintain an existing grid of
viewing angles. It is quite clear
BS EN 29241-7. We believe this
ment for more details.
recessed luminaires. Here we
that the ceiling in the second
is the correct course of action,
www.zumtobelstaff.co.uk/
recommend an alternative
installation appears considerably
rather than designing the entire
screentesting
design approach which we call
brighter, even though the illumi-
WORKPLACE LIGHTING – PAST, PRESENT AND FUTURE
27
Dark louvred fittings give an impression of a dark ceiling while self-luminous luminaires quite evidently make the ceiling appear brighter.
nance of the ceiling surfaces is
To demo nstr ate furt her the
LIGHT or SYNTO, make a
Guide) “the creation of a com-
the same.
importance of CBI, Zumtobel
strong contribution to the CBI
fortable, stimulating visual en-
Staff has developed special
of a space, whereas non-self-
vironment by careful control of
The only conclusi on is that the
software based on the repu-
luminous luminaires (such as
surface brightness and contrast
brightness of the luminaires
table, well-established CIE Glare
standard “dark light” louvres)
ratios”, how can CBI not be
themselves makes a real contri-
Alg orit hm, to enable accurate
have a negative effect on CBI.
taken into account?
bution to the ceiling’s overall
calculations to be made of the
In both cases the CBI effect
brightness, because the eye
exact additional brightness
must be taken into account,
For further information about
combines the different bright-
gained from the use of self-lumi-
because brightness contrasts
CBI or information on our CBI
ness contrasts within the field
nous, dual component fittings.
strongly influence the cognitive
calculation software, go to our
of view. This is the principle of
The resu lts come in the form o f
experience of a space and a
website:
the term Ceiling Brightness
a table of CBI values for lumi-
users’ appreciation of its visual
www.zumtobelstaff.co.uk/CBI
Impression (CBI). The use of
naires viewed both crosswise
quality.
self-luminous, dual component
and endwise, which can then be
fittings can be seen to have a
added to the existing percen-
There is no logi c t o CIBSE and
positive effect on how the en-
tage of task illuminance on the
SLL’s refusal to allow luminaire
vironment appears – and, at the
ceiling, to derive the total ceiling
brightness to be considered as
same time, dark, non-self-lumi-
brightness (see website for
an important, contributory factor
nous luminaires can have a
more details).
in the apparent brightness of
negative effect on CBI.
the ceiling. If the overall objecIn conclusion, dual component
tive of any lighting design is (in
luminaires, such as MELLOW
the words of the BCO Fit-out
Key Issues in Workplace Lighting
WORKPLACE LIGHTING – PAST, PRESENT AND FUTURE
3. Walls in the Cellular Office
4. Guaranteeing Conformity
29
We feel that the Declaration of Conformity is a useful vehicle for allowing and encouraging
The ligh ting of wall s b ecomes a
The concept of the Decl arat ion
good designers the freedom to
major issue in cellular offices,
of Conformity, to be signed by
work “outside the box”, to pro-
which tend to be the premium
designers at the end of a light-
duce creative, visually interest-
office spaces arranged around
ing project, to guarantee its
ing lighting schemes. In such
the perimeter of the building.
compliance with codes on ergo-
cases, only trained, experienced
Most often two of the four walls
nomics, health and energy use,
members of the CIBSE Society
will comprise windows and
was proposed in the latest LG3
of Light & Lighting (SLL), the
glazed interior partitions. The
document – probably in too
International Association of
window wall will require effec-
hurried a fashion, without suffi-
Lighting Designers (IALD) and
tive, light-coloured blinds for
cient consultation. As a result
the European Lighting Design-
solar control by day and to aid
take-up has been patchy, partly
ers’ Association (ELDA) should
the lit effect after dark, when
because it is not a legal obliga-
be given the responsibility for
they serve to reflect light back
tion and designers are worried
issuing a Declaration of Confor-
into the room, rather than the
about it affecting their professio-
mity to LG3 or Part L.
window appearing as an unlit
nal indemnity. The main drivers
dark hole.
of the Declaration of Conformity are Zumtobel Staff and the
We would generally recommend
BCO, whose Fit-Out Guide calls
multi-component luminaires for
for the artificial lighting to be
such spaces to increase the
“provided with a Certificate of
degree of ceiling brightness –
Conformity to LG3 and Part L”.
these could be direct/indirect systems or dual component fittings (see page 50). Where downlighters are used, it is important to select one of the interior walls and make sure that it is well lit, through the use of additional perimeter wall
Society of Light and Lighting
International Association of Lighting Designers
washers.
Without windows, providing good illuminance on some walls makes all the difference.
LG3 2001: Certificate of Conformity
European Lighting Designers’ Association
Natural Light, Active Light & Balanced Light
WORKPLACE LIGHTING – PAST, PRESENT AND FUTURE
“Surfaces define the shape of our world; light allows us to
1. Working with Daylight
see them .”
31
Diffuse daylight from an over-
during this process, of lighting
cast, but possibly still quite
quality. This is because lightin g
bright, sky solves many of the
control system sellers are, in the
– George M Whiteside, On the
While artificial lighting has be-
problems associated with direc-
main, electrically biased, rather
Surface of Things
come increasingly sophisticated
tional sunlight. The light quality
than qualified in lighting. They
in recent years, it can’t compare
is generally diffuse with slow
tend to consider energy as the
with our greatest light source –
rates of change and reduced
number one, easily quantifiable
daylight. Daylight and sunlight is
contrasts.
target, while issues such as glare, contrast and the psychol-
free, unlimited, non-polluting and full of variety – and research
Despite the contribution daylight
ogy of the lit space, do not im-
shows that access to daylit
can make, modern artificial
pinge on their thinking. Zumtobel
views is seen as highly desirable
lighting is nearly always planned
Staff believes that simply dim-
by office users.
with the “worst case” scenario
ming down or switching off
in mind – i.e. that it is completely
artificial lighting, as daylight
So on visual comfort and energy-
dark outside. Many buildings
increases, is an over-simplified
saving grounds, any modern
employ conventional switching
approach – in fact, in many
workplace must recognise the
techniques which often mean
situations it may be desirable
presence and desirability of day-
that all the light fixtures remain
to increase the light output of
light – and should be designed
switched on, irrespective of the
artificial lighting as daylight
to make best use of it, in a fully
daylight state. More sophisti-
increases.
integrated manner.
cated buildings often employ various forms of photocell-based
However, natural daylight pro-
lighting control system, which
vides both a threat and an
are, on the whole, usually speci-
opportunity. Direct sunlight can
fied to achieve one purpose
create uncomfortable visual
alone – energy savings. This
conditions – excessive illumi-
usually means that as daylight
nance, discomfort and disability
increases, artificial lighting is
glare, screen reflections, and
dimmed; and when daylight
sometimes constant, rapid
reaches a sufficient level, it is
change – as well as thermal dis-
eventually switched off.
comfort. Brightness contrasts within a space can be consider-
While the energy savings accrued
able for people moving in and
by such a system are signifi-
out of a direct sunlit area.
cant, little account is taken
Natural Light, Active Light & Balanced Light
The highly sophisticated blinds used here turn conventional wisdom on its head. When fully open they allow an unrestricted exterior view but with possible glare issues. The compensation for this are the bright interior surfaces.
When the blinds are fully closed the view out is partially preserved and the glare threat eliminated. However, contrary to conventional thinking, ceiling illuminance is incr eased because the blinds are designed as “sun scoops”.
We also believe that the provi-
lit effect within the space.
provided in the basic Cat A fit-
sion of blinds should be part of
Without blinds, the windows
out for office developments (see
the fundamental lighting design
become “black holes” after
page 16–17). Instead, they tend
package for any building. While
dark, allowing a great deal of
to be provided as part of a Cat
blinds are conventionally seen
wasted light to exit the building.
B, tenant fit-out after the lighting design and installation has
as part of the architectural design, their relevance to lighting
Manually controlled blinds are
long been completed. A sub-
should not be under-estimated.
the norm but experience shows
standard, uncoordinated result
During the day properly desig-
that user positioning invariably
is almost inevitable.
ned, light coloured blinds can
leads to a chaotic and messy
be used to maximise the advan-
appearance. Electrically operat-
tages of daylight, while avoiding
ed, automatically controlled
the downside of glare – and
blinds are normally outside the
at the same time, they can pre-
scope of ordinary control sys-
serve important exterior views
tems that typically use internal,
from inside the building. Particu-
room photocells which cannot
larly in small cellular offices,
cope with sophisticated require-
they also have a vital role to
ments. The provision of blinds,
play at night, by acting as light
preferably properly automated
reflectors on one, or occasio-
and controlled, is a fundamental
nally, two window walls, which
factor in the visual comfort of an
has a huge influence on the
interior. Yet they are seldom
WORKPLACE LIGHTING – PAST, PRESENT AND FUTURE
33
n o d n o L , y a M & r e t h g u a l S
These 2 photographs are of the same office but inside and outside the perimeter zone. The areas are functionally similar but are fundamentally different in their access to daylight and therefore require different but complimentary lighting approaches.
2. Lighting for the Perimeter Zone
closer to the centre of the
sections here tend to be solid,
types for the daylight and deep
building may experience the en-
so precluding rows of recessed
plan zones. Either area could
vironment as gloomy and poorly
downlight troughs.
use Combination lighting or
Moving into the building away
lit, due to the contrast of their
from the windows, we come
space with the perimeter.
across the “transition zone” or “perimeter zone” between natu-
In this situation there is a strong
rally lit and wholly artificially lit
argument for different lighting
interiors. This often neglected
systems to be used in perimeter
area is critically important in
and deeper plan areas, to ease
determining the appearance,
the transition from daylight to
feel and balance of the entire
artificial light. However, the
space. For a start, the contribu-
standard solution has been to
tion of daylight can, depending
apply a uniform, regular array
on the window design, remain
across both these areas, ignor-
significant even considerable
ing that they are completely
distances into the space. For
different (except at night). Alter-
example, while high levels of
natively there is a strong ten-
daylight within the perimeter
dency to put circular recessed
areas tend to create bright,
downlights along the window
upbeat environments, those
wall, for no rational reason
workers who are positioned
other than the fact that ceiling
Balanced lighting, both of which Where possible, Zumtobel Staff
could also be Active Light sys-
advocates designing specific
tems.
and different lighting layouts and
Full height windows allow high levels of daylight but the extreme risk of glare makes blinds essential. The choice of blinds in this situation follows good practice – they are light in colour and preserve a view. The artificial lighting illuminates all surfaces providing a good balance of brightnesses.
Natural Light, Active Light & Balanced Light
These two scenes show how, by using the LA TRAVE direct/indirect lighting system, the lighting ambience can be changed dynamically across the day to suit different conditions.
The best Acti ve Ligh t s ystems
carefully designed lighting
allow:
scenarios, based on the kind of
Daylight changes constantly in
• Changing intensity of light
research outlined on pages
quantity, directional characteris-
• Changing direction of light
12–16, can both enhance and
tics and colour. The Active Light
• Changing colour of light
echo exterior illumination – and
concept, pioneered by Zumtobel
• Changing patterns of daylight
enhance people’s motivation
3. Active Light
Staff, is an attempt to introduce
through blind control
an element of change into artificial lighting in order to mimic
At the same time , b y t aking
the patterns of daylight. Surveys
into account our “circadian
show that people prefer the
rhythms”, which are determined
dynamic, constantly changing
by our biological clock and
character of natural lighting and
synchronised by daylight, it is
the objective of artificial lighting
possible to influence human
ought to come as close as pos-
physiology and psychology, and
sible to this ideal.
thus increase motivation and performance. From an ergonomic point of view, it is desirable that the working environment changes over the course of the day, in order to enhance the attention of staff. A series of
and willingness to perform.
WORKPLACE LIGHTING – PAST, PRESENT AND FUTURE
A b alanc ed l ight insta llati on which also uses most of the prin cipl es o f Acti ve L ight .
4. Balanced Light
Dimming the two light sources
35
A c ombi natio n o f rec essed dual comp onent lumi naires and perim eter down lights. A new standard at Canary Wharf.
5. Combination Lighting
(or components within a single The most i mpor tant aspe ct of
fitting) gives access to quantity
Combination Lighting is a rather
the Balanced Light concept
variations, while the separate,
simpler lighting set-up which
is that it offers variable Flux
selective control of the direct
involves two or more types of
Fraction Ratios (FFR), which is
and indirect lighting compo-
luminaire to achieve any lighting
to say the potential to vary the
nents can be used to alter
effect – for example a simple
upward and downward lighting
fundamentally the directional
downlight, combined with a peri-
components. This can be achie-
character of the light. Equipping
meter wallwasher. In its simplest
ved using a single luminaire,
the luminaires with mixed colour
form, Combination Lighting
such as the Zumtobel Staff La
temperature light sources also
could be just bulk switched
Trave fit ting , e quip ped with sep-
allows fundamental colour tem-
on/off, or separately switched,
arately controllable lamps for
perature changes, making it
or dimmed – and the FFR
direct or indirect lighting. This
possible to balance the colour
needn’t necessarily change.
allows almost infinite variation in
characteristics of the lighting
the character of the lighting.
from warm and homely through
Alte rnatively, B alanced Lightin g
to cool and businesslike.
might be achieved by a combination of two luminaire types, such as a downlight and a freestanding uplight.
LUXMATE EMOTION Workspace combines intuitive control and extremely professional use of DALI technology without actuators and dimmers; a specific ACT IVE LIGH T s crip t b ased on scientific and ergonomic knowhow can be prepared for office lighting.
Natural Light, Active Light & Balanced Light
This novel “partial” blind system is automatically activated at night and at certain times of the day. The suspended LIGHTFIELD luminaires create very even lighting to the ceiling, walls and closed blinds.
6. Controls The BCO Fit-out Guide states
Here the blinds are lowered sufficiently to filter out glare at high angles but allow sunlight to penetrate at low levels, preserving the wonderful patterns and shadows of daylight.
can be easily “fooled”, since
Even Zumtobel Staff Basic day-
Any art ific ial lightin g d eser ves
they measure a combination of
light systems use sensors which
the use of lighting controls, the
natural and artificial light.
are aimed out of a window
most sophisticated of which
in order to register accurate
offer control of individual lumi-
that lighting controls are a fundamental part of lighting design.
While changing light levels are
changes in natural lighting,
naires, or even the individual
The simples t c ontr ols prov ide
desirable, the illogical fluctuation
rather than measuring a mis-
lamps within those luminaires.
energy savings and flexibility
of illuminance resulting from
leading combination of daylight
The cont rols soft ware should
but more sophisticated systems
poorly designed sensors is one
and artificial light.
permit a variety of scenes to be
can be used to integrate day-
of the main reasons why day-
light in a more genuine way.
light control systems are often
The Basi c d ayli ght modu le then
at any time. For Active Light
Measuring incoming daylight
sabotaged by users. By con-
allows three separate groups of
situations, specific Active Light
and adjusting artificial lighting
trast, Luxmate Professional*
luminaires to respond differently
software, which is easy-to-use
levels accordingly seems like a
daylight systems use a roof-
to daylight. So, for example,
yet highly sophisticated, is
simple method of integrating
mounted sensor which measur-
a row of perimeter luminaires
essential.
artificial and natural light. Yet
es the quantity of light, its
illuminating the wall sections
user acceptance of this simple
direction and overall sky bright-
between the windows, or the
technique can be very low
ness, in order to register accu-
window mullions, could be
unless lighting controls are
rate changes in the amount and
programmed to dim up as day-
carefully designed. Most sys-
quantity of daylight and adjust
light increases. This will reduce
tems employ ceiling-mounted
the lighting and blinds automati-
the contrast between wall and/
sensors, which measure inci-
cally.
or mullions and the windows
dent light in the room – but they
pre-programmed and called up
themselves.
* www.luxmate.co.uk
WORKPLACE LIGHTING – PAST, PRESENT AND FUTURE
These two photos show how scene-setting controls can create a totally different ambience and lighting balance within a space.
7. Scene Setting
which infers there should be several luminaire types, each
The valu e of scene s etti ng as
performing a different function.
a lighting control technique
In this way users can generate
has largely been lost in recent
their own “stage sets” to create
years. Over-complicated con-
different lighting moods within
trols, which force the end user
the space, for different activities.
to default to factory pre-sets,
Realistically, such scene settings
coupled with poor understand-
can only be orchestrated when
ing by controls professionals
the space planning and function
of lighting issues, means that
of the room is known, and the
balanced and easy-to-use
interplay of blind control for
scene-set systems are few and
daylight is integrated into the
far between.
various scenes.
Scene setting is often misunderstood as being the ability to preset several different lighting levels of one luminaire type in a given room. Its real value involves the ability to choose different lit effects in a room,
Scene setting can even be applied to circulatory areas.
37