315:
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power adjustment factor credits that can be applied to the lighting design. The 2009 International Energy
Conservation Code (IECC) recognizes daylight zones around vertical fenestration and skylights, and requires that the lighting in these zones be controlled separately from the general lighting in the space. The 2010
103:
facing the desktops in order to detect the amount of light on the work surface, as placing the sensor on the desktop itself would be impractical. When sensors were placed on desktops in an office building, an penalty of 24% on energy saving occurred. In both the open- and closed-loop configurations,
297:
Title 24-2008 recognizes primary and secondary daylight zones. At least 50% of the general lighting in primary zones must be controlled separately from other lighting, with automatic control required for larger zones. The code encourages automatic daylight harvesting in secondary zones by awarding
133:
Dimming systems are generally more expensive than on-off systems. They have the potential to save more energy, because they can reduce electric light output when daylight can only partially meet the needs of the space. However, dimming systems may also require a little more energy for their basic
129:
on-off switching. Another variant of on-off switching is step switching (sometimes referred to as "bi-level switching"), in which multiple lamps in a single light fixture can be switched on and off independent of each other. This allows for typically one or two steps between full output and zero.
124:
may be continuously adjusted in proportion to the amount of daylight available. If the electric lighting is on-off only, then an electric lighting fixture or lamp must remain on at full output until daylight can meet the entire recommended light level for the space. Non-dimming variants include
225:. Systems that dim or switch electric lighting in a distracting manner, or that produce overall light levels that are perceived as too low, can be sabotaged by occupants. (For example, simply taping over a sensor will create constant electric lighting at maximum output.)
384:
302:
energy standard, expected to be published in the fall 2010, is also expected to address daylight harvesting. Meanwhile, ASHRAE 189.1, the first of a generation of sustainable construction codes, defines daylight zones and requires daylight harvesting control.
228:
The adoption of daylight harvesting technologies has been hampered by high costs and imperfect performance of the technologies. However, studies have shown that by using daylight harvesting technologies, owners can see an average annual energy savings of 24%.
245:, the more likely it is that a building owner will invest in the system. Costs vary for a whole host of local factors, but generally if energy costs rise, or the cost of the control hardware and installation falls, the payback period will be reduced.
914:
Baylon, D.; Storm, P. (2008). "Comparison of commercial LEED buildings and non-LEED buildings within the 2002-2004 Pacific
Northwest commercial building stock". Proceedings of ACEEE Summer Study on Energy Efficiency in Buildings (Pacific Grove, CA).
95:, the photosensor detects the amount of available daylight only, and can be positioned on the building's exterior wall or roof, or inside the building facing the window or skylight. In a closed-loop system, the photosensor detects the total
147:
is deployed in, and its usage. Clearly, savings can only accrue in spaces with substantial daylight where electric lighting would have been otherwise used. Therefore, daylight harvesting works best in spaces with access to conventional or
134:
operation. If a dimming system is well-calibrated, the occupants of the space will not notice changes in electric lighting due to daylight harvesting, whereas they are very likely to notice the changes due to on-off or step switching.
240:
There is an incremental cost to daylight harvesting systems. Dividing this cost by the annual energy savings provides a "simple payback", the number of years for the system to pay for itself. The shorter the calculated
142:
Several studies have recorded the energy savings due to daylight harvesting. Energy savings for electric lighting in the range of 20-60% are common. Savings are very dependent on the type of space the light harvesting
288:
measures. Therefore, daylight harvesting is a common feature of green buildings. Thus green building practices are increasing the production of daylight harvesting components, leading to lower prices.
704:
104:
the signal from the photosensor must be carefully calibrated to accurately indicate the effect of exterior daylight variations on the light level on 'important function' areas in the space.
290:
Many electric utilities provide financial incentives for their customers to save energy. One such incentive is rebates on daylight harvesting systems , which also reduces payback periods.
981:
824:
Leslie, R.P., R. Raghavan, O. Howlett, and C. Eaton. 2005 The
Potential of Simplified Concepts for Daylight Harvesting. Lighting Research and Technology 37 (1): 21-40. Online at:
120:
device, in the electric lighting system which can reduce the electric lighting, by shutting off or dimming fixtures as appropriate. If the electric lighting is dimmable, then the
125:
having multiple non-adjacent light fixtures such as alternate units in the ceiling 'grid layout,' or daylight source adjacent fixtures near windows or skylights, linked for
855:
35:
that are able to dim or switch electric lighting in response to changing daylight availability. The term
Daylight Harvesting has become the standard in the fields of
232:
One method of predicting energy savings is to use commercially available software programs, such as TRACE 700 or (freeware) DOE-2, which considers thermal loads.
990:
269:
446:
928:"National Grid's lighting incentive and eligibility requirements manual for Massachusetts, Rhode Island and Nantucket customers, Design 2000plus Program"
672:
99:
amount of light, from both daylight and electric sources in the space. For example, in an office a closed-loop photosensor can be positioned on the
486:
760:
727:
1061:
284:, and certification at various levels is awarded for reaching a given number of points. One of the principal ways to gain points is through
91:, in open-loop or closed-loop systems. Photosensors are used to adjust electric lighting based on the available daylight in the space. In an
1006:
882:
639:
793:
59:. This light level will vary according to the needs and use of the space; for example, the commonly recommended light level for
1066:
888:. 3rd International Conference on Smart and Sustainable Built Environments, Delft, the Netherlands, 15–19 June. Archived from
1081:
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435:
ANSI-IESNA; Newsham, G. R. (2004). "American
National Standard Practice for Office Lighting, RP-1". ANSI-IESNA.
358:
258:
221:
Impressive energy savings estimates may not be realized in practice due to poor system design, calibration, or
40:
679:
536:"Using support vector machine to detect desk illuminance sensor blockage for closed-loop daylight harvesting"
1040:
1016:
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or other window shading devices, and compromising the daylight harvesting system. Even partially deployed
265:
825:
490:
180:
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In addition, energy codes and standards are beginning to address daylight harvesting. For example, the
175:; and where electric lighting would otherwise be left on for long periods. Such spaces have included
767:
734:
547:
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392:
92:
96:
883:"Post-occupancy evaluation of energy and indoor environment quality in green buildings: a review"
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National
Research Council Institute for Research in Construction (NRC-IRC) Lighting Research
555:
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761:"Impact of window blinds on daylight-linked dimming and automatic on/off lighting controls"
994:
646:
1035:
590:. Journal of the Illuminating Engineering Society, 18(1). pp. 70–94. Archived from
551:
396:
280:. All of these programs offer points for various building design features that promote
953:"California's Energy Efficiency Standards for Residential and Nonresidential Buildings"
645:. Lawrence Berkeley National Laboratory, LBNL-39945. pp. Chapter 8. Archived from
353:
281:
254:
242:
215:
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121:
705:"Understand compatibility, performance, and dimming issues in LED lighting (MAGAZINE)"
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800:
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55:
Daylight harvesting systems are typically designed to maintain a minimum recommended
117:
68:
956:
560:
535:
385:"A sensor-less LED dimming system based on daylight harvesting with BIPV systems"
1000:
343:
299:
164:
80:
56:
348:
310:
160:
149:
88:
728:"Energy saving lighting control systems for open-plan offices: a field study"
591:
585:"Improving the performance of photo-electrically controlled lighting systems"
314:
84:
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405:
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36:
24:
20:
616:
http://www.lrc.rpi.edu/programs/daylighting/pdf/14005DayswitchReport.pdf
383:
Yoo, Seunghwan; Kim, Jonghun; Jang, Cheol-Yong; Jeong, Hakgeun (2014).
100:
60:
984:
California
Lighting Technology Center, University of California, Davis
826:
http://www.lrc.rpi.edu/programs/daylighting/rp_simplifiedconcepts.asp
673:"Photosensors: dimming and switching systems for daylight harvesting"
273:
211:
192:
176:
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http://www.lrc.rpi.edu/programs/daylighting/pdf/DaySwitchDemoRpt.pdf
726:
Galasiu, A. D.; Newsham, G. R.; Suvagau, C.; Sander, D. M. (2007).
475:
http://www.lrc.rpi.edu/programs/NLPIP/PDF/VIEW/SR_Photosensors.pdf
184:
64:
1043:
a renovation project utilizing daylight harvesting technology
638:
O’Connor, J.; Lee, E.; Rubinstein, F.; Selkowitz, S. (1997).
447:"Photosensor Dimming | Recommended Solutions | LRC"
79:
All daylight harvesting systems use a light level sensor, a
982:
Cost
Effective Simplified Controls for Daylight Harvesting
678:. Lighting Research Center, NLPIP, 11(1). Archived from
837:
766:. Solar Energy, 76(5). pp. 523–544. Archived from
261:
design and building practices. Various green building
799:. Northwest Energy Efficiency Alliance. Archived from
27:
needed to properly light a space, in order to reduce
759:
Galasiu, A. D.; Atif, M.R.; MacDonald, R.A. (2004).
534:
Kent, M.G.; Khao Huynh; Schiavon; Selkowitz (2022).
112:
The signal from the photosensor is interpreted by a
583:Rubinstein, F.; Ward, G.; Verderber, R. (1989).
487:"National Lightning Product Information Program"
733:. Leukos, 4(1). pp. 7–29. Archived from
470:
468:
8:
202:by increasing the size of windows. Daylight
1036:Daylight Dividends, a research organization
514:"Photosensors: Technology and Major Trends"
489:. Lighting Research Center. Archived from
257:-sustainable building movement encourages
559:
404:
794:"Sidelighting Photocontrols Field Study"
198:It is too simplistic to try to increase
83:, to detect the prevailing light level,
375:
210:for occupants, causing them to deploy
7:
1041:Welch Allyn Headquarters Renovations
792:Heschong Mahone Group, Inc. (2006).
640:"Tips for Daylighting with Windows"
512:Dilouie, Craig (23 December 2009).
14:
1022:Harvest Daylight and Reap Rewards
881:Birt, B.; Newsham, G. R. (2009).
236:Payback, and drivers for adoption
23:to offset the amount of electric
856:"INTEGRATED DAYLIGHTING SYSTEMS"
313:
268:exist around the world, such as
218:can cut energy savings in half.
988:Daylight Harvesting Made Simple
31:. This is accomplished using
1:
1062:Architectural lighting design
561:10.1016/j.enbuild.2022.112443
183:, interior public multistory
997:California Energy Commission
391:. 22 Suppl 1 (S1): A132-43.
51:System design and components
1003:Whole Building Design Guide
108:Control modules and dimming
1098:
993:25 February 2012 at the
359:Sustainable architecture
259:sustainable architecture
41:sustainable architecture
33:lighting control systems
114:lighting control system
1067:Energy-saving lighting
955:. 2008. Archived from
926:National Grid (2009).
295:California Energy Code
1082:Solar-powered devices
116:module, an automated
1077:Sustainable building
1072:Building engineering
1031:Dayswitch technology
671:Bierman, A. (2007).
540:Energy and Buildings
406:10.1364/OE.22.00A132
1007:Daylight Harvesting
862:on 26 February 2016
652:on 16 November 2013
552:2022EneBu.27412443K
493:on 3 September 2014
397:2014OExpr..22A.132Y
334:Passive daylighting
266:certification marks
169:passive daylighting
122:artificial lighting
17:Daylight harvesting
1009:Implementation by
915:pp. 4.1–4.12.
806:on 2 February 2009
364:Sustainable design
339:Active daylighting
71:) on the desktop.
45:active daylighting
29:energy consumption
1026:Daintree Networks
453:on 20 August 2010
204:over-illumination
167:walls, and other
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93:open-loop system
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995:Wayback Machine
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282:sustainability
276:, HKBeam, and
255:green building
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249:Sustainability
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243:payback period
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200:energy savings
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75:Photosensors
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1001:Daylighting
937:3 September
899:3 September
866:1 September
810:3 September
711:1 September
689:3 September
656:3 September
601:6 September
519:1 September
497:1 September
420:1 September
344:Illuminance
329:Daylighting
300:ASHRAE 90.1
165:glass block
97:photometric
81:photosensor
57:light level
1051:Categories
777:4 December
546:: 112443.
370:References
349:Brightness
278:Green Star
206:may cause
161:light tube
150:clerestory
89:brightness
744:15 August
570:252103056
157:skylights
85:luminance
1057:Lighting
991:Archived
842:doe2.com
457:5 August
415:24921990
307:See also
263:ecolabel
173:sunlight
163:groups,
37:lighting
25:lighting
21:daylight
963:6 April
548:Bibcode
393:Bibcode
193:schools
177:offices
153:windows
101:ceiling
63:is 500
61:offices
838:"Home"
568:
413:
274:BREEAM
212:blinds
185:plazas
127:module
43:, and
1013:Co-op
931:(PDF)
893:(PDF)
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588:(PDF)
566:S2CID
208:glare
181:atria
965:2010
939:2009
901:2009
868:2014
812:2009
779:2013
746:2009
713:2014
691:2009
658:2009
603:2009
521:2014
499:2014
459:2010
422:2014
411:PMID
270:LEED
253:The
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556:doi
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