This is a study of daylighting in an automatically controlled office environment. The objective is to identify any correlations between horizontal and vertical illuminances and to determine if daylight controls can be applied to predict and regulate both illuminances. Two sets of real-time measurements were made, complemented by computer simulations. The results showed that the vertical illuminance at the eye depends on the portion of sky in the visual field. The average ratio between vertical and horizontal illuminances was relatively constant at 1.5, even though the external sky conditions were variable. This implies that the vertical illuminance at the eye can be predicted with acceptable level of accuracy if the horizontal illuminance on the working plane is known.
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References
1.
BersonDMDunnFATakaoM. Phototransduction by retinal ganglion cells that set the circadian clock. Science2002; 295: 1070–1073.
2.
BrainardGCHanifinJP. Photons, clocks, and consciousness. Journal of Biological Rhythms2005; 20: 314–325.
3.
LockleySWBrainardGCCzeislerCA. High sensitivity of the human circadian melatonin rhythm to resetting by short wavelength light. Journal of Clinical Endocrinology and Metabolism2003; 88: 4502–4505.
4.
BrainardGCHanifinJPRollagMDGreesonJByrneBGlickmanGGernerESanfordB. Human melatonin regulation is not mediated by the three cone photopic visual system. Journal of Clinical Endocrinology and Metabolism2001; 86: 433–436.
5.
CajochenCMünchMKobialkaSKräuchiKSteinerROelhafenPOrgülSWirz-JusticeA. High sensitivity of human melatonin, alertness, thermoregulation, and heart rate to short wavelength light. Journal ofClinical Endocrinology and Metabolism2005; 90: 1311–1316.
6.
LockleySWEvansEEScheerFABrainardGCCzeislerCAAeschbachD. Short-wavelength sensitivity for the direct effects of light on alertness, vigilance, and the waking electroencephalogram in humans. Sleep2006; 29: 161–168.
7.
Heschong L. Windows and Offices: A Study of Office Worker Performance and the Indoor Environment, Technical Report. Sacramento: California Energy Commission, 2003.
8.
DogrusoyITTureyenM. A field study on determination of preferences for windows in office environments. Building and Environment2007; 42: 3660–3668.
9.
MillsPRTomkinsSCSchlangenJM. The effect of high correlated colour temperature office lighting on employee wellbeing and work performance. Journal of Circadian Rhythms2007; 5: 2–2.
10.
HoffmannGGuflerVGriesmacherbABartenbachCCanazeicMStagglcSSchobersbergerW. Effects of variable lighting intensities and colour temperatures on sulphatoxymelatonin and subjective mood in an experimental office workplace. Applied Ergonomics2008; 39: 719–728.
11.
HubalekSBrinkMSchierzC. Office workers’ daily exposure to light and its influence on sleep quality and mood. Lighting Research and Technology2010; 42: 33–50.
12.
Aries M. Human lighting demands: healthy lighting in an office environment. PhD Thesis, Eindhoven: Eindhoven University of Technology, 2005.
13.
European Committee for Standardization, EN 12464-1: The Lighting of Workplaces, Brussels: European Committee for Standardization, 2004.
14.
BoivinDBDuffyJFKronauerRECzeislerCA. Dose-response relationships for resetting of human circadian clock by light. Nature1996; 379: 540–542.
15.
ZeitzerJDijkDKronauerRBrownECzeislerC. Sensitivity of the human circadian pacemaker to nocturnal light: melatonin phase resetting and suppression. Journal of Physiology2000; 526: 695–702.
16.
CajochenCZeitzerJCzeislerCDijkD. Dose-response relationship for light intensity and ocular and electroencephalographic correlates of human alertness. Behavioural Brain Research2000; 115: 75–83.
17.
Schierz C. Leben wir in der ‘‘biologischen Dunkelheit’’?: Proceedings of the Licht 2002. Maastricht, Sept 22–25: 2002: 381–389.
18.
ReaMSFigueiroMGBulloughJD. Circadian photobiology: an emerging framework for lighting practice and research. Lighting Research and Technology2002; 34: 177–190.
19.
British Standards Institution, BS 8206-2:2008 Lighting for Buildings, Code of Practice for Daylighting, London: British Standards Institution, 2008.
20.
KristlŽKoširMTrobec LahMKrainerA. Fuzzy control system for thermal and visual comfort in building. Renewable Energy2007; 33: 1–12.
21.
Košir M, Kristl Ž, Krainer A. Parametrical study of fuzzy control approaches for regulating thermal and optical flows. EuroSun 2006: Conference Proceedings, Glasgow. Abingdon: International Solar Energy Society, 2006.
22.
Trobec LahMZupančičBPeterneljJKrainerA. Daylight illuminance control with fuzzy logic. Solar Energy2006; 80: 307–321.
23.
Trobec LahMZupančičBKrainerA. Fuzzy control for the illumination and temperature comfort in a test chamber. Building and Environment2005; 40: 1626–1637.
24.
Košir M, Kristl Ž, Krainer A. Control system for integral regulation of internal building conditions. Energy and the Environment 2008: Conference proceedings. Opatija: Croatian Solar Energy Association, 2008.
25.
Košir M, Kristl Ž, Krainer A. Automated fuzzy logic based shading device controller for mid-season cooling. EuroSun 2008: Conference Proceedings, Lisboa. Lisboa: Sociedade Portuguesa de Energia Solar, 2008.
26.
RADIANCE 4.0 – Synthetic Imaging System: US: Building Technologies Department, Lawrence Berkeley Laboratory, CA, 2010.
