DAYLIGHT IN OFFICE BUILDINGS: IMPACT OF BUILDING DESIGN ON PERSONAL LIGHT EXPOSURES, SLEEP AND MOOD*
Lighting design for office buildings has focused largely on the amount of light for visibility, strategies to reduce visual discomfort, and the use of daylight as a means to reduce energy in buildings. Little attention has been given to understanding how light affects occupants' psychological and physiological systems, including circadian functions that regulate sleep, mood, and alertness. The specific goals of the present study were to: (1) perform photometric measurements at workstations in winter and late spring, and (2) analyze the impacts of personal light exposure on circadian entrainment using a wearable light and activity measurement device. Reported here are the results of the measurements performed during two seasons in a building located in the Northwest region of the United States.