LIGHTING DESIGN AS A FUNCTION OF USER COMFORT AND PERFORMANCE IN INDIAN WORK SPACES

摘要

Office employees spend a majority of their time (60% on workdays) in work spaces, and the environment of those spaces has a significant effect on their performance. Lighting is an important component of indoor environmental quality that affects the visual environment and users' visual comfort in interior spaces. Lighting is critical to human functioning as it affects humans both physiologically and psychologically. This paper presents a study of 15 randomly selected offices in the city of Nagpur, India, that were lit either completely by electric lighting or by a combination of daylight and electric lighting. The study was conducted during three seasons (winter, summer, and monsoon) in Nagpur's hot, dry climate. We investigated whether there was an association or correlation between users' perceptions about the lighting conditions in their offices and the actual measured illuminance levels in the offices. We used a qualitative survey, conducted during the summer season, to measure user perceptions; illuminance levels in the offices were measured in all three seasons. We also compared the measured illuminance levels with the prescribed standards for work spaces and used Yule's coefficient of association to investigate the association between measured illuminance levels and users' visual comfort, performance, and satisfaction with and perceptions about the illuminance levels in their offices. Additionally, we performed a chi-square test to determine users' preferences for the type of lighting (only electric lighting or a combination of daylight and electric lighting) in their work spaces. Results of a correlation analysis showed a consistent preference for mixed lighting. A discussion of how providing optimal lighting conditions may lead to cost and energy savings follows.