daylight factor

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factor, daylight

The ratio of daylight illuminance received at a given point inside a room to the simultaneous illuminance on a horizontal plane outside exposed to an unobstructed sky. It is usually expressed as a percentage, 5% or more being considered a well-lit room.
Millodot: Dictionary of Optometry and Visual Science, 7th edition. © 2009 Butterworth-Heinemann
References in periodicals archive ?
This paper investigates to adequate the daylighting performance in terms of illuminance level (lux) and daylight factor (DF) in low cost high-rise residential building in tropical area.
The most popular and most used formula to measure and analyze day lighting performance in buildings is the percentage daylight factor [1],[2]&[3].
The objective of study is to analysis the influence of light shelf device on the illuminance and daylight factor levels.
In this study, daylight availability was predicted using parameters such as daylight factor, daily radiant energy, and sunlight patterns.
For example, "for many years the yardstick metric of the Daylight Factor (DF) was the benchmark metric.
The most common expression of this would be the daylight factor. (See USGBC LEED for New Construction Credit 8.1 Daylight & Views: Daylight 75% of Spaces, Path 2: Prescriptive for more information.) Additional considerations are user controls that allow adjustments to the amount of light admitted to the space.
These included all teaching spaces to have a 2% daylight factor as well as the brightly coloured facade windows to create natural ventilation.
And, with the importance of light and the extent of its power to change moods and environments upper most in my mind, I may well continue to venture into the arena of ballast factor, daylight factor, cosine law and even units of luminance.