Daylight quotient

The daylight quotient (symbol: D , unit:%) is a measure of the daylight supply of rooms in buildings. It indicates the ratio of the illuminance E (measured in lux ) in the room to the illuminance outside when the sky is overcast:

${\displaystyle D={\frac {E_{innen}}{E_{aussen}}}*100}$

The daylight quotient is used by various regulations as an evaluation criterion for the daylight supply of rooms.

The technical regulations for workplaces (ASR) are relevant here . These prescribe a daylight quotient greater than 2% for workplaces in Germany, and greater than 4% for roof skylights. The daylight quotient D at workplaces is the ratio of the illuminance at a point in the interior E p to the illuminance in the open air without a building E a with an overcast sky (formula: D = E p / E ax 100%). To determine the daylight quotient, according to ASR A3.4, illuminance measuring devices must be used that correspond at least to class C according to DIN 5035 part 6, edition 2006-11.

swell

• ASR A3.4 "Lighting" - BAuA. Retrieved January 18, 2020 . 
• DIANE, Switzerland
• VDI 6011