Estimation of "daylight autonomy" and "useful daylight illuminances" for industrial parks of Tehran

Apart from visual effects of daylight it has observed to elicit powerful non visual effects. It controls the circadian rhythm of hormone secretions and body temperature with implications for sleep/wake states, alertness, mood and behavior. In this study new metrics called "Daylight Autonomy" and "Useful Daylight Illuminance" were calculated utilizing south facing vertical illuminance values for industrial parks of Tehran province.

Measurement of south facing vertical values was carried out between 12 July and 1 August 2007 in three measuring stations (Hamadan, Eshtehard and Kerman). Synchronically calculation of corresponding values was performed using method of Illuminating Engineering Society of North America (IESNA, 2000). Once a proper model was fitted between measured and calculated values, prediction of south facing vertical illuminances was undertaken for 11 industrial parks of Tehran in a working year. Consequently metrics of "Daylight Authonomy" and "Useful Daylight Illuminances" were estimated for an assumed workplace in industrial parks.

Minimum, maximum, mean and standard deviation of predicted values for total data found to be 5, 88.32, 50.14 and 23.35 KLux respectively. Values of "Daylight Authonomy" and "Useful Daylight illuminances" were found to be 56% and 56%- 100% respectively.

There is high potentiality for daylightv availability and energy conservation in industrial parks. The maximum external illuminance was found 88 KLux for all industrial parks.This value could produce internal illuminace exceede 630 Klux which could not make glare and discomfort for occupants.