Cylindrical illuminance and its importance in integrating daylight with artificial light

The cylindrical illuminance provided by artificial lighting and daylight on the working plane are determined. This enables the role of daylight integration with artificial lighting to be evaluated. The integration was carried out for two cases: the first in which the total horizontal illuminance at a point equalled 554 lux and the second case in which the total cylindrical illuminance at the same point equalled 150 lux. The results show that the role of daylight is greater in the second case.