Comparison between Dynamic and Static Metrics for Daylight Evaluation in the Case of Obstructed Buildings

Abstract

Daylight in buildings can be evaluated using dynamic and static daylight metrics. The daylight factor is a static daylight metric which evaluates daylight conditions under the overcast sky model according to the International Commission on Illumination. However, the dynamic daylight metrics (e.g. daylight autonomy, spatial daylight autonomy, useful daylight illuminance) can be more complex evaluation criteria because they are based on annual daylight illuminance data for a building site. While the daylight factor value depends only on a room geometry, optical properties of surfaces and positioning of daylight obstructions, the dynamic daylight metrics also include an effect of a building location, window orientation or building occupancy pattern. The article deals with a comparison of a daylight evaluation using dynamic and static daylight metrics in the case of buildings whose daylight is obstructed by external barriers.

Impact of Window Design on Dynamic Daylight Performance in an Office Building in Iran

“…daylight factors (DF) is a static daylight metric that calculates under overcast conditions. However, dynamic daylight metrics such as spatial daylight autonomy (sDA), useful daylight illuminance (UDI), and annual sunlight exposure (ASE) are according to annual daylight illuminance data, thus the room location, the window orientation, or building occupancy pattern affect the calculation of results [5,6].…”