Effective Simulation of Spatial Daylight Autonomy and Annual Sunlight Exposure

Abstract

Nowadays the daylight analysis is widely used by architects because it influences on the room usage and comfortability. The natural daylight has a lot of benefits. There are many issues related to the daylight which affects the function and perception of the illuminated area. The issues are direct sunlight and discomfort glare, illumination level and distribution on the working plane. The correct building design that takes into account the daylight analysis aspects leads to decrease of the artificial light usage and energy saving. So simulation of the metrics used in daylight analysis is an important task. The paper considers the simulation of two main standard characteristics widely used in the modern daylight estimation: spatial Daylight Autonomy (sDA) and Annual Sunlight Exposure (ASE). The calculation of both metrics is regulated by the Illuminating Engineering Society (IES) standards. The metric calculation provides daylight illumination data for whole year with one hour step. This means that several thousand simulations have to be run. So effective light simulation methods must be elaborated and used here. The paper presents the methods which deal with rather complex and precise building models under daylight illumination and realistic environment. Spatial Daylight Autonomy metric is calculated considering blinds control that opens or closes them depending on the over-exposure by the direct sunlight. Thus, simulation of sDA involves an optimization procedure defining blinds configuration at each hourly moment. The sDA and ASE calculations for architecture scene are provided as examples.