Title Analysis of Useful Daylight Illuminance(UDI) by Dynamic Daylight Simulation Using Weather Data
Authors Ko Dong-Hwan
Page pp.321-331
ISSN 12269093
Keywords Daylighting ; Autodesk ECOTECT 2010 ; Daylight Factor ; Dynamic Simulation ; Weather Data ; Daylight Autonomy ; UDI
Abstract Currently our top priorities are increasing building energy efficiency and the number of green building certifications. Although daylighting is highly beneficial for reducing building energy consumption and improving the indoor environmental quality, daylighting applications are scarcely considered, especially during the schematic design process, because of complex inputs and simulation processes. Therefore, daylighting simulations were performed using Autodesk Ecotect 2010, which has various advantages such as easy user interface and simple simulation processes. Moreover, dynamic daylight simulations were performed using weather data. Static simulations are performed to compute static metrics such as daylight factor (DF), whereas dynamic simulations are performed for dynamic metrics such as daylight autonomy (DA) and useful daylight illuminance (UDI) using annual weather data. On the basis of DA and UDI analysis results, variations in annual daylight performances were studied. A parametric and regression analysis of the window-to-wall ratio (WWR) and visible transmittance (VT) showed that DF and DA increased with WWR and VT. Moreover, UDI can be reduced when WWR and VT are higher or lower than the optimum values, because UDI above 2,000 lux and below 100 lux can be achieved by using proper window designs. It can be concluded that this new daylight criteria, UDI, will enable architects to obtain better fenestration designs by considering the useful daylight range, window properties, and weather data in the design process.