Daylight distribution patterns in light wells in residential buildings in Penang, Malaysia

Abstract

This paper focuses on the daylight distribution pattern in the light well in high rise residential buildings in Penang, Malaysia. Light well is a vertical void through all of the floors of a building which is designed to distribute daylight to adjacent spaces. The size of the light well is determined by the UBBL or the Malaysian Uniform Building By Laws (1984) clause no 40. The suitability of the clause is questioned when the original 8 storey residential buildings in the 1980s have risen up to 40 storeys after the year 2000. Eight case study buildings of varied heights and well sizes were carried out and natural illumination data were taken at well centres at each floor to be compared to the illumination outside. The percentage daylight factor (%DF) data were then calculated. The distinct pattern of daylight distribution from each case study was determined. The pattern of daylight factor values derived were found to be similar – very high illumination values at the top 3 floors; ample light for the next 4 to 5 floors while below those categories the light distribution were found to be quite low requiring artificial lighting almost 24 hours. However, this depends also on the A/H (area/height) index ratios and on the design of well – whether all enclosed, with supplementary side openings or others. Computer simulations using Ecotect were carried out to compare the simulated daylighting pattern of the well to field work. The daylighting pattern was found to be similar with advantages to the simulated graphical outputs. Suggestions as to how light well designs can be improved especially in buildings under the bright Malaysian skies were concluded.