PERTANIKA JOURNAL OF SOCIAL SCIENCES AND HUMANITIES

The aim of this paper is to interrogate the principle of heat gain by the Overall Thermal Transfer Value (OTTV) through residential building facades. This study proposes three façade configurations as case studies to determine their capability of achieving the OTTV set by the current residential standards. Utilising the OTTV formula provided by the Malaysian Standards, the OTTV of each case study was calculated using parameters including Window-to-Wall Ratio (WWR), Shading Coefficient (SC), U-values and solar absorption (a). Results showed that each of the façade generated OTTV exceeding the regulation of 50 Wm-2. The study uncovered the increase in WWR leading to the increase in OTTV. The OTTV increased alongside window areas due primarily to the high amount of heat gained through windows, a constituent component of OTTV. Simultaneously, high Shading Coefficient (SC) and U-values were found to cause the high amount of solar heat gained through windows. The result underpins the impacts of high solar heat gain particularly from windows of a building envelope on OTTV. Recommendations for improvement of OTTV of the residential façades are also discussed.