Effectiveness of free running passive cooling strategies for indoor thermal environments: Example from a two-storey corner terrace house in Malaysia

The widespread use of air-conditioning to achieve indoor cooling of residential buildings has caused increased electricity consumption. Effective passive cooling strategies, such as natural ventilation, are important for reducing energy consumption. Field measurements of thermal performance for a corner terrace house in Kuala Lumpur were conducted to clarify the effectiveness of free running (FR) ventilation as a passive cooling strategy with configurations: without ventilation, full ventilation, day ventilation, and night ventilation. Measurements were conducted for all bedrooms and a family area on the first floor. For comparison, a mixed mode (MM) consisting of FR, ventilation with a ceiling fan, and cooling with an air-conditioner, which represents the actual conditions of this house, was measured in the living and dining area on the ground floor. Operative temperature was compared with the predicted temperature using an adaptive thermal comfort equation (ACE) under relevant international standards. The mean indoor temperature under FR was approximately 27~37 °C, and 27~33 °C in MM. Full ventilation and day ventilation recorded better correlation between outdoor and indoor temperature compared with no ventilation and night ventilation. Furthermore, compared with the ACE for a hot-humid climate, MM ventilation resulted in an operative temperature 58% less than the acceptable comfort temperature; thus, it performed better and was closer to international standards than was FR ventilation, which resulted in an operative temperature of 27% less than the acceptable comfort temperature. FR was not adequate to provide comfortable conditions without assistance from MM.