This study investigates the effectiveness of night ventilation technique for residential buildings in hothumid
climate of Malaysia. This paper firstly presents the results of a survey on usage patterns of
windows and air-conditioners in typical Malaysian residential areas. Secondly, the effects of different
natural ventilation strategies on indoor thermal environment for Malaysian terraced houses are
evaluated based on the results of a full-scale field experiment. The results show that the majority of
occupants tend to apply not night ventilation but daytime ventilation in Malaysian residential areas. It
can be seen from the field experiment that night ventilation would provide better thermal comfort for
occupants in Malaysian terraced houses compared with the other ventilation strategies in terms of
operative temperature. However, when the evaporative heat loss of occupants is taken into account by
using SET*, the night ventilation would not be the superior technique to the others in providing daytime
thermal comfort mainly due to the high humidity conditions. Therefore, the indoor humidity control
during the daytime such as by dehumidification would be needed when the night ventilation technique
is applied to Malaysian terraced houses. Otherwise, full-day ventilation would be a better option
compared with night ventilation.