Effect of rain on the heat gain through building walls in tropical climates

A study was carried out to investigate the heat and moisture transfer through porous building watts exposed to outdoor weather conditions including rain. A mathematical model which can account for rain effects on exterior building watts was developed. The model was verified under laboratory and outdoor conditions. The calibrated model was used to study the effects of rain on heat gain through two typical building walls subjected to known weather conditions. It was found that significant overestimation of the heat gain through porous watts could take place if rain effects were not accounted for.