Air temperature is often taken as the main design parameter for thermal comfort. Hence, it is essential for occupants’
well-being, productivity and efficiency [19]. [20] concluded from their field study conducted in Singapore for
classrooms (mechanically ventilated by fans) that the acceptable temperature range is from 27.1ºC to 29.3ºC,
implying that the ASHRAE Standard 55 is not wholly applicable in the free running buildings in the tropical
climate. [21] studied the thermal comfort conditions in classrooms in Hawaii (naturally ventilated and air conditioned types). Neutral temperatures (temperature at which majority of people felt neither too warm nor too
cold) for the two types of classrooms were 26.8ºC and 27.4ºC. As important as these studies are, their findings have
not yet emerged into comprehensive and widely accepted guidelines for tropical naturally ventilated buildings [22].
In reality, occupants are comfortable in a wider range of conditions.