Center for the Built Environment

The main purpose of this paper is to summarise the key findings of ASHRAE research project RP-702, a field investigation of indoor climates and occupant comfort in 12 air conditioned office buildings in Townsville, located in Australia's tropical north. The project replicates an earlier ASHRAE investigation in San Francisco (RP-462), the main purpose being to field-validate the ASHRAE comfort chart (Standard 55) in a tropical setting.

A total of 836 subjects provided 1234 sets of questionnaire responses, each being accompanied by a full set of physical indoor climatic measurements from laboratory-grade instrumentation. In addition to the physical measurements were detailed estimates of each building occupant's metabolism and clothing insulation.

The physical environmental results are compared with ASHRAE Standard 55-1992 prescriptions and the subjective data on thermal acceptability are compared with laboratory-based comfort models and standards. Gender and seasonal effects were minor and many of the differences from earlier San Francisco results were explicable in terms of clothing patterns. Most of the thermal dissatisfaction expressed within Standard 55's comofrt zone in Townsville office buildings was associated with requests for higher air velocities.