Objective and subjective approaches wereperformed to find out whether thermal comfort was influenced by air exchange rate in an air-conditioned office room at UPM, Malaysia. Thermal comfort field experiment and survey were conducted under 14 windows-door opening arrangement, simultaneously, the tracer gas decay method has been applied during the experimental procedures to estimate air exchange rate. The thermal comforts Fanger's indices (PMV and PPD) werecalculated. Results of60 survey responses to thermal comfort questions in office and indoor air quality are presented. It was found that there are relationship between ACH and thermal comfort and three linear regression equations of PMV versus ACH canbe derived for this office.
