MO-2309 (RP-118) -- The Measurement and Prediction of Thermal Comfort PDF

For nearly 50 years the American Society of Heating, Refrigerating, and Air Conditioning Engineers, Inc. (ASHRAE) has supported research in thermal comfort. From these efforts, recommendations have been made and Standards published prescribing the physical limits of the comfortable thermal environment.

More recently, thermal comfort research has moved away from an empirical approach to one of theoretical modeling. In these almost purely mathematical exercises, factors such as dry bulb, wet bulb, and mean radiant temperatures, and air movement are combined with clothing, level of physical activity and exposure time to predict the thermal sensation. When these equations are solved, their validity is tested against real data.

While this approach provides a needed supplement to our understanding of man's response to the thermal environment, too often it ignores the very nature of the thermal sensation itself. In particular, it fail to consider the principle of individual differences between and within subjects, the psychology of affectivity and its measurement, and above all the statistical theory involved in sampling and the levels of confidence that can be placed in the results of empirical studies. The discussion that follows is addressed to these topics. In addition to a brief elementary review of statistics, the paper will examine the thermal sensation and the problems associated with its measurement and prediction.