Influence of indoor air temperature on human thermal comfort, motivation and performance

In this study, subjective experiments were conducted to evaluate the effects of air temperature on thermal comfort, motivation, performance and their relationship. Steady-state environments at five different temperatures (22 degrees C, 24 degrees C, 26 degrees C, 29 degrees C, 32 degrees C) were created in a climate chamber. Thirty six subjects (eighteen males and eighteen females) were recruited and they were divided into Group A and Group B. Group A was exposed to all five temperature conditions while Group B was only exposed to 26 degrees C. Thermal sensation, thermal comfort, motivation and workload were measured with questionnaires. The task was memory typing and the number of correct letters was used to evaluate performance. It has been proven in this study that the learning effect was greatly affected by temperature. Under warm or cold discomfort environment or when the temperature was frequently changing, the learning rate was slowed down. Motivation improved when people were more comfortable and performance also increased because of higher motivation. So the change in performance was not only contributed by objective environment factors (air temperature in this study) but also by subjective factors like motivation. Stepwise regression showed that the change of human performance could be better explained by the change of motivation than the change of air temperature. Significance test shows that the optimum temperature range for performance in this study was between 22 degrees C (slightly cold) and 26 degrees C (a little higher than neutral). Warm discomfort environment had negative effect on both motivation and performance. (c) 2013 Elsevier Ltd. All rights reserved.