Thermal perceptions and preferences of individuals outdoors cannot be entirely explained by the energy balance of the human body. They are also affected by psychological and behavioural factors or the so‐called thermal adaptation. To examine the effect of thermal adaptation on seasonal outdoor thermal comfort, 1644 interviews with concurrent micrometeorological measurements were conducted outdoors in central Taiwan. Results indicate a deviation of 1.3 °C standard effective temperature (SET*) in neutral temperatures between hot and cool seasons, and a deviation of 1.8 °C SET* in preferred temperature between hot and cool seasons. Additionally, although subjects' temperature and sunshine preferences were highly correlated with SET*, they diverged between seasons for identical SET* exposures in the two seasons. Analysis reveals that people's thermal perceptions were strongly related to the air temperature (Ta) and mean radiant temperature (Tmrt), but not significant to air speed and air humidity. These results demonstrate that thermal adaptation markedly influences seasonal outdoor thermal comfort, knowledge of which may be useful in the planning and design of outdoor environments in hot–humid regions. Copyright © 2010 Royal Meteorological Society

This study investigated the thermal sensation of elderly people in Taiwan, older than 60 years, in indoor microclimate at home, and their requirements for establishing thermal comfort. The study was conducted using both a thermal sensation questionnaire and measurement of indoor climatic parameters underlying the thermal environment. Survey results were compared with those reported by Cheng and Hwang (2008, J. Tongji Univ., 38, 817–822) for non‐elders to study the variation between different age groups in requirements of indoor thermal comfort. The results show that the predominant strategy of thermal adaptation for elders was window‐opening in the summer and clothing adjustment in the winter. The temperature of thermal neutrality was 25.2°C and 23.2°C for the summer and the winter, respectively. Logistically regressed probit modeling on percentage of predicted dissatisfied (PPD) against mean thermal sensation vote revealed that the sensation votes corresponding to a PPD of 20% were ± 0.75 for elders, about ± 0.10 less than the levels projected by ISO 7730 model. The range of operative temperature for 80% thermal acceptability for elders in the summer was 23.2–27.1°C, narrower than the range of 23.0–28.6°C reported for non‐elders. This is likely a result of a difference in the selection of adaptive strategies. Taiwan in the last decade has seen a rapid growth in the elderly population in its societal structure, and as such the quality of indoor thermal comfort increasingly concerns the elderly people. This study presents the results from field‐surveying elders residing in major geographical areas of Taiwan, and discusses the requirements of these elders for indoor thermal comfort in different seasons. Through a comparison with the requirements by non‐elders, this study demonstrates the unique sensitivity of elders toward indoor thermal quality and the selection of adaptive strategies that need to be considered when a thermal comfort zone is attempted in a household of members consisting of different age groups.