Abstract: Indoor temperature measurement of an enclosed gymnasium under membrane structure with natural ventilation was carried out during winter period. Air temperatures were measured from six positions with different heights and directions. Parameters relating to thermal environment were obtained, including indoor irradiation, velocity, globe temperature and relative humidity. This paper aimed to study indoor temperature distribution of the gymnasium and evaluate its thermal comfort by revised PMV-PPD index (aPMV-aPPD index). The results show that indoor irradiance is the main factor which effects the variation of indoor temperature. Mean air temperature inside was 3℃ higher than that outside. Air temperatures near the interior surface of the membrane roof kept higher in vertical direction and both amplitude and phase of the temperature decayed at positions in lower altitude. The aPMV value of the gymnasium inside ranged from -1.2 to -0.5 while aPPD varied from 15% to 40%. Without thermal insulation design in membrane structures, indoor environment in enclosed gymnasium hardly satisfies comfortable requirement under natural ventilation condition.

Key words: thermal environment, thermal comfort evaluation, membrane structure, enclosed gymnasium