Assessment of predictive models of thermal comfort in offices in the Brazilian subtropical climate

Abstract The objective of this study is to compare the subjective responses of office users located in the Brazilian subtropical climate over the four seasons, using ASHRAE 55 (2017) thermal comfort models (both analytical and adaptive). Field studies on thermal comfort were carried out in four office buildings in Florianópolis/Brazil for two years. One of the buildings operated with central air-conditioning system, while the other buildings operated with hybrid ventilation (users controlled the air-conditioning system and the operation of openings). Thermal comfort questionnaires were applied at the same time and in the same space in which measurements of the environmental variables (air temperature, relative humidity, mean radiant temperature and air velocity) were performed. More than 7,500 user responses were collected during the field study and compared to the ASHRAE 55 models. The analytical model overestimated users' cold and warm sensations and did not adequately estimate the percentage of dissatisfied users in all seasons and buildings. During the natural ventilation operation, users of buildings with hybrid ventilation adapted to the indoor thermal variations according to the adaptive thermal comfort model.