Investigating occupant’s thermal disposition in mixed-mode offices: A field study on thermal comfort in a Brazilian subtropical climate

In this work, we aim to investigate occupant’s thermal disposition in mixed-mode offices. Thermal disposition can be described as a person’s self-assessment of his/her own thermal sensitivity. Classic field studies on thermal comfort were conducted in mixed-mode offices located in the city of Florianópolis (Brazil). Occupants manually controlled the mixed-mode strategy through the operation of both operable windows and unitary air-conditioning system for cooling. Occupants were asked to assess their thermal perception through a questionnaire while air temperature, globe temperature, air velocity and relative humidity were measured in situ. Statistical analysis was performed separating the data by occupant’s thermal disposition. Thermal disposition was also investigated according to gender, age, body mass index and prior exposure to air-conditioning in relation to thermal discomfort. More than two thousand seven hundred questionnaires were collected during the field campaign that took a year. Results indicated that there is an agreement between thermal sensation and thermal disposition, i.e., occupants that are more sensitive to heat presented a higher thermal sensation under equivalent thermal conditions and vice-versa. Results from this study have shown an interesting way of categorising occupants according to their thermal disposition, which could be used to improve the design of personalised conditioning systems.