Clarifying thermal comfort of healthcare occupants in tropical region: A case of indoor environment in Thai hospitals

Because the thermal environment affects both physical and psychological health, the issue of maintaining comfort in hospital is vital. For assessing the hospital indoor environment, it is still doubtful whether the predicted mean vote (PMV) model and comfort criteria of ASHRAE Standard 55 are applicable to healthcare occupants. The number of studies that have examined thermal comfort in healthcare is very limited. Therefore, this research aims to clarify the thermal comfort of healthcare occupants, validate the usability of the PMV model and determine whether the comfort criteria of current hospital standards are suitable for a tropical region. A field survey was conducted in two general hospitals in Bangkok. The data sets of patients, visitors and staff were analysed separately to understand their specific requirements. This was done by comparing objective parameters according to comfort criteria of ASHRAE Standard 55 and subjective measurements of actual comfort. The results showed that the PMV model mismatched thermal comfort for healthcare occupants in the tropics, particularly for medical staff. The preferred temperature for the thermal comfort of tropical occupants was slightly colder than neutral, although patients preferred warmer temperatures than other occupants. The acceptable temperature range for patient, visitor, and medical staff are at 21.8-27.9, 22.0-27.1, and 24.1-25.6 degrees C respectively, which is warmer than suggested by the Thai standard. As a result, to optimally enhance the comfort and health of occupants in a healthcare facility in tropical regions, the standard used for hospital environments must be carefully integrated and revised in accordance with the different requirements for the thermal comfort of various healthcare occupants. (C) 2017 Elsevier B.V. All rights reserved.