Thermal comfort and indoor air quality in hospitals in the subtropics: Analysis of operating rooms and waiting rooms conditions

The indoor air quality should provide adequate temperature and humidity levels, free from harmful pollution concentration. Proper heating, ventilation and air-conditioning (HVAC) system management is crucial in hospitals to prevent transmission of contaminated air and diseases. To verify whether healthcare facilities meet standard criteria for thermal comfort and indoor air quality, a field investigation in waiting and operating rooms was conducted in six hospitals in Brazil, in the summer. Thermal comfort parameters, carbon dioxide (CO2) concentration and differential air pressure were collected in loco. The results demonstrated that CO2 concentration was over 1,000 ppm in four waiting rooms, and no positive pressure was guaranteed in the operating room. The medical staff showed different thermal sensation variations in zone 1 (around the operating table) and zone 2 (remaining space around zone 1). In conclusion, most operating rooms had significant contamination risks and did not provide thermal comfort conditions to occupants. Due to improper HVAC design or high occupational density, air change rates were insufficient to guarantee adequate air renewal in the waiting rooms. There is an opportunity to improve the operation and maintenance process to provide healthy and comfortable environments in healthcare facilities, reducing nosocomial infections, especially during pandemic times.