Occupant perceptions on the thermal comfort guidelines in air-conditioned offices in Colombo, Sri Lanka

ASHRAE Standard 55 sets the minimum requirements for thermal comfort in built environments. However, this standard is more appropriate to cold climates of the western countries than to hot climates of the tropical countries like Sri Lanka. This research was conducted to investigate the thermal comfort perceptions of the occupants of air-conditioned office environments located in hot and humid regions using a case study conducted in office environments in Colombo in Sri Lanka. A mixed research approach was used in two phases to collect the required data. Phase 1 which had ten expert interviews was followed by Phase 2 which had a questionnaire survey conducted among 144 individuals working in 36 air conditioned offices. The data collected were analysed using NVivo and SPSS software. Six parameters, namely temperature, humidity, air velocity, mean radiant temperature, average metabolic rate and average clothing level of each of the 36 office environments considered were examined for their compliance with ASHRAE Standard 55. Six of the environments did not comply with the thermal comfort range specified in the ASHRAE Standard.