Thermal Comfort Analysis on the Residential Buildings in Sarawak

Abstract

Thermal comfort is a subjective response that reflects the contentment between one’s state of mind and the current environment. The energy consumption of the building sector has rapidly increased due to improved living standards and rising expectations of residents regarding thermal comfort. Mechanical ventilation, especially air conditioning systems, is essential for hot and humid countries aiming to achieve an ideal indoor comfort condition. However, such cooling systems often consume a significant amount of electricity, which contradicts the concept of energy conservation. Therefore, thermal comfort assessment is a method that can be employed to address this issue. Evaluating the thermal perception of occupants can subsequently facilitate more efficient electricity usage, aligning with the goal of energy conservation. In this study, a thermal comfort analysis was conducted on free-running residential buildings in Sarawak. These buildings were naturally ventilated with minimal use of mechanical ventilation systems. Physical measurements and subjective assessments were employed to evaluate the thermal responses of the residents based on various sensation and comfort scales, including the ASHRAE scale, Bedford scale, thermal acceptability scale, and thermal preference scale. Additionally, the widely used PMV model was utilized to predict the thermal sensation experienced by the residents. The results of the study indicated that the Bedford scale exhibited the highest percentage of acceptable responses, followed by the ASHRAE scale, thermal acceptability scale, and thermal preference scale. The PMV model was observed to overpredict the residents’ thermal responses. The comfort temperatures derived from the study were 27.5 ∘C, 28.1 ∘C, and 26.2 ∘C according to the ASHRAE scale, Bedford scale, and PMV model, respectively. Based on the actual percentage of dissatisfaction that ensures 80% satisfaction, the acceptable indoor temperature range was found to be 27.3 ∘C to 29.6 ∘C. Similarly, the acceptable range for relative humidity was 74.0% to 92.0%, and for air velocity, it was 0.18 m/s to 0.66 m/s.
 Keywords: thermal comfort, thermal perception, sensation, comfort scales