Thermal comfort study in malaysian universities airconditioning office rooms with various set-point temperatures

Abstract

Thermal perception in colder and warmer air-conditioner settings could help navigate cooling energy in hot and humid climates in fulfilling occupants’ comfort needs. The desire to be outside one’s current thermal environment could signal that the thermal comfort needs are not being met. The study of preferred temperature could reveal the link between thermal comfort and preference. Additionally, several contextual factors could affect thermal comfort. This study investigated comfort temperatures, occupants’ preferred temperature and the effect of personal and building characteristics on thermal comfort. A semi-controlled field study was conducted in nineteen office spaces yielding 628 samples from 42 occupants. Four set-point temperature conditions: Original, Original ±2 °C, and MS Standard, were established to explore thermal comfort in biased and non-biased environments. The results showed that the majority of the occupants felt more comfortable when the indoor air temperature was increased. The overall comfort temperature estimated via Griffith’s method was 24.6 °C, and the proportion of comfort votes depleted when the operative temperature reached 26 °C. The investigation of thermal preference revealed that occupants wanted to be in a colder environment despite already being in a comfortable state. The preferred temperature was approximately 23.9 ℃ using the probit method. Analysis via t-test and one-way analysis of variance showed that those with higher Body Mass Index (BMI) and above-average body surface area had significantly lower comfort temperature and preferred much more humid surroundings. Statistically, the characteristics of a building have the most impact in determining the comfort temperature. Larger offices with more than five-people occupancy had significantly lower comfort temperatures, and offices with no shading device, opened window blinds, and tiled flooring had higher comfort temperatures. The findings of this study would most benefit engineers, architects, and policymakers to chart sustainable building design that prioritises occupants’ comfort.