Effect of Office Design Characteristics and Anthropometrics on Thermal Comfort in Malaysian Universities Air-Conditioned Buildings

¹ Malaysia-Japan International Institute of Technology, Universiti Teknologi Malaysia, Kuala Lumpur, Malaysia
² Faculty of Environmental Studies, Tokyo City University, Yokohama 224-8551, Japan
³ Faculty of Mechanical Engineering, Universtiti Teknologi MARA, 40450 Shah Alam Selangor, Malaysia

^* Corresponding author: sheikh.kl@utm.my

Abstract

Apart from indoor environmental and personal factors, contextual factors have significantly influenced several thermal comfort studies. In air-conditioned spaces, thermal comfort is conveniently attainable by adjusting the temperature settings, but indoor design elements might alter thermal perceptions and provide adaptive opportunities. This study examines the influence of office design characteristics and anthropometrics on thermal comfort parameters and perceptions. Nineteen university offices in Kuala Lumpur and Shah Alam, comprised of twelve shared and seven private spaces, were investigated, and 628 responses were collected from 42 participants with even gender distributions. The results showed that room occupancy and size were statistically significant with Griffiths’ comfort temperature. Offices with five or more people had lower mean comfort temperature (24.1 ℃) than private offices (25.0 ℃). The mean comfort temperature in offices larger than 80 m² was 23.7 ℃ with warmer thermal preference, while offices smaller than 40 m² were approximately one-degree Celsius higher. Offices with no shading device, window blinds opened, and tiled floorings had mean comfort temperatures higher than 25.0 ℃. The findings also indicated that offices with more than a 60% glazing ratio have a slightly higher mean comfort temperature at 24.9 ℃. The thermal sensation during closed blinds was much cooler than opened ones. The anthropometry of the human body impacts how heat is regulated; thus, respondents with higher Body Mass Index (BMI) and above-average body surface area (higher than 1.7 m²) had significantly lower comfort temperatures and preferred more humid surroundings. Mean comfort temperature was statistically significant with BMI with a noticeable difference between underweight (25.1 ℃), normal (24.5 ℃), and obese (23.9 ℃) BMIs. In this study, it is recommended that BMI be considered when positioning occupants in shared offices, and window blinds are an integral shading device for adjusting indoor thermal comfort levels.