1Ephraim Cletus Etim, & 2Anyoghe Enya Akwa (AUTHORS)
¹Department of Architectural Technology, Federal Polytechnic, Ugep, Nigeria
²Department of Civil Engineering Technology, Federal Polytechnic, Ugep, Nigeria
Corresponding Author’s Email: empraimetim747@gmail.com
ABSTRACT: Building materials and their properties, such as surface color and reflectivity, play a critical role in indoor thermal conditions, yet their interactions on thermal comfort and energy consumption are still not well understood in many emerging climates. This research explores the effects of surface reflectivity on indoor thermal performance through a numerical simulation model in MATLAB. A dynamic model of heat balance was developed to assess indoor temperature, thermal comfort (predicted mean vote, PMV), and cooling energy demand for a range of reflectivity values (0.2-0.8). The model shows that higher reflectivity results in substantial indoor temperature reduction (2.16-3.0°C), as peak indoor temperatures decrease from 34°C (low reflectivity) to 30°C (high reflectivity). This, in turn, enhances thermal comfort, with PMV values changing from +2.30 (warm discomfort) to about +0.19 (near neutral comfort). The energy analysis reveals that the cooling load is decreased by about 16.27% from nearly 5080 kWh/day (low reflectivity) to 5980 kWh/day (high reflectivity). The results show the impact of surface reflectivity on thermal comfort and energy demand. Finally, the research demonstrates that surface reflectivity is an effective passive cooling technique, especially in warm climates, and has important implications for building design and energy efficiency.
Keywords: Surface Reflectivity; Thermal Perception; Energy Efficiency; Thermal Comfort; Modelling; Sustainable Building