Impact of building envelope design modification on indoor temperature in classrooms in typical Omani schools

In Oman's hot-arid climate, school buildings often experience elevated indoor temperatures due to inefficient building envelope designs, resulting in a heavy reliance on air conditioning systems and high energy consumption. To address this issue, this study aims to evaluate indoor air temperature in typical Omani school buildings and determine how modifications to key envelope components, such as walls, roofs, and glazing, can improve indoor temperature conditions and enhance thermal comfort. A mixed-method approach was adopted, combining field measurements with computer simulation. Indoor temperature and relative humidity were monitored in selected classrooms, while DesignBuilder software was used to model existing conditions and test alternative envelope configurations. This integrated method is appropriate for quantifying the thermal performance of building envelopes under realistic climatic and operational settings. Results showed that baseline classrooms reached average indoor temperatures of 33 °C in summer and 24.5 °C in winter, exceeding recommended comfort limits during hot periods. The most effective design alternative reduced indoor temperature by up to 2.3 °C and increased the number of hours within the comfort range by 29%. The study concludes that optimizing wall insulation, roof composition, and glazing selection can significantly improve indoor thermal comfort and energy efficiency in Omani schools, providing practical design guidance for future educational buildings in hot-arid climates.