An evaluation of the influence of occupancy diversity on office building energy efficiency and ADPI in hot regions

This study investigates the impact of occupancy diversity on air distribution efficiency and energy use in office buildings located in hot, arid regions, focusing on Air Change Effectiveness (ACE) and the Air Diffusion Performance Index (ADPI). This is relevant in countries as Kuwait, where outdoor temperatures exceed 50°C. Air conditioning accounts for a substantial portion of energy consumption in both residential and commercial buildings. Enhancing HVAC performance while maintaining occupant comfort can reduce energy demand and support sustainability goals. Over one-year, environmental and performance data were collected from three office buildings, including temperature, relative humidity, carbon dioxide (CO 2 ), particulate matter, ACE, and ADPI. Measurements were obtained using power meters, indoor air quality monitors, and real-time sensors, supplemented by occupant comfort surveys. Building 1 maintained an average indoor temperature of 22.4°C, CO 2 concentration of 439.5 ppm, and AQI of 97.5. Building 2 recorded higher temperature (24.5°C) and CO 2 levels (493.9 ppm), with ADPI of 94.4%, compared to 100% in Buildings 1 and 3. Building 3, which includes both ground and first floors, was analyzed to assess vertical variations in occupancy distribution and HVAC performance. The corresponding results are presented separately to enable detailed comparison across spatial configurations. PMV analysis indicated increased discomfort with rising humidity. Therefore, integrating occupancy diversity with optimized HVAC control enhances thermal comfort and energy efficiency in extreme climates. In Kuwait the building sector is a major energy consumer with residential and commercial buildings requiring a large amount of energy, mainly due to the high demand for air conditioning. Improving HVAC performance and optimizing building energy management are therefore critical strategies to reduce peak demand, lower operational costs, and support national decarbonization objectives.