Numerical analysis of passive and active cooling strategies with rooftop solar integration for indoor comfort and energy efficiency of community clinics in Bangladesh

Bangladesh’s hot and humid climate poses significant challenges to maintaining thermal comfort and energy efficiency in rural community clinics. This study examines the effect of false ceiling with varying air gaps between the roof and false ceiling, mechanical ventilation and rooftop solar panel integration on indoor temperature and total annual energy consumption in a single storey 3.5 m height clinic. Incorporating a false ceiling with air gaps of 0.15 m, 0.20 m, 0.30 m and 0.40 m lower mean indoor temperature by 2.4 °C, 2.54 °C, 2.71 °C and 2.9 °C respectively while total annual energy consumption decreases by 10.25%, 11.77%, 13.72% and 15.54% compared to the base case of without false ceiling and without mechanical ventilation. The addition of mechanical ventilation within the air gap further improves performance. For 0.40 m air gap, at 3, 4.5 and 6 ACH (Air Changes per Hour) mechanical ventilation rate means indoor temperature reductions are 3.25 °C, 3.59 °C and 3.88 °C and total annual energy savings reach 20.43%, 23.49% and 25.33% respectively. Integrating rooftop solar panels with the 0.30 m air gap and 6 ACH mechanical ventilation rate achieves the most effective performance, reducing mean indoor temperature by 4.68 °C and total annual energy consumption by 35.01% relative to the base case. These findings indicate that a combination of optimized air gap between the roof and false ceiling, active mechanical ventilation and rooftop solar integration can significantly improve thermal comfort and energy efficiency and provides an affordable and feasible approach to sustainable design of rural community clinics in Bangladesh.