Comparing Scheduled, Occupancy-Based, and Adaptive Setpoint Controls for Energy-Efficient and Comfortable HVAC Operation in Educational Buildings

Abstract

HVAC systems in educational buildings often operate according to fixed schedules, which can result in unnecessary cooling during periods of low or zero occupancy. This study evaluates an occupancy-based adaptive setpoint control strategy to reduce cooling energy consumption while maintaining acceptable thermal comfort. Three control strategies—schedule-based, occupancy-based, and occupancy-based adaptive setpoint control—were compared using building energy simulation. The simulations were conducted with OpenStudio and EnergyPlus for two educational spaces with different occupancy characteristics at Politeknik Elektronika Negeri Surabaya, using the same building, weather, internal-load, and HVAC configurations. The simulation covered the academic period from 18 August to 5 December 2025 with a 10-minute timestep. Energy performance was evaluated from cooling-coil electricity consumption, while thermal comfort was assessed using Predicted Mean Vote (PMV), Predicted Percentage of Dissatisfied (PPD), and discomfort hours. The occupancy-based strategy reduced cooling-coil electricity consumption by 14.52% compared with schedule-based control. The adaptive setpoint strategy achieved a 32.15% reduction compared with the schedule-based baseline and resulted in 23.7 discomfort hours. These results indicate that occupancy information combined with rule-based setpoint adaptation can reduce cooling energy consumption while providing a basis for evaluating the associated thermal comfort performance.