Exploring the Feasible Regulation Region of Building HVAC Systems Within Hygro-Thermal Comfort

Heating, Ventilation, and Air Conditioning (HVAC) systems are widely recognized as promising demand response (DR) resources for enhancing grid flexibility. Despite extensive research on evaluating the regulation capacity of HVAC systems, the role of humidity in air dynamic description and occupant comfort assessment during DR has been overlooked. This paper addresses these gaps by exploring the feasible regulation region of HVAC systems while meeting occupant hygro-thermal comfort. Firstly, a comprehensive model of HVAC systems is developed to describe the hygro-thermal air dynamics and equipment characteristics. Subsequently, the hygro-thermal comfort area is defined to establish permissible temperature and humidity boundaries. Based on key constraints, the hygro-thermal air dynamics are categorized into 3 distinct types. Moreover, a novel criterion is proposed to identify these dynamics without requiring full knowledge of boundary conditions. On this basis, the maximum regulation capacities are quantitatively evaluated to explore the feasible regulation region throughout the day. Finally, numerical case studies are conducted to validate the proposed approach. The results demonstrate that humidity plays a crucial role in the operating power and the feasible regulation region of HVAC systems. Incorporating humidity improves hygro-thermal comfort, thereby encouraging more occupant participation in DR programs.