Field study of heat pump-assisted hybrid desiccant cooling system for thermal environment control and energy consumption under different load patterns

In modern buildings, indoor humidity must be effectively controlled for thermal comfort and to inhibit the breeding of mold and mildew. To exclude the dependence on additional regeneration heat source for desiccant cooling system, this field study used heat pump-assisted hybrid desiccant cooling (HPDC) systems, which place the evaporator upstream of dehumidification side of the desiccant wheel to perform pre-cooling and pre-dehumidification. The main purpose was to investigate the thermal environment control and energy-saving effects of HPDC systems under different load pattern scenarios; Field studies were conducted in residential buildings, public space, and classrooms. When operating in the first scenario, the electricity consumption of the HPDC system was 37.4% and 14% lower than that of conventional electric heat pumps (EHPs) under different wall thermal-storage conditions. In the second scenario, high dehumidification load led to large adsorption heat, causing indoor temperature to rise continually until the indoor humidity reached the design level. Through the field study in the classroom, the dehumidification mode and cooling mode switching approach can effectively improve indoor temperature control problems and reduce energy consumption by 14% compared to EHP. This field study covers possible application scenarios for HPDC systems, demonstrating the feasibility of replacing conventional air conditioning.