Simulated hygrothermal performance of a desiccant-assisted hybrid air/water conditioning system in a mixed humid climate under dynamic load

Previous work by the same authors has shown that in mixed-humid climates, tight, super-insulated residential structures can experience high humidity events in summer months. Standard, commercially available vapor compression-based air conditioners struggle to control humidity in such structures with low cooling loads. Therefore a desiccant-assisted heat pump system for tight, super-insulated residential structures is proposed. This paper first reviews solid desiccant cooling cycles. Then a hybrid desiccant cooling cycle is explained and a prototype machine based on the cycle is described. The machine, known as HAWC (hybrid air/water conditioner), accomplishes cooling, dehumidification, ventilation, and domestic hot water heating. This paper models the HAWC within the framework of dynamic building energy modeling software and concludes that a refined version of the HAWC prototype is capable of completely eliminating high humidity events in the summer time while still saving energy as compared to a traditional HVAC system.