Review on heat pump coupled desiccant wheel dehumidification and air conditioning systems in buildings

Dehumidification and air conditioning are important for providing comfort environment and guarantee the industrial production. Hybrid heat pump and desiccant wheel system can achieve air conditioning and dehumidification with high evaporation temperature, and reduces energy consumption by recovering condensation energy for desiccant wheel regeneration. This paper aims to summarize the research about hybrid heat pump and desiccant wheel system, and to provide some potential research directions for improving the system performance and applicability. The development and configurations of the hybrid system is reviewed and categorised into conventional heat pump and desiccant wheel system, auxiliary heating for hybrid system, high temperature heat pump and desiccant wheel system, two-stage desiccant wheel system and new concept of hybrid system. It can be generalized that the study is mainly focused on providing different system combination methods, while the design of components, especially the desiccant wheel, is not meticulous enough. The operation and test conditions are different in studies, and there is lack of the comparison of different systems for providing the more suitable system configuration. For the second part of this paper, the application of the hybrid system in civil buildings for cooling and dehumidification, humidity control for industrial and production, air humidification and air cleaning are reviewed. It is found that the hybrid system is of multi-function, and has wide application scenarios for different requirement. The application of the system is seldom towards industrial production field, and the long-term operation is mainly researched through simulation method. Long term testing or experiment is highly recommended for improving the operation strategies.