Abstract
A hybrid system with a vapor compression heat pump and a desiccant rotor was developed to enable the frost-free and drain-free operation of air-cooled air conditioners. If the occurrence of frost on the heat exchanger of the outdoor unit can be avoided, the heat transfer performance can be improved by narrowing the fin pitch of the heat exchanger, thereby improving the coefficient of performance, COP, of the system. To achieve drain-free operation in summer, three types of hybrid systems were constructed and their performance was tested: a standard desiccant hybrid air conditioner, one with a high-performance heat exchanger, and one with a pre-cooler. The experimental results showed that the system with a high-performance heat exchanger improved the COP, and the system with a pre-cooler achieved drain-free operation at the rated cooling condition. Thus, it can be concluded that a desiccant hybrid air conditioner equipped with both a high-performance heat exchanger and a pre-cooler can achieve drain-free operation with a high COP.
