Air conditioning system with enthalpy recovery for space heating and air humidification: An experimental and numerical investigation

This study presents the evaluation of an air conditioning system with enthalpy recovery for space heating and air humidification. Desiccant assisted air conditioning is potentially beneficial against other air conditioning processes in terms of air humidification, counteracting dry indoor air conditions during winter. Furthermore, the overall process can be operated efficiently relying on renewable energy sources. The objective of this work is to investigate a geothermal and desiccant assisted system for different system configurations experimentally and numerically during winter operation. The experimental investigation focuses on differences in system performance for two desiccant materials, lithium chloride and silica gel. Experimental results show that moisture recovery relying on a desiccant wheel with silica gel is beneficial against lithium chloride. An average moisture recovery efficiency of 0.83 was achieved for silica gel. Thermal comfort was maintained on a high level throughout the winter seasons investigated. Based on component and system simulation models, system performance is shown for different boundary conditions during winter requiring space heating and humidification to ensure comfortable indoor air conditions. The simulation results show a reduction in primary energy demand for heat supply by up to 54% by using a high efficient ground-coupled heat pump without backup system. (C) 2020 The Author(s). Published by Elsevier Ltd.