Experimental investigation of a ground-coupled air conditioning system with desiccant assisted enthalpy recovery during winter mode

Abstract

In the framework of a research project at Hamburg University of Technology the combination of an open cycle desiccant assisted air conditioning system and a geothermal system is investigated experimentally by means of a test facility during summer and winter. The system is designed to use a large amount of renewable energies and to reduce electricity demand for air conditioning. Thus, the main objectives of this study are the investigation of the overall system performance and evaluation of geothermal assisted heat supply during winter mode for a temperate climate region, based on measured data. As an important comfort aspect, moisture recovery is considered in detail in terms of coupled heat and mass transfer within the enthalpy wheel; related energy demands are limited to auxiliary energies. Different reference systems are defined to evaluate the performance of the investigated system in terms of energy demand required for air treatment, especially air humidification. The geothermal system is an essential subsystem regarding seasonal storage of thermal energy. Thus, the influence of heat supply using a ground-coupled heat pump on soil temperature development is investigated. Besides system evaluation, measured data regarding thermal comfort are presented.