Study on Heating Performance of Hybrid Heat Pump System Using Geothermal Source and Solar Heat for Protected Horticulture

Abstract

In this study a hybrid heating system based on geothermal source and solar heat was developed in order to save energy for greenhouse heating and its field performance was evaluated. Developed system are composed of following parts: water tank, heat exchanger, heat pump, fan coil unit and heat storage unit. The working performance test was carried out in a greenhouse cultivating oriental orchids being managed by 23°C. Field performance test results showed that average heating coefficient of performance (COPh) was 3.4 for the period from mid-January to mid-March 2013. Heating coefficient of performance (COPh) of developed hybrid heat pump system was more sensitive to water tank temperature than outside air temperature. This study showed that developed hybrid heat pump system has a potential to save the heating costs up to 91% compared to conventional agricultural oil heaters.