Solar-panels-assisted heat pump - a sustainable system for domestic low-temperature space heating applications

Direct expansion solar panels assisted heat pump systems (DX SAHP) have been extensively used in many applications. In the DX-SAHP systems the solar collector and the heat pump are combined into one unit so as to convey the solar energy to the refrigerant. The current work is aimed at examining the use of the DX-SAHP for low temperature space heating applications. The solar collector is used as the evaporator, where refrigerant is directly vaporized due to solar energy input. The thermal performance is examined at the laboratory and also modelled in parallel using computer program. Results point out that the DX-SAHP using solar panels for space heating systems when compared to the conventional solar-assisted heat pump systems, where two components used for one single purpose (DX-SAHPs combine two processes; absorbing solar energy and vaporize refrigerant) is promising as substitute in terms of both energy conserving as well as economic viability. This innovative design results in higher heat transfer coefficient in solar collector-evaporator, lower system losses due to low evaporating temperature and reduces overall system cost.