Tiles as solar air heater to support a heat pump for residential air conditioning

Abstract

Solar air heaters are seen as a promising option for reducing the building energy demand in particular when combined with heat pumps. In this work, a modeling tool to predict the performances of heat pump driven by solar heater is developed. In particular, the channel between the base of the roof and the tiles is considered. As a case study, a detached house in northern Italy is taken into consideration. Results show that the air temperature variation ranges from 2 °C to 20 °C leading to a heat recovered between 2 kW and 7 kW in winter and summer time, respectively. There is no significant variation of air temperature and heat recovered between the two considered orientation (N-S and E-W), whilst the integration of the PV cell in the tile reduces the thermal energy by 15%. The heat recovered enhances the heat pump COP, reducing the Primary Energy Consumption of a conventional heat pump by 5%, and achieved with limited additional costs. The impact of the electricity generated is more important also because the excess can be sold to the grid and not wasted as for the heat recovered in summer time.