Heating performance of combined heating system with direct-gain windows and photovoltaic driven electrothermal film heating floors

Jia Jikang, Si Pengfei, Rong Xiangyang, Liu Xichen, Li Pengyu and Shi Lijun

2020.05.21

Aiming at the problem of low indoor air temperature in traditional plateau passive solar buildings at night, proposes a combined heating system with direct-gain windows and photovoltaic driven electrothermal film heating floors. The dynamic simulation results of a practical engineering show that the indoor air temperature of typical rooms is 17.0-23.2 ℃ and the floor surface temperature is 21.0-26.0 ℃, which can meet the comfort requirement. The photovoltaic Trombe wall technology can increase indoor air temperature by 1.5-3.2 ℃ and the floor surface temperature by 1.8-2.5 ℃. For a typical day in winter, the daily accumulated net heat gain per unit area of the direct-gain window is 1.487 kWh/m2, and the daily accumulated net heat gain per unit area of the photovoltaic Trombe wall is 0.900 kWh/m2. The area of the direct-gain window should be increased as much as possible to improve the heat collection of the passive solar energy buildings. Among the total building heat consumption, the heat consumption of outdoor air accounts for 60% and the heat transmission of non-transparent enclosure only accounts for 6%. The wall insulation has limited effect on further improving the building performance, and controlling the penetration of outdoor air should be the main method of improving the building thermal performance.