Numerical Investigation of a Solar PVT Air Collector Used for Preheating the Ventilating Air in Tertiary Building Under the Climatic Conditions of Fez, Morocco

This work deals with the study of the thermal and electrical inflows of a photovoltaic / thermal air collector (PVT). This system is used to preheat the fresh air entering a tertiary building of an area of 300 m(2) and to supply electricity to the fans to ensure the required airflow. A numerical model based on the balance energy equations is used to evaluate the hourly variation of PV cell temperature, outlet air temperature, electrical cell efficiency, thermal efficiency, useful thermal heat gain and useful electrical gain. The saved thermal and electrical energies are then evaluated. The results show that a PVT air collector with a fixed total area of A(tot)=13 m(2) and an airflow rate of m(a)=0.25 kg/s, can involve a thermal energy saving equal to 38.3% of the total energy requested to preheat the incoming air to the considered building. This represents an annual thermal energy saving of 3148.36 kWh. In addition, the electrical efficiency is enhanced by 2%, which leads to an annual electrical energy saving of 73.77 kWh.