Photovoltaic/thermal (PV/T) is an integrated panel simultaneously producing combined heat and electricity. In order to examine the effect of the dimensional, operational, and environmental parameters, energetic and exergetic analyses of solar PV/T air collector systems are investigated. A theoretical model has been developed and the differential equations of energy are numerically solved. To confirm the reliability and accuracy of the present solution, first, comparison studies are performed with the available data in the literature, where good agreement between the obtained values and those existing in the literature was achieved. Then by using the validated model, the effects of the presence of glass cover, packing factor, channel depth, mass flow rate, solar irradiance, collector length, and the fin’s parameters on the performance of the systems have been studied. The results show that exergy analysis is necessary for making better design decisions.