Shading and increased temperature decrease the efficiency of photovoltaic (PV) systems. Dust accumulation is one type of shading that PV systems face during operation, while the increased temperature can be attributed to environmental conditions at places where the PV system is installed. Both issues affecting the efficiency of PV systems can be avoided by using a well-designed ventilation system that helps in reducing dust accumulation and the temperature of PV modules. The present work suggests the use of forced air flow of the return air of an air conditioning system to reduce the PV modules’ temperature of operation in addition to reducing the dust accumulation on their surface. An analytical study is presented considering the problem as a forced convection between fluid flow and plane surface. The upstream effects on the Heating, Ventilating and Air Conditioning (HVAC) system are investigated and evaluated.