A semi-transparent photovoltaics integrated airflow window system can increase energy efficiency and enhance the interior space of a room thermally and visually when designed properly. This paper presents results of Computational Fluid Dynamics (CFD) simulation of combined buoyancy- and mechanical-driven airflow and heat transfer through room with a photovoltaic airflow window with different inlet positions and multiple openings and air velocities for ventilation cooling in London conditions in summer. The predicted flow patterns and temperature distribution in the room have been used to determine the most appropriate PV transparency level applied for summer season and the flow rate volume under optimal velocity. Results have revealed that the ventilation rate should be sufficiently high to remove the heat gains in summer.