Abstract PV ventilated glazing technology for application in warm climate provides energy saving opportunities through the reduction in air-conditioning load, the daylight utilization, and the green electric power generation. In a working environment, the use of semi-transparent a-Si glazing is deemed better than the one with non-transparent c-Si solar cells. This paper reports an evaluation of its integrated performance using a small office room in Hong Kong as an example. An energy model of a PV ventilated window system is first introduced. Based on this together with the TMY weather data of Hong Kong and the daylight simulation capability of the EnergyPlus program, the overall performance analysis have been executed for different window orientations. It was found that a solar cell transmittance in the range of 0.45–0.55 could achieve the best electricity saving.