The thermal performance of the airflow window systems was studied numerically using the finite-volume method. Effort was directed towards the reduction in space cooling load for the exhausting and the semi-exhausting triple-glazed airflow windows. The effects of various parameters such as exhausting airflow rate, solar insolation, and aspect ratio were presented. Some qualitative and quantitative comparisons between two systems were made. It was disclosed that the space-heat gain was considerably reduced by increasing the exhausting airflow rate, and the decrease in the space-heat gain of the semi-exhausting airflow window was larger than that of the exhausting airflow window by about 10W throughout most of the Re range (except the range of near Re = 0) of this numerical work. Copyright (c) 2005 John Wiley & Sons, Ltd.