The aim of the analysis was to determine the effect of window air inlets on the distribution of thermal and humidity parameters of an office room in the heating period. The analysis included two cases: case 1 - window without air inlet, case 2 - window with air inlet. Furthermore, the model includes objects that simulate two people. In order to verify the CFD analysis, tests were performed for the case 1. The results show the difference between a window with and without air inlets.