The following graphic gives you an indication of which fan size is right for your individual room. The information applies to square rooms with the corresponding room height. Long, tubular rooms should be divided into several squares, since every ceiling fan has a round effective area. So e.g. For example, a room 10 meters long and 4 meters wide can be divided into 2 areas of 4 x 4 m (16m²). With a room height of 2.5 m, 2 ceiling fans with a diameter of 103 cm or 120 cm should be selected based on the graphic to ensure proper ventilation.