Thermal climate is defined as thermal comfort and indoor air quality. Both issues are important for the perception of a room. For example, in office environments, complaints about draft, too hot, too cold, and dry eyes causes a lot of irritation among employees. Poor indoor air quality, for example by poor ventilation, can cause various health problems such as dry eyes, headaches, tiredness, difficulty concentrating and dry throat (the so called Sick Building Syndrome symptoms). Also the possibilities for personal control of the indoor environment play an important role in the perception and comfort of a room. To prevent complaints, and illness, during a design process all the elements of the indoor climate (and the indoor environment) must be considered from the start. Examples are the location of the air inlet or the proper selection of a cooling- and heating system.