Based on the human perception the response regarding the small variation of temperature or relative humidity is not the same. Thus occupants can report a "dry sensation" or irritation of respiration system due to a polluted environment accusing air humidity variations [5]. VOC can be identified by occupants based on odor but in [6] there is presented that the occupants are not able to identify an odor source, because they are living in an environment with odors from non-natural sources. Therefore they are not able to identify the sources that have an impact on their health. Any questionnaires that are used to identify the sources might be involuntary partially completed