An evaluation of the potential for energy savings in thermal distribution systems in residential and small commercial buildings has been carried out. Thermal distribution systems are the ductwork, piping, or other means used to transport heat or cooling effect from the equipment that produces the heat or cooling to the building spaces in which it is used. This evaluation was divided into four stages.
A total of 177 measurements have been performed in apartments in multi-story buildings without mechanical ventilation. The buildings comprised renovated and non-renovated buildings built between 1930 and 1960. Measurements of air change rate and relative humidity have been performed using passive measurement techniques including a passive multiple tracer gas technique, the so-called PFT-technique. In each apartment the main bedroom has been investigated separately. In addition, the occupants completed a questionnaire concerning their use of the dwelling.