Energy efficient ventilation of bathrooms.

This paper reports on the findings from two extensive laboratory studies of ventilation of bathrooms of different sizes and layout of ventilation. The ventilation flow rates were varied. Moisture production were due to laundering and shower baths. In one of the studies the bathroom was provided with a drying cabinet. The extract air was forced to pass through the drying cabinet which was connected to the extract ventilation system of the house by a duct running from the cabinet to the extract air terminal device. Two alternative connections of the drying cabinet to ventilation system of the house were tested; a standard hose directly connected to the extract terminal device (direct extraction) and a hose wich ends just before the terminal device (indirect extraction). To save energy the drying cabinet was not heated but provided with a small mixing fan to enhance the mixing within the cabinet. Two alternative locations of the intake of air to the drying cabinet were tested. The humidity, air-exchange efficiency and local mean age of air were monitored during the test. The drying of the wash was recorded by continuously recording the change of weight of the wash. Selection of layout of ventilation was based on results of recorded distribution of local mean age and the target for moisture exposure was to minimise the time of exposure of relative humidity higher than 70 %.