Blower Door |
Blower door measurement is a standardized means of quantitative measurement of the airtightness of a building. It is used to determine how often the volume of air inside a building is replaced per hour at a specific pressure difference to air from outside.
In order to build up this pressure difference a frame covered with foil is inserted into an open outside door (entrance door or balcony door). A fan is installed in an opening in the foil. The speed of the fan is controlled so that it adjusts to a defined pressure between exterior and interior room. To maintain this pressure the fan must convey a volume flow as high as that which escapes through leakage points in the building
To arrive at a convincing characteristic value (n50) of airtightness, the volume flow measured is divided by the volume of the building. While the pressure difference is built up (there is under pressure in the house) leakage points in the external envelope of the building can easily be detected. Leakage spots can even be felt with the bare hand. We can say that the draught comes from every nook and cranny.
Further aids with which to locate leakage spots are smoke machines, airspeed meters and thermography. The pressure difference built up is incidentally so small that it is not felt by humans other than as a draught. It corresponds to the pressure of a 5 mm high water column.
Blower door measurement should be carried out on all buildings as it gives important insight into the quality of a building. The varying building codes in different countries provide that houses should be equipped with an air-impermeable layer. This is stipulated in the Energy Saving Regulations. For the degree of airtightness, given, compulsory limit values apply and must be fulfilled.This can definitely be guaranteed with ISOCELL’s complete system.
ISOCELL employs certified examiners to test the airtightness of buildings and also sells the latest technology on this sector in the form of the „Blowtest“ brand of appliances.
Should you have any questions, please contact our Technical Department or your sales contact.
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