The door fan is a high volume and lower pressure fan, which is mounted into the doorway of a building or suite. The fan is used to create an air pressure difference from inside to outside, which facilitates air leakage testing and measurement of air tightness of the building enclosure. It is also used in combination with other tools like a smoke generator to locate air barrier discontinuities, or a water spray rack to undertake water penetration testing.

RDH has worked with Retrotec Energy Innovations to develop test procedures where enclosure air leakage and intersuite air leakage can be accurately measured within multifamily residential buildings using a multiple fan door approach. This is useful in the diagnostic of enclosure-related problems and as part of the commissioning process of new buildings.