The Blower Door Testing Experts

Blower Door Testing – A Blower Door is a common name used to describe the combination of testing equipment required when undertaking an air leakage test or air permeability test.

The testing standard EN13829 allows that the Certified Air Leakage Tester can ‘Connect the air-moving equipment to the building envelope using a window, door, or vent opening’ it is typically built into one of the external doors and this is where the name was derived.

A Blower Door consists of 3 major components – the actual calibrated variable-speed & controlled fan, a calibrated manometer (this is a sensitive device to measure pressure differentials connected to a series of tubes which indicates the pressure difference between the inside and outside of the building) and lastly the adjustable frame set up which allows the fan to be held in the testing door whilst forming an air tight seal at the same time.


Blower Door Testing

The Blower Door is typically used to under pressurise the building so that the cracks & gaps can be found using technologies such as a smoke generator or thermography but it is difficult to beat the advantage that the experienced tester has.

The building normally has a pressure differential of +/- 50 Pa and a testing sequence is undertaken in accordance with the testing standard. Prior to testing the Blower Door can be operated to fault find and advise the client of where the problems are and give them an opportunity to address them before the test so that the test outcome can be maximised.

The air flow of the fan or the Blower Door fan itself can be reversed to overpressurise the Building which tests the building envelope in the opposite direction. This can be very useful or in some cases (e.g. Passive House Standard, NZEB) to verify the consistency of external elements (e.g. windows which open outwards will perform slightly better when the building is being under pressurised as the seals are pulled tighter).