Blower Door Test Method A

The blower door test Method A is applies on the building under “conditions of use”, i.e. when the work has been completed. The blower door test method A aims at simulating the conditions of use of the building. To that end, we take the following steps:

  • Close all external fixtures (that must be installed, unlike what happens with the Blower Door Test Method B where all the openings are sealed). Internal doors, on the other hand, need to remain completely open.
  • Plug up all syphons and exhaust ducts, if still without their accessories.
  • Leave the hood exhaust duct open (if a valve is installed, we keep it open).
  • Leave the gas exhaust hole open.
  • Check that the electric system be installed according to the design and finished as in the use conditions. 
  • Check that the eventual mechanical ventilation is turned off and sealed.
  • Leave any fireplace flues open (we check that the unit is ash-free).
  • Keep the eventual mail slot open.

These precautions allow us to carry out the Blower Door Test Method A under the heating or cooling system conditions of use and to evaluate its real usage.


During the Blower Door Testthermographic inspection to detect air leakage and infiltrations.

If you are interested in a Blower Door Test Method A