The Air Test

The test involves preparing the dwelling for test, setting up test equipment, undertaking the test, and checking that a valid test has been achieved using the test software.  The equipment to be brought to site includes the blower door [calibrated fan and power supplies], door mounting system, manometer, barometer, anemometer, and thermometer.  Other measuring, inspection, and miscellaneous tools are also brought to site.

 

As a general rule the required time on site is approximately two to three hours depending on ease of access / size of property.  It is also necessary to have the design air leakage data where applicable [used in the TER / DER calc for warrant submission] in order that this figure can be checked.  The building envelope area will have been calculated and a check should be undertaken to establish if sufficient fan power is available.

At the start of the test procedure the door to mount the blower door equipment will be selected and at this point access will need to be restricted to other parties.  The dwelling will then be prepared by closing all external doors and windows, opening all internal doors, ensuring all trickle vents are closed, sealing all necessary vents, ensuring all traps are sealed with water, and that all mechanical systems / combustion systems are turned off.

 

Having prepared the dwelling for testing it is necessary to record a series of environmental conditions including temperatures, wind speed, barometric pressure, and internal / external pressure differentials.  The dwelling will then be pressurised / depressurised and a series flow pressures and building pressures will be recorded.  Having completed the pressure testing a final set of environmental measurements will be taken.  All data will then be entered into the test software and the outcome assessed.  If the test is valid and the results in line with the design / Building Regulations then testing procedure is complete.   If there are any problems with the test then these will be assessed and it may be that a re-test is undertaken to establish a valid test.  If the house fails for reasons outwith the test procedure then the client  / developer / builder will need to address the integrity of the envelope / undertake remedial works.  A second test will then need to be undertaken to establish compliance