What is a building airtightness test?

A building airtightness test is a method for directly measuring the air leakage rate created by leakages in a building enclosure or component.

A building airtightness test is a method for directly measuring the amount of airflow created by leakages in a building enclosure.
There are a number of ways to measure the airtightness (see FAQ ‘What are existing methods to estimate building airtightness? Are there other test methods apart from fan pressurisation?’, but the most common method is the fan pressurisation test.
In this case, a measurement is taken of the air flow rate required to pressurise or depressurise an enclosure, in order to quantify the air leakages of the envelope of the enclosure. A fan, temporarily installed in the enclosure, (also called a blower door, see FAQ ‘What is a Blower Door?’) is used to pressurise or depressurise the enclosure to a known and controlled pressure with respect to outdoors, usually up to 50 to 100 Pascal.
This allows for a stable investigative environment, as this induced pressure is usually enough to negate any stack effect and wind induced pressures.
The aim of this type of measurement is to relate the pressure differential across the building envelope to the air flow rate required to produce it, in order to quantify the building airtightness. The higher the flow rate required to produce a given pressure difference, the less airtight the enclosure. [1].

References

[1] M. Limb, “Technical note AIVC 36- Air Infiltration and Ventilation Glossary,” International Energy Agency energy conservation in buildings and community systems programme, 1992. Available at: https://www.aivc.org/resource/tn-36-air-infiltration-and-ventilation-glossary?volume=33978

See also

Posted in: Building Airtightness