The blower door test, pressurisation test or air tightness measurement is a practical method used to investigate and detect air leaks, heat loss or odours in a building.
Air is blown in and out of the building using a fan and this creates a pressure difference between the indoor and outdoor climate which artificially accentuates existing air leaks. Thermal imaging camera or smoke sticks are used to detect leaks in a quick and efficient manner.
The blower door test can be carried out from a windtight space (blower door test method B) and this allows adjustments to be made to the finishes. Within the scope of the EPB calculation, a complete airtight finish is required (blower door test method A). Only the results of the test method A may be used in the final EPB reporting calculation.
The purpose of the blower-door test is to measure the airtightness of a building. Building owners currently use the results from the airtightness test as part of EPB reporting (fall in E-level). This test perfectly indicates the building’s energy efficiency and it is mandatory as well for passive constructions.
With the introduction of the quality framework in 2015, our office was certified and registered as an accredited airtightness inspector. Regular controls by quality bodies ensure that the tests are implemented in accordance with the guidelines outlined in the technical specifications. Each measurement is issued with a certificate, which guarantees the quality (in accordance with STS-P 71-3) and the integrity of the measurements.
Fact: “A building that is 15% more airtight will consume 10% less energy.”
- Hidden air leaks, heat losses and odours are quickly detected.
- Good airtightness guarantees better living comfort.
- Optimal heating and ventilation performance.
- Improved air quality.
- A better result on the Energy Performance Certificate.
- Lower E-level.
- Energy savings thanks to better airtightness.
Airtightness test type B (provisional measurement)
This measurement is taken when the building is finished, is wind and watertight, and when all technical facilities are installed. At this stage, the interior finishings will not have been applied yet (internal plastering work, finishing of sloping roof or attic floor…), which means that any existing defects can be corrected before the finishing work is started.
Results from a type B measurement are NOT legally accepted in the EPB calculations.
Airtightness test type A (final measurement)
In order to ensure a legally valid measurement, the building must be finished in such a way that it is close to its real use condition. The airtightness layer and the building interior finishes must be in place (internal plastering work, finishing of sloping roof or attic floor, vapour barrier, technical installations, floor finishing, finishes around windows…).
Results from a type A measurement ARE legally accepted in the final EPB calculations.
The official EPB calculation software automatically takes a predetermined standard value into account in the absence of a leakage flow rate (12m³/h/m²) in a building. Using this value, which is considered very poor, will have a negative impact on the E-level value.
The results of the type A airtightness test make it possible to precisely calculate the leakage flow rate, which provides a better result than the standard value in 96% of all measurements. By applying this better result in the EPB software, the E-level will decrease.
A low E-level is present in an energy-efficient and environmentally friendly building, with low energy costs and a significantly high level of living comfort.
- appointment and/or initial site visit;
- determination of protected volume and loss area for the building to be measured;
- preparation of the building in accordance with STS-P 71-3;
- setting up the blower door measuring system;
- measurements under and overpressure in accordance with NBN EN 13829;
- calculation of ventilation rate and leakage rate;
- taking the necessary digital photographs;
- drafting and submitting a report with the results in accordance with STS-P 71-3.
Good airtightness not only affects energy consumption, but it also has a positive influence on the calculated E-level for a building. The government has directly linked premiums, subsidies and tax benefits to this E-level to reward investment in airtightness.
The general rule is: “The lower the E-level, the greater the premiums, subsidies and tax benefits that can be obtained.“
If you have built a new energy-efficient home, for which an energy performance certificate has been issued, you may be eligible for a reduction in property tax.