SRPS EN ISO 9972:2016 · accredited
Blower door test and air permeability.
We measure how airtight the building envelope is: a fan in the doorway creates a pressure difference and we measure how much air passes through window joints, service penetrations and cracks. The test is within our ATS scope of accreditation.
- ATS 01-008accredited lab
- ISO/IEC 17025:2017
- since 2001accredited
- ABlower door fan
- BDigital manometer
- CAir leak locations
- Dn50 result
- 1Fan and membrane fitted in the doorway
- 2Pressure difference up to 50 Pa
- 3Air enters through joints and cracks
- 4n50 result and leak locations
What we measure
Blower door test
Building air permeability
Air leakage rate at a pressure difference and the n50 air change rate, by fan pressurization.
Apartments and test zones
Testing of individual apartments and test zones, including the SRPS U.J5.100 method.
Leak locations
We locate where air gets in, with thermography where useful.
Testing before finishes
Testing before services and façades are closed lets you fix leaks while it is cheap.
Accreditation and standards
ATS 01-008 scope of accreditation
The tests on this page are covered by the scope of accreditation of our Testing and Measurement Laboratory. Reports carry the accreditation mark; methods and ranges are listed below.
- Accreditation No.
- ATS 01-008
- Standard
- ISO/IEC 17025:2017
- Initial accreditation
- 3 Sep 2001
- Valid until
- 15 Mar 2027
| Subject | Test | Range | Reference document |
|---|---|---|---|
| Apartments and buildings | Air permeability testing of apartments | — | SRPS U.J5.100:1984 (withdrawn) |
| Air permeability of buildings – fan pressurization method | 50–39 000 m³/h | SRPS EN ISO 9972:2016 |
Process
How it works
- 01
Preparing the building
Windows and external doors are closed; vents and flues are temporarily sealed.
- 02
Fitting the fan
The blower door frame with membrane and fan goes into the external doorway.
- 03
Pressure series
We depressurize and pressurize in steps up to 50 Pa and beyond and record the flow.
- 04
Locating leaks
Under depressurization we find where air enters.
- 05
Calculation
The air permeability and n50 are calculated from the flow–pressure curve.
- 06
Report
A test report with results and recommendations.
What you get
Report and results
- Test report to EN ISO 9972:2016
- Flow vs. pressure-difference curve
- n50 air change rate and derived values
- Test zone and building preparation
- Leak locations and recommendations
Who needs it
Who we work for
- Low-energy and passive house developers
- Window and façade contractors
- Energy efficiency designers
- Buyers of new homes
- Building managers planning energy retrofits
FAQ
Frequently asked questions
What is a blower door test?
It is an air-tightness test of the building envelope. A fan in the doorway creates a pressure difference and the air permeability is calculated from the measured flow. The method is described in EN ISO 9972:2016.
What does n50 mean?
n50 is the number of air changes per hour at a 50 Pa pressure difference. Lower is tighter.
Is the test accredited?
Yes. Building air permeability to SRPS EN ISO 9972:2016 (range 50–39,000 m³/h) and apartment air permeability to SRPS U.J5.100:1984 are in our ATS 01-008 scope.
When is the best time to test?
When the envelope is complete but interior linings are still open, so leaks are easy to fix. Finished buildings can be tested too.
How long does it take?
For a house or apartment usually a few hours on site, depending on preparation and the number of zones.
Do I need it for an energy passport?
The result can be used as input to the energy calculation; whether it is required depends on the project and the client.
Contact
Tell us what needs testing.
Send the building type, location and the test you need, and we will reply with a quote and a date.
