Air Tightness Testing – Low Energy
PassivHaus, EnerPHit, and similar low energy schemes prioritise the importance of the building fabric being well insulated and airtight so that other energy saving measures/design can be fully effective.
Passive House requires certified properties to achieve less than 0.6 air changes per hour which is the equivalent of less than 1 m3.h-1.m-2 @50Pa, which is tight but the design also incorporates suitable ventilation strategies.
We undertake air tightness testing of PassivHaus houses, apartment blocks and commercial properties.
Testing typically involves preliminary tests and identification of leakage paths to confirm performance at an earlier stage ahead of a test on completion to confirm the final air tightness performance. The result is based on the average of negative and positive pressure tests.
Our test engineers are ATTMA registered for Low Energy Scheme air testing to TSL4. For more information on air tightness and the testing, please visit our FAQ
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Air Testing Process
Our air test engineers are home-based and well-placed to cover Greater London and the City, Kent, Essex, Surrey, Sussex, Hampshire, Berkshire, Buckinghamshire, Oxfordshire, Hertfordshire, Bedfordshire and Cambridgeshire, we are able to test all over the UK.
We are happy to talk through what is involved, what to watch out for, and when to test. We can provide guidance and checklists.
We provide an indicative price based on the size of the building and location, ahead of issuing a formal quote based on PDF drawings. We can look at pencilling in dates to suit your programme, our lead times are typically 1-2 weeks but we can often fit in single tests at shorter notice.
For PassivHaus and similar it is advisable to undertake preliminary testing at key stages in the formation of the air seal barrier to confirm the build is on track to meet these demanding targets ahead of a final air test:
- Air barrier complete
- Services installed
- Practical completion
We confirm a date. Our engineer will call you ahead of the test date to talk you through the preparation and process plus agree the timings.
4. On the day of testing
We would talk you through what would need temporary sealing would need to be done in advance of our arrival.
We conduct the test. Testing is done through negative and positive pressure tests whereby fans are installed into a doorway of the building and used to create a measurable difference between the pressure inside and outside of the building. The amount of air needed to maintain this difference can be used to indicate the volume of air escaping through the fabric (what would be draughts in the building’s day-to-day life).
If the building doesn’t achieve its target at the first time of asking, we can use our equipment to move air and/or smoke to identify the leakage paths. If these can be addressed relatively quickly, then we can repeat the test on the same day.
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