There are few things in life are as sure as an air leakage test (if performed by a competent Air tightness testing professional)!

All tests we undertake are carried out in accordance with EN 13829:2000 – Thermal Performance of Buildings – Determination of Air Permeability of Buildings – Fan Pressurization Method (this is the European air tightness testing standard and has national interpretations)and the requirements of the National Standards Authority of Ireland (NASI) Certified Air Tightness Tester Scheme.

Only the final test on practical completion is valid for Building Regulations purposes (i.e. a first fix trest or one performed during a construction element [timber frame erection] is not valid for use to comply with Part (L) but is indicative of the envelope at that stage). This has been confirmed as the accepted methodology for inclusion in a BER calculation (DEAP software) by the SEAI in their reference REF-73577-P0L3.

This is what we mean about builders and practicality – show them the leaks and they will understand what the problem is, how to fix and will not repeat the same error again.

Why is air leakage testing important?

Whether a house has natural ventilation or is to be fitted with one of the many mechanical ventilation systems it is important that the ventilation be controlled and designed to operate within an acceptable atmosphere.

An adequate amount of ventilation (Part (F) of the Building Regulations) is required for healthy living but uncontrolled ventilation can lead to many types of long term construction damage as well as providing an unhealthy atmosphere for the building occupants or users.  This applies therefore to both domestic dwellings as well as commercial buildings.

Our Air Tightness Testing experts cover the whole of Ireland

This is extremely important if the house is to comply overall with Part (L) and the DEAP calculation is marginal and only just compliant with the CPC and or the EPC as the adjustment between a good test and the backstop value could be enough to prevent the house from being compliant.

At 2eva.ie, we are one of Ireland’s leading and most experienced air leakage testing companies and have been undertaking tests since 2008 and in the interim have performed tests on hundreds of buildings of all types and are expert at advising clients on how to maximise the tested value in conjunction with their DEAP calculation for compliance.

So what does a good test look like?

Air leakage tests happen when a pressure difference of typically 50 Pascals (Pa) is generated between the inside and outside of the building in comparison to natural air pressure using a fan suitable for this purpose.  This can be either under pressure (i.e. air is pulled out of the building) or overpressure (i.e. air is blown into the building) and ideally a combination test of both.

Our Air Tightness Testing experts cover the whole of Ireland

The n50 is expressed in air changes per hour (ac/h).  It is the relationship between the total volume of air in m³ and how often leaks in the building envelope allow the air to exchange at 50 Pascals air pressure difference.  This reference is often used when installing a mechanical ventilation system.

Air permeability rate per hour at 50 Pascals pressure difference which is called the q50.

The q50 is the air permeability rate and is expressed as m³/hr/m².  It is an expression of the amount of air leaked from the dwelling in relation to the total exposed surface area of the building (i.e. the ground floor, all exposed ceilings and all external walls) at 50 Pascals air pressure difference.

Critically it is the air permeability rate that is relevant for Irish Building Regulations.

The q50 test result is then divided by 20 and inputted into the DEAP calculation to improve the BER and prove compliance.

Best practise in domestic dwellings calls for an ac/h rate of:

1. 3.0 ac/h   –  natural ventilation (i.e. with wall vents) – very easy to achieve
2. 1.5 ac/h    –  with mechanical ventilation
3. 0.6 ac/h   –  Passive House Standard

NSAI or INAB?

The National Standards Authority of Ireland (NSAI) and the Irish National Accreditation Board (INAB) are the two recognised accreditation bodies of air leakage testers in Ireland.

The testing standard is EN 13829 and both bodies certify testers to this standard and operate the scheme under their own system.

The most common scheme is the NSAI scheme and the vast majority of testers in Ireland are accredited through the NSAI (2eva is accredited through the NSAI).

The main difference between the two schemes are that the NSAI audit and certifies each individual tester via its initial and annual audit whereas the INAB accredits the testing company and it is then up to the company to determine if their employees are fit to test.

Commercial & Industrial Building Testing (incl. clean rooms & data centres)

2eva.ie has made significant investment in training and equipment to undertake testing using fans connected together which multiples the building volumes that can be tested.

Where clients do not elect to have a first fix test done then 2eva.ie would encourage them to consider purchasing the low cost and effective Zephair Pre Pro which helps them to find leaks in the continuous air tight layer prior to testing and ensures that the final testing outcome is maximised.  Built simply and quickly into a door or window the fan under-pressurises the building so you can find the leaks!