Air Tightness Testers

MBIE Feb2020 Report Section on Airtightness Testing in Buildings

Air pressure testing (Blower door) is a relatively simple way of determining how airtight a building is. Openings in the building are blocked and calibrated fans are installed in an external door. When the building is pressurised (or depressurised) to 50 Pascal’s, the amount of air moved and the differential pressure is measured. From these measurements, the amount of air leakage in m³/(hr.m²) is determined. The reason airtightness is preferred in modern construction is because, as the wet-dry cycle is compromised for weathertightness and energy efficiency reasons, any air leakage carries orders of magnitude more moisture into the fabric of the building, exacerbating the wetting that occurs (approximately 1600x more). Crucially, this moisture tends to stay in the fabric causing mould, rot, corrosion etc.

Air leakage also carries heating (or cooling) energy, reducing the efficiency of a building. Belgium, Czech Republic, Denmark, Estonia, France, Germany, Ireland, Italy, the Netherlands, Norway, Portugal and many states un the U.S. use air pressure testing as a means of assessing the energy efficiency and health of a building. Air pressure testing will become mandatory in Britain this year.

The ABCB (Australia Building Code Board) implemented a number of actions following their acknowledgement of the major condensation problems they are currently experiencing in their building stock. The ABCB has introduced an optional compliance pathway JV4 which uses air pressure testing as a means of gathering data about the building stock. The Australian Government and the ATTMA (air tightness testing and measuring association) are also embarking on a pilot scheme in Canberra with non-mandatory limits with the similar objective of collecting data to establish just how inefficient and condensation prone their housing stock is. Initial indications are that Australian buildings are approximately 2 times leakier than the Florida state code and 5 times leakier that the New York State code.

The Australian approach is to implement airtightness into regulation relatively gently. A nonmandatory and easily achievable limit of 10 m³/(hr.m²) has been set. As the skill of the industry increases, the intention is that the limits will gradually tighten.

There is currently no data available on the airtightness of the New Zealand building stock. BRANZ have however identified that 49% of New Zealand buildings have visible black mould growth – a good indicator for hidden interstitial mould."
Full Report Here

Organizations/Equipment Providers



If you know of someone in NZ who should be added to this list please let us know who they are and their contact details

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    This is a collection of folks performing airtightness testing in NZ and is not an endorsement of their skill or a recommendation that they know what they are doing. “caveat emptor” (let the buyer beware).