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NSAI Certified Air Tightness Testing

Hession Energy provide NSAI Certified Air Tightness Testing in Galway, Limerick, Dublin and Ireland Nationwide.

We carry out pre tests and final tests to be used in the final BER reports. On each test we use smoke pins to show the Home Owner any air leaks and if possible try and seal these leaks at no extra cost.

What Is Air Tightness Testing?

Air Tightness Testing is an assessment of the air permeability, tightness or leakage of a building. The process of air testing shows the buildings’ performance at retaining conditioned air and the loss of conditioned air through the structure of the building. Hession Energy blower door systems consist of a door panel which temporarily seals an open doorway and a calibrated fan. The air permeability is then calculated using the pressure difference between inside and outside of the building, and the air flow rate between the fan(s) to produce that pressure difference.

Why Carry Out Air Tightness Testing?
  • Air tightness testing or air pressure testing is mandatory for all new dwellings

  • New dwellings must not exceed 5/m2/hr/m2

  • Improve thermal comfort (balanced temperature maintained)

  • Eliminate warm air escaping the dwelling

  • Eliminate drafts localised cold spots

  • Improving heat recovery ventilation units efficiency

  • Gauge to see how good the building fabric is constructed

How Do We Differ With Our Air Tightness Testing Method?

If your house fails, we don’t walk away. We’ll talk to you and offer advice on what you need to do to pass the air permeability test. With our input, in many cases it will be possible to fix the problem on the day. If getting an air tightness test carried by Hession Energy we encourage the home owner to be present so they can learn how their building fabric is performing and if there is any air leakages in the windows frames identify it and report it to the supplier to rectify.


How To Achieve Your Target Air Pressure Test

  • Engage with the architect, engineer and builder and identify potential air leaks areas together at the design stage

  • Plan an air tightness strategy for that area. For example the attic hatch is the largest penetration in the ceiling one possible solutions is installing an attach hatch that has an airtight seal on the door and then use a tape from the attic frame to the surrounding timber joist

  • Use air and wind tight products to windows, doors and ceilings

  • Carry out a blower door pre test during construction with the builder and use a smoke pin and market each area on the site plan where the penetration is located

  • Engage in all trades working on the project a common occurrences for example is the air tightness membranes is installed and a trade person pierces the membrane to run his pipe work and he doesn’t seal around the pentation

  • Have spare air tightness tapes on site so if the membrane is broken it can be fixed without hiding the problem

  • Quality workmanship and choosing the correct building products are key to achieving your target air pressure test. Spending massive money on air tightness products is pointless if the workmanship is there to install correctly


Common Air Leakage Areas In New Builds

  • Attic hatches

  • Pipe penetrations through the building fabric etc waste water pipe

  • Door and Windows frames

  • Wall sockets, light fitting and the fuse board

  • Where the wall vents or mechanical fan meets the wall

  • Stoves incorrectly installed

  • The ceiling junction etc hollow core meets the inner leaf block work

  • Behind skirting boards

House Air Pressure Testing In Galway, Limerick, Dublin And Ireland Nationwide

Hession Energy offer accurate and appropriate air pressure testing services. We provide affordable and quick house pressure testing services across Ireland and we offer superior quality residential blower testing services to our customers across different areas including home builders, construction organisations and small and large developers.


The air permeability level of a building should be well in accordance with the limit specified by the Building’s Regulations. In case it fails to pass the air tightness test, then the building won’t be considered to be energy efficient. We offer quick and cost-effective air pressure testing services for Part L Building Regulations for air tight testing compliance required by construction companies, house builders, large and small developers and self-builders all over Ireland.

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