Why test?

What is air tightness testing?

Air tightness testing (or air permeability) refers to the infiltration of cold air into a building and the escape of heated air out of the building, through gaps, holes and cracks etc. in the structural fabric.

What are the benefits to building an airtight dwelling?

Achieving a good level of airtightness is an important factor in ensuring the best possible energy efficiency of the dwelling and the comfort of the occupants. The benefits of improved insulation levels and energy efficient heating systems will be vastly reduced if warm air can escape and cold air can flow in.

As airtightness improves, the energy needed for heating the building reduces. However, it is neither comfortable nor safe to live in an airtight dwelling without adequate ventilation. Therefore, when constructing an airtight dwelling it is important to also provide controlled ventilation: build tight and ventilate right.

Why do I need an air tightness test?

Air tightness testing has been mandatory in Scotland since the change in building regulations in February 2023. The new version of the energy standards in Scottish Buildings, known as ‘Section 6 (Energy)’ came into force on 1st February 2023. As a result, any new domestic or non-domestic builds subject to a building warrant application on and from 1st February 2023 are required to demonstrate compliance with Section 6 2022

How can air tightness be assured in a dwelling?

To limit the effects of air leakage, you first need to understand how it is occurring, this is where diagnostic Air Tightness Testing and the knowledge of the tester can help;

Involvement at design stage can help to highlight and potential problem areas or construction issues.
Good relationships with main contractors/foreman can help a smooth construction phase with any issues being ironed out during the build and not after a failed test
Periodic site visits to check on the ongoing build stages and some pre-testing may be advantageous to ensure that any problem areas are dealt with in good time.
The tester is always available, onsite or off, to answer any questions the contractor may have in relation to the air tightness of the build.

Note: Under normal circumstances it will be the site foreman who will ensure that air tightness is delivered as per design and will communicate directly with the Tester

How is the air tightness test carried out?

Site preparations are the first item on the Tester’s list, including temporary sealing of chimney flues, mechanical fans and air combustion vents, ensuring there is water in all traps and toilets and making sure there is a 240V power supply either in the building or available to the tester. The test engineer will then calculate the envelope area of the building to include ceilings, walls and floors, the Floor area and the volume of the building.

Several measurements are taken to determine the environmental conditions, including; wind speeds, internal and external temperatures and barometric pressure readings. Air is then extracted from or added to the building using a calibrated fan unit.
The configuration of the fan is dependent on the surface area of the building envelope. The test engineer will record the airflow rates and measure the resulting pressure differentials across the building at set intervals. The entire process should take no longer than two hours to complete.

If the building passes, the completed test report is sent directly to the client within 48 hours of carrying out the test. If the building fails the test, Atlantic Air can use a number of survey techniques (e.g. smoke testing) to locate the cause of the problem and advise on the most practical remedial action. In 99% of cases problem areas are identified/ fixed and a retest is carried out on the same day at no extra cost.