What Is An Air Permeability Test?

Air permeability testing is a vital part of the building process in which the result helps to determine the energy efficiency of a building or structure. An air tightness test shows the air leakage of a structure and therefore shows us how it can affect the energy performance.

Key Points Of An Air Permeability Test:

  • Energy efficient buildings will be more air tight with a lower air leakage rate per hour.
  • An air permeability value target is set when the Energy Performance Certificate is undertaken with the test at the end of the construction period.
  • Air permeability tests are conducted to help improve energy efficiency levels as well as the quality of the build.
  • The test can help verify the standards of the components and materials used, as well as workmanship.

In April 2002, legislation was introduced by the UK government which aimed to enforce high standards of air tightness in new builds. The testing methods enforced were set out by ATTMA (Air Tightness Testing and Measurement Association). ATTMA was officially recognised and authorised by the government to create standards of air permeability testing. The method ATTMA TSL1 was created for dwellings, where as ATTMA TSL2 was required for non dwellings.

How Is An Air Permeability Test Conducted?

An air permeability test takes the area of a building envelope and measures the air leakage leakage rate. The air leakage rate is measured per hour per square metre by specialist equipment. An air permeability test requires blower door testing equipment. The door testing equipment is placed on an external opening, usually the front door. This blower door equipment is essentially a large fan. Moreover, the equipment is used to pressurise the building at different pressures. The level of air leakage is measured to determine the efficiency of the building.

Air Permeability Testing Door

There are three levels of air tests, which vary depending on the building type. We tend to focus our tests on level 1 air permeability tests.

A level 1 test is used for single or smaller dwellings up to a 4000m³ and typically involves just a single door blower, which applies for most buildings tested as each dwelling is normally less than 4000m³.

Ways To Improve The Results Of An Air Permeability Test

There are many ways to improve the results of an air permeability test. The planning process is vital in ensuring that a building meets air permeability standards. Furthermore, constant inspection throughout the project can also help to improve air leakage rates. An air tightness strategy is vital in achieving high standards. Below are some ways to improve the results of an air permeability test.

Seal Waste Pipes

  • Ensure that waste pipes are fully sealed to restrict the flow of air. Sealant or pre compressed expanding foam strips can be used seal pipework. Expanding foam should be avoided as it may shrink and break the seal.

Quality Check Windows & Doors

  • Ensure that windows and doors are fitted with the utmost workmanship to avoid unnecessary air leakage. Any leaks or cracks must be sealed.

Take Care With Light Fittings

  • Air tight boxes can be installed over the fitting in the ceiling void to reduce leakage. Another option would be to seal any holes around the light fittings and pull cords in the ceiling.

Reduce Air Leakage In Cupboards & Loft Hatches

  • Loft hatches and eaves cupboard doors can be a victim of air leakage. Take care in sealing those areas to reduce the level of air leakage and therefore improve your energy rating.

Quality Check Radiator Pipes & Manifolds

  • Radiator pipes and manifolds are not always sealed correctly and are simply covered with carpet. This will cause air leakage so it is vital that any piping is correctly sealed when penetrating a wall or flooring.

Test Multiple Times

  • It is a good idea to test twice for air permeability. The first test can be made during the initial stage, which is before improvements are made for air tightness. The second test should be made on completion of work.

An air permeability test is an important stage of a building development and therefore special care and attention must be taken to ensure high standards. A building that is energy efficient would require less energy to run and therefore would have lower running costs. The reduction of energy usage is better for the environment, which is why much importance is placed on air permeability testing. A benefit to the introduction of air permeability standards is that the overall quality of build will need to be higher, which enhances living conditions for the inhabitants.

Call us today for an assessment on 020 3372 4430
Or you can email us at info@af-acoustics.com

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