First of all, what is an air pressure test?

An air pressure test is used to determine how airtight a building is; in other words, how well it prevents air from passing through it. This is also known as the building's air permeability.  Air leakage can escape through unrestrained means of a building. These leakages can happen if there are holes, cracks and gaps in the building's materials, for example in the walls, floors or ceilings. An unnecessary amount of air leakage can distress the building's energy efficiency, creating less energy efficiency within the property and making it more expensive to run. This is because when air leaks out, it causes a loss of heating or cooling, as well as reducing the air quality.

By following a few simple steps, you can help ensure your Air Pressure Test goes as smoothly as possible!

• - All external walls, floors, and roofs are correctly fitted and completely installed.
• - Make sure all windows and doors are in place and secured, and that they are again fitted correctly.
• - There are no gaps around light fittings or sockets. This is a common place for air leakage!
• - Another place where air leaks is around the plumbing. These penetrations must be filled before your test!
• - To prevent any airflow in and out of the building, all other service pipes must also be properly secured.
• - Skirting boards must be fitted top and bottom.
• - Make sure there are no gaps behind all units, such as kitchen units and baths
• - Loft hatches sealed.
• - There must be a standard size door in the property
  • - Systems specifically designed for ventilation purposes are not included in this test. Our engineers tape all extractor fans, chimneys, MVHR units, etc. Overall, this will give you an accurate score that you can rely on.

How's it actually done?

A qualified engineer will set up a momentary fan in the doorway, ensuring all internal doors are opened, temporary seal trickle vents and any other openings are closed. By increasing or decreasing pressure, we can then measure the differential pressure. The total air flow required to attain a pressure differential of 50 Pa, which is calculated and divided by the total building envelope area. This then provides the leakage rate of m³/h.m² @ 50 Pa. This calculation will show the air permeability of the building, which will tell us how airtight it is.

If you'd like more information, check out our video content, we update this regularly!