Air tightness testing is the established approach to measure how much air is lost through uncontrollable leaks in a building. It’s also known as an air leakage test or air pressure test, and it’s a useful way to learn about a building’s energy efficiency. In recent times, energy efficiency has become an important factor when inspecting buildings, thanks largely to the uptake of new materials for building envelopes and a push for more strict building regulations.
As a result, homeowners and home buyers expect a higher level of insulation and airtightness for their properties due to the benefits it provides in terms of energy savings and environmental impact. In this article, we’re going to provide you with the ultimate guide to airtight testing so that you know what it is, why it’s important and how it works.
What is air tightness?
Air tightness is a measurement of how much air leaks from the interior of a building when there’s a difference in pressure between the interior and exterior of the structure. The wind is typically the main cause of the difference in pressure between an indoor and outdoor space, so when the wind blows against the side of a building, a positive pressure pushes into it. On the other side of the building, negative pressure builds up and essentially sucks air from the structure. In some cases, even a gentle breeze is enough to build significant pressure differences between the inside and outside of a building.
What is air tightness testing?
Air tightness testing, sometimes known as air permeability testing, is the standard approach used to assess the total amount of air lost in a building via leaks in the envelope of the structure. The test is a useful way to measure the total amount of air that manages to escape through cracks, gaps and other paths for leakage in a building.
The more air-tight a building is, then the less energy is lost and wasted via leakage of heated air. If a building is strongly air-tight, then the environmental impact of the structure is dramatically reduced and energy costs are lower too. High air tightness scores can explain up to 50 % of the heat lost by a building, so it’s a big portion of heat loss. With that said, if a building is too air-tight, then it’s a warning sign that there isn’t sufficient ventilation. This, in turn, can lead to various issues, such as condensation and mould buildup. So it’s important to find a balance in air tightness to avoid losing too much heat and mitigate the risk of mould growth.
How do you pass an air tightness test?
The way to pass an air tightness test is quite simple due to the standardised method of measurement used. So, to pass the air tightness test, building structures must have an air permeability rating that scores lower than 10 m3 / h / m2.
What buildings require an air tightness test?
Under the new legislation, all new build properties and conversions require an air tightness test to ensure that air tightness is sufficient for the building. This includes both residential properties and commercial buildings.
What are the benefits of an air tightness test?
There are several benefits associated with air tightness testing, such as:
• Lowers carbon dioxide emissions
• Mitigates heat loss and helps keep energy bills down
• Ensures compliance with the latest building regulations
What are the common areas in a building for air leaks?
Air leaks happen in a few common areas in a building, so it’s always worth checking them first. These areas include:
• Attics
• Between floor joists
• Wiring or plumbing holes
• Open or exposed soffit
• Any recessed lighting
• Furnace flues
How does an air tightness test work?
The air tightness test uses specialised tools such as door blower testing equipment to pressurise the building and test the pressure differences.
There are different testing levels for air tightness, depending on the type of building, its size and its shape. Below are the three different levels:
• Level 1: For single swellings and smaller buildings of up to 4,000 m3 envelope volume
• Level 2: For simple and complicated buildings greater than 4,000 m3 envelope volume
• Level 3: For high-rise buildings, phased and zonal handover structures
For more information about the air tightness testing services offered by Airtight Testing Staffordshire, contact us today at 01785 593525.