Everything You Need to Know About Blower Door Tests

Parts of coastal New South Wales and Victoria endured one of their coldest winters to date, despite average annual temperatures higher across the rest of the country. With work from home regimens affecting many workers, the cold was felt by millions in our biggest cities. Not only the change in weather, but the infamously meagre levels of insulation in Aussie homes has seen people snapping up aircons and heaters in record numbers, and running up electricity bills. This is especially true in older suburbs with houses that have escaped relatively new building standards.

While most new developments have homes exceeding the minimal insulation requirements for the climate zone, a thorough home inspection can help you ascertain if any other work is needed, and what outlying costs like potential repairs and future electricity and gas will be. To get a better picture, a blower door test conducted by a certified tester will determine the air-tightness of your home.

What is a Blower Door Test?

Source: forbes.com

A blower door test is used to quantify the amount of air leakage in a residential or commercial building. Air can leak through windows, ceilings, walls and floors. Gaps and cracks can lead to uncomfortable drafts, lower air quality, more pollutants and moisture and mildew buildup. This not only poses health risks but is also detrimental to overall structural rigidity. After the test is completed, homeowners have the relevant information to conduct any needed repairs or changes to ventilation and heating.

The Equipment Used

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A blower door test kit consists of a calibrated fan that is installed in a sealed window or exterior door frame. During the test, all other openings to the outside are closed. When the fan is turned on, it creates a pressure difference between the outside and inside, that is the fan sucks the air out of the home through any path it can find. These are the leaks, gaps or cracks that you may have suspected and a few that you didn’t know were there. With the fan calibrated at the specified air pressure, testers determine the amount of air leakage. If the conditions don’t allow for the pressure of the home to be lowered, then the fan is used in reverse, blowing air into the house and increasing the air pressure inside. Results are measured by a digital pressure gauge and compared to recommended values as specified in current building codes.

An industry-spec blower test kit can be programmed to different air pressure values, from 15 cubic metres per hour in finding the smallest leaks, to over 6000 cubic metres for larger homes and buildings with multiple or larger leaks. Besides air pressure, tests also record temperatures and humidity levels. Infrared cameras are especially useful in this aspect. Results are relayed via apps on mobile phones or computers to tenants or relevant parties.

Reasons for a Blower Door Test

Source: hvacservices.com
  • Indoor Air Quality – Blower door tests evaluate the air quality inside the home. Pollutants like dust, smoke, mould spores and volatile organic compounds worsen existing health issues and can be the cause of new ones. They can identify the type of pollutant, the source and the quantity entering the house. Results from tests conducted with blower door test kits can help maintain the balance between ventilation and air-tightness of the home to provide for the healthiest living environment. For more on indoor air quality read up on the government recommendations.
  • Energy Consumption – Air leakage due to cracks and gaps in places like window sills, ceilings or roofing, and inadequate or insufficient insulation can increase energy consumption. Aussie homes, particularly in the southern states have little in the way of insulation, and this is felt during cold winter months. Air leakage only exacerbates the problem. A blower door test identifies the location of leakage, meaning tenants and owners can take the next step in sealing problem areas. You’ll not only have lower electricity bills but also more comfortable ambient temperatures equally distributed throughout the house.
  • Air-conditioners and heaters will work optimally once the leakage has been repaired. This means they’ll consume less power in achieving the same temperatures, and won’t have to work as hard. If you haven’t got an installed air-con, a properly sealed house saves you money when buying the appropriate unit for the specific size of the room or house.
  • Structural Damage – Testing for air leakage can reveal other hidden problems. Structural damage caused by negligence during building, or accumulated over longer periods because of issues with condensation, humidity or mould will save tenants and homeowners money if revealed on time.

How Much Does a Blower Door Test Cost?

A blower door test costs approximately $500 for residential buildings, and is roughly equal to your winter electricity bill. The costs cover the use of the blower door test kit equipment and labour. Tests last anywhere between two to four hours. Ensure that you hire a certified company or tester, that will promptly provide you will the relevant test results, and recommendations for any needed repairs or upgrades to your home.

Twenty years from now you will be more disappointed by the things that you didn’t do than by the ones you did do.