New Construction Air Leakage Testing

What Is Air Leakage?

Air leakage is any unwanted airflow that occurs in a building or home. Pressure variations between the air inside a home and the atmosphere outside will cause air to flow from the area with higher pressure to the area with lower pressure. Although air leakage typically happens when high-pressure air inside a home flows outside, it can also happen when high-pressure air outside flows inside a home.

What Is an Air Leakage Test?

You might already know of obvious places where air leakage occurs in your home, such as around doors and windows. However, you also have to fill less obvious gaps to make sure your home is properly sealed. An air leakage test is a clean, nondestructive way to determine where air is leaking into or out of a home.

Since it's estimated that air leakage accounts for between 25% and 40% of energy used to heat and cool a home, having an air leakage test is an excellent way to help reduce energy bills and save money.

Visual Inspection

One way you can complete your own air leakage test is to do a visual inspection around your home. First, walk around the outside of your house and inspect places where two different building materials meet. These spots can include:

  • Outdoor water faucets.
  • Exterior corners.
  • Where the foundation meets the siding or brick.
  • Where chimneys meet the siding or brick.

You should also inspect the following areas inside your home for any gaps or cracks:

  • Door and window frames.
  • Weather stripping around doors and windows.
  • Electrical outlets.
  • Switch plates.
  • Mail slots.
  • Baseboards.
  • Electric wire and gas pipe entrances.
  • Cable television and phone line entrances.
  • Attic hatches.
  • Fireplace dampers.
  • Vents and fans.
  • Wall- or window-mounted air conditioners.
  • Dryer vent openings in the wall.

As you're inspecting these areas, make sure the caulking and weather-stripping are applied properly and in good condition. You shouldn't see any gaps or cracks in the caulking or weather-stripping. If you can see daylight, air is leaking in or out. Additionally, as you're checking your doors and windows, see if you can rattle them. Movement can indicate air leakage.

Blower Door Test

While a visual inspection you complete yourself can indicate some places where air leakage is occurring, it won't give you the full picture. For that, you should set up a blower door test performed by professionals like those at Energy Diagnostics.

During a blower door test, all of the windows and doors are properly closed and a large fan is placed in the main entry doorway to pull out air from inside of the house. This causes outside air to get sucked into the house through leakage points. While the fan is on, a technician will go to each room in the house to find the air leaks. Sometimes the gaps or cracks are so big you can actually hear or see where air is entering the house. However, the technician can also use other tools to detect smaller leaks.

One such tool is heatless smoke. As the technician moves the smoke near windows, doors, and other places where gaps can occur, the smoke will get sucked through the leakage spot and indicate a gap that needs to be filled. A technician can also use a special camera that can detect slight temperature differences. As the technician moves the camera over different surfaces, contrasting colors will indicate potential air leakage areas.

Sealing Air Leakage Gaps

After the technician finishes the blower door test, you'll have a good idea of where air leaks are occurring and what type of impact this is having on your comfort and energy bills. The next step is coming up with a plan to seal the air leaks.

It's often important to start in the attic since this is where a significant amount of air leaks out in a home. The next best place to focus on is the basement or crawl space areas. When you seal gaps and cracks here, you eliminate a major place where cold air can leak inside. With those places taken care of, you can finally focus on the main living spaces in your home.

Benefits of Sealing Air Leakage Gaps

Once a technician completes a blower door test, he or she can often use the results of the test to determine your home's air changes per hour (ACH). A passive house, which is considered an ultra-low energy building, has to have 0.6 ACH or lower. Most new construction homes tend to have an ACH of around 3. While 3 doesn't seem like a high number, even this amount of air change per hour means a significant amount of air inside the home is replaced every day.

Not only will this amount of air leakage mean higher heating and cooling bills, but it can also affect the durability of your home. Leaking air is often humid. As humid air finds its way through cracks and gaps in your walls, it can condense and leave behind moisture. This moisture will then create mold and rot. In addition to lowering the air quality in your home, the mold and rot can also cause you to have to perform expensive renovations to fix the damage.

If you're interested in pinpointing air leaks around your house so you can lower your energy bills, the professionals at Energy Diagnostics can help. We have rated and inspected over 60,000 homes, and we can complete an air leakage test that will help you identify where air leaks are occurring. Contact us today to learn more about our services.