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How to Find and Seal Air Leaks in Your Home

By NOPEC on September 22, 2020

Reducing the amount of air that leaks in and out of your home can be a cost-effective way to lower your heating and cooling costs on your energy bill. Think your home is completely sealed shut? Not so fast—according to the U.S. Department of Energy, most homes have enough air leaks to add up to the equivalent of a two-foot hole. While this may not be such a bad problem on a nice, temperate day, your energy consumption will surely spike on a hot summer day or a cold winter’s night. Below, we described a few ways to detect and seal air leaks in your home to help keep energy costs low.

Conduct a Visual Air Leak Inspection

Conducting a visual inspection is the first step to detecting air leaks in your home. You will have to inspect both the inside and outside of your home to make sure you identify all air leaks.

When assessing the outside of your home, the important areas to check include everywhere two different types of building materials meet. For instance, you should check outdoor water faucets, exterior corners, where the exterior siding and foundation meet, and where the siding meets the chimney.

The indoor visual inspection should include areas that have gaps or cracks that could cause an air leak. Examine everything from the electrical outlets and switch plates to the baseboards and door frames. Be sure to look at the windows, attic hatches, and baseboards, too.

As you check the windows, see if they rattle. If the windows are shifting or rattling, air may be leaking out. Similarly, if there is light coming through the door frame, then there is plenty of room for air to pass through. When inspecting things like dryer vents and fans, pay close attention to any gaps around the pipes and wires. If there are cracked pieces of caulking or weatherstripping, the air is likely leaking through it. This same method can be used throughout your home by using a flashlight. Shine it over gaps to identify any cracks or holes that allow the light to pass through.

Perform a Pressurization Test

Another way to find air leaks in your home is by performing a pressurization test, which will allow you to pinpoint even the smallest cracks and leaks. The first step to perform the pressurization test is to turn off all appliances that use gas, such as a gas-burning stove, furnace, or water heater, and close all the doors, windows, and fireplace flues. Then, turn on every exhaust fan in your home that blows air outside, such as bathroom fans, stove vents, and your dryer (or, you can use a large window fan to pull air out of the rooms).

Next, you can light an incense stick and wave it near common leak sites or areas where you think leaks may be occurring. If the smoke is blown out of the room, there is a draft, which means you have found a leak. Another option is to use a damp hand and feel for a leak since drafts will feel cool on your skin.

Check Your Insulation

Checking the insulation in your home is another way to find air leaks. This can be a bit tricky since the amount of insulation required at the time your home was built may be different than what current energy efficiency standards suggest.

The goal of insulation is to make sure that the warm air in your home stays inside during the winter. It would serve no purpose to spend money heating your living room only to have that warm air escape into your uninsulated garage! To determine if your insulation is sufficient for your home’s needs, you’ll need to measure its thermal resistance (R-value), or the capacity of your insulation to resist heat flow. You’ll likely need the assistance of a professional in order to do so, but it will be worth the investment. The U.S. Environmental Protection Agency (EPA) estimates that homeowners can save an average of 15 percent on heating and cooling costs (or an average of 11 percent on total energy costs) simply by adding insulation in attics, floors over crawl spaces, and basements. 

Seal Your Air Leaks

It may be simple enough to seal drafts coming from your doors, windows, and baseboards with weatherstripping or caulking. A qualified technician can help you pinpoint and seal other air leaks that are harder to find or reach, especially when it comes to installing insulation or sealing air leaks around fireplace chimneys, furnaces, and water heater vents.

The U.S. Department of Energy provides some additional tips for sealing your home, which include:

  • Caulking and sealing air leaks where plumbing, ducting, or electrical wiring comes through the walls, floors, ceilings, and soffits over cabinets.
  • Installing foam gaskets behind outlet and switch plates on walls.
  • Keeping your fireplace flue damper tightly closed when not in use.
  • Replacing door bottoms and thresholds with ones that have pliable sealing gaskets.
  • Covering single-pane windows with storm windows or replacing them with more efficient double-pane windows.
  • Covering your kitchen exhaust fan to stop air leaks when not in use.
  • Checking your dryer vent to be sure it is not blocked.

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Tags: NOPEC, Energy Efficiency
Categories: Energy Efficiency

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