With the arrival of chilly weather, we become aware of cold air leaking into the home, and our instinct is to plug up the leaks. But sealing the house too tight can be more harmful than a leaky house. Controlled ventilation and proper air sealing is the goal.
What is Air Leakage?
Air leakage – also known as air infiltration – is unwanted amounts of outside air entering the house through cracks and small openings. A leaky house allows moisture, dust and allergens into the home, making it unhealthy. As air pressure changes in your home, these same leaks also allow heated air to escape outside. These air leaks waste energy dollars because it costs more to heat a home that’s letting air sneak out through cracks and openings.
Where Does the Air Leak?
Air leakage can account for 50% of your heating costs, and the pie chart above shows the most common areas where unwanted cold air seeps into the home.
A good analogy is to think of going outside on a cold, windy day wearing an expensive, good quality winter coat all decked out with thermal fleece and water repellent, but if you don’t zip it up, you get none of the warmth benefits you paid for.
You need to zip up your home by sealing air leaks. The most efficient replacement windows and extra insulation cannot help reduce your heating bills if the areas around them let in the cold air. You can have reduced energy bills, and increased comfort and health by identifying air infiltration points and sealing them up.
How Do I Find the Air Leaks?
Two of the most effective ways of finding air infiltration weaknesses in your home is with a blower door test and infrared thermal imaging. Both of these tests can be performed during a home energy audit.
Testing the air-tightness of a home using a variable speed fan called a blower door will help reveal air leakage sites. A door-panel system with a calibrated fan and pressure gauges is set up in an exterior door and is typically used to create negative pressure that will pull air through cracks and penetrations in your home. The tighter the building, the less air is needed from the blower door fan to create a desired change in building pressure.
An infrared thermal camera shows surface temperature differences, which pinpoints exactly where air leaks compromise efficiency. The pictures above show a patio door as seen through the infrared camera, with the blue areas revealing cold outside air leaking in. Solutions for stopping this leak include adjusting the door and the threshold, and repairing and/or replacing the weather seal around the door.
Start with a Home Energy Audit
A home energy audit by an experienced and certified energy auditor who will assess and recommend solutions is the best way to take control of your comfort, health and energy bills. Choosing a company that can assess, recommend and perform the solutions increases your efficiency and peace of mind.
Mosby Building Arts has a deep bench of Certified Green Professionals, and energy auditors trained and authorized by the Building Performance Institute, Energy Star and the Missouri Department of Natural Resources. Take advantage of their knowledge and experience to perform the solutions that will benefit you the most. You can work the Mosby energy experts to develop a master plan of which improvements will bring immediate results, and which improvements will create a larger return-on-investment.