According to Energy Star, between 25 and 40 percent of the energy used to heat and cool your home is wasted through air leakage. Air leakage is just what it sounds like: places where air seeps into or out of your home through cracks and holes. In addition to causing strain on your HVAC unit and allowing cold drafts into your home, air leakage can decrease indoor air quality and allow in moisture, pests and noise. Air leakage is incredibly common in houses 10 to 20 years old or older, and most Americans have no idea that it’s a problem they’re experiencing. Below, we’ll outline some of the common places you can find air leaks in your house, and what you can do about them.

The Problem with Air Leakage

With air leaks, you have air flowing into and out of the house, both of which cause problems for your HVAC unit, decrease your comfort and waste energy. As we say in East Tennessee, an air leak let’s all the “bought air” out—you end up paying to heat or cool more air than you need, making your HVAC unit work harder than it needs to. When air leaks into your house, it contains moisture, allergens and pollutants that clog up your HVAC unit’s air filter and again causes a strain on the system.   

When people hesitate to air seal their house, it’s because of the idea that houses ‘need to breathe.’ While you do need to circulate fresh air into your home, relying on air leakage for natural ventilation means you’re filling your home with air from over your garage that contains car exhaust or air from a garden bed that contains pollen and insects.

Air sealing your house means that you get to choose when and where the ventilation occurs: through open windows, bathroom and kitchen exhausts or a mechanical ventilation system like an attic fan, attic vent or subfloor venting. While it is possible to over-seal or overtighten your home, it’s very difficult to do unless your house is 10 years old or younger.

Where to Find Air Leaks in Your House   

Air leaks are easiest to find during cold and windy weather. Some leaks, like those from a drafty window or door or around a major appliance like an oven or refrigerator are easy to spot. You can literally feel the difference in temperature around these areas, especially during the winter months. But if you’re unsure, a quick visual inspection can help you find the majority of leaks in your house. Some common areas where you might find cracks and gaps that cause air leaks include:

  • Door and window frames
  • Electrical outlets
  • Where plumbing passes through to exterior walls
  • Places where electrical cords or gas lines enter the house
  • Phone and cable chord entry points
  • Fireplaces
  • Bathroom and kitchen vents and fans
  • Dryer vents
  • Recessed lighting
  • Basement wall penetrations
  • Attic entrances and whole home fans

The Department of Energy provides an excellent graphic that shows exactly where to look for air leakage trouble spots in your home. You can also purchase infrared temperature guns that help you locate where the cold drafts originate.

If you’re ready to take the next step beyond a visual inspection, you can hire a qualified technician to conduct an energy assessment, specifically a blower door test, where technicians turn off your HVAC unit and depressurize your home, then use non-toxic smoke pencils or infrared cameras to detect air leaks.  

How to Fix Air Leaks in Your House

If You Want to DIY Your Air Leaks: Caulking, foam sealant and weather stripping are easy, cost-effective ways of fixing many of the air leaks in your house yourself. Caulk is a great tool around door and window frames and for small gaps around fixtures and frames like attic fans and recessed lighting. For larger holes, you can use sealant foam that expands into hard to reach gaps like where plumbing passes through exterior walls or around phone or cable entry points. Both foam and caulk can be trimmed and painted in most cases to make sure that any repairs aren’t obvious.

Weatherstripping is the air sealant of choice around any area that moves, particularly windows and doors. You can easily attach a rubber weather strip to the bottom of your entry door or add foam weather stripping with adhesive backing to window gaps.

If You Want Professional Air Sealing: Professional air sealing can significantly decrease your energy and utility bills and extend the life of your HVAC unit. Professional sealing usually includes metal flashing around areas of your roof and chimney as well as increased insulation, in addition to caulking and weatherstripping. It also usually includes spray foam insulation, which can be expensive but provides excellent air sealing because it can reach the crevices between walls that might not be insulated in an older home. But be aware, if you have a gas HVAC unit, your professionals might not be able to use spray foam insulation because the unit needs to draw air from around it for combustion. 

East Tennessee HVAC Installation and Maintenance

City Heating and Air Conditioning is dedicated to making sure your HVAC units run as efficiently as possible and help you avoid any emergency repairs. While our experienced HVAC technicians know how to clean and maintain units with the utmost expertise, sometimes factors outside the HVAC unit play a large role in its longevity. Air sealing falls into this category—it’s an excellent way to keep your HVAC unit healthy for years to come that doesn’t actually involve HVAC maintenance.

If you believe you might be wasting money on your energy bill or overtaxing your HVAC because of air leaks, first schedule an HVAC maintenance appointment to make sure it’s to the source of the problem. Give City Heating and Air Conditioning a call at 865-938-1005 or fill out our online form, and we’ll be happy to examine your HVAC unit and give you our best advice.