If your home’s “envelope” has been penetrated by cracks, holes and other air leaks, your energy spending has probably increased, while your comfort levels have been reduced. Although they may seem small and insignificant, air leaks are capable of introducing unconditioned air into your home, while simultaneously allowing the heated or cooled air from your house to escape. Not only does this detract from your home’s energy efficiency, but it can also result in uneven household temperatures, and poor indoor air quality. In order to fight these problems, here’s a simple guide to pinpointing leak sources, and how to go about air sealing a home.
Locating Air Leaks
The first step to air sealing a home involves doing a bit of investigative work. Although some air leaks, like drafts under doors and around windows, are obvious, other leak sources might not be as noticeable to the untrained eye. Because of this, it’s in your best interest to work with an HVAC contractor who can conduct a blower test in order to gauge how airtight your home is, where air is leaking, and where insulation is lacking. In addition to this, there are two ways for you to conduct a do-it-yourself air leak inspection:
- Visual inspection – As you walk around your home’s exterior perimeter, check for any obvious cracks or holes that may be located where two different types of building materials intersect. These “hot spots” for air leaks may include water faucets, areas where the home’s siding and chimney comes together, places where the foundation touches the house’s exterior brick or siding, and all corners. From here, evaluate your home’s interior for leaks. Some of the most common locations for leaks include electrical outlets, utility/plumbing service entrances, window-mounted air conditioners, switch plates, doorways, windows and places where dryer vents penetrate your walls.
- Building pressurization test – On a cool, windy day, turn off all of your household combustion appliances (e.g., gas furnaces, water heaters). After shutting all windows, exterior doors, and fireplace flues, light an incense or smoke stick and walk around the interior walls of your home, moving the stick near to common leak sources. If the smoke wavers, you have detected a leak.
Tips for Air Sealing a Home
Weatherstripping and the application of caulk compounds are the most common ways to go about air sealing a home. While weatherstripping works best for sealing moving components like windows and doors, caulk should be used for sealing small cracks in stationary locations. Here are some tips for using caulk and weatherstripping materials when air sealing a home:
- Weatherstripping – Your primary goal, when weatherstripping, should be to seal your home against leaks in moving components, while still allowing windows and doors to open and close easily. Because friction, foot traffic, weather and other conditions could affect the wear and tear of your weatherstripping, it’s smart to talk to your contractor about which materials will work best for your project. For low-traffic areas, a low-cost felt and open-cell foam product will work, whereas Vinyl weatherstripping is more expensive but will prove more durable and resistant to moisture. To determine how much material you’ll need, add all perimeters of the windows or doors that you plan to weatherstrip and add 5-10 percent for waste. Weatherstripping should always be applied to a clean, dry surface, and window or door operability should be tested after sealing.
- Caulking – When making plans to purchase caulk, be mindful that you’ll need about half a cartridge for each window and door that you need to seal, and approximately four cartridges for your home’s foundation sill. There are numerous caulking compounds available, each with their own advantages. Water-based foam sealants, for instance, are ideal for small cracks, while polyurethane expandable foam spray will work well on larger cracks in non-friction areas. After cleaning and drying the surface to be sealed, apply the caulk in a continuous stream, at a 45-degree angle. If any caulk oozes out of the gap, you may push it back in with a putty knife.
Consider Sealing Your Ducts
Air sealing a home is futile if you have leaky ducts with poorly sealed connections. By having your ductwork professionally inspected, sealed and/or repaired, you can effectively avoid problems related to uneven household temperatures, high utility bills and excess strain being put on your HVAC equipment.
For more helpful information on air sealing a home, contact the experts at Bryans United Air Conditioning. We have been serving residents of the Metro New Orleans area since 1982.
Written by Zach Mouton