I expect to get hit by wind when I’m on the ferry to Victoria, BC Canada, but not when I’m sitting in my living room. All too often, air leaks drive down the efficiency of our homes by leaking conditioned air into unconditioned spaces or directly to the outdoors. Identifying and sealing these common air leaks will make a big difference on your home’s efficiency.

Floors, Walls, and Ceilings
Floors, walls, and ceilings make up 30% of all air leaks in residential structures. Much of these leaks need to be addressed during the construction of the home; however, many can be fixed after a home has been in use for years. Much will depend on how much access you have to the areas in question. For example, the place where walls and ceilings meet is often a problem for small air leaks; however, you likely will not be able to access that area because it is behind your drywall. Fix what you can now and be aware of other potential leaks for future construction projects. If you seal up the big leaks first, you’ll see quick improvement. In fact, the bigger leaks may actually be accentuating the smaller leaks by adding a suction force to them as the bigger leaks waste conditioned air.

1. Ensure the envelope is well insulated. Adding insulation can improve the efficiency of your home and can reduce air leaks. Use caulk and vapor barriers where possible to seal the framing. For example, from within the attic.
2. Check for proper insulation around recessed light cans.
3. Add rigid insulation to the top of attic access doors or install an insulating attic access cover.
4. Add rigid insulation beneath any crawlspace access doors that open to the conditioned space.
5. Insulate crawlspaces yet allow for proper ventilation.
6. Install 6 mil or stronger plastic underneath the house on the crawlspace floor.

Much of the duct work will be enclosed in the walls of your home so you won’t be able to access it. What is available to you is the ductwork in the attic, basement, and/or crawlspace. Focus your attention here as the ducts are within unconditioned space. Any air leaks here will heavily impact your efficiency where as leaks within a conditioned space such as the second floor joists simply drops into the conditioned space of the home and is not very impactful on overall efficiency.  Seal leaks in ductwork.

1. Pull insulation back from the joints of the ductwork to expose all pipe connections.
2. Use duct sealing caulk on all joints.
3. After caulk has dried, apply duct tape (the real stuff, not the household version) to all joints.
4. Replace the insulation and tape the joints of the insulation with duct tape.

Fireplace/Wood Stove

1. Close flue dampers when not in use.
2. Check that insulation requirements around chimney stack are in place.
3. Caulk the chimney collar where the chimney enters the ceiling.
4. Use tight fitting, glass doors on fireplaces. Keep doors closed when not in use.

Plumbing Wall Penetrations

1. Seal all penetrations in exterior walls. This includes pipes, ductwork, and other penetrations.
a. Look at all penetrations in exterior walls.
b. Remove pipe collars around plumbing and spray expansion foam into the open space around the pipe within the wall.
c. Once the foam has dried, cut it flush with the wall.
d. Caulk any remaining gaps between the pipe and the wall and replace the collar.

Doors and Windows

1. Weather-stripping around doors and windows is usually to blame for their leaks. Upgrade the quality of your weather-stripping and you will save a lot of energy.
2. Check the quality of your windows and doors. If they are old, you may want to consider replacing them.
3. Install storm windows on older windows if you cannot replace them.
4. Install storm doors on all exterior doors. Be sure to include a spring closing mechanism.
Fans, Vents and Electrical Outlets
1. Seal all exterior wall penetrations as outlined above.
2. Install air-sealing gaskets to all exterior wall electrical switches, plugs, and fixtures.
3. Install baffles on fans.
4. Seal the dryer vent and ensure the dryer vent baffle works.