Air sealing is one of the most cost-effective ways to improve the comfort and energy efficiency of your home. Hire a certified professional contractor for best results.
Why Air Sealing?
Most homeowners know that proper insulation helps keep a house warm in summer and cool in winter. Insulation works by blocking the flow of heat through a surface such as a wall or roof. But insulation does not necessarily block the movement of air. This is especially true when there are cracks, holes, or other gaps that can be found in a typical house.
Think of insulation as a sweater — it can keep you warm when the air outside is cold, but it does not really block the wind. For that you need a windbreaker. Air sealing acts like a windbreaker.
Air leaks can make your home feel drafty and uncomfortable and place an unnecessary strain on heating and cooling equipment, which decreases their efficiency and raises your energy bills. Air leaks can also let in moisture that can warp and damage wood and lead to mold.
Air Leak Locations
Air leaks can occur anywhere in the home where gaps exist. Those around windows and doors are the most obvious, but there are often many smaller and less detectable ones. Other places to find air leaks are where rising warm air is replaced by cooler air (as often happens between an attic and the conditioned spaces below) or where exposed insulation contains dirty spots (showing air infiltration).
Air leaks also often occur where brick and wood siding or foundations and walls meet. At least 19 key areas (shown in the illustration above) have been identified where air sealing can improve a home’s energy efficiency, comfort, and building durability.
Finding and Sealing Air Leaks in an Existing Home
It is best to hire a professional energy auditor who will first carry out a home energy assessment in order to find air leaks, determine the best course of action for sealing those leaks, and carry out the upgrade work. Many homeowners, however, elect to use a do-it-yourself approach to finding and sealing air leaks. This approach can be effective for obvious leaks such as around door frames and exterior wall penetrations for pipes, vents, electrical fixtures and wires, and around ducts and fans. However, this approach will not work for small and hard to detect leaks, especially those in attics of existing homes that may be covered by layers of insulation.
Doing It Yourself
If you are going to undertake a do-ityourself approach to air sealing those readily accessible parts of your home where there are obvious air leaks, you have a number of materials available to you. They include:
- Caulk, including acrylic latex and high temperature-resistant silicone caulk (for sealing around flues, vents and pipes associated with chimneys, furnaces, and water heaters; however, it is recommended that you go to a professional contractor for such air sealing needs);
- Spray foam, including expandable polyurethane (which may also be used for insulation) and waterbased foams;
- Weather-stripping (such as around doors and between window frames and sashes), including tension seal, felt, reinforced foam, rubber tape, aluminum or stainless steel door sweeps, metal gaskets, bulb or fin seals, and other types of interlocking metal channels.
Source: Tap Insulation