Cracks and air leaks can lead to energy loss and waste money on your heating and cooling bills. Air sealing is one of the best energy efficiency improvements you can make to your home.
Air sealing will not just reduce energy costs; it will also improve your home's comfort and keep its value. Keeping moist air out helps to
prevent mold, corrosion and wood rot problems.
Finding Air Leaks
Look at areas where different materials meet, such as between brick and wood siding, between the foundation and walls, and between the chimney and siding.
Here is a list of places to look for air leaks:
- Door frames
- Window frames
- Mail chutes
- Electrical service entrances
- Natural gas or propane pipes
- Cable TV and phone lines
- Outdoor water faucets
- Places where dryer vents pass through walls
- Bricks, siding, stucco, and foundation
- Air conditioners
- Vents and fans
For a thorough and accurate measurement of air leakage in your home, hire a qualified technician to conduct an energy audit. Be sure they use a blower door test. A blower door test, which depressurizes a home, can reveal the location of many leaks.
A good way of finding leaks yourself is to follow these steps:
- Close all doors and windows
- Shut off your furnace or air conditioner
- Turn on your clothes dryer in the tumble dry mode so it pushes air out the vent
- Turn on kitchen and bathroom vent fans
- Now go around inside the house hunting for air sneaking in
You can use smoke from a cigarette or incense stick to see the airflow. Another trick is to use a candle and watch how the flame moves as you move it around windows and doors. Please be careful with fire.
If there is a big temperature difference between indoor air and outdoor air, an infrared thermometer can be used to scan for air leaks. INSERT ADVERT
In industrial situations, I have used spray foam shaving cream to find small air and vacuum leaks. But, the mess makes this a poor idea at home.
Air Sealing Techniques
Once you have located air leaks, you can then apply air-sealing materials as needed. Two common materials include caulking and weather stripping. Most experts agree that caulking and weather stripping will pay for themselves in energy savings within one year.
Caulk forms a flexible seal for cracks, gaps, or joints less than ¼" wide. You can use a caulking compound to seal air leaks in a variety of places throughout your home, including around windows and door frames.
Most caulking compounds come in disposable cartridges. When deciding how much caulking to purchase, consider that you will probably need a half-cartridge per window or door. You may need as many as four cartridges for the foundation sill.
Before applying caulk remove any old caulking and clean the area that you are working on. For best performance, follow all manufacturers' instructions. For more information on caulking HOW TO CAULK AROUND THE HOUSE
Weather stripping can be applied to seal air leaks around movable objects, such as doors and windows. To determine how much weather stripping you will need, add up the perimeter lengths of all windows and doors to be weather stripped, and then add 5% to 10% to accommodate any waste.
Weather stripping comes in varying depths and widths, and there is a variety of weather stripping materials available: foam, felt, vinyl, aluminum, and bronze. You need to choose a type of weather stripping that will withstand the friction, weather, temperature changes, and wear and tear associated with its location. IN LINK
For example, when applied to a door bottom or threshold, weather stripping could drag on carpet or erode because of foot traffic. Here is a link about door sweeps and thresholds HOW TO SAVE ENERGY WITH A DOOR SWEEP
When applying, consult the instructions on the weather stripping package. In general, weather stripping should be applied to clean, dry surfaces at temperatures above 20°F.