Cold outside air finds its way in to your house via unsealed cracks and holes. This unwanted source of air is called infiltration, and it can represent a significant amount of wasted energy, particularly in older homes.
You don’t necessarily need high-tech tests conducted by a professional residential energy auditor to locate the leaks. Depending on the complexity of your home, an audit may cost several hundred dollars. Instead, you can employ low-tech tests, such as using the smoke from burning incense, or you can simply use your hand to feel where the air is moving. Once you know where the air is coming in, you can probably seal the leaks yourself with caulk or weather stripping.
The most common major sources of air infiltration in older homes are…
- Between the top of the foundation and the bottom of the wooden floor supports
- Chimney flues (close flue damper when not in operation)
- Between chimney and interior walls
- Around door and window frames
- Door thresholds
- Around attic access door or hatch
- Cracks in bricks, stucco, siding, and foundation
- Crawl spaces
- Window A/C units
Smaller sources include…
- Electrical, natural gas, phone line, and cable TV service entrances
- Mail chutes
- Electric wall outlets
- Exterior dryer vent that doesn’t close when dryer is off
It is possible that installing enough caulking and weather stripping can make a house too tight (not enough air for proper combustion at gas-fired boilers, furnaces, and water heaters). Therefore, it’s best to consult the EPA’s Do-It-Yourself Guide to Sealing and Insulating website prior to installing the caulking and weather stripping.
By reducing air leaks in your home, the EPA estimates that you can save at least 10% on your heating and cooling bills. In addition, the barriers created by caulking and weather stripping can prevent the intrusion of dirt, moisture, and even noise. Other tips for saving money through winterproofing appear in the infographic below (Courtesy of mint.com).
