I know my house leaks heat in winter. But is sealing my home really that important?
Yes, it really is. We estimate air leaks can account for up to 30 percent of heating energy lost in a home. That is the equivalent of throwing 30 cents of every dollar spent on heating out the window.
“Air sealing is one of the most cost-effective things residents can do. Even if you have attic insulation, by sealing your home the insulation will do a better job,” said Rick Cantonwine, Clark Public Utilities energy counselor. “The payback is good and worth doing.”
• First, find the leaks. Before you can seal air leaks, you need to find them. You can hire an expert to conduct a blower door test or do your own detective work.
According to Rick Shulenbarger of Energy Solutions in Vancouver, a blower door test typically costs around $125. The test is simple — a large exhaust fan draws air from inside the closed-up home, lowering the indoor air pressure. This causes the higher air pressure outside to be pulled in through any cracks and openings. The test also looks for leaking furnace duct work.
“Most houses leak about one to one-and-a-half times what they should and 20 percent of them leak four to five times that,” Shulenbarger said. “That doesn’t mean these are older homes either. Houses built in the 1940s and 1950s were built tighter than many newer homes.”
Another, less sophisticated, way to find leaks is to run your dampened hand around windows, doors, attic hatches and along basement rim joists. In the attic, you’ll be able to feel air rising from the house around wiring holes, plumbing vents and ceiling fixtures, such as recessed lights or bathroom fans.
Shulenbarger said the idea is to find the larger leaks.
“Typically in ranch houses with a crawl space there is a gap where the base of the wall meets the floor,” he said. “These can leak more than the doors and windows combined. The most realistic time to seal the gap with caulk or foam is when you take up floor coverings.”
• Plug the leaks. There are numerous sealants on the market. Do some research and find the correct type for the specific application.
For smaller openings, use foam or caulking. Around doors, install weather-stripping. Caulk around outside windows with a quality exterior caulk that can be painted to match the house exterior.
• Seal any duct work. Duct work can leak as much as 20 percent of a furnace’s heated air. Not only does that cost you in higher energy bills, it also means your furnace is working harder than necessary. Seal duct seams and joints with mastic duct sealant to stop all leaks.
“House sealing is really about making people feel more comfortable — to feel fewer drafts and also save energy,” Shulenbarger said.
The Energy Adviser is written by members of the energy counselor team of Clark Public Utilities, who provide conservation and energy use information to utility customers. Send questions to energyadviser@clarkpud.com or to Energy Adviser, c/o Clark Public Utilities, P.O. Box 8900, Vancouver, WA. 98668. A panel of local energy efficiency and energy product specialists will review your questions. Previous topics are available at http://www.clarkpublicutilities.com.
