The War on Winter
By Tom Matthews
When the temperature drops and cold weather rolls in, it’s time to prepare your home for winter inside and out. Sealing off air leaks and installing adequate insulation are two of the most effective ways to save energy,
Search for Leaks
Whether through walls, floors, the ceiling or ductwork, air leaks represent money out the window. In cold weather, warm air rises into the attic of the home. As it enters the attic, it leaves the living space, which you’re paying to heat. It also pulls in cold outdoor air from other cracks and crevices in the home, around doors and windows, and through the basement. In essence, these leaks create a vicious cycle that can drain away energy and money. Inspect your home care-fully for any leaks, which can be difficult to find when hidden beneath insulation. Some common problem areas include the attic hatch, plumbing vents, wiring holes, recessed lights and the soffit boxes that contain them.
A simple way to check for air leaks is to use a burning candle. On a cool, windy day, close all doors and windows and turn off the furnace. Turn on all the vent fans in the house to encourage the leaks. Move the lit candle around the edges of doors and windows. Look for the smoke to flutter or the flame to flicker, which indicates a leak.
Test the rooms’ temperature.
If temperatures differ more than 1 or 2 degrees in various areas of a room, it may be poorly sealed. Apply weather-stripping and/or caulking as necessary, then retake the temperatures. (If the differences persist, you may have an HVAC airflow problem.)
Certain spots in the home are particularly vulnerable to air leaks. Check round the furnace flue or the duct chaseway (the box that hides the ducts) for leaks. Next, investigate indoor areas including heating and dryer vent penetrations, gaping baseboards and cracks along sill plates and floor-to-wall junctions. On the outside, look for leaks at the bottom of siding edges where they meet the foundation, along garage ceiling and wall joints, and all electric, gas and A/C penetrations. Also examine the basement rim joists and all windows and doors.
Consider investing in an infra-red thermometer for a DIY home energy audit. For as little as a hundred bucks, handheld laser-sighted tools can help detect energy loss around doors and windows, insulation, ductwork and other areas throughout the home.
Fill the Gaps
Once you’ve pinpointed air leaks, close them off. Use caulking between nonmoving parts of the home with caulking/sealant. You can use a wide variety of products, such as caulk with foam backer rods (for large gaps), as well as silicone-, water-, or rubber-based sealants.
The easiest way to parse the many options in caulks/sealants is to pay close attention to the indications on the packaging, making sure they match the job at hand. Whether the product is flexible, waterproof, paintable, or contains a mildewcide additive, all features should be listed prominently on the label, and you generally get what you pay for.