Weatherize

September's Sustainable Living Tip

"Weatherize" your home by sealing air leaks, controlling moisture and adding insulation. You'll enhance your health and comfort, while saving money and the planet!

More Facts About Weatherization

1. "Weatherizing" a home means making it more comfortable and efficient in both winter and summer by preventing unwanted air leaks, eliminating excessive moisture, and controlling heat flow.
2. Most households spend more on heating and cooling their house than any other use of energy.
3. A typical house that burns fuel for heating releases almost twice as much air pollution annually as a typical car. (By contrast, homes that heat with clean green electricity emit no air pollution.)
   
4. The "mileage" (i.e. energy efficiency) of a home that burns heating oil is called its K-factor, measured in degree days per gallon. The higher the K-factor, the better.
5. Older homes often have a K-factor below 5. Newer homes can achieve K-factors above 10. If you take automatic delivery of heating oil, your bill should list your K-factor. (This is how your oil company determines how often to come fill your tank.)
6. Keep track of your home's K-factor to see whether the weatherization measures you're taking are getting results.
   
7. The best way to start weatherizing a home is to use weather stripping, caulk or spray foam to seal air leaks around doors, windows, sills, electrical outlets, and vent pipes. These are easy projects that a home owner or a handy man can do.
8. Seals around windows and doors eventually wear out, so inspect every year to identify weatherstripping that needs replacing.
9. Sealing air leaks along the walls in an unheated basement is especially important to avoid freezing pipes. Older homes have gaps where the wood sill meets the stone or concrete foundation. The most effective way to seal these is to use a spray foam gun kit instead of wasteful disposable spray cans.
10. Forty percent of all air leaks occur in the attic. Be careful when sealing leaks around chimneys; if you don't understand your local fire code hire a certified weatherization technician to handle air sealing your attic.
11. Control moisture in kitchens and bathrooms by installing fans that exhaust to the outside.
    
12. Check your attic and walls to see if yours is among the 65% of homes that need more insulation. You should have about 16 inches of insulation in your attic.
    
13. The best place to add insulation is in your attic, but do this after you've sealed air leaks. If you hire an insulation company, ask them about air sealing. They should list specific steps they'll take to seal air leaks. If they don't, consider hiring someone else.
    
14. Oak Ridge National Laboratory recommends insulating an existing home in Maine's climate to the following standards: attic R-49 (about 16 inches of cellulose), walls R-13, floors R-30, and basement and crawlspace walls R-25.
15. If your basement is unheated, either insulate the floor above it, or the walls. Be sure to seal air leaks first before installing batt insulation, or use a spray foam that will simultaneously seal air leaks and insulate.
16. All windows at night, and north-facing windows all the time, suffer a net loss of heat via radiation. To minimize heat loss, install storm windows (either exterior or interior) and close drapes or blinds whenever possible.
17. Because heating systems are most efficient when properly sized, and are properly sized according to the heat loss characteristics of the building they heat, you'll save the most money and energy if you reduce your heat loss through insulating and air sealing before replacing your heating system.
18. If you heat with oil, gas or wood, ensure that your flue is providing a proper draw to exhaust combustion fumes. Fresh air must be available for combustion to occur safely; many heating systems draw their combustion air from the heated living space and exhaust it outdoors. (In other words, they suck cold air into your home.)
19. Solar and electric space heaters are simpler, safer and cleaner than boilers or furnaces. Since they do not burn anything, they do not draw in cold air. If you can switch to clean electric heat, you can dramatically improve your environmental profile and live comfortably in a very energy efficient home.
    
20. Very tightly air sealed homes should install passive ventilation or heat recovery ventilators to provide fresh air.
21. Tightly sealed homes should use safe cleaners, paints and adhesives that don't diminish indoor air quality.
22. Properly designed super-insulated passive solar homes in Maine's climate do not need central heating systems because sunlight provides the baseline heat. Electric space heaters supplement the sun's energy.
    
23. The U.S. Department of Energy's EnergySmart Home Scale (E-Scale) is a way to rate a home's energy performance. The typical new home is a 100 on the E-Scale, whereas the typical existing home is a 130 (i.e. uses 30% more energy). An Energy Star home is an 85 on the scale.
24. By installing solar panels, wind turbines and other renewable energy systems, a home can generate its own energy, thereby lowering its score on the E-Scale.
    
25. One industry observer predicts that by 2050, 67% of new housing starts will have an E-Scale score of 0 or better (i.e. produce as much or more energy than they use).