Lowering Your Energy Bill This Winter

This winter, save money and stay warm. Keep your energy bill and your pollution output low this winter by taking a whole-house approach to heating.

• During the heating season, keep the draperies and shades on your south facing windows open during the day to allow the sunlight to enter your home and closed at night to reduce the chill you may feel from cold windows.
• Insulate the floor of your attic. Heat always flows from warmer spaces to colder spaces, and that's why you should insulate your attic. Consider adding insulation in unfinished basement walls and crawlspaces too.
• Install a programmable thermostat to automatically adjust your home's temp setting when you are away or sleeping.
• Replace furnace filters regularly and properly maintain and clean heating equipment.
• Weatherize your home—caulk and weatherstrip any doors and windows that leak air.
• Switch to compact fluorescent light bulbs. They cost a bit more, but you can save about $50 over the life of just one bulb.

Dreaded Ice Dams

Ice dams sometimes occur on sloping roofs in climates with freezing temperatures. When the temperature in your attic is above freezing, it causes snow on the roof to melt and run down the sloping roof. When the snowmelt runs down the roof and hits the colder eaves, it refreezes. If this cycle repeats over several days, the freezing snowmelt builds up and forms a dam of ice, behind which water ponds. The ponding water can back up under the roof covering and leak into the attic or along exterior walls. Research shows keeping the attic air temperature below freezing when the outside air temperature is in the low 20s can reduce the occurrence of ice dams. Research has shown sun exposure in the winter has little effect on attic air temperature. Warm air from living spaces below penetrating into the attic is usually the culprit in the formation of ice dams.

Condensation of water vapor on cold surfaces in attics can cause attic wood products to rot, which can lead to costly repairs. Condensation typically occurs when warm, moist air migrates into the attic from living spaces below. Research indicates unusually high humidity levels in the home's living spaces is strongly associated with attic condensation problems. Building codes have some requirements that attempt to prevent the problems of ice dams and attic condensation. But codes do not address all the issues, and many houses are built without following building codes. It is the builder or designer's job to understand the relationship of humidity and air movement when designing and constructing the house so these problems don't occur.

Some of problems experienced with ice dams: leaking roof (height of leak depends on extent of ice dam); wet, ineffective insulation; stained or cracked plaster or drywall; rotting timber; stained, blistered or peeling paint.

A few tips to help with the ice dam battle: Prevent warm, moist air in living spaces from infiltrating into the attic with a good air barrier and appropriate water vapor control at the base of the attic. Provide good attic ventilation to replace warm air in the attic with cold outside air. Provide adequate attic insulation to reduce the transmission of heat into the attic from living spaces below.

'Tis the season to rifle through your dreaded attic, looking for last year's holiday decorations. While you are up there, take some time to make a visual inspection of your attic. First, check the roof and gable vents to make sure they are clear because the screens can act like lint traps. These vents are paramount because they keep the attic cool during summer. You don't want to get stuck checking these vents in the summer, when temperatures can soar into the 100s. In cold climates, a combination of high, inside relative humidity (60% or above) and low outside temperature (30 degrees F or below) may cause condensation on the underside of the roof sheathing. Condensation develops from a combination of high relative humidity and temperature differentials. Condensation cannot form when the relative humidity is low, or the temperature is high. Even in moderate climates with high relative humidity, the day-night temperature cycle, combined with high humidity, may cause condensation on the underside of the roof sheathing. The result is a series of problems such as wet (and consequently less effective) insulation, wood decay, and peeling paint. These conditions may go unnoticed until considerable damage has been done.

Just take a few moments and double check your vents. Remember that unobstructed vents allow moist air to escape from the attic in cold weather, lessening the possibility of condensation and mildew in the attic. While you're up there, check for wasp nests and other signs of pests. During the winter months, wasps are dormant and their nests are easier to remove.