This past winter I had an awful ice dam problem. A friend of mine says to set up a fan blowing out of an attic vent when the cold weather returns, to bring heat up from the house and to keep the attic too warm for ice dams to form. Is there an energy-efficient fan designed for this purpose? I ask because it seems like I'd use a lot of electricity to keep a fan running all winter.

You're wise to address the problem of ice dams, not only because they can damage your roof but also because they're a sign that the heat in your house (which you pay for) is escaping into your attic. The way to prevent ice dams isn't to bring heat into the attic but to keep it from reaching the attic. In other words: A fan is not your solution.

I'll explain: Ice dams form when heat escapes into your attic, warms the underside of your roof and melts snow, which trickles down to the cold edge/eave, where it freezes. So, keep the heat in your house! That's done by a thorough job of sealing anyplace where air can escape from the heated house into the attic and then making sure that you've got at least 12 inches of well-installed insulation on the attic floor. Likely places for air leaks include attic hatches, pulldown attic stairs, the attic floor above pocket doors, gaps around plumbing and wiring and more.

The safest, most accurate and comprehensive way to seal air leaks is to hire a professional. A Home Performance with ENERGY STAR® contractor can use diagnostic equipment to find air leaks. The contractor can then fix the leaks and perform any necessary insulation work. You can find a list of these specially trained, certified contractors at www.efficiencyvermont.com.

After shelling out so much money for heat this winter, we're going to do something about it. Is it a good idea to replace our drafty windows with energy-efficient windows? They seem to be a good thing, but I want to be sure before we spend the money.

Good-quality, energy-efficient windows do a great job of increasing comfort and lowering heat loss. But you're right to think before investing. It's generally not a good financial move to replace old windows for energysaving purposes alone, because the high cost of the purchase is rarely paid back by energy savings.

The cost-effective time to buy high-performance windows is when you must buy new windows anyway. Like, when you're building a new home, putting on an addition, or replacing nonfunctional windows. Otherwise, it's possible to improve old windows to make them perform nearly as well as new ones but at a fraction of the cost.

Replace cracked panes and glazing and be sure that sashes close and latch properly. Use a window weatherization kit, available at hardware stores. Install storm windows. If you have space between the sash and the frame, ask at your hardware store for a flat spring called a V seal. See if you have functioning sash weights. If you don't, get a cap designed to close the opening where the weight used to hang. Use caulk to seal any gaps around window frames.

The best approach to reducing drafts is to take a look at your entire home. When air escapes to the outdoors through one area of a house, it can create incoming drafts elsewhere. The first place to look is anywhere air can escape to the attic. Likely places include attic hatches, pull-down attic stairs, the attic floor above pocket doors, plumbing, and wiring and more. Seal gaps and make sure that you've got at least 12 inches of well-installed insulation on the attic floor. A Home Performance with ENERGY STAR® contractor can find and fix leaks and perform any necessary insulation work. You can find a list of these specially trained, certified contractors at www.efficiencyvermont.com. Good luck and stay warm!