QUESTION: Please tell me what you've got against attic fans. The upstairs of my house gets blazing hot in the summer and I thought it was due to heat from the attic seeping into the living area and that an attic fan would help that. Why don't you like these fans?ANSWER: The concept is perfect but the costs make them less desirable. Anything you can do to lower the heat in your attic in summer is a great idea, since you're absolutely correct — when temperatures climb high in hot weather (and an attic can easily get well over 100 degrees Fahrenheit), they can heat up the insulation and radiate downward into the home's living space. Keep the attic cooler and you'll keep unwanted heat out of the house.The problem is that these fans were really popular years ago when electricity costs were so much lower. Today, the cost of operating electric whole-house and attic fans can be significant, greatly reducing any potential savings. You're much better off making sure your attic is adequately insulated and using strategies such as an attic radiant barrier, light-colored shingles if you live in a hot climate, and even installing a solar-powered attic ventilator that will keep the air moving out through the soffit and ridge vents but without requiring electric power to operate.Good attic ventilation can be very effective in keeping a home comfortable in hot weather. Just don't spend all the potential savings on electric costs for the products that give you that ventilation. Passive strategies can be much more cost-effective.

QUESTION: We were surprised recently when we visited friends who always talk about their energy-efficient home and found that the house was filled with every type of electric-powered gadget imaginable. Isn't this contradiction wasting energy?ANSWER: This sounds to me sort of like snacking on doughnuts and a diet soda. You've uncovered one of the dirty little secrets of why all energy-saving strategies don't work. Scientists call this the "take back effect" — a theory that says that people who do things to make their home energy-efficient sometimes feel that they can now afford to do some of the energy-wasting things they'd like. They rationalize keeping their thermostat high in winter, for example, because they feel they're saving money with their compact fluorescent light bulbs.

Ken Sheinkopf is a communications specialist with the American Solar Energy Society.