Help me settle a bet with my son-in-law. He thinks that insulation is bad for a house. He says that high fuel bills are just the cost of letting in fresh air and preventing mold and window condensation in the house. I say he’s paying high bills and freezing all winter for no good reason. Who’s right? Free beer at a Red Sox game is at stake!

Well, you’ve each got a point. Your son-in-law is right that fresh air is essential for the health of a house and its occupants. But a person doesn’t have to be uncomfortable or pay high energy bills to have fresh air. In fact, a leaky, drafty house is far from a guarantee of fresh indoor air, mold prevention, or condensation control.I’ll explain: When you allow outdoor air to enter through gaps and cracks in the house, you’re breathing air that has passed through walls, crawl spaces, the attic, and the basement. In the process, you’re bringing in particles of things like dust, dirt, and mold. And if you allow parts of a house’s interior to grow cold, you may create conditions for condensation and mold growth.

Fortunately, the way to minimize these situations is also the way to lower energy costs and increase comfort. I’m talking about a good job of air sealing and insulation, along with low-energy, quiet ENERGY STAR^® bath fans, vented to the outdoors. These fans are a key part of mold and condensation prevention, because they remove moisture. The amount of energy that an ENERGY STAR bath fan uses will cost far less than the heat bills in a poorly insulated house. Also, the amount of warm indoor air removed by a ventilation system is less than the heat lost through uncontrolled air leaks.

Financial incentives are available for homeowners who get this work done by a certified Home Performance with ENERGY STAR contractor. If your son-in-law is interested in learning more, he can visit our Home Performance section. Have fun at the game. Maybe you can each buy a round.

- Li Ling for Ask The Home Team