My gas lawn mower is finally broken beyond repair, so I've been borrowing a friend's battery powered mower. I'm thinking of getting one in the spring if it doesn't mean paying a lot in electric bills for recharging. My friend doesn't keep track of his bills, so I'm hoping you can tell me how much it'll cost to keep this kind of mower charged.

Sure thing. Charging these mowers doesn't cost much. Your exact cost will depend on the model you use, your electricity rate on your utility bills, and how often you need to charge the mower. But I can give you an estimate for one charge for a specific mower, using Vermont's current average residential electricity rate of 14 cents per kilowatt hour.

Let's say you get a mower that runs for 45-60 minutes on a 36- volt battery. A full recharge of that battery will cost about seven cents in electricity. Multiply that amount by the number of times you expect you'll recharge, and you've got a season's worth of estimated charging costs.

As you can see, you aren't likely to see a big difference in your electricity bills. But you will definitely notice the difference in air quality. Some estimates put the contribution of gas mowers to nationwide air pollution as high as five percent. This is due to poor combustion of gas and oil and to spills during refueling. Thanks for asking about a topic that lots of people are thinking about these days.

- Li Ling for The Home Team

In your column, you recommended ENERGY STAR® bath fans for saving energy. Isn't the best way to save energy to just open the bathroom window?

In ideal conditions, sure. Unfortunately, those conditions aren't available every day or in every home. Some bathroom windows are positioned on a side of the house or in relation to other windows in a way that doesn't provide sufficient air exchange. Sometimes, the humidity outside isn't lower than inside, or the outside air is still. And on most winter days, you could pay more to heat the air coming from an open window than it would cost to use a bath fan.

My advice is to take as much control over indoor air as possible to prevent problems that excess moisture can cause. Those problems can include unhealthy indoor air from mold and mildew, costly wood rot, and more cosmetic problems like damage to paint. ENERGY STAR qualified baths fan are energy-efficient, run quietly, and give you the ability to effectively control the airflow in your home. If you decided to install one of these fans, you can ask the folks at your local hardware store if they stock them or if they'd order one for you.

- Kathleen for The Home Team