Q. I read in your column that an inefficient furnace fan could raise electric bills. Is it worth it to upgrade the fan in my 20-year-old gas furnace?
A. Im sorry to say that you wont be able to find a higher-efficiency furnace fan motor that can easily be installed in your furnace. These motors can only be found in certain new gas furnaces. Technically, its possible to custom-retrofit an older furnace to make it compatible with a new, efficient fan motor, but the cost of this effort would likely be more than its worth.
All this may be beside the point, however, because a 20-year-old furnace could be reaching the end of its useful life. I recommend asking the person who does the regular maintenance for your furnace to assess its condition. If its time to replace, look for a high-efficiency condensing gas furnace with a BPM (brushless permanent magnet) fan motor or with an ECM motor if its from General Electric. This type of furnace could save you anywhere from $20 to $50 per year in electricity, plus a fair amount of gas.
Q. I just bought a 1,000 square-foot condo with electric heat. If I switch to a gas boiler and baseboard heat, how long would it take for the system to pay for itself in energy savings? Im just looking for a ballpark figure. Two years? 30 years? The condo is on one level, with no basement or attic.
A. Youre wise to consider this switch. The most expensive way to heat a home in Vermont is with electricity. Your savings will largely depend on how much you pay for gas. If you use natural gas, the payback may be in the 8-14 year range. If you will use propane, which is more expensive than natural gas, your payback time may be 14-24 years. These estimates factor in the higher cost of installing a system through finished space in a home without a basement.