Q I am going to buy a propane-powered emergency generator. Can I vent it through my furnace chimney, which is also used to vent a natural gas water heater? There is an outside air intake about 8 feet from the proposed generator site, and a CO detector about the same distance.

A No. Equipment such as your generator MUST be installed and used as directed in the manufacturer's instructions. Any departure from the guidelines puts you at great risk for serious injury or death.

There are many reasons why venting through your furnace chimney is a bad idea, from the mundane, such as compromising the engine's cooling ability by having it in a confined space, to the extremely serious, such as the incompatibility of the engine's pressurized exhaust with the vent serving the water heater.

The U.S. Consumer Product Safety Commission, Underwriters Laboratory and manufacturers have worked to provide clear directions for the installation and use of a portable generator. It is vital that you carefully follow them.

Phil Smith, state energy specialist, Minnesota Department of Commerce

Another explanation Several readers responded to the April 7 column in which a reader questioned a shopper's use of a food-stamp card to buy high-energy drinks and over-the-counter medications. Here is one of the responses:

The person who asked about restrictions on food-stamp money should also realize that some people get "cash" benefits from the government. That money can be used on anything but alcohol and tobacco purchases. The food-stamp money and the "cash" money use the same card. The young man [buying the goods] could have been using the "cash" part of the card, not the food stamp. A person standing behind him would have no way of knowing. Before assuming that the young man was using food-stamp money in a way he wasn't supposed to, maybe the author of the letter should realize that the man could possibly have a sick wife at home, and didn't know what kind of cold medicine to buy. As for the high-energy malt drinks, maybe he's in school, or has a new baby at home, and wanted to be alert and awake.

Send your questions to Fixit in care of the Star Tribune, 425 Portland Av. S., Minneapolis, MN 55488, or call 612-673-9033, or e-mail fixit@startribune.com. Sorry, Fixit cannot supply individual replies.