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No matter where you live in the country, efficient heating will do more than just save on fuel bills. Properly installed, a new system can distribute heat more evenly and continuously than an old one, making your home a cozier place.

But what type of central-heating system will best suit your needs? There are a few from which to choose.

Gas furnace. Most new systems across the country use a gas furnace, which heats air and uses a blower to circulate it through ductwork. How efficiently a furnace converts gas into heat is reflected in its annual fuel-utilization efficiency (AFUE) rating, which is measured as a percentage. The higher the percentage, the more heat the furnace can extract from each therm (100,000 Btu) of gas. Gas furnaces have generally become more efficient. A unit made in the early 1970s typically has an AFUE of about 65 percent. Today, the lowest efficiency allowed by federal law for new gas furnaces is 78 percent. The most efficient models have an AFUE as high as 97 percent.

Heat pumps. Heat pumps are the preferred way to heat in the South and Southwest, where winters are mild and electricity is relatively cheap. These units, predominantly electric appliances, wring heat from the ground or outdoor air and pump it into your home using a blower. When it gets hot outside, they run in reverse and act as an air conditioner, drawing heat from indoor air and pumping it outdoors. When the temperature drops, heat pumps can't produce as much heat and must be supplemented, often with built-in electric elements that kick in automatically and provide expensive, less-efficient heating. Size (or capacity) is measured in British thermal units per hour (Btu/hr.), and efficiency is reflected in the unit's heating seasonal performance factor, or HSPF. The ratings for new heat pumps range from 6.8, the minimum allowed, to about 10.

Oil furnaces and boilers. These oil-fired counterparts to gas furnaces draw oil from a tank located in the basement, garage or - less desirably, since it may leak - underground. Only homeowners who already own an oil unit and who live in a region where oil is widely distributed are likely to consider this option.

In-floor radiant heating systems. These turn a home's floors into radiators. Heated water from a boiler is routed through special plastic tubing installed on the subfloor and covered with concrete, gypsum-based concrete or built-up finished flooring.

Alternately, an electric heating grid can be used in lieu of the water piping, but these systems are less efficient than a heat pump, and electricity is more than three times as expensive as other heating fuels.

While radiant heating systems are relatively slow to warm up and cool down, they provide even heat with no drafts or noise. And they're an effective way to warm large areas - especially those with high ceilings.

If you're installing a new system, seek referrals and get price quotes from at least three contractors. They should show you proof of bonding and insurance, plus any required contractor's licenses.

It's a plus if they're certified by North American Technician Excellence (NATE), a trade organization, and have several years' experience. But don't be so quick to extinguish your old furnace. Despite the improved efficiency and comfort of most new units, it is generally more cost-effective to repair a furnace than it is to replace it. An exception is when a key component such as the heat exchanger - the element that draws heat from the burned fuel - or control module fails. Then you're probably better off replacing, especially if the furnace is more than about 15 years old.

By the editors of Consumer Reports at