Heating with gas
A guide to choosing furnace size, efficiency, and features.

Replacing or improving a furnace may not pay off as handsomely as it did during the energy crisis of the late 1970s. But it may deliver steady, modest savings. And efficient heating isn't only about money. Because today's furnaces burn less fuel to generate heat, they are less polluting than their predecessors. Some models also produce heat more continuously than older furnaces, increasing comfort.

Heat pumps that wring heat from the ground or from outdoor air (and reverse the process in summer, to act as an air conditioner) are the preferred way to heat in the South and Southwest, and oil furnaces have a niche in older homes, mostly in the Northeast. But the majority of new central-heating systems use a gas furnace, the focus of this report.

THE BASIC CHOICES

How do most people go about buying a furnace? First, they contact contractors. To prepare this report, we did, too. More than 500 specialists in residential heating and air conditioning told us about their experiences in installing and maintaining heating equipment.

The two major manufacturers of gas furnaces are United Technology (Carrier, Bryant, Heil, Tempstar, and Comfortmaker brands) and Goodman (Janitrol and Amana). Other brands include Rheem (Ruud), American Standard (Trane), and Lennox (Armstrong). All offer furnaces in a range of capacities and efficiencies, and we think manufacturers generally deliver on those specifications. Each brand offers a generally similar array of key features.