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Furnace Reviews

By: Kelly Burgess on September 01, 2017

Editor's Note:
Upgrading to a higher efficiency furnace can save you money over the long term. This buyer's guide offers the cutting edge information you need to make the right decision. We examine gas and oil furnaces, boilers, heat pumps and radiant floor heating.

90 percent AFUE gas furnace
Best Reviewed

High-efficiency gas furnace

Replacing your old gas furnace with a high-efficiency condensing gas furnace with an AFUE rating of 90 percent will save money, experts say. Even an upgrade from an 80 percent AFUE furnace saves $8 or so for every $100 you spend on heating. Whether this savings is enough to offset the extra up-front cost will depend on factors such as climate, utility rates, the efficiency of your old equipment and the energy efficiency of your home. However, experts say that if you live in an area with harsh winters, such as the Northeast or the Midwest, a condensing furnace most likely will pay for itself over time. See our full review »

80 percent AFUE gas furnace
Best Reviewed

Budget gas furnace

If you live in a state with milder winters, an 80 percent AFUE furnace may be all you need. The initial cost and installment cost is much less than a furnace with an AFUE of greater than 90 percent, and experts say an 80 percent AFUE gas furnace is likely to be considerably more efficient than the older unit you're replacing. However, the break-even period will depend on your gas rates and how they change over time. See our full review »

90 percent AFUE oil furnace
Best Reviewed

Oil furnace

Although gas furnaces are the most common type, many homes have oil furnaces. Oil-burning furnaces are less efficient on average than gas furnaces, but they can have AFUE ratings as high as 95 percent. As with gas furnaces, a more energy efficient oil furnace will cost more, but will use less fuel over time. In addition, it is estimated that upgrading to a more energy efficient oil furnace can cut CO2 emissions by 2.5 tons per year. See our full review »

95 percent AFUE Boiler Review
Best Reviewed

High efficiency boiler

Boilers heat water that is transferred to radiators, baseboard heaters or radiant floor systems throughout the home, thus providing heat circulation within a room. Hot water heating systems, also known as hydronic heating, are less common than forced air systems, but are the preferred form of heating system for many because this type of heat does not dry the air and circulates fewer airborne particles. Although this type of system is usually found in older homes, it's becoming increasingly popular once again in new construction. As with furnaces, replacing an old, inefficient boiler with a new, high-efficiency unit can pay off very quickly, say experts. Boilers can be fueled by oil, gas or electricity, just as with other types of heating plants. See our full review »

Heat Pump Review
Runners Up

Heating system for moderate climates

Heat pumps may initially cost more than other heating systems to install, but reviewers say you'll quickly make up the difference in energy savings. A heat pump runs on electricity and draws heat from the external air or from the ground, transferring warm air to cool air, and vice versa -- in much the same way a refrigerator stays cold. Heat pumps are best for moderate climates and might need to be used in conjunction with secondary heat sources, such as space heaters; they are not appropriate for areas with harsh winters, unless you have a very energy efficient home.

Radiant Floor Heating Review
Runners Up

Radiant floor heating

Unless you have unlimited financial resources, it isn't practical to replace your entire heating system with radiant floor heating, but installing radiant floor heating in a single, smaller room, such as a bathroom or kitchen, is becoming an increasingly popular option. Hydronic radiant heat systems bring heat up from the floor via hot water flowing through pipes; electric systems use cables built into the floor, or mats with electrically conducive plastics. Depending on your expertise, and the scope of the project, installing a radiant floor can be tackled by a handy homeowner, experts say.

Types of Furnaces

Gas Furnaces

Gas is the most common fuel for hot air furnaces in the U.S. because natural gas is plentiful and relatively affordable compared to other fuel sources. Federal regulations require a minimum AFUE (annual fuel utilization efficiency; see below for more information) of 90 percent for furnace upgrades and new installations in 30 northern states in the U.S.; at least 80 percent elsewhere.

Oil Furnaces

Although oil is less commonly used in the U.S., it's a necessity in places where natural gas is not an option -- and a preferred fuel for those who prefer to live more "off the grid." Upgrading to an oil furnace with an AFUE of at least 90 percent can cut CO2 emissions by 2.5 tons per year, as well as saving on energy costs.

Boilers

Instead of heating air which is then distributed through the house via a duct system, boilers, also known as hydronic heating, heat water that is then transferred to radiators, baseboard heaters or radiant floor systems throughout the home. Boilers can powered by gas, oil, or electricity.

Heat Pumps

Although they're only appropriate for milder climates, heat pumps are a highly affordable, efficient method of heating. Heat pumps are powered by electricity and work by constantly transporting warm air from one place to another.

Radiant Floor Heating

With radiant floor heating systems, warm air rises from the floor, rather than circulating around the room. They're best for specific rooms or areas -- such as a chilly, tiled bathroom floor. In many cases, installing radiant floor heating is a job that a handy do-it-yourselfer can tackle.

Improving your furnace can save you money

Most people are locked in to their furnace type -- you buy a home, it has a gas, oil, or electric-powered furnace, so that's what you live with. Replacing a furnace is never an inexpensive proposition, and completely retrofitting a system -- for example, replacing forced air with hydronic (hot water) heat can be prohibitively expensive.

The good news is that replacing an older furnace with a newer, more efficient furnace can result in significant cost savings -- as well as being a positive step for the environment. The federal government is keenly interested in the effect on the environment of home heating systems and, as a result, as of May 1, 2013, federal regulations for non-weatherized furnaces of all types went into effect that require a minimum annual fuel utilization efficiency (AFUE) rating of 80 percent for gas furnaces, 83 percent for oil furnaces. On Jan. 1, 2015, additional regulations went into effect for weatherized furnaces requiring a minimum AFUE of 81 percent for gas, and 78 percent for oil. However, in 30 northern states, the standards for gas furnaces are more stringent -- requiring a minimum AFUE of 90 percent. Weatherized furnaces are generally installed outdoors and non-weatherized furnaces are installed indoors.

Replacing an ailing or old furnace might also get you a local tax credit or a rebate from your utility company. For a complete, state-by-state list of credits and rebates, visit the Database of State Incentives for Renewables & Efficiency (DSIRE) website.

Also, keep in mind that, if you're using only one room of your house, or if one room that you use a lot is particularly chilly, you might be able to warm up your space without cranking up the heat. Space heaters or electric blankets, which we cover in their own reports, may help with that.

How to choose a furnace

Unless you are a near professional-level do-it-yourselfer, experts say you must work with a reliable contractor and let that person's expertise guide you in choosing a furnace. A skilled heating, ventilation and air conditioning (HVAC) contractor will evaluate your home's energy needs and help you choose a furnace that is the right size and efficiency for you, based on a number of factors.

With few exceptions, furnaces and installation are sold as package deals along with the installation. Any contractor you work with should offer you a choice of furnace models with different efficiency ratings and should provide an estimate of annual operating costs for each one. Most contractors specialize in working with certain brands of furnaces, and some work with only one particular brand. This can be an advantage, because it means the contractor has most likely received specialized training from that manufacturer. However, it also means that your furnace choices will be limited to that one brand. If you get an estimate from a contractor who deals only in one brand, get estimates from other contractors as well, making sure the furnaces they recommend are equivalent in size and efficiency.

Another tip from experts is to steer clear of companies that offer to give you an estimate over the phone. A reliable estimate must be based on a thorough survey of your home. The contractor should consider such factors as the size of the house, insulation levels, number and type of windows and the climate in your area. He or she should inspect your ductwork (if any) for air leaks and insulation level and measure airflow levels. The contractor should also ask you about any problems you have had with your existing heating system. Based on all this information, the contractor can perform a heat-load calculation to determine the proper size of your new furnace.

A contractor should never base this decision on the size of your existing furnace. Many homes have furnaces that are too large, partly because sizing methods have improved and partly because buildings have become more energy efficient. A furnace that is too large will not only cost more to install and operate, but it may not heat your home as evenly as one that is properly sized. A good contractor should evaluate your entire heating system and make appropriate suggestions for improving the overall energy efficiency of your home. This may allow you to purchase a smaller furnace and save money.

Contact several contractors and get an estimate in writing from each one. Most sources recommend getting at least three estimates. If you already know a reputable HVAC contractor, start your search with that person. Focus on local companies, and look for contractors who are licensed and insured.

The written estimate you get from each contractor should spell out all the details about the installation. It should describe the equipment to be installed, the work to be done, the costs for materials and labor and the payment schedule. It should also describe the equipment and installation warranties and provide a firm date for completion of the project. Make sure bids include all costs associated with the project, including permit fees (if required). Compare all your estimates and make sure that they cover the same work and the same type of equipment.

It may be tempting to go with the contractor who offers you the lowest estimate, but experts warn that price is not the most important consideration. For example, very low bids may not include routine services and customary warranties. If one contractor's bid is dramatically different from the others, don't hesitate to ask why. It's possible that this contractor has noticed something that others missed -- or vice versa.

How we evaluated furnaces

No publications or web sites conduct comparative reviews of furnaces or comprehensively rate individual models, and it's easy to understand why. A tester would have to install furnaces in identical homes to compare them. How well a furnace functions depends on the installation of the whole system, including ductwork and venting. Factors such as climate, home size, insulation, window condition and usage will also affect performance. Even evaluating the long-term reliability of a particular model is problematic because furnaces are made to last 15 to 20 years, and technology can change a lot over such a long period.

However, there are a number of helpful sources in detailing the types of furnaces available, new furnace technology, and how to choose the right furnace for you home, as well as discussions of whether or not a new furnace will be cost-effective. The U.S. Department of Energy and the American Council for an Energy-Efficient Economy (ACEEE), which maintains the website SmarterHouse.org, have a number of helpful resources. ConsumerReports.org offers a free furnace buying guide, although it covers only gas furnaces. In addition, we found sites directed at do-it-yourselfers and home improvement topics, such as BobVila.com and ThisOldHouse.com to be very helpful.

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