Furnace Replacement: A Buyer’s Guide
Key takeaways:
• AFUE ratings and the number of heating stages are important factors.
• More efficient systems will cost more upfront but can help reduce energy consumption in the long term.
• Hiring the right HVAC contractor is your key to comfort.
By Anne Fonda
Is your furnace failing to keep your house warm? Are your gas bills skyrocketing? Are you tired of paying more expensive furnace repair bills more frequently? Did your furnace stop working at all?
You’re smart to be doing some research about furnace replacement. Whether you need a furnace installed this week or you’re planning ahead, informed decisions are the best ones. A new furnace will last 15-20 years or so, so you want to make the right choice. We’ve pulled together some tips to help you choose the right gas furnace for your home.
Tip #1: Choose an energy-efficient furnace
Furnace efficiency is measured by its Annual Fuel Utilization Efficiency (AFUE).The higher the AFUE rating, the more efficient the furnace is at turning fuel into heat. If you want more of your hard-earned money to go towards heating your home rather than going up the chimney as flue gas, go for a furnace with a higher efficiency rating.
The table below shows what we’re talking about.
| AFUE Rating | Percent of Fuel Used in Heating | Percent of Fuel That Vents as Flue Gas |
| 80 AFUE | 80% or 80 cents for each dollar | 20% or 20 cents for each dollar spent |
| 92 AFUE | 92% or 92 cents for each dollar | 8% or 8 cents for each dollar spent |
| 96 AFUE | 96% or 96 cents for each dollar | 4% or 4 cents for each dollar spent |
| Up to 97.3 AFUE | 97.3% or 97.3 cents for each dollar | 2.7% or 2.7 cents for each dollar spent |
Heating
as Flue Gas
If your furnace runs hard for several months every year, the difference in operating costs can really add up. If you have milder winters and fuel efficiency isn’t a priority, and you want a lower upfront purchase price, an 80 AFUE furnace might be right for you.
“A high-efficiency furnace makes sense in regions with colder climates and higher utility costs. These furnaces use less gas to produce the same amount of heat, which translates to lower energy bills for homeowners.”
- Amy Gulas, Senior Product Manager
Tip #2: Choose between a non-condensing and a condensing furnace
A non-condensing furnace typically has an AFUE of 80 and one heat exchanger. A condensing furnace typically has an AFUE of 90 or higher and has a secondary heat exchanger, which means the furnace turns more natural gas into heat.
Recently, the Department of Energy (DOE) mandated that residential gas furnaces manufactured after December 18 , 2028, must meet a minimum efficiency standard of 95% annual fuel utilization efficiency (AFUE). This rule, recently upheld by a federal court, phases out non-condensing furnaces, many of which have an AFUE of 80%.
What this means for homeowners
If you currently have an 80 AFUE furnace, you will still be able to replace it with another furnace of the same kind, as there is no regulatory change affecting the sale of previously manufactured furnaces.
You could also choose a higher efficiency condensing furnace, available today. Just be aware that the condensing furnaces cost more, and installation costs will be higher, due to the high-efficiency furnace system requirements, including:
- Installing a furnace condensate drain line
- Drilling two holes in an exterior wall or roof, the size of the PVC pipe
- Installing PVC intake and exhaust pipes that vent to the outdoors above the snow line
Condensing furnaces have been around a while. If you’re replacing a condensing furnace, it may not require the additional work on the drain line or intake and exhaust lines.
Tip #3: Consider the number of heating stages
Furnaces are available in single-stage, two-stage, and modulating. The number of heating stages a furnace has will affect your comfort and the price of the unit as well. The more stages, the more it will cost.
A single-stage furnace is like a light switch - it’s either on or off. This means it’s either blowing hot air full blast or it’s off. This may lead to uneven heating and reduced comfort. A two-stage furnace is like a dimmer switch with two settings (high and low) while a modulating furnace is like a full dimmer switch with multiple heating stages to offer precise comfort.
Similarly, a furnace with a variable-speed blower motor will cost more than other models. If you have (or plan to get) a variable-speed air conditioner or heat pump, you’ll want a furnace with a variable-speed blower for compatibility and to get the full benefits of a variable-speed system.
Tip #4: Consider replacing the outdoor unit at the same time
If your AC unit or heat pump is older, consider replacing the entire HVAC system at the same time to help maximize efficiency. It’s also cheaper to replace both the indoor unit and the outdoor unit at the same time rather than a year or two apart, because of reduced labor and price increases on the HVAC units.
“My advice to anyone who may have an aging heating and cooling system that requires frequent repairs is to consider replacing the whole system versus just one component. Typically, with an older system, the technology has become obsolete, and new parts are not completely compatible with older systems.”
-Kimberly Sexton, Senior Systems Engineer, Trane Technologies
Consider replacing an AC unit with an electric heat pump. Paired with a gas furnace, this system is called a dual-fuel heat pump system, or hybrid heating system. Depending on the efficiency and type of heat pump (cold climate heat pump or not), the heat pump covers the heating duties until the temperature is around freezing, or into the single digits or lower for a cold climate heat pump.
When temperatures drop far enough that the heat pump can’t heat efficiently, the gas furnace takes over. Once outdoor temperatures rise again, the heat pump resumes heating your home. And in the warmer months, the heat pump cools your home just like a central air conditioner would.
Tip #5: Choose a reliable brand with a good warranty
You’ve heard the phrase “You get what you pay for.” Just like you might be willing to pay more for a personal vehicle that has the fuel efficiency, trim, and features you want, you can expect to pay more for a premium, reliable HVAC brand.
American Standard furnaces might not be the cheapest out there, but they are built to last and have an outstanding warranty to back that up. Invest in a quality furnace to provide cozy comfort for years to come.
Tip #6: Choose the right HVAC company
A new furnace or HVAC system is only as good as the HVAC company that installs it. Make sure the installer you choose performs a load calculation to ensure proper sizing of your heating and air conditioning system. Make sure they’re licensed and insured, and trained by the manufacturer to install the systems they sell.
Learn more about how to find the best HVAC service near you.
Get a free estimate for furnace replacement
Contact your local American Standard dealer to set up an in-home consultation. They can give you estimates for several tiers of furnaces and help you determine which one is right for your home.
Be sure to ask about HVAC financing, which can help you afford the cost of a new furnace or HVAC system by making monthly payments.
Anne Fonda, Content Writer
A Content Writer with Trane Technologies, Anne Fonda researches topics and writes for Trane® and associated residential HVAC brands. She works in collaboration with Trane Technologies subject matter experts, offering easy-to-understand, informative content on complex topics. Her goal is to help consumers make informed decisions on the products and services they need.
She has written for HVAC and other service provider websites for over 16 years. Before transitioning to web content writing, Anne had a 14-year stint as an award-winning journalist. She graduated cum laude from the University of Missouri-Columbia School of Journalism.
When she’s not working, Anne enjoys playing word games, reading, gardening, spending time with family, and visiting gardens and museums.
Expert review by Amy Gulas, Senior Product Manager, Furnaces
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