American Standard’s Best Furnaces
We’ve identified the top 3 natural gas furnaces based on heating stages, efficiency, and value. As you’ll see, the categories intersect.
By Anne Fonda
Are you tired of shelling out money for furnace repairs? Is your furnace failing to keep your home comfortable? If you’re thinking furnace replacement is in your future, you’re smart to be researching the best furnaces. We can’t speak for the other guys, but we can tell you about our furnaces and why we routinely rank among the best furnace brands.
In this article, you’ll learn about:
Factors to consider when choosing a new furnace
There are four main factors to consider when it’s time to choose a new furnace - size, efficiency, number of heating stages, and cost.
Sizing
Size matters when it comes to gas furnace replacement and your HVAC system as a whole. A furnace that is too small can struggle to heat your home evenly. A furnace that is too big will waste energy and may wear out faster.
Your home’s size in square feet and the climate where you live are the two biggest factors in determining what size furnace you need. How well your home is insulated can also be a factor, as can the number of windows and exterior doors.
Furnace capacity is measured in British Thermal Units (BTUs). One BTU equals the amount of energy needed to increase the temperature of one pound of water by one degree Fahrenheit. In the U.S., the average home will require between 30 to 60 BTUs per square foot, depending on the climate zone heating factor for where you live.
The best way to ensure you get the right size furnace is to work with licensed and experienced HVAC professionals.
Efficiency
Annual Fuel Utilization Efficiency (AFUE) is a furnace efficiency rating that measures how efficiently a gas furnace turns fuel into heat. An AFUE rating of 90 means that the furnace utilizes approximately 90% of the fuel to provide warmth to your home, while the remaining 10% escapes as exhaust.
The higher the AFUE rating, the more efficient the unit is. To qualify for federal energy tax credits and local rebates, a gas furnace must meet certain efficiency requirements, as shown in the table below.
| Equipment | Required AFUE Rating |
| ENERGY STAR® Certified | Rating of 90% AFUE or greater for U.S. South gas furnaces Rating of 95% AFUE or greater for U.S. North gas furnaces |
| CEE Tier 3 for 25C Tax Credit | Rating of 97% or higher |
Source: ENERGY STAR®
Condensing gas furnace meaning
A condensing gas furnace adds to the efficiency. A condensing furnace is a high-efficiency unit that has two heat exchangers. If you have a condensing gas furnace, or a higher efficiency furnace (90%+ AFUE), you will have both a primary and a secondary heat exchanger.
When a furnace burns natural gas, fuel oil, or propane fuel, its exhaust/combustion by-products enter and travel through the primary heat exchanger. The hot flue gas heats the metal as the gas makes its way to the exhaust outlet of the furnace. As this occurs, the hot metal heats the air circulating over the exterior of the heat exchanger.
If you have a secondary heat exchanger, the combustion exhaust that leaves the primary heat exchanger will enter into the secondary unit. The secondary heat exchanger releases additional heat from the flue gas, causing water vapor to form. This change of state from water as a vapor to a liquid releases latent heat in the secondary heat exchanger, bringing the furnace to an even higher level of efficiency.
Number of heating stages
Gas furnaces have 1,2, or multiple heating stages. Let’s see what each system entails.
Single-stage
A single-stage furnace has just one heating stage. That means the unit is either on and running at 100%, or it’s off. It runs until it reaches the set temperature on your thermostat, and then shuts off. It turns on again when the temperature falls a few degrees. A single-stage furnace is less efficient than some other furnaces but is also the most affordable option of the 3.
Two-stage
As the name implies, a two-state furnace has two heating stages. This gives it an advantage in the single-stage vs two-stage furnace debate. The furnace burner can run at two different stages. For example, 60% and 100%.
The furnace would be in the first, or lower stage during most of the fall season, while it would spend more time running at 100% during frigid temperatures during a polar vortex. The capability to heat in two different stages can make a two-stage furnace more efficient at heating and maintaining a comfort level than a single-stage unit. A two-stage furnace will cost more than a comparable single-stage unit, but less than a modulating furnace.
Modulating
A modulating furnace has multiple heating stages, ranging from about 40%-100% capacity. With a modulating furnace gas valve, they can increase capacity (fuel burned) by as little as .5% at a time, as the thermostat dictates. Because a modulating furnace can manage temperature so precisely, they usually run continuously at a very low setting.
This makes them very efficient. A modulating furnace also costs more upfront than the other two. However, they may help pay for the cost difference with reduced fuel consumption leading to reduced heating expenses.
Cost
How much does a new furnace cost? The cost of furnace replacement will depend on several factors, including the heating capacity (size of the unit), number of heating stages, efficiency ratings, and more. The best way to get figures for your furnace replacement cost is to get quotes from several HVAC companies near you.
You can help offset your furnace installation cost by choosing an energy-efficient unit that qualifies for energy tax credits, rebates, and other savings offers. HVAC financing can help you spread out payments over several years.
Most efficient: Platinum 95 Gas Furnace (modulating)
The Platinum 95 Gas Furnace is our most efficient unit. It has a lot going for it, including:
- AFUE up to 97.3%
- Modulating gas valve for numerous heat stages
- Compatible with two-stage outdoor units
- Communicates with other HVAC system components via the AccuLink™ Communicating System
- Variable-speed fan motor for evenly distributed air
- Comfort-R™ technology for humidity control in the summer
- Variable speed draft inducer to enhance comfort and efficiency
- Cleanable filter
- Insulated blower compartment
- Self-diagnosing integrated furnace control
- Silicon nitride hot surface igniter
- Durable insulated heat exchanger cabinet
- Stainless steel secondary heat exchanger
- Lifetime limited warranty on heat exchangers
- 10-year limited warranty on functional parts
This unit meets the ENERGY STAR® efficiency and CEE Tier 3 requirements to be eligible for federal tax credits as well as state and local rebates.
Best middle option: Gold S9V2-VS Gas Furnace (two-stage)
The Gold S9V2-VS Gas Furnace is a mid-range choice between our most efficient furnace and our best-value furnace. Features include:
- AFUE 97%
- Two-stage heating
- Compatible with two-stage outdoor units
- Variable-speed fan motor for evenly distributed air
- Comfort-R™ technology for humidity control in the summer
- Variable speed draft inducer to enhance comfort and efficiency
- Insulated blower compartment
- Self-diagnosing integrated furnace control
- Silicon nitride hot surface igniter
- Durable insulated heat exchanger cabinet
- Stainless steel secondary heat exchanger
- Lifetime limited warranty on heat exchangers
- 10-year limited warranty on functional parts
This unit meets the ENERGY STAR® efficiency and CEE Tier 3 requirements to be eligible for federal tax credits as well as state and local rebates
Best value: Silver S9X1 Gas Furnace (single-stage)
The Silver S9X1 Gas Furnace single heating stage furnace earns the title of our best-value furnace. It combines energy efficiency with an affordable price point. Features include:
- AFUE up to 96%
- Single-stage heating
- Compatible with two-stage outdoor units
- Insulated blower compartment
- Self-diagnosing integrated furnace control
- Silicon nitride hot surface igniter
- Durable insulated heat exchanger cabinet
- Stainless steel secondary heat exchanger
- Lifetime limited warranty on heat exchangers
- 10-year limited warranty on functional parts
This unit meets the ENERGY STAR® efficiency requirements to be eligible for state and local rebates.
Why choose an American Standard® furnace
American Standard® is routinely ranked among the best furnace brands and best HVAC brands overall. Architectural Digest also recently ranked our furnaces as best for extreme climates. We also routinely rank highly among America’s Most Trusted® HVAC Brands.
For over 100 years, we’ve designed and manufactured some of the most awarded, well-engineered heating and cooling equipment and earned a reputation for doing things right.
Set up a free quote for furnace replacement
Contact your local American Standard dealer to set up a free onsite quote for furnace replacement. Consider replacing your older AC unit at the same time or upgrading to a heat pump for a dual-fuel system. Your dealer will help you find the best American Standard furnace for your needs and budget.
Browse our furnaces.
Anne Fonda, Content Writer at Trane Technologies
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 John Kim, Senior Product Manager, Furnaces
Related articles
