Upgrade To A High Efficiency Gas Furnace
A high efficiency furnace is a heating system designed to convert 90% or more of its fuel into heat for your home, with Carrier models such as the 59MN7 reaching up to 98.5% AFUE. By wasting significantly less energy than older, standard models, a high efficiency gas furnace can help lower heating bills, reduce environmental impact, and provides more consistent indoor comfort.
According to the Department of Energy, heating your home typically represents about 44% of the average family's utility bills. [1] That’s a significant investment. When it comes to furnaces, “efficiency” refers to how effectively they can convert heating energy from a fuel source into warm, comfortable heat for your home. Carrier high efficiency gas furnaces can provide up to 98.5% AFUE efficiency.
What is a High Efficiency Gas Furnace?
According to Carrier, a high efficiency gas furnace is a furnace with an AFUE rating of 90% or higher. Carrier's highest-efficiency gas furnace reaches up to 98.5% AFUE.
AFUE stands for Annual Fuel Utilization Efficiency. It measures how much heat the furnace captures from the fuel it consumes. For example, a 95% AFUE furnace converts 95% of the fuel into heat and only wastes 5%. This rating is determined by measuring the heat in British Thermal Units (BTU) compared to the fuel used.
The Department of Energy requires all manufacturers to display a furnace’s efficiency on a yellow Energy Guide sticker. Efficiency standards evolve, so investing in high efficiency furnaces now prepares your home for future standards.
Why Choose a High Efficiency Gas Furnace?
Kevin Dickson, president of Energy Services Air Conditioning, Heating and Electrical in Naperville, Illinois, explains the major selling points for homeowners:
The top reason that a homeowner should consider a high-efficiency furnace is the potential for energy savings, which means lower heating bills.. High-efficiency furnaces also provide additional safety due to the sealed combustion that brings in outdoor air. They also often qualify for rebates with local utility companies.
Benefits of Upgrading To A High-Efficiency Furnace
- Cost Savings: Because these models excel at converting fuel into heat, you need less fuel to maintain comfort.
- Environmental Impact: Higher efficiency results in fewer emissions.
- Enhanced Comfort: Many Carrier high efficiency furnaces include technology that produces quieter operation and more consistent temperatures.
- Safety: Sealed combustion systems use outdoor air for combustion, which can improve safety and efficiency.
Is a High Efficiency Furnace Worth the Investment?
Opting for high-efficiency gas furnace installation furnace often makes financial sense.
Older heating systems may operate at 56–70% AFUE efficiency, which falls far below today’s standards. In contrast, modern high efficiency models operate in the 90–98.5% AFUE range. Since heating is likely the largest expense on your utility bill, this upgrade can offer a path to savings. High-efficiency furnaces may qualify for local utility rebates in your market as well.
Long-Term Value vs. Upfront Cost
While high efficiency furnaces often come with higher price tags, the initial difference may be offset over time by reduced heating energy use, depending on fuel prices, climate, home efficiency, and equipment usage. A new system also offers new equipment features and warranty coverage compared with an aging system.
As you consider your options, look into the cost of a new furnace, have a reputable HVAC contractor estimate energy costs, and factor in potential furnace repairs for your current system.
Note: This article compares select fuel sources. Other systems, like air-source heat pumps and geothermal heat pumps, operate differently. Learn more about a heat pump vs. furnace.
High Efficiency Gas Furnace Comparison
Carrier offers high-efficiency gas furnaces across its Infinity®, Performance™, and Comfort™ series. The following comparison highlights three current Carrier models:
| Carrier furnace | AFUE | Heating technology | Blower |
|---|---|---|---|
| Infinity® 98 Gas Furnace (59MN7) | Up to 98.5% | Modulating; 1% adjustments from 40–100% capacity | Variable-speed |
| Performance™ 97 Gas Furnace (59TP7) | Up to 97% | Two-stage | Variable 25-speed |
| Comfort™ 96 Gas Furnace (59SC6) | Up to 97% | Single-stage | Multi 18-speed |
*Warranty terms vary by equipment, registration, jurisdiction, and program eligibility. See Carrier's current warranty documentation for complete terms.
Carrier's Infinity® 98 Gas Furnace uses a modulating gas valve that can make 1% adjustments between 40% and 100% capacity. This allows the furnace to adjust its heating output more precisely to changing demand.
High Efficiency Oil Furnaces vs. Gas
High efficiency oil furnaces can cost less to operate per BTU generated than other types, but they typically max out at an AFUE rating of about 86.6%.
Compared to the 90–98.5% ratings of natural gas furnaces or the 100% AFUE rating of electric resistance furnaces, oil is less efficient. However, in regions without access to natural gas pipelines, the highest efficiency oil furnace remains a viable option for home heating.
Comparing Energy Efficient Heating Types
Forced air furnaces generally work on the same principle: heat is extracted in a heat exchanger and circulated through ductwork. However, the fuel source dictates the efficiency and cost.
Natural Gas Furnace
Natural gas is the most common heating source in the U.S. [2]. It is widely available and generally the least expensive per BTU. Consequently, a high efficiency gas furnace (90–98.5% AFUE) can use less fuel to produce a given amount of heat than a lower-efficiency furnace. Browse the best Carrier furnaces to see options for every budget.
Electricity
Electric furnaces are technically 100% efficient at converting energy to heat. However, electricity is often more expensive than natural gas or propane, leading to higher operating costs in many regions.
Fuel Oil
Common in the Northeast U.S., fuel oil requires a storage tank and delivery. While less efficient than gas (topping out around 86.6% AFUE), newer models can sometimes use cleaner-burning biodiesel mixtures.
Propane Furnaces
Propane is a clean-burning alternative to oil. While Carrier does not manufacture dedicated propane furnaces, select Carrier furnaces can be converted for use with propane using an approved conversion kit and professional installation.
What Features Define High Efficiency Furnaces?
An energy efficient furnace squeezes extra heat from fuel using advanced technology not found on standard models.
- Secondary Heat Exchangers: To achieve 90% AFUE, a furnace typically uses two heat exchangers. The primary captures the first portion of heat, while the secondary heat exchanger captures additional heat from combustion gases.
- Greenspeed® Intelligence: Found in our Infinity® 98 Gas Furnace, this integrates a modulating gas valve and variable-speed blower motor. The modulating gas valve can adjust heating output in 1% increments from 40–100% capacity to match changing heating demand.
- ComfortFan™ Technology: Allows you to control fan speeds for optimized air circulation.
- Sealed Combustion: Pulls air from outside for combustion, helping improve safety and efficiency.
Ready to improve your home's comfort? Connect with a local Carrier furnace expert to schedule professional furnace installation.
When Does a High Efficiency Gas Furnace Make Sense?
- Climate: A high efficiency furnace may provide greater energy savings in climates where the furnace operates frequently throughout the heating season. Actual savings depend on climate, fuel prices, home efficiency, equipment sizing, and how much the furnace operates.
- Home Size and Furnace Sizing: A high efficiency furnace should be properly sized for the home's heating load rather than selected based solely on square footage. An HVAC professional can perform a load calculation and recommend the appropriate capacity.
- Venting and Condensate: High-efficiency gas furnaces are typically condensing furnaces. They use a secondary heat exchanger to extract additional heat, which causes water vapor in the exhaust to condense. As a result, these systems typically require appropriate venting and a condensate drain.
- Installation: Proper installation is essential to achieving the furnace's rated performance. A qualified HVAC professional can evaluate sizing, venting, drainage, ductwork, combustion requirements, and local code requirements.
Ready to improve your home's comfort? Connect with a local Carrier furnace expert to schedule professional furnace installation.
Frequently Asked Questions
Standard-efficiency furnaces typically have an AFUE of 80%, meaning 20% of the fuel energy is wasted. A high efficiency furnace has an AFUE of 90–98.5%, utilizing secondary heat exchangers to capture more heat and waste significantly less fuel.
The installed cost generally ranges from $3,800 to $12,000. High efficiency furnaces sit at the higher end of this scale due to advanced technology, but they offer greater long-term savings on operating costs.
According to the Department of Energy, upgrading from 80% to 95% efficiency can save around $73 annually, though this varies by climate and usage. [3] Payback is calculated by subtracting rebates from the installed cost, then dividing by annual energy savings.
Yes, investing in a high efficiency gas furnace can be worth it for many homeowners planning to stay in their homes for several years. The reduced monthly energy bills, improved comfort, and potential for rebates help offset the initial investment, particularly in colder climates where the furnace runs frequently.
Gas furnaces require access to a natural gas line, which isn't available in all areas. They also require professional installation and strict adherence to safety protocols regarding ventilation and carbon monoxide. However, for most homes with gas access, they remain the most cost-effective heating solution.
About The Expert Reviewer: Seth Faber is a Product Manager for Residential Furnaces at Carrier Corporation, where he helps develop dependable, high-performance heating solutions that deliver reliable comfort while meeting evolving homeowner needs, energy efficiency standards, and industry regulations.
About The Author: Ryan Mayes is a Senior Digital Brand Marketing Manager at Carrier who focuses on creating clear, helpful resources on HVAC topics. Ryan’s goal is to guide readers toward smart, confident decisions about their indoor comfort.