What is the efficiency of a standard gas furnace?

Author: Orrin Parker  |  Last update: Friday, June 6, 2025

Standard Efficiency : The most basic furnace being manufactured today, a standard or mid-efficiency furnace has an AFUE rating of around 80%. High Efficiency : If a furnace is considered a 'high-efficiency furnace,' it is rated as 90% AFUE or more.

What is a good efficiency rating for a gas furnace?

A standard efficiency furnace provides 80% annual fuel utilization efficiency (AFUE). In this type of furnace, 20% of the energy produced by natural gas is expelled as exhaust. High-efficiency furnaces offer 90% or more AFUE. These days, 95% AFUE is a common rating among new gas-powered furnaces.

Is a 96% furnace better than an 80% furnace?

The higher the AFUE, the less money you have to spend to keep your house cozy all winter long. Which is definitely a good thing. And, FYI, a 96% AFUE gas furnace is about the best you can find.

How efficient is a 20 year old gas furnace?

An 18 to 20-year-old furnace will measure more than 20% inefficiency, meaning 80% of the power (gas or electricity) goes to heating your home, while 20% is wasted. A new high-efficiency furnace will read between 90-95 AFUE, meaning 90-95% of the power used goes to heating your home, and only 5 – 10% is wasted.

Is a 95% furnace worth it?

Having a furnace with a 95% AFUE rating might seem like the best choice, but there are several reasons why it might not be the best choice for you. Not only do high-efficiency furnaces have higher upfront costs than mid-efficiency models, but they also cost more to install.

How A Gas Furnace Works (Animated Schematic)

Are newer gas furnaces more efficient?

Construction has been improved: Today's furnaces are better constructed, with lighter materials and more energy-efficient engines.

How efficient is a 10 year old furnace?

Even the most efficient heating systems lose efficiency as they age. You can subtract about 5% efficiency for each year of your heating system's operation: on average, a 10-year-old furnace with 95% efficiency will only be operating at about 45% efficiency today.

Is it better to undersize or oversize a furnace?

Even a slightly undersized furnace will accomplish the job the majority of the time. Taking things down a few sizes will more than likely solve some of your common heating problems like too high of a utility bill while half of your house is blazing and the other half is an icebox.

Is it worth fixing a 15 year old furnace?

While furnaces can last longer with proper maintenance, they often become less efficient and more prone to breakdowns as they age. Repairing a 15-year-old furnace can provide a temporary solution, but it may be a better long-term investment to consider replacing it.

What are the disadvantages of high-efficiency furnaces?

Disadvantages of high-efficiency furnaces
  • Higher purchase cost – Energy-efficient models typically have a higher price tag than standard models.
  • Compatibility issues – Newer, more efficient models may be incompatible with your existing HVAC system or infrastructure.

What is the most reliable gas furnace brand?

The 5 Best Furnace Brands
  • Carrier Furnace: Best Warranty.
  • Lennox Furnace: Best Company Reputation.
  • Bryant Furnace: Best for Durability.
  • Trane Furnace: Most Years of Experience.
  • Amana Furnace: Best for Efficiency.

Does my gas furnace qualify for tax credits?

ENERGY STAR certified gas furnaces with AFUE ≥ 97% are eligible. Note: Under the tax code, eligible equipment must “meet or exceed the highest efficiency tier (not including any advanced tier) established by the Consortium for Energy Efficiency which is in effect as of the beginning of the calendar year.”

Which is better, single or 2 stage furnace?

Although maintenance is always recommended, a two-stage furnace should have better longevity since there's less wear and tear on the unit from less starting and stopping. With improved airflow, the air filter will more effectively capture pollutants and allergens, leading to cleaner indoor air quality.

How much is a furnace for a 1500 square foot house?

Gas Furnace: $3,000 – $6,000. Electric Furnace: $2,500 – $5,000.

How do I check my furnace efficiency?

The AFUE Rating on Your Furnace

There's a simple way to find out the energy efficiency of your home's furnace: Look at its AFUE rating. This number, found on the cabinet or in the user manual, is the Annual Fuel Utilization Efficiency measurement.

Can you still buy low efficiency furnaces?

Low Efficiency : No longer in production, furnaces with an AFUE rating of approximately 55% to 78% are considered low-efficiency heating equipment. Standard Efficiency : The most basic furnace being manufactured today, a standard or mid-efficiency furnace has an AFUE rating of around 80%.

What is the average life expectancy of a gas furnace?

However, most gas furnaces typically last between 15 to 20 years before efficiency declines and repair costs increase, so it's wise to consider replacement around the 15-year mark to ensure optimal performance and safety.

Is a 20 year old furnace too old?

The average life expectancy of furnaces in homes today is between 16 and 20 years. If your furnace is close to this age or older, you should begin shopping.

Why is replacing a furnace so expensive?

Installation Entails More than Just the Furnace

For a gas-powered furnace, a contractor must set up a gas connection and vent. Installing an electric furnace requires running wiring, adding a circuit breaker, or perhaps updating an electrical panel. Holes are often drilled for pipes and wires.

How much does a furnace cost for a 2000 sq ft home?

This can lead to a wide range of installation costs. The national average cost for installing a gas furnace in a 2,000 sq. ft. home is $4,000 to $8,000, with most people paying around $6,000 for a high-efficiency gas furnace installed with minor modifications to update the vent and drain.

Can I put a stronger blower in my furnace?

Can I put a bigger blower motor in my furnace so it will perform better? While upgrading blower motor sizes is possible, you might not need to install a replacement motor at all. Sometimes a simple repair is all you need to get your furnace fully functional again.

What is the correct size furnace for a 1500 square foot house?

A 1,500-square-foot home will require between 45,000 to 90,000 BTUs.

What time of year is cheapest to replace furnace?

For people taking a proactive approach, doing a furnace replacement during the “shoulder seasons” of spring and autumn may offer lower prices, shorter lead times, and a better selection of products and service appointment availability.

Can my furnace last 30 years?

While some units can last more than 30 years, this is extremely rare, and the average lifespan of a gas furnace is around 15 to 30 years.

Do you need a new thermostat with a high efficiency furnace?

That depends entirely on the make and model furnace that you choose. Many, but not all, high-efficiency furnaces have thermostats built in. One safe assumption to make is that if you're replacing your furnace then your thermostat probably needs to be updated as well.

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