What Is AFUE Rating?

If your furnace has been acting up lately, you might be in the market for a new heating system. In your search, you probably ran across the term AFUE. What does this acronym mean and how does it affect which furnace you purchase?

For answers to all your questions regarding AFUE ratings, contact Jack Lehr Heating, Cooling & Electric today at 610-596-9967!

Why Does AFUE Rating Matter?

AFUE is the efficiency rating given to heating equipment, including furnaces and boilers. The letters stand for annual fuel utilization efficiency. This is a ratio of heat output to total fuel consumption.

Older furnaces often perform at an efficiency of about 60 AFUE, meaning only 60 percent of the burned fuel ends up as usable heat for your home. Today’s most efficient furnaces are over 98 AFUE, meaning less than 2 percent of fuel escapes up the chimney with exhaust fumes. Upgrading from a 60 AFUE furnace to one rated at 98 AFUE could save you 38 percent on your heating bills.

It’s important to know that AFUE rating doesn’t take heat loss from leaky ductwork into account. In extreme cases, this wastes 35 percent or more of the heated air traveling through the ducts. To help you get the most from your furnace, make sure the ductwork is sealed and insulated.

You might also notice when shopping for a new furnace that all-electric models have AFUE ratings between 95 and 100. This may seem impressive, but because of the higher cost of electricity compared to natural gas, all-electric furnaces are still more expensive to operate. If electricity is your only fuel choice, consider a heat pump instead.

How to Compare Furnace Efficiencies

The Federal Trade Commission requires all new furnaces and boilers to display their AFUE rating prominently so consumers can compare heating efficiencies as an important factor in their purchasing decision. While you can discern a great deal about a furnace’s performance based on its AFUE rating alone, it’s also wise to compare equipment features. Here’s what you’ll typically find with heaters at different performance levels:

Old, low-efficiency furnaces:

• Natural draft operation creates a flow of combustion gases
• A continuously burning pilot light is needed to ignite the burners
• Efficiency is about 60 to 70 AFUE

Newer, mid-efficiency furnaces:

• An exhaust fan offers more precise control over the flow of combustion gases
• Electronic ignition eliminates the need for an inefficient pilot light
• Compact, lightweight equipment reduces cycling losses
• Efficiency is about 80 to 85 AFUE

New, high-efficiency furnaces:

• A second heat exchanger found in condensing furnaces extracts as much heat from the fuel source as possible
• Sealed combustion, which means the furnace draws air from outside and mixes it with fuel at a controlled rate, maximizes efficiency
• A variable speed air handler adjusts airflow for more even temperatures
• Flue pipe is usually white plastic
• Efficiency is about 90 to 98.5 AFUE

HVAC Services in Allentown, PA

Now that you understand AFUE ratings and the impact of furnace efficiency on your comfort level and utility bills, it’s time to start comparing replacement options. While our cold winter climate here in Pennsylvania most likely means you will benefit from the highest AFUE rating possible, the heating experts at Jack Lehr will help to ensure it. We’ll calculate the payback period of different efficiency ratings and compare them to the purchase price to ensure your investment is cost-effective.

To begin the furnace replacement process in your Greater Lehigh Valley home, request a free estimate today or give us a call at 610-596-9967!