SEER vs. AFUE: The Importance of Understanding the Difference

The U.S. Government Publishing Office’s Electronic Code of Federal Regulations lists the energy and water conservation standards for a variety of consumer products, including furnaces and air conditioners. The minimum standards applied to these heating and air conditioning systems are measured in AFUE for furnaces and SEER for air conditioners and heat pumps. To help you make a more informed decision when considering new HVAC equipment for your Greater Raleigh home, here’s a breakdown of the two ratings:

SEER: Seasonal Energy Efficiency Ratio

SEER is a measure of the total cooling power of a central air conditioner or heat pump over the course of an average cooling season. It is determined by dividing the system’s total seasonal cooling, expressed in BTUs, by the watt-hours of electricity the system consumes to provide that cooling. This rating indicates how efficiently a piece of cooling equipment is expected to operate throughout the season. The minimum industry standard is 13 SEER.

AFUE: Annual Fuel Utilization Efficiency

AFUE is a comparison between the amount of heat delivered to your home by your furnace during a normal heating season and the amount of fuel your furnace requires to generate that heat. Expressed as a percentage, AFUE indicates how much of the fuel the furnace consumes is actually converted to usable heat. An AFUE of 90 percent means that nine-tenths of every BTU of energy used to run the furnace is returned to the home as heat.

What’s the Difference?

The most obvious difference between SEER and AFUE is that the former measures cooling efficiency and the latter heating efficiency. Another difference is that while both ratings compare energy input with cooling or heating output, SEER compares BTUs with watt-hours and AFUE compares BTUs with BTUs. This is why the resulting ratings look so different. Because AFUE compares identical units, it’s a little easier to grasp how efficiently a furnace uses fuel. However, SEER is a bit more difficult to visualize — and this is where air conditioning standards, which set a minimum of 13 SEER, can help. It’s also where your HVAC contractor can help.

If you have questions about heating and air conditioning efficiency, give Mitchell Heating & Cooling a call today. We can help you get the most efficient unit for your heating and cooling dollar.

Compliance Settings
Increase Font Size
Simplified Font
Underline Links
Highlight Links