How the meaning of AFUE, HSPF and SEER can affect your household budget.

AFUE
AFUE (Annual Fuel Utilization Efficiency) is the standard measurement of efficiency for gas and oil-fired furnaces. Given in percentages, this number tells you how much of your fuel is used to heat your home and how much fuel is wasted. The higher the AFUE rating, the greater the efficiency. If a furnace has a rating of 80% AFUE rating, the furnace converts 80% of the fuel that you supply to heat -- the other 20% is lost out of the chimney.

Cost Savings: If you have an older furnace (with an AFUE of approximately 60%), you could save up to 40% on your heating bills by replacing it with a new high efficiency furnace! The cost to replace your old, inefficient furnace is paid back through lower utility bills.

HSPF
HSPF (Heating Seasonal Performance Factor) is the efficiency measurement used to gauge the efficiency of the heating mode of heat pumps. The higher the number, the greater the efficiency and cost-savings. Today's models of heat pumps are required to have a 6.8 HSPF.

Cost Savings: Higher efficiency in heat pumps and air conditioners usually means higher intial equipment cost but lower utility bills. If you live in a warm and/or humid climate, you will probably see the higher cost of a high efficiency air conditioner or heat pump paid back (through lower utility bills) in a few short years.

The Heating Season Performance Factor, or HSPF, can be thought of as the "averaged factor" for an entire heating season. HSPF is calculated by taking the total annual heating requirements, including all energy inputs (defrost and back-up heating energy included) divided by the total electric power used.

The industry standard rating system compares BTUs of heat output to watts of electrical energy consumed. There are 3.4 BTUs per watt of electricity an HSPF of 6.8 corresponds roughly with an averaged factor of 2. Remember a 6.8 HSPF is required as a minimum for today’s heat pump.

HSPF is an abbreviation for Heating Seasonal Performance Factor. It is the most commonly used measure of the heating efficiency of heat pumps. (The cooling efficiency of a heat pump is measured by its SEER.)

The important takeaway from this definition is that the HSPF is a seasonal measure (meaning that it takes into account the fact that the heat pumps rarely for as long as is optimal during Spring and Fall). A heat pump with a high HSPF is more efficient than a heat pump with a low HSPF. New heat pumps manufactured after 2005 are required to have an HSPF of at least 7.7. The most efficient heat pumps have an HSPF of 10.

SEER
What is SEER? How does it apply to the energy efficiency of air conditioners?
The efficiency of central air conditioning units is governed by U.S. law and regulated by the U.S. Department of Energy (DOE). Every air conditioning unit is assigned an efficiency rating known as its “seasonal energy efficiency ratio" or SEER. The SEER is defined as the total cooling output (in British thermal units or Btu) provided by the unit during its normal annual usage period divided by its total energy input (in watt-hours) during the same period.

After finalizing a seven-year public review process, the Clinton Administration improved the air conditioner efficiency standard from SEER 10, which was established by Congress in 1987, to SEER 13.

SEER (Seasonal Energy Efficiency Ratio) is the measure of efficiency by which the cooling process of air conditioners and heat pumps is rated. The higher the SEER number, the greater the efficiency, which yields greater energy savings.