Glossary of Terms

Understand Industry Terms and Abbreviations

SEER - Seasonal Energy Efficiency Ratio
This is a system for rating the efficiency of cooling equipment. It is calculated by dividing the cooling capacity of a continuously operating air conditioner by the electric power input. The higher the SEER, the less your unit will cost to operate.
HSPF - Heating Seasonal Performance Factor
This measurement is similar to SEER, but it measures the efficiency of the heating portion of your heat pump. Like the SEER, HSPF industry minimums have risen in recent years. The current industry minimum is 6.80 HSPF.
Sound Ratings
In recent years, HVAC equipment has not only gotten more energy efficient, it has gotten quieter. Although sound does not affect the efficiency of a unit, it can certainly affect your comfort. If your unit has a low sound level, you (and your neighbors) will hardly notice when it is operating.
db - Decibel
A term to describe the relative loudness of a sound. Typically, heat pumps and air conditioners are between the sound of a human voice (70 db) and a blender (88 db).
SRN - Sound Rating Number
A unit based on ARI tests. Average sound ratings range from 74 to 80 db. The lower the SRN rating, the quieter the unit
HVAC - Heating, Ventilating and Air Conditioning
This term applies both to the heating and cooling industry and to the products they manufacture.
ARI - Air Conditioning and Refrigeration Institute
A non-profit, voluntary organization comprised of HVAC manufacturers. ARI publishes standards for testing and rating heat pumps and air conditioners and ensures a level of quality within the industry.
DOE - The Department of Energy
This is the federal agency that sets the HVAC industry efficiency standards.
Btu - British Thermal Unit
This is the amount of heat that will raise or lower the temperature of one pound of water by one degree Fahrenheit.
Btuh - British thermal units per hour
A measure of heat transfer rate.
COP - Coefficient of Performance
This is a measurement of comparison of a heat pump's heating capacity to the amount of electricity required to operate it. Since a heat pump is less efficient at lower outside temperatures, the COP falls as the temperature drops. To aid you in comparing efficiency, ARI provides the COP for two temperatures, 47° F and 17° F.
Ton - A ton is 12,000 Btuh
A typical single family residence uses air conditioning or heat pumps ranging between two and five tons of capacity.
Watt - (W)
A unit of electrical power
Kilowatt - (kW)
One thousand watts
KWh - Kilowatt-hour
A unit of electrical energy equal to the work done by one kilowatt acting for one hour