Evcon™ Home Comfort Glossary

Scroll through this page to learn some of the most common HVAC industry terms and acronyms you need to know:


Annual Fuel Utilization Efficiency. A measure of a furnace's heating efficiency. The higher the AFUE, the more efficient the product. The government's established minimum AFUE rating for furnaces is 78%.

Air Conditioner:

Assembly of equipment for the simultaneous control of air temperature, relative humidity, purity, and ventilation.

Air Handler:

The piece of equipment in the central air conditioning or heat pump system that moves heated or cooled air throughout a home's ductwork. In some systems a furnace handles this function.


British Thermal Unit. The amount of heat required to raise the temperature of one pound of water (about one pint) by one degree F.


The pump that moves the refrigerant from the indoor evaporator coil to the outdoor condensing unit and back to the evaporator. The compressor functions as the heart of the system, because it circulates the refrigerant in a loop.

Condensing/Outdoor Unit:

The portion of a central air conditioning system that is located outside the home and functions as a heat transfer point for collecting heat from and dispelling heat to the outside air.

Condenser Coil:

A network of refrigerant-filled tubes where heat leaves the hot refrigerant vapor. The vapor then condenses into a liquid capable of absorbing more heat.

Evaporator Coil:

The portion of a heat pump or central air conditioning system that is located in the home and functions as the heat transfer point for warming or cooling indoor air.

Heat Pump:

An air conditioner that contains a valve that allows it to alternate between heating and cooling.

Heat Source:

A body of air or liquid from which heat is collected. With Evcon™ heat pumps, the air outside the home is used as the heat source during the heating cycle.


Abbreviations for heating, ventilation and air conditioning, the three main functions of an indoor home comfort system.


Heating Seasonal Performance Factor. A measure of a heat pump's heating efficiency. The higher the HSPF, the more efficient the product. There is no government established minimum HSPF rating for heat pumps.


Seasonal Energy Efficiency Ratio. A measure of an air conditioner's cooling efficiency. The higher the SEER, the more efficient the product. The government's established minimum SEER rating for air conditioners manufactured after January 2006 is 13.

Single Package:

A year-round heating and air conditioning system that has all of the components completely encased in one unit placed outside the home.


A temperature control device mounted on the wall to send signals to turn the system on and off to maintain a comfortable temperature. Programmable thermostats provide more control settings to operate the system more effectively and more efficiently.

Evcon: Consistenly comfortable. Always reliable.
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