AFUE - Annual Fuel Utilization Efficiency. A measure of a gas furnace's efficiency in converting fuel to energy.
BTU - British Thermal Unit. The amount of heat it takes to raise one pound of water one degree Fahrenheit. In a home it is the measure of heat given off when fuel is burned for heating or the measure of heat extracted from your home for cooling.
CFM - Cubic Feet Per Minute. A standard measurement of airflow. A typical system requires 400 CFM per ton of air conditioning.
Compressor - The heart of an air conditioning or heat pump system. It is part of the outdoor unit and pumps refrigerant in order to meet the cooling requirements of the system.
Condenser Coil or Outdoor Coil - In an air conditioner, the coil dissipates heat from the refrigerant, changing the refrigerant from vapor to liquid. In a heat pump system, it absorbs heat from outdoors.
Damper - Found in ductwork, this moveable plate opens and closes to control airflow. It is also used in zoning to regulate airflow to certain rooms.
Ductwork - Pipes or channels that carry air throughout your home.
Evaporator Coil or Indoor Coil - The other half of your air conditioning system that is located inside your home in the indoor unit. This is where the refrigerant evaporates as it absorbs heat from the air that has passed over the coil.
Gas Furnace Heat Exchanger - Located in the furnace, the heat exchanger transfers heat to the surrounding air, which is then pumped throughout your home.
HSPE - Heating Seasonal Performance Factor. This rating is used in measuring the heating efficiency of a heat pump. The higher the number, the more efficient the unit.
Package Unit - A heating and cooling system contained in one outdoor unit. A package unit is typically installed either beside, on top of the home or in the attic.
Refrigerant - A chemical that produces a refrigerating effect while expanding and vaporizing. Most residential conditioning systems contain R-22. R-22 is regulated by international controls in the United States by the Environmental Protection Agency. It is scheduled to be in production until 2020.
SEER - Seasonal Energy Efficiency Ratio. A measure of cooling efficiency for air conditioners and heat pumps. The higher the SEER the more efficient the unit.
Split System - The combination of an outdoor unit (air conditioner or heat pump) with an indoor unit (furnace or air handler). Split systems must be matched for optimum efficiency.
Thermostat - A thermostat consists of a series of sensors and relays that monitor and control the functions of a heating and cooling system.
Ton - A unit of measurement used for determining cooling capacity. One ton is the equivalent of 12,000 BTU's per hour.
Zoning - A method of dividing a home into different comfort zones so each zone can be independently controlled, depending on use and need
