AFUE – Annual Fuel Utilization Efficiency. A measure of a gas furnace’s efficiency in converting fuel into energy. The higher the rating, the more efficient the unit. For example: A rating of 90 means approximately 90 percent of the fuel is used to provide warmth to your home, while the remaining 10 percent escapes as exhaust. Air Handler – The indoor part of the central air conditioning or heat pump system that moves the cooled or heated air throughout the ductwork of your home. An air handler is usually a furnace or blower coil.

Air Handler

BTU – British Thermal Unit. The amount of energy that’s needed to change the temperature of one pound of water by one degree Fahrenheit. For your home, it represents the measure of heat given off when fuel is burned for heating or the measure of heat extracted from your home for cooling. This is what the heat removed from your home is measured in.


CAE – Combined Annual Efficiency. The measure of the amount of heat produced for every dollar of fuel consumed for both home heating and water heating.


Capacity – The output or producing ability of a piece of cooling or heating equipment. Cooling and heating capacities are referred to as BTU’s


Carbon Monoxide – An odorless, poisonous, flammable gas produced when carbon burns with insufficient air and can be deadly to humans.


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 pumps the refrigerant into the Condenser coil, then out and into the Evaporator coil and finally back to be re-circulated. It is part of the outdoor unit and pumps refrigerant in order to meet the cooling requirements of the system.


Condensing Unit – Consists of the compressor, condenser coil and the fan.


Condenser Coil or Outdoor Coil – In an air conditioner, like a radiator on a car, the coil releases heat from the refrigerant. The cooler outdoor air passing through the coil will change or “condense” the refrigerant from vapor to liquid.


Damper – Found in ductwork, this movable plate opens and closes to control airflow. Dampers can be used to balance airflow in a duct system (adjusted manually during installation and then locked in place). They are also used in zoning to regulate airflow to certain rooms.


Ductless Mini Split Heat Pump System – These systems are used when a conventional forced air system will not fit in the home. They are ideal for garage conversions, casitas, computer rooms or single areas that require their own separate thermostat control. Size ratings are up to 21.0 SEER. You can also use up to 4 indoor fan coils with one outdoor AC condenser.


Ductwork – Pipes or channels that carry air throughout your home. Ductwork is critical to performance.


Evaporator Coil or Indoor Coil – Like another radiator, this one gets cold and as the blower from your furnace/system passes warm “indoor” air across it, the air gets cold and cools down your indoor environment (it gets cold and takes the heat and moisture out of the air). The warmer indoor air passing through the coil will change or “evaporate” the refrigerant from a liquid to a vapor (it then returns to the compressor as a vapor to be re-compressed).


Gas Furnace Heat Exchanger – Located in the furnace, the heat exchanger (also known as a fire-box) transfers heat to the surrounding air from your blower, which is then circulated throughout your home.


HSPF – 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.


HVAC – Heating Ventilation Air Conditioning


Package Unit – A heating and cooling system combined in one package. A package unit is typically installed on top of the home or building, or sometimes can be on the ground level. Most commercial applications have Package Units, while most homes have split systems.


R-410A Puron – On January 1, 2010 Federal Law will require all A/C manufacturers to switch over to the use of R-410A Freon in all condensing units. The R-410A Freon which is “Ozone Friendly” will replace the R-22 Freon due to the reduction in the chlorine component which is found in R-22.


Refrigerant – This is the real name for what people like to call Freon, or now a new name called Puron. It’s the fluid and gas that evaporates and condenses throughout your system, absorbing heat in the evaporator coil and then releasing heat in the condenser coil . Most residential air conditioning systems contain R-22 refrigerant. R-22 is regulated by international controls under the Montreal Protocol and in the United States by the Environmental Protection agency. It is scheduled to be in production until the year 2020. It’s used in approximately 95 percent of air conditioning equipment in the U.S. today. Refrigerant R-410a (Puron) is quickly becoming the new standard for residential systems. Also see R-410A Freon.


SEER – Seasonal Energy Efficiency Ratio/Rating. A measure of cooling efficiency for air conditioners and heat pumps. The higher the seer, the more energy efficient the unit. The governments minimum SEER rating is 13. It’s similar to comparing miles per gallon in automobiles.


Single Package Unit – A heating and cooling system contained in one outdoor unit.


Split system – The most common residential system in the country. The furnace and evaporator coil (or air handler) are inside the home (usually located in the attic, a closet or in an attached garage), and they are connected to the condensing unit with refrigerant piping. 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 in order to regulate the temperature indoors.


Ton – The unit used to measure the capacity of an air conditioning system. One ton of air conditioning moves 12,000 BTU’s of heat energy per hour from your home.


Variable Airflow System – An exclusive feature of a high efficiency home comfort system. This method of ramping airflow gives you greater humidity control in cooling and provides warmer air during heating start up.


Zoning – A method of dividing a home into different comfort zones so each zone can be independently controlled depending on the use and need. Zoning enables you to shut off areas that are not in use without creating a back pressure in your duct system (which happens when you simply close off you register vents), causing the equipment to work harder and higher energy bills.