A heat exchanger containing two diagonal coils that are connected together in a manner that resembles the letter "A". Back to the top.

Abbreviation for equipment capable of operating on alternating or direct current. Back to the top.

Annual Fuel Utilization Efficiency. A measure of a gas furnace's efficiency in converting fuel to energy. The higher the rating, the more efficient the unit. The unit is more efficient when the r [..]

A piece of machinery that removes unwanted particles from moving air. Back to the top.

A system for controlling the humidity, ventilation, and temperature in a building or vehicle. Back to the top.

The amount of air the system circulates through your home, indicated in cubic feet per minute (cfm). Correct airflow depends on the indoor unit, the ductwork, the outdoor unit, and even whether the fi [..]

The portion of the central air conditioning or heat pump system that moves cooled or heated air throughout a home's ductwork. In some systems a furnace will handle this function. Back to the top.

Air Conditioning & Refrigeration Institute. Back to the top.

American Society of Heating, Refrigeration and Air Conditioning Engineer Back to the top.

British thermal unit. The standard of measurement used to guage the amount of heat required to raise the temperature of one pound of water by one degree (Fahrenheit). Back to the top.