Glossary of Terms

We’re here to help you understand the world of HVAC.


Found in ductwork, this movable plate opens and closes to control airflow. Dampers are used effectively in zoning to regulate airflow to certain rooms.


American Standard’s tough, time-tested compressor.


A furnace that pulls in return air from the top and expels warm air at the bottom.


Pipes or channels that carry air throughout your home.


The coil that is inside your house in a split system. In the evaporator, refrigerant evaporates and absorbs heat from air passed over the coil.


The best gas furnace available today. Available only from American Standard.


A device for the transfer of heat energy from the source to the conveying medium.


The best heat pump available today. Available only from American Standard.


A furnace that lies on its side, pulling in return air from one side and expelling warm air from the other.


A device that injects water vapor into heated air as the air is expelled from the furnace.


The amount of moisture in the air. Air conditioners remove moisture for added comfort.


Heating Seasonal Performance Factor. Refers to the efficiency of the heating mode of heat pumps over an entire heating season. The higher the number, the more efficient the unit.


Heating, ventilation and air conditioning.


Integrally Controlled Motor. A specially engineered, variable-speed motor used in American Standard’s top-of-the-line indoor units. ICM motors are more than 90 percent efficient versus 60 percent efficient for conventional motors. Continuous comfort, quiet operation and ultimate system efficiency are the benefits of the indoor products graced with the ICM motor.


A piece of air conditioning and heating equipment in which all components are located in one cabinet. Used occasionally in residential applications, the packaged unit is installed either beside or on top of the home.


A substance that produces a refrigerating effect while expanding or vaporizing.


Set of two copper lines connecting the outdoor unit and the indoor unit.


Seasonal Energy Efficiency Ratio, a rating that measures the cooling efficiency of a heat pump or air conditioner. The higher the number, the more efficient the unit.


Seasonal Extreme Environmental Test. It’s the American Standard torture chamber for heating and air conditioning systems, where five years of service are condensed into 16 torturous weeks.


Constructed of thousands of tiny spines bonded to continuous aluminum refrigerant tubing, this revolutionary, patented coil is used in Allegiance and Heritage products. Because of its greater surface area, Spine Fin has greater heat transfer capabilities – it’s also unbeatable in providing retained efficiency over time.


Refers to a comfort system configuration consisting of components in two locations. Common examples include an outside unit, such as an air conditioner, and an indoor unit, such as a furnace and coil.s.


A device in a heat pump that reverses the flow of refrigerant as the system is switched from cooling to heating. Also called a reversing valve or four-way.


A temperature control device, typically found on a wall inside the home. It consists of a series of sensors and relays that monitor and control the functions of a heating and cooling system. American Standard’s programmable thermostats allow you to program different levels of comfort for different times of the day.


A unit of measurement used for determining cooling.