HVAC(R): Heating Ventilation and Air Conditioning an R may be added to represent Refrigeration.
Split system: Refrigeration system where the refrigerant is piped from one part to another, such as residential heat pump or a c system.
Packaged or self-contained: Refrigeration system where everything including the air moving hardware is kept in one box, such as a window air conditioner or a roof-top unit.
Forced air: heating and or cooling system that connects to the conditioned space with duct-work that uses air as the moving fluid. The heating or cooling can come from any number of sources.
Radiant: System that uses hot surfaces to radiate or convect heat into the environment. Without the use of fans or blowers
Heat Pump: Refrigeration device that can be used to move heat to or from air or water, or to or from air to water then the water is used to heat or cool air. In some parts of the world they are also known as Reverse Cycle .
Evaporator: The part of a refrigeration system that gets cold. It is called the evaporator because it is the part of the system that evaporates the refrigerant from liquid to vapor.
Condenser: The part of a refrigeration system that gives up heat from the refrigerant and changes the refrigerant from a vapor to a liquid. Condensers can be either water cooled or air cooled.
Compressor: The heart of any refrigeration system that pumps the refrigerant.
(absorption systems that use ammonia or lithium bromide do not have compressors). Compressors can be reciprocating, rotary, scroll, disc, or screw.
Receiver: Tank on the liquid side of a system that holds excess refrigerant in the system that needs to be there for proper operation.
Accumulator: Tank on the suction side of a system that holds excess refrigerant to prevent slugging the compressor with liquid.
Outdoor coil: The coil on a heat pump system that is located out side or in the ground loop of a ground sourced heat pump. This is so not to be confused with the condenser on an airconditioning system.
Indoor coil: The coil on a heat pump that is located inside. This is so not to be confused with the evaporator on an air conditioning system.