DEFINATIONS :


AXIAL FAN : Type of fan where pressure is produced due to an increase
In air velocity through the rotating impeller, the air flow
through the fan is parallel to the impeller axis.


CENTRIFUGAL FAN : Type of fan where pressure and velocity are produced by the
centrifugal action of the rotating impeller and the velocity
of air leaving the tip of the impeller.


COMPRESSOR : A refrigerant compressor converts input electricity Into
mechanical energy in order to remove heat from air.


CONDENSER : The heat exchanger in a mechanical refrigeration cycle removes heat from the hot, high pressure refrigerant vapor, the removal of heat converts the vapor into a liquid.


CHILLER : A machine which uses mechanical energy to chill water
through the vapor compression refrigeration cycle. Chillers can
be air or water cooled , and typically have centrifugal,
reciprocating or screw compressors.


CONDENSATION : Condensation occurs when water vapor is converted to liquid.


COOLING COIL : A coil which is used to lower the temperature of an air stream.
heat is transferred from the air stream to chilled water or
refrigerant circulating through the coil tubes.


DUCT : A passageway made of galvanized sheet metal or other
suitable material that is used to distribute the air needed
to heat, ventilate, or cool the conditioned spaces.


DAMPER : A device used to control the flow of air within a duct.


DEHUMIDIFICATION : Process where moisture is removed from the air.


DEHUMIDIFIER : A device which removes moisture from the air.


DIFFUSER : A device which evenly distributes high velocity supply air into
the conditioned space.


DISTRIBUTION : The transportation of conditioned air or water throughout a facility.


FAN COIL UNITS : Fan coil units (FCU) are typically mounted In the ceiling at
each zone and contain a blower, air filter and water coil
or coils.


FILTER : A device which removes particulate contaminants from an
air stream.


HEATING COIL : A coil used to increase the temperature of an air stream.
heat is transferred to the air stream from hot water circulating
through the coil tubes.


PACKAGED UNITS : HVAC units that contain all components for a complete air
cooled refrigeration cycle in one unit.


PLENUM : An enclosure that is part of the air distribution system and is
distinguished by having almost uniform air pressure.


BOTTOM OF PIPE : BOP is the distance between the finished floor level to the
bottom of the pipe.


BOTTOM OF DUCT : BOD is the distance between the finished floor level to the
bottom of the duct.