GLOSSARY
Capacitor, Motor Running
Single or dual rated (two posts vs. three posts) devise which limits current and is
perma-nently (hence phrase PSC - Permanent Split Capacitor) installed, in
series, between the motors run and start wind-ings. The current limiting
characteristics prevent the start winding from burning. Also improves motor's
efficiency (improves power factor) by realigning the motor's voltage and current
sin waves. A PSC motor will generally con-sume 40-50% less electricity when
compared to an equivalent Shaded Pole design motor.
Capacitor, Motor Starting
Device utilized in single phase compressors and/or electric motors to boost
starting torque. Reduces inrush current (lights dimming) and associated internal
heat generated with the motor windings. Typically black in color and cylindrical.
CFM
A standard of airflow measurement. Cubic feet per minute.
Coil, Condenser
The coil dissipates heat from the refrigerant. Hot vapor refrigerant is
compressed by the compres-sor, and the refrigerant condenses from a vapor to
a liquid state. Subcooling of condensed liquid occurs when all vapor is
condensed.
Coil, Evaporator
Where heat is absorbed by warm air passing across. Liquid refrigerant boils as
it is metered into coil, and changes from liquid to vapor.
Cold
A sensation felt as a result of the absence of heat.
Compressor
The heart or "pump" within an air conditioning or heat pump system. The
compressor maintains ade-quate pressure to cause refrigerant to condense and
flow in sufficient quantities to meet the cooling requirements of the system.
Damper
Valve for controlling airflow. Found in duct work, movable plate opens and closes
to control airflow. Can be manually or automatically controlled to regulate airflow
to desired system zones.
Decibel (dB)
Unit used for measuring relative loudness of sounds. One decibel is equal to
approximate difference of loudness ordinarily detectable by human ear, the
range of which is about 130 decibels on scale beginning with one for faintest
audible sound.
Ductwork
Round or rectangular pipes or controlled paths acting as conduit for return,
mixed, makeup, supply or exhaust air. Supply air is downstream of high
pressure side of fan. Return air is upstream of low pressure inlet of fan.
Ebulator
A pointed or sharp edged solid substance inserted in flooded type evaporators
to improve evaporation (boiling) of refrigerant in coil.
Economizer
A mechanism that removes flash gas from the evaporator.
Eddy Currents
Induced currents flowing in a core.
Fahrenheit Scale
On a Fahrenheit thermometer, under standard atmospheric pressure, boiling
point of water is 212 degrees. and freezing point is 32 degrees above zero on
its scale.
Fan
A radial or axial flow device used for moving or producing artificial currents of
air.
Farad
Unit of electrical capacity; capacity of a condenser which, when charged with
one coulomb of electricity, gives difference of potential of one volt.
