Refrigeration and Air Conditioning
Technology
Absolute Pressure - -gauge pressure + atmospheric pressure, normally 14.696 at sea
level at 70F
Absolute Zero Temperature - -The lowest obtainable temperature where molecular
motion stops, -460°F and -273°C.
Absorbent (Attractant) - -The salt solution used to attract water in an aborption chiller
Absorber - -The part of an absortion chiller where the water is absorbed by the salt
solution
Absorption - -The process by which one substance is absorbed by another
Absorption air-Conditioning chiller - -A system using a salt substance, water, and heat
to provide cooling for an air conditioning system
ABS pipe - -Acrylonitrile-butadiene-styrene plastic pipe used for water, drains, waste,
and venting
ACCA Manual J - -The Air Conditioning Contractors of America Manual that facilitates
the calculations of heat gains and heat losses in residentials structures
Accumulator - -A storage tank located in the suction line. It allows small amounts of
liquid refrigerant to boil away before entering the compressor. Sometimes used to store
excess refrigerant in heat pump systems during winter cycles.
Acetylene - -A gas often used with air or oxygen for welding, brazing or soldering
applications
ACH - -Air changes per hour
ACH50 - -Air changes per hour of air leakage while the blower door is connected and
pulling 50 pascal of vaccum on the house
Acid-contaminated system - -A refrigeration system that contains acid due to
contamination
"A" Coil - -An evaporator coil that can be used for upflow, downflow, and horizontal-flow
applications. It actually consists of two coils shaped like a letter "A"
AIR