Refrigeration Terms And Their Meaning; Components And Their Function - Rheem 325 II Series Service Instructions Manual

REFRIGERATION TERMS AND THEIR MEANING

Condense – The action of a substance as it releases heat and changes state from a
vapour (gas) to a liquid.
Evaporate – The action of a substance as it absorbs heat and changes state from a liquid
to a vapour (gas).
Heat of Compression – The heat energy added to a substance by the act of compressing
it.
High Side – Components and pipework of a refrigeration system operating at high
pressure, generally the compressor case where a rotary compressor is utilised, discharge
line, condenser, liquid line, liquid receiver where utilised and filter drier.
Latent Heat – The „hidden‟ heat energy that causes a change in state of a substance,
without changing its temperature.
Low Side – Components and pipework of a refrigeration system operating at low
pressure, generally the evaporator, suction line and suction accumulator.
Saturated Liquid – A liquid at the point that it will boil with any increase in temperature, at
a given pressure.
Saturated Vapour – A vapour at the point that it will condense with any decrease in
temperature, at a given pressure.
Subcooled Liquid – A liquid at a temperature below its saturation point, at a given
pressure.
Superheated Vapour – A vapour (gas) at a temperature above its saturation point, at a
given pressure.

COMPONENTS AND THEIR FUNCTION

Anode (Sacrificial) – A metal alloy electrode installed in the water heater cylinder that
protects the cylinder from corrosion by galvanic action.
Compressor – An electromechanical device that increases the pressure of superheated
refrigerant vapour by decreasing its volume, as well as increasing its temperature due to
the addition of the heat of compression. The increase in pressure causes the refrigerant to
circulate through the refrigeration system.
Condenser – A heat exchanger containing three chambers; one for the refrigerant, one for
water and a third separating chamber which is open to atmosphere. The refrigerant enters
the condenser as a high pressure, high temperature superheated refrigerant vapour and
gives off its heat. This heat is absorbed by the water from the storage tank which is being
circulated through the water chamber in the condenser. As the refrigerant gives off its heat
and becomes cooler, it condenses (changes state) to a saturated liquid. Cooling of the
saturated liquid refrigerant continues such that it becomes subcooled.
Diffuser – A plastic device installed in the cold water inlet of the water heater cylinder to
assist with stratification. It also acts as a fitting liner.
Discharge Check Valve – A valve in the refrigerant discharge line that allows refrigerant
to move in one direction only. The valve prevents refrigerant migrating back into the
compressor when the refrigeration system is not operating.
TM077: 325 & 410 Series II Heat Pump Service Instructions
9
Rev 00: Issued April 2014
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