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A Primer on Refrigeration and Refrigerants
Refrigeration may seem like an engineering marvel, but it is quite simple. Any type of refrigeration
(including your home air conditioning) uses the process of removing heat from one area and transferring
it to another. Cold air isn’t being “made” inside a fridge, but instead the heat is removed from inside the
refrigerated box (whether it’s a reach-in refrigerator or large walk-in cooler or your home in the case of
air conditioning) and moved somewhere else (either outside of the box, or outside of the building).
Compressor: The heart of the refrigeration cycle. It compresses the refrigerant gas, increasing
its pressure and temperature. This high-pressure, high-temperature gas then moves to the condenser
coils.
Condenser Coils: Located outside of the refrigerated box, either above or below the unit or in the
case of a “remote” system, located in another part of the building or outside. These coils allow the hot
refrigerant gas to release its heat to the surrounding air. As the refrigerant cools down, it condenses
into a liquid state. There is always a fan blowing over these coils. A common problem is dust collecting
in the fins around the coil reducing the air flow and reducing the effectiveness of the whole system and
adding more work to the compressor.
Throttling Device: The throttling device is either a thermal expansion valve (usually referred to
as a “TX Valve”) or a capillary tube. A capillary tube is a very long copper tube with a very small internal
diameter, usually coiled up to occupy less space. When the refrigerant leaves the condenser and the
throttling device, the pressure drops quickly and significantly. This sudden drop in pressure then creates
the cooling affect.
Evaporator Coils: These coils are located
inside the refrigerated compartment. The low-
pressure refrigerant absorbs heat from the inside
of the refrigerator as it evaporates, thereby cooling
the air inside the compartment. Most fridges have a
fan that helps to circulate air over the coil. However,
in some refrigerated display cases (such as deli or
meat display cases), no fan is used to reduce the
drying of ingredients (like steaks or pastries).
Refrigerant: The working fluid that circulates
through the system. It has a low boiling point,
which allows it to evaporate and absorb heat at low
temperatures and condense and release heat at
higher temperatures.
An update to one of the many kitchens at Red Shores in Charlottetown,
PEI expertly completed by Ferguson Sales out of Charlottetown, PEI.
Visit Ferguson Sales at www.fergusonsales.ca