Commercial Refrigeration Systems
What are three important items to consider in the design of commercial refrigeration
systems? - Answers -The equipment design must ensure that the quality of the product
being cooled remains satisfactory, a minimum amount of energy must be used to
perform the operation, and the process must be operated to comply with the laws
relating to protecting the environment.
Refrigeration is divided into four broad areas based on the evaporator coil temperature.
What are these? - Answers -High, medium, low, and cryogenic temperatures.
List the essential components required for a basic refrigeration system. - Answers -
Compressor, condenser, metering device, and evaporator.
List the important accessories common to commercial refrigeration systems. - Answers
-High/low pressure control, condenser fan, receiver tank, suction to liquid line heat
exchanger, filter drier, evaporator fan, thermostat, and suction line accumulator.
What type of system makes possible using a single compressor to control a number of
different case or fixture temperatures? - Answers -Multiple evaporator systems.
What would be installed in the suction line from the lowest temperature coil in a multiple
evaporator system? - Answers -A check valve.
List the three ways that evaporator temperature can be controlled. - Answers -
Conventional thermostat, a suction pressure cut-out control, or an evaporator pressure
regulator.
What type of system would be used when the refrigeration load varies over a wide
range, such as in a supermarket? - Answers -Multiple compressor systems.
Explain a method used on walk-in coolers and freezers to help prevent warm air from
entering the case when the door is opened. - Answers -To prevent some of this warm
air from entering the case, some systems will have a door switch that will shut off the
fans when the door is opened
Why do commercial refrigeration systems need a defrost system? - Answers -Since
most refrigeration systems operate at evaporating temperatures below 32°F, frost will
accumulate on an evaporator surface. This frost must be removed on a regular basis;
otherwise it will begin to insulate the surface of the evaporator and prohibit the
transmission of heat from the product to the refrigerant within the evaporator
