Although it is commonly believed that walk-in coolers work the same way as household refrigerators, these two types of cooling units actually operate in very different ways. Refrigerators use the cold air that is generated by the freezer within them to keep the refrigerator section cold. Walk-coolers generates the cold air that they need to keep the air the temperature that the thermostat is set at, using fans and a condenser that cycles on and off in order to maintain the temperature of the unit. In this way the technology that operates a walk-in cooler is more similar to the way an air conditioner works than a refrigerator.
The Condenser Unit and the Thermostat
It is the thermostat that controls the temperature in a walk-in cooler. When the temperature inside the unit starts to raise above the temperature the thermostat is set at, the condenser unit switches on and starts a new cooling cycle. The fans in the unit then pull air inside the cool room repair and over the coils of the condenser. The coolant that is inside of the coils removes the heat from the air as it passes over them. The cooled air then moves out the back of the unit, and is a little colder than when it was pulled in. This continues until the temperature of the air either matches or is colder than the temperature on the thermostat. The coolant in the condenser coils is constantly pumped during the cooling cycle; this makes sure that the coolant won’t heat up too much before cooling down again.
There is another cycle that ensures that the condenser doesn’t freeze up and become covered in ice and frost. If the temperature falls too low (generally around 35 degrees Fahrenheit), the fans start again, but without the coolant in the coils cycling through. This gradually warms the condenser coils and the temperature starts to rise. This defrost cycle will stop when the temperature inside the cooler is back within appropriate range.
One important factor in an effective walk-in cooler is its insulation. Standard walk-in coolers have between 2 and 4 inches of Styrofoam insulation within their walls along with a rubber sealing gasket around the door that helps ensure that it is both well-insulated and airtight. The Styrofoam and sealing gasket keep outside temperatures from influencing the air inside the cooler, and make sure the condenser has to cool only the air that is inside the unit.