Mobile commercial refrigeration is alike to the refrigeration which occurs in the home refrigerator. The food homeowner keep in the refrig¬erator is stored at a temperature lower than the room temper¬ature. Typically, the fresh food compartment temperature is about 35°F. Heat is realised from the room moves through the walls of the refrigerator from the warm room (typically 75°F) to the cooler temperature in the refrigerator. Heat travels normally and naturally from a warm to a cool medium.
If the heat that is transferred into the refrigerator remains in the refrigerator, it will warm the food products, and spoil¬age will occur. This heat may be removed from the refriger¬ator by mechanical means using the refrigeration equipment furnished with the refrigerator. This mechanical means re¬quires energy, or work. Because most readers are familiar with the pressures and temperatures of R22 used in AC units, many illustrations of commercial refrigeration are also presented using R22. Hopefully, this will make it easier to understand the differences and similarities between the two types of applications. The more popular refrigerants used in new commercial refrigeration are R134a and R404A. Some R22 equipments are still being produced but at a lesser volume as the phase-out year 2010 approaches. The use of blended refrigerants has required technicians to learn new skills but has not been the problem the industry once feared.
The heat is transferred into a cold refrigerant coil and pumped with the system compressor to the condenser where it is released into the room. This is much like using a sponge to move water from one place to another. When a dry sponge is allowed to absorb water in a puddle and homeowner take the wet sponge to a container and squeeze it the exert energy, much like a compressor in the refrigeration system. Another example of refrigeration is a central air- conditioning system in a residence. It absorbs heat from the home by passing indoor air at about 75°F over a coil that is cooled to about 40°F. Heat will transfer from the room air to the coil cooling the air. This cooled air may be mixed with the room air, lowering its temperature. This process is called air conditioning, but it is also refrigeration at a higher temperature degree than the home refrigerator. It is frequently known high-temperature refrigeration. mobile commercial refrigeration differs from domestic (house-hold) refrigeration because it is located in commercial business locations. The food store, fast food restaurant, drug store, flower shop, and food processing plant are only a few of the applications for commercial refrigeration. Some of the systems are plug-in appliances, such as a small reach-in ice storage bin at the local convenience store.