Hi everybody,

Refrigeration controllers play a critical role in maintaining the temperature and managing the defrost cycles of a refrigeration system. The temperature control function ensures that the room temperature is kept within a desired range, while the defrost management function helps to prevent the buildup of ice on the evaporator, which can hamper the transfer of heat from the air to the refrigerant.

It's also interesting to note the different defrosting methods used in refrigeration systems, such as recirculation defrosting, electric defrosting, and hot gas defrosting. Each method has its own advantages and disadvantages, and the choice of method may depend on factors such as the size of the refrigeration system and the type of refrigerant used.

Finally, the mention of electronic injection control and pressure transducers highlights the increasing complexity of modern refrigeration systems, and the importance of choosing the right controller for the job.


The use of electronic expansion valves in refrigeration controllers can provide a clue for the controller as to whether a defrost can be skipped or not. This is based on the vaporization temperature and the degree to which the electronic expansion valve is open after defrost. Refrigeration controllers without electronic expansion valves can still detect when defrost is necessary by monitoring the temperature on the defrost sensor or looking at the total cooling time.

By using defrost on demand functionality, refrigeration controllers can help to save energy and reduce the frequency of unnecessary defrosts. This is important because defrost cycles can consume a significant amount of energy, and reducing their frequency can help to lower energy costs and improve the efficiency of the refrigeration system.

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• FAQ For Defrost control