Harry Parker has been in the HVACR industry for more than 30 years and has been a trainer in the industry for some 27 years. Presently he is a freelance trainer. He may be reached at const_trainer@yahoo.com.
When a refrigeration system is designed to maintain a product temperature at or below the freezing temperature of water, there will always be a necessity for the system evaporator to be defrosted at some sort of interval (due to the fact that air may contain large quantities of moisture).