In the electrical defrost, one or more resistors are mounted near the coil. In general, such resistors are fixed by holes within the serpentine tubular bundle or fixed to the air inlet region of the serpentine. Often, resistors are also placed in the evaporator drain. Although it is the simplest method of control, it is the most expensive method, given the high cost of electricity compared to hot gas defrost, where the heating source is provided by the compression process itself.
Electric thawing is more common in commercial refrigeration applications than in industrial plants. In the electrical defrost, the solenoid valve is closed, and a time programmer initiates the defrost energizing the resistors. Here a small differentiation must be made in the defrost automation. For refrigeration chambers, the fans are switched off during defrost, whereas in the case of display units (counters) the fan must remain switched on during the process. For exhibitors the resistance must be fined.
