Defrosting a Commercial Freezer
Your commercial freezer needs to run at optimal temperatures in order to keep food products fresh and preserved. Beware though – a build-up of frost on the evaporator coils can result in spoilt food, high energy bills, and costly repairs! Just Fridge offers this handy advice to keep your commercial freezers frost-free…
Preventing frost build-up
When it comes to a walk-in freezers or remote cabinets, staff should enter and exit the freezer quickly, and avoid leaving the doors open for longer than necessary. This minimises the amount of warm air entering the unit, which can cause the compressor to keep running. If your freezer needs restocking or repacking, rather shut off the refrigeration system and fan motors so that there’s no air turbulence or negative pressure to encourage warmer air to rush inside the freezer.
Most commercial freezer units are equipped with auto-defrost systems, especially where temperatures need to be maintained at or below freezing. This feature automatically shuts down the refrigeration system when ice has built up around the evaporator coils. The type of auto-defrost control on a commercial freezer depends on the freezer model, the running temperature, the products stored, and how often the doors are opened:
• In some cases, a normal compressor off-cycle will kick in and this can be enough to keep the condenser coils frost-free
• Others may have a defrost timer which shuts off the compressor, but keeps the evaporator fans running, allowing room temperature air to melt any frost
• Walk-in freezers with extremely low temperatures usually have a timer that shuts off the evaporator fans before defrost heaters or elements turn on to melt any frost off the coil surfaces and warm the drain pan. The system will only turn the evaporator fans on once the refrigeration system has cooled the coils down.
What is the normal defrost cycle of a commercial freezer?
The number of defrost cycles for a commercial freezer should be three to four times a day, set for specific times, and should ultimately kick in when there’s enough frost build-up – 15-20 minutes should give the heaters enough time to defrost the coils. Do note: If your freezer has an automatic defrost control, the equipment still needs to be regularly checked and serviced, so at least once a week ensure that the coils are free of ice and that water can exit freely down the drain line. If you find that your freezer is battling to reach the correct temperature settings, and can’t seem to manage an adequate defrost cycle, you may need to do a forced shut down to allow it to defrost properly, or call in a refrigeration technician. Remember, we have a dedicated servicing department to take care of all your commercial fridge services and repairs.