Nick Griffiths
Walk-in freezers provide a controlled environment for storing a range of perishable goods at sub-zero temperatures. Essential to the operation of a range of industries such as logistics and food production, they preserve the quality and extend the shelf life of key products and materials while ensuring safety. Walk-in freezers are the optimal solution in many settings.
How do walk-in freezers work, how is safety maintained, what are their running costs, and what maintenance is required?
What is the sequence of operation on a walk-in freezer?
There is a specific sequence of steps to be taken to ensure that the temperature inside a walk-in freezer remains within the desired range. When asking how walk-in freezers work it’s important to understand the process by which a walk-in freezer maintains the required temperature.
Typically, a walk-in freezer will operate using the following steps:
The thermostat controls the temperature within the freezer. This is set within the desired range and if the temperature within the freezer rises above that set point the refrigeration cycle will be triggered.
The refrigeration cycle starts with the compressor. This compresses the refrigerant gas, raising its temperature and pressure.
The refrigerant gas now flows to the condenser coils. These are usually located outside the freezer, where the refrigerant releases its heat and then condenses back into liquid form.
The liquid refrigerant passes through an expansion valve. This reduces the pressure, allowing the temperature of the refrigerant to drop considerably.
The cold refrigerant then flows through the freezer’s evaporator coils. As it absorbs heat from the interior of the freezer, it then evaporates back into gas. This removes heat from the freezer and lowers the internal temperature.
The cold air that’s generated by the evaporator coils is then circulated throughout the freezer by a fan. This ensures that all areas of the freezer are cooled.
As soon as the desired temperature has been reached the thermostat will shut off the compressor. This ends the refrigeration cycle until the temperature in the walk-in freezer rises again.
Are walk-in freezers expensive to run?
Alongside considering how do walk-in freezers work the overall cost of running a walk-in freezer also needs to be taken into account. A well-designed, professionally installed and maintained walk-in freezer should be cost-effective to run.
Several factors will influence the cost of running a walk-in freezer, with size and capacity usually being the most significant. Because a greater volume of air needs to be cooled, larger freezers will require more energy, leading to higher energy consumption. Another significant factor is the quality of insulation, with better-insulated freezers retaining cold air more effectively. This reduces the workload on the refrigeration system and energy demands. Conversely, poor insulation increases energy usage and costs.
The lower the temperature setting, the more energy will be required to operate the walk-in freezer. Maintaining a temperature below -18°C will require more energy than maintaining temperatures closer to freezing. Frequently opening and closing the freezer door allows warm air to enter. This forces the system to work harder to return to the desired temperature. Reducing the usage of the door will reduce energy consumption.
Regular maintenance, such as cleaning condenser coils and checking for leaks, can ensure that the freezer operates efficiently. Regular professional servicing can also identify any problems at an early stage, lowering the risk of issues developing that could drive up running costs.
How often should a walk-in freezer defrost?
Regular defrosting of walk-in freezers is essential to prevent the buildup of ice on the evaporator coils. Ice accumulation reduces the efficiency of the freezer by insulating the coils and making it harder for them to absorb heat.
Many walk-in freezers are equipped with automatic defrost systems. These are set to defrost the freezer at regular intervals. During the defrost cycle, the refrigeration system shuts down allowing heaters to melt any accumulated ice. This melted ice is then drained out of the freezer before normal operation is resumed.
Manual defrosting is essential for freezers without an automatic defrost system. The frequency that this is carried out will depend on how the freezer is used. Factors such as how often the door is opened and the humidity level inside will all determine how frequently the defrosting needs to take place. Typically, manual defrosting should be carried out every few weeks, or sooner if there has been significant ice build-up
Professional cold room installation from ICE
At ICE Ltd, we have nearly 9 decades of experience in bespoke refrigeration solutions.
Our expert team can design, supply, install, and maintain your cold room or walk-in freezer, ensuring that it performs consistently.
Contact us to find out more about professional cold room installation and how it can benefit your business.