A walk-in cooler and/or freezer plays a critical role in any kitchen as it serves as the bank for food storage. With operators using more locally sourced and seasonally fresh product, the space they need to hold food at safe temperatures continues to increase.
Walk-in coolers store cold items for use within a couple of days. Operators should not use this equipment to pull temperatures of hot food down quickly as they would with a blast chiller.
Walk-in cooler and freezer sizes and configurations can vary from a small 6-foot-by-6-foot unit up to any size cold storage warehouse. To figure out the size of an ideal walk-in cooler or freezer, consider the maximum amount of food inventory an operation requires and how much shelving it will take to hold those items.
Key construction criteria includes strength, durability, insulation value and a tight fit at the seams. These attributes can help ensure a long-lasting and trouble-free walk-in cooler or freezer.
The product the walk-in will store and the location of the unit also determine what finish an operator should consider. For example, aluminum is not recommended for poultry, and galvanized steel is not ideal when aesthetics is a factor or when the walk-in is exposed to outdoor elements due to the natural process of discoloration or oxidation.
The standard walk-in floor in the industry is .080 or .100 aluminum, which is typically made to withstand 600 pounds per square foot of stationary floor load. Rolling traffic plays a factor in how well a walk-in floor holds up and the type of floor an operator should choose. A heavy-duty floor is recommended for heavy-traffic applications. For applications where there will be a pallet jack or forklift traffic, a concrete wearing floor on top of the prefab floor or an insulated slab is best.
The compressor’s horsepower depends on the size of the walk-in and application. When sizing, always consider the humidity in the room where the walk-in freezer will sit. The typical box load calculations are 80 degrees F at 50 percent relative humidity in the kitchen with two door openings per hour; if the walk-in freezer will sit outdoors, consider the ambient temperature, particularly in states with extremely high humidity.
Operators can choose from a variety of bells and whistles when purchasing a walk-in cooler or freezer. The most common are peep windows, LED lights, vinyl strip curtains, alarm systems that include temperature monitoring for HACCP documentation, door status monitoring, light control and heater wire control for doors and port windows. Basic refrigeration systems are typically provided as remote preassembled or self-contained precharged systems. Floor innovations to protect from rolling carts and updated ceiling structures to eliminate posted beams that take up shelving space also are available.
Proper installation of the walk-in cooler and freezer goes a long way toward ensuring the unit does not encounter any issues. The foundation must be plumb and level prior to the walk-in installation. The sequence in which the crew installs the walk-in panels helps ensure a quality and tight fit, which helps the unit maintain the proper temperatures.
With today’s walk-ins, temperature control and record keeping for HACCP are becoming more important.
“Even though it costs more, operators should consider walk-ins with some sort of control system that monitors temperatures and provides warnings when the necessary temperatures are not reached,” says Juan Martinez, principal at Profitality, a Miami-based foodservice consulting firm.
Door placement represents another key consideration. Operators can place a freezer walk-in within a refrigerated walk-in, with a door inside the refrigerated section. “When this is done, temperatures are more consistent, since the freezer contents are not exposed to ambient kitchen temperatures,” says Martinez.
Operators also should think about accessibility since in some instances, it makes more sense to have an individual door rather than double doors, which take up storage space. “It’s important to think about how the walk-in will be used, the frequency of staff going in and out and how it will fit with the rest of the kitchen layout,” says Martinez.
Figuring out the amount and timing of deliveries in relation to the available space also plays a key role in sizing the unit. “Space today is at a premium, but if all the perishables cannot be stored in the walk-in, it’s necessary to consider other alternatives,” says Martinez. “It’s convenient if night shipments can be loaded onto a dolly and rolled into the walk-in for storage.”
Other storage considerations include box sizes, sales volume, product mix and types of shelving available.
“Operators should assume all walk-in space will be used 100 percent,” says Martinez. “They will need to build that buffer in and try to figure out analytically the space that’s needed as well as the type and number of shelves.”
Operators can choose from custom and prefabricated walk-ins. “I’ve been told walk-ins constructed on-site that become a part of the building may depreciate faster because there is no leeway in terms of the shape,” says Martinez.
Cleaning & Maintenance
Operators should regularly make several checks on their walk-in units.
“The thought of getting hinges and gaskets replaced is on the bottom of the to-do list,” says Steve Long, service technician at K&D Factory Service Inc., Altoona, Pa. “Though true for many types of commercial cooking and refrigeration equipment, we find this to be especially the case with walk-in coolers and freezers.”
Use a damp soapy cloth to clean the entire unit inside and out. How often that should take place will vary by operation. Food particles left behind are unsanitary, especially if the operator turns off the unit nightly. Keep door gaskets clean, and inspect them for wear and tear. A gasket that fails to seal will allow too much moisture to enter the compartment and either freeze the evaporator coil or flood the drain pan or floor of the cooler.
“Once you can access the condensing components, the coil should be cleaned regularly,” says Long. “The condensing fan blows air across coils to release the heat. This process often pulls in lots of dust that inevitably builds up on the coils and limits the airflow, thereby not sufficiently dispersing the heat. The problems increase at an exponential rate once this begins.”
Walk-ins likely have remote condensing units, often on the roof, with large components to cool the larger space. “Extra care should be taken to make sure walk-in doors are kept closed,” says Long. “Often, they are propped open while restocking or conducting inventory. While convenient for staff, this makes hard work for the cooling system and, over time, can lead to premature failures.”
Walk-ins should have a biannual planned maintenance program. “Doing so has proven over time, on average, to decrease the amount of break fix service calls,” says Long.
However, there will likely come a time when the walk-in unit requires service. A few things to look for when deciding if a repair is necessary include wide temperature fluctuations, slow recovery time, not cooling, electrical smell, doors not closing or sealing properly, constantly icing up, and several other issues that less commonly occur.
These units are built to last, but everything has an expiration date. The lifespan of a refrigerated piece of equipment is subject to a multitude of variables.