Types: Walk-in refrigerators and freezers may be pre-engineered (or prefabricated) in standard or custom sizes, or built into kitchens. Units may be located inside or outside a facility, built with or without floors and they may contain in-place or remote condensers.
Factory pre-assembled walk-ins ship from the factory and are completely ready to set in place.
Capacities/Footprints: Prefab walk-ins can be constructed to fit any operation's storage space needs.
Walk-ins can start as small as 15 cu. ft. and be as large as 400,000 square feet for outdoor use. In figuring capacity, on average, 1 cu. ft. of open storage area will accommodate about 28 lbs. of solid food.
Energy Sources(s): The horsepower of walk-in compressors varies, depending on how the foodservice operator uses the unit. Compressors will generally use anywhere from a fraction of one horsepower to six, but can go as high as 40. The compressor voltage for all sizes is typically 208/230.
Manufacturing Method: Most walk-in boxes, given their cold-holding storage functions, are made using prefabricated panels with urethane insulation sandwiched between aluminum, stainless steel or other "skin" materials such as high-density urethane or fiberglass. Manufacturers rate panel insulation with an R-value, and most manufacturers' panels are rated around R-30, which requires about 4 inches of insulation. Panels also are available with 5 inches and 6 inches of insulation, which have higher R-values.
Panels are mass-produced in standard sizes, normally 1, 2 and 4 feet in width, and heights of 7½, 8½ and 9½ feet. When 12˝ by 12˝ corner panels and floor and ceiling panels are added, manufacturers can produce just about any size walk-ins needed in 1-foot increments.
Refrigeration systems provide cooling for walk-in compartments and may be purchased from a panel manufacturer or separately from a refrigeration contractor.
Panels are available in a variety of finishes on both the interior and exterior.
Standard Features: Quality door designs are vital to effective use of walk-ins as doors receive the maximum stress during use. Rigid, reinforced door frames and heavy-duty hinges provide maximum durability. Inside door releases are a standard safety feature that operators can specify as a push-bar for hands-free operation.
New Features/Technology/Options: Newer door technology includes self-adjusting hinges that can be modified in the field to fix door sags or droops and strap hinges to accommodate heavy-duty doors. Alarm systems are available that alert operators if temperatures are unexpectedly fluctuating or signal if the walk-in door is ajar too long. Bluetooth connectivity also can alert operators if temperatures are off. Newer LED lighting and motion detector light systems that conserve electricity are other optional features.
Key Kitchen Applications: Walk-in refrigerators and freezers are primarily used to chill or freeze, and safely hold large quantities of both raw and cooked products. They support daily production activities and preserve an inventory of foods against future customer demand.
Purchasing Guidelines: From their compressors and doors to their shapes and sizes, walk-ins are extremely complex pieces of equipment. Factors for operators to consider when deciding whether to purchase a walk-in include: the amount of storage space needed, a location convenient to work areas and drain lines, and the type and condition of floor and ceilings to ensure proper load bearing and ventilation. Knowledge of the surrounding facility is especially important. If, for example, the building's floor tiles will be discontinued into the walk-in, the tile needs to have the appropriate thickness so the door panels can be raised to allow for the proper clearance. Consider the weight and frequency of traffic to determine what type of flooring is needed. If heavy-loaded carts will be used or there will be heavy shelving inside, a reinforced floor or even a structural floor should be considered. If the walk-in will have floor panels, it would be helpful to have an interior or exterior floor ramp for easier access.
The method of product storage should also be considered in determining the height of a walk-in. If hand storage is used, 7-foot-6-inch or 8-foot-6-inch height should be sufficient. If palletizing or rack storage is required, however, higher ceilings, larger door openings and aisle ways may be needed. Determine what type of products will be stored in the walk-in. Depending on an item's density and temperature, it may take longer to pull down to the correct temperature and a larger refrigeration system may be necessary to compensate.
Maintenance Requirements: Preventive maintenance for walk-ins' refrigeration systems involves ensuring proper air flow and ventilation in condensors' areas and routine cleaning of condenser coils by a certified technician.
Food Safety and Sanitation Essentials: Holding foods in a safely chilled or frozen state to avoid cross-contamination and keeping products at consistent, safe temperatures are a walk-in's primary food safety function. A walk-in's temperature monitoring and recording systems can help operators comply with HACCP guidelines, and can be especially useful in cook-chill storage of pre-made foods. If possible, designate separate sections of a walk-in cooler for raw and ready-to-eat products. This will minimize the chances of cross-contamination. Place at least one accurate thermometer in the warmest part of the walk-in cooler to measure the air temperature. It is better to have several placed throughout the unit. Keep shelves at least 6 feet off the floor for ease of cleaning and low enough on top to prevent the food from touching the ceiling. Arrange items in such a manner that good cold air circulation is maintained around all food.