Walk-in refrigerators and freezers can be an integral part of any foodservice operation because of their ability to store food products at desired temperatures. Here is an overview of these important pieces of foodservice equipment.

Foodservice operators can purchase a walk-in refrigerator or freezer in virtually any shape and size. Walk-ins can be as small as 15 cubic feet and as large as 400,000 sq. ft. Multi-level walk-ins also are available. Coolers are more likely to be larger than freezers.

One expert estimates that approximately 90 percent of walk-ins are custom fabricated. This allows operators to design the unit to best fit their needs. Quick-ship, off-the-shelf walk-ins also are available in set sizes. These include either remote or packaged refrigeration systems that contain a condensing unit and evaporator coil in one housing.

Walk-ins can be built from a wood frame box, high-density rail or Polyurethane foam. Polystyrene units, which are less energy efficient than foamed-in models, also are available. The outside of these units is typically constructed of stainless steel, aluminum or galvanized aluminum. Less common architectural finishes, such as aggregate or brick veneer, are offered, as well. Wall thickness varies from 4" or 5" for freezers and 3½" for coolers.

In recent years, most of the innovation with these units has had to do with foam and foam injection systems. Today, this insulation is CFC-free and offers improved energy efficiency.

Depending on whether units are coolers or freezers, walk-in temperatures range from -15 to 40 degrees F.

Smaller walk-ins typically include a ½-hp compressor and maintain a 35-degree F temperature, while freezers use a 1-hp compressor to maintain a -10-degree F temperature. The larger the walk-in, the greater the horsepower needed.

The Energy Independence and Security Act (EISA), which went into effect January 1, 2009, requires that freezers have a minimum R value of 32 when tested per ASTM-C518 standards at an operating temperature of 20 degrees F. Coolers must have a minimum R value of 25 when tested at 55 degrees F.

A variety of door configurations, including sliding, bi-parting and single styles, are available in electric and manual versions. Doors with windows also are offered when visibility into the walk-in is required.

Newer technology includes Bluetooth connectivity, which alerts operators when appropriate temperatures are not being maintained. Alarm systems can be used to signal when walk-in doors are left open. Also, motion detector lighting ensures that lights are not left on unnecessarily. In addition, temperature monitoring and recording systems can help operators comply with HACCP guidelines.

Many walk-ins have a system that controls the walk-in door's heater wires and lights, while monitoring temperature and other aspects of the unit.