Thanks to the convenience factor, frozen ready meals, proteins, snacks, bakery, fruits and vegetables, and desserts are in high demand in the U.S. A Research and Markets’ report valued the 2023 U.S. frozen food market at $76 billion. The report also forecasts the market reaching $92.94 billion by 2029—a compound annual growth rate (CAGR) of 3.41%. To keep up, the cold storage real estate market is likewise on a growth trajectory. Colliers forecasts a 13.2% annual increase through 2030. That equates to a corresponding increase in pallet rack systems designed for freezers.
Rack Configuration Maximizes Freezer Space Efficiency
Frozen foods generally require temperatures from 10°F to -40°F. Because attaining and maintaining these low temperatures is costly, facility owners look for highly dense storage solutions, said Beth Randrup, Engineering Project Manager at Steel King Industries. The company is a member of the Rack Manufacturers Institute (RMI).
“The majority of the pallet rack systems for freezers we design are drive-in rack,” she said. “Operations want to maximize the storage density, and drive-in rack accomplishes that goal.”
Having a denser rack system in a freezer also compensates for storage space lost to wider travel aisles, continued Randrup.
“Because forklift operators wear heavy coats with hoods or hats to help them stay warm, they can also experience limited visibility. Depending on the specifications of the fork truck they’re driving, it’s generally a best practice to give them wider aisles to navigate through to reduce the risk of a rack impact,” she explained. “Generally, 10 to 12 feet is a good rule of thumb.”
The placement of building columns can also impact a freezer rack layout. Randrup noted that a rack engineer will design the system layout so that the columns are ideally within or in between the racking. In instances where that isn’t possible, the rack layout leaves building columns in wider aisles that accommodate fork truck travel.
“Another feature that freezer warehouses often have are curbs around the perimeter of the walls and the bases of all the building columns. Those can interfere with the rack design and layout,” she noted. “It’s always a good idea for the rack engineer to make a site visit to verify the building column layout, take measurements, and make note of any other features that might impact the design.”
Guarding Protects Rack and Other Equipment
Most freezer warehouses use ammonia-based equipment to generate sub-zero temperatures. Pipes and evaporators running near the ceiling of the building convey the ammonia throughout the freezer system, creating a chill.
“Ammonia is toxic, so protecting those lines from an impact by a pallet load as an operator raises it overhead is extremely critical,” Randrup said. “Nearly every freezer rack installation will incorporate top ties at the top of the racks. Because of their restricted visibility, the top ties prevent an operator from lifting a load too high and hitting the ammonia lines.”
The steel used in the racking is also generally more substantial, as the loads it supports are also heavier, said Randrup. “Heavy, dense pallets of frozen foods, for example, can weigh between 2,500 and 3,500 pounds. That typically calls for 4-inch channel rack.”
Despite its inherent robustness, freezer rack still benefits from utilizing protective guarding to help it withstand impacts.
“Best practice is to install guards at the end of exposed rows of rack. Also, it’s a good idea to reinforce the front—or aisle-facing—columns with an additional box channel in the upright, and add angle deflectors,” she noted. Likewise, using heavier beams and channel rub rails within the frame of a drive-in rack can also help guide a forklift operator entering and exiting the structure, minimizing the risk of damage.
Special Considerations When Installing Pallet Rack Systems for Freezers
Building freezer warehouses is at least two to three times more expensive than building ambient temperature facilities. That is due to additional insulation, the freezer equipment used to create the colder temperatures, and high-speed doors that open and close quickly to keep the cold in, among others.
“Additionally, the colder the temperatures in the freezer, the more expensive the installation will be,” Randrup noted. “The installers have to wear layers of thermal protection, which can slow them down. Just like the associates who work in a freezer, installers also have to come out of the cold environment regularly to warm up. Both of those factors increase the installation time and cost.”
Freezer Rack Coating Options
Unlike refrigerated coolers, which tend to be high-humidity environments, freezer warehouses are generally dry. That generally means corrosion won’t be a problem. Therefore, the decision about whether to choose galvanized rack components versus painted components often depends on the type of product handled.
“If it’s a freezer facility handling frozen fresh meats, then the rack needs galvanized finish for sanitation and washdown procedures,” Randrup explained. “Conversely, completely sealed foods—like shrink-wrapped cartons of ice cream stacked on a pallet and stretch-wrapped, for example—are unlikely to leak or cause contamination. In those cases, a standard paint finish is fine.”
Find Additional Rack Design Best Practices
Want more information about rack designs for temperature-controlled areas? RMI offers several resources and publications. These include “Considerations for the Planning and Use of Industrial Steel Storage Racks” and the white paper “Material Properties of Cold-Formed Steel Under Subzero Temperatures.” Or, connect with the members of RMI for additional insights, recommendations, and guidance via mhi.org/rmi.
