The rapid increase in online grocery shopping fueled by the COVID 19 pandemic is creating renewed pressure for greater cold storage capacity and greater efficiencies in those facilities.
Online grocery shopping was a growing trend before the pandemic but skyrocketed amid stay-at-home orders and the increased awareness of the convenience of having groceries delivered. The pandemic increased adoption of online shopping to a level several years ahead of what was anticipated pre-COVID.
New construction, expansion of existing facilities, and incorporation of more efficient storage and handling systems are helping the industry meet changing market conditions.
Despite the relatively high cost of cold storage construction compared to warehouse construction, the market is expected to grow to more than $18.5 billion by 2027 from a 2019 level of $7 billion, according to Emergen Research.
Prior to the pandemic, 3 to 4 percent of grocery shopping was done online. During the depths of the pandemic, as much as 60 percent of consumers were buying groceries online. Many of those online shoppers got hooked and are sticking with the method even as brick-and-mortar stores return to pre-Covid operating procedures. This year, 11 percent of grocery sales are projected to be done online, and 20.5 percent by 2026.
Food and Beverage Industry Seeks Higher Cold Storage Capacity
The food and beverage industry is scrambling to respond to the change in shopping methods. As companies look to new or updated cold storage facilities, and as systems integrators and equipment dealers collaborate to develop that warehousing, the special conditions of the cold storage environment must be kept in mind.
Racking systems in cold storage facilities face conditions not found in other warehouses or distribution centers. With their higher per-square-foot cost (2.5 to 3 times the square-foot cost of a regular warehouse), high-density pallet storage is even more important. That means tighter conditions for lift operators and others to deal with – all while working at temperatures that can slow reaction time. The racking system thus needs to be designed to withstand errant contact with forklifts and for efficient transit routing, so workers are exposed to frigid conditions as little as possible. That’s all while supporting high through-put so perishable food remains safe and fresh.
Five Basic Pallet Racking Types for Cold Storage
Those criteria are met to varying degrees by five basic types of cold storage pallet racking, including drive-in, pushback, pallet flow, automated storage and retrieval systems (AR/SR), and selective. The type you choose will be based on through-put needs, selectivity needs, workflow, and potential expansion needs. All types of cold storage racks can be designed to maximize storage capacity, so construction and installation costs are not excessive.
Drive-in racking systems are often the choice for cooler and freezer facilities, as they can accommodate up to 75% more pallets than selective racking. High-density storage is provided by allowing pallets to be stored multiple positions deep. That also reduces the space needed for aisles. Pallets are loaded onto and off the racking system at the same point, so if first-in, first-out (FIFO) handling is essential, drive-in racking might not be the preferred choice.
Like the above, drive-through racking systems allow high-density storage, but are designed for loading on one side and unloading on the other, supporting first-in, first-out freshness requirements.
Pushback racking systems also accommodate multiple-depth pallet storage, commonly two to five deep. In these systems, access to the pallets can be on one or both sides of the racking system. Because of the depth options, pushback racking can hold up to 90% more storage than a selective system. Pallets are loaded onto wheeled carts at each level of the racking. Inclined rails allow pallets to roll to the front of the rack as the most-forward pallet is removed.
Pallet-flow racking systems, like pushback systems, take advantage of gravity to ensure that pallets are easily accessible from the front of the racking. But in these high-density systems, pallets are loaded on one side and unloaded on the other. Thus, first-in, first-out handling is assured, supporting freshness requirements of food handling. Carton-flow systems have similar attributes, but store cartons rather than pallets.
AR/SR racking allow for deep and tall designs that maximize product density and can minimize heat loss when they are designed with small openings for pallets to flow into or out of the cold storage area.
Selective racking is the most common type of pallet storage and allow easy and immediate access to any pallet as storage is only one pallet deep. Selective racking allows higher density than floor storage, but not nearly as much as the previously described types. One advantage of this type of storage is the ability to accommodate different pallet sizes.
Structural Integrity Considerations
Cold temperatures can affect the structural integrity of racking systems – especially pallet racking for freezers. Thus, structural steel racking is recommended for coolers and freezers. The issue is not with the storage capability of the racks but, rather, with potential damage from improper contact by forklifts or other material handling vehicle. In cold storage warehouses, limited maneuverability from the high-density design can lead to a greater incidence of forklift contact with the racking.
Hot-rolled steel is used to manufacture the uprights and beams of structural steel racking. Horizontal and diagonal bracing and heavy duty foot protectors enhance the durability of the racking in cold environments. While such construction creates a higher up-front cost for structural storage rack, that can be more than offset by lower maintenance costs, greater safety for people working in the facilities, increased load capacities, and resistance to seismic forces.
Steel King’s SK3000 pallet racking is manufactured from high C-channel structural steel and is ideal for use in a cold storage racking system. Standard footpads are made of 7-gauge steel plates and are welded to each column, efficiently dispersing floor loads. A heavier duty footpad is also available. As a modular system, the SK3000 can be designed to easily accommodate changing or expanding storage needs in cold storage facilities.