Editor’s Note: In today’s Thursday Feature, we take a look at the unique problems faced by cold storage warehouses, and how technological improvements are providing new solutions.
Cold storage warehouses are used to store more than $200 billion worth of refrigerated and frozen food products each year. But they also are commonly used in the pharmaceutical, petrochemical, and high-tech electronic industries.
On the face of it, the objective of a cold storage warehouse seems straightforward: Keep the facility cold so that the temperature-sensitive products that are stored there aren’t ruined.
Different Temperature Zones
But maintaining a cold storage warehouse is actually a lot more complicated than that. For example, different areas of the same warehouse need to be kept at different temperatures based on the type of products that are stored there: Fresh produce should be held at 55 degrees F, dairy products need to be held just above freezing at 34 degrees F, meat should be stored just below freezing at 28 degrees F, and ice cream should be held at -10 degrees F.
Changing Zone Sizes
At the same time, the size of these temperature-zoned areas often needs to be expanded or contracted, depending on the amount of products that are being held there. In a traditional warehouse, reconfiguring the layout is relatively easy: You can just move pallets of materials around or stack them up until they fit.
But with cold storage facilities, temperature has to be taken into account. One solution is to use a modular curtain wall system. This low-cost option gives operators the flexibility to expand or contract temperature-controlled storage areas at will.
That’s important because refrigerating air costs more than heating it. So when curtain walls can be used to instead of building entirely new storage areas with aluminum-covered insulated walls, cost savings can result.
Cold Temperatures Sap Battery Power
Another problem is that extremely cold temperatures sap power from electric batteries. When operating in cold storage facilities, the average forklift battery can decline between 20% and 50% faster than it would in a standard warehouse environment. So a battery rated for eight hours of continuous work might only last four to six hours in a refrigerated or frozen environment.
That’s why electric forklifts that are used in cold storage warehouses often have higher voltage batteries. For example, when a forklift is fitted with a battery rated for 12 hours, even if the cycle reduction due to temperature is 25% it will still be operable for an 8-hour shift.
Keeping Workers Warm and Productive
And then there’s the human factor. People who work in cold storage facilities need to bundle up to keep warm.
But when operators are wearing thick gloves, it’s harder for them to press the buttons on scanning devices and other tools. That’s why special equipment is often used that features oversized buttons that are large enough to be pushed easily by workers dressed for the extreme cold. Similarly, tablets with touchscreens need to be adjusted so that they are sensitive enough to respond to the touch of a glove, rather than a naked finger.
Similarly, tablets with touchscreens need to be adjusted so that they are sensitive enough to recognize the cool touch of a glove, rather than the warmth of a naked finger.
Effect of Cold on Electronics
The battery life of these devices also is affected by the cold. So some devices designed for use in cold storage conditions include seals that can withstand frequent temperature changes as they are moved between zones.
Some also include heat sources inside their housings to prevent their electronics from freezing.
Maximizing the Cold
It’s more efficient to chill smaller areas than it is larger ones. So cold storage facilities are often designed to maximize the amount of products that are stored in temperature zones. This typically includes high-density storage that features deep and tall racks to maximize cube capacity and minimize the zone’s footprint.
It’s also critical to conserve cold air as much as possible. Anytime a door is open or a curtain is pulled back, a heat exchange occurs, increasing the temperature of the zoned area. Restoring the zone to the required temperature costs money, so minimizing the amount of warmer air that enters a temperature controlled area is critical.
A solution used by many cold storage facilities is automated storage and retrieval systems that allow for pallets to pass in and out through a small opening that can be instantly sealed once the products have passed through.
Maintaining Product Temperature
Finally, there’s the temperature of the products themselves. Every time a product is removed from a freezer to warmer area — such as when it needs to be picked and palletized for shipment — it heats up. So when it is returned to the freezer, its heat signature raises the temperature of the zone slightly. Plus, passing from cold to warm and back again can cause moisture buildup on the products, which can cause ice crystals to form when they are sent back into colder zones, potentially affecting product quality.
But new robotic technology allows palletizing to be don inside freezers. They feature special seals, energy supplies, and temperature-resistant lubricants.
The operators of cold storage warehouse face unique challenges. But new technological solutions can improve efficiency and reduce costs.