THE KEY CONTROL elements of any public refrigerated warehousing (PRW) operation are air, moisture, and temperature. Better control of these factors equates to better refrigeration, more efficient use of utilities (electricity) and refrigerant (ammonia), and greater confidence that warehoused products (usually perishable food products) won’t spoil from temperature deviations.
So, how does a modern PRW operation meet the challenge of keeping cold air in a storage area and keeping the ambient (surrounding) air out — especially when forklift operators are continually moving about with product placement and retrieval? Well, technology helps. PRW construction today is better than it’s ever been.
Walls in refrigeration operations usually are rigid sandwiches of closed-cell urethane on the inside and coated metal on the outside. These walls provide a better insulation R-factor and a better barrier against moisture. Moisture is the real enemy of refrigeration operations because it expands when it freezes, and that can lead to air leaks. Air leaks lead to moisture and heat infiltration — all a vicious cycle if not controlled.
The metal-covered urethane walls usually are six to eight inches thick. Six-inch-thick walls are used for storage areas where the temperature is maintained at 0° Fahrenheit. These areas are for breads and protein items like chicken, beef, pork, and fish. Eight-inch-thick walls are for deep-freeze units with a temperature range of -15 to minus 20 degrees. Typical deep-freeze products include ice creams, high-sugar items like popsicles, and “IQF” (individually quick frozen) items like breaded shrimp, scallops, and chicken breasts.
Refrigeration efficiency in cold-storage warehousing is a fascinating topic, and there’s more to tell about it. We’ll continue with the subject next month, discussing the evolution of high-tech equipment and controls.
This column is sponsored by Adams Cold Storage.
column by BEN ADAMS, JR.
BIO: Ben Adams Jr. is an owner and president of Adams Cold Storage, LLC, in Auburndale. He has been directly involved in citrus production, warehousing and distribution, as well as state and community support, since 1980. His facility incorporates 200,000 square feet of multi-temperature warehousing, with an extensive expansion project currently under way.