Cold Rooms 101

The use of refrigerator-based equipment is a requirement of all food service operations–large or small–almost without exception. And being of such common occurrence, it’s normal to take such equipment for granted.

However, like many other aspects of food service equipment, there’s always an opportunity to learn more about the use and function of refrigeration. Try to answer the following questions:

* Does a refrigeration system pump cold air into a unit to lower the temperature of the food therein? Or, does it extract the heat from the food to lower its temperature?

* What is the correct temperature for holding refrigerated meats, vegetables, beverages, etc.?

* How long should it take to reduce cooked product temperatures from 140[degrees]F to below 40[degrees]F?

* Based on meal volume, what size in cubic feet should a raw bulk storage cooler be?

* Is a water-cooled refrigeration system faster than an air-cooled system?

The correct answers may not have been obvious for some of you. Refrigeration and their cooling systems are very complicated and specialized pieces of equipment that require significant analysis before the proper equipment, size and type can be determined for a particular facility.

Even though freezers and refrigerators are technically classified under the heading of refrigeration, this discussion will focus on coolers or refrigerators. (For freezers, see March 15, 2004, FSD, Equipment Clinic, p. 68.)

Many types: Let’s begin with the various types of cooler applications. Walk-ins, step-ins, reach-ins, roll-ins, under counter, sandwich/pizza open tops, cold pans, display cases (closed and open-air, self-service), blast chillers, mobile, and beverage are the types of coolers used in our industry. Combine the type with options such as self-contained, remote rack, indoor vs. outdoor, individual vs. parallel systems, water-cooled vs. air-cooled, door configuration, roll-in, pass through, etc., and one understands the complexity of the matter.

A refrigeration system extracts the heat from food to lower its temperature. In determining the type and options you need, size and capacity must be carefully analyzed. The following outlines some helpful advice on how to determine and select coolers that will meet your operating requirements.

The first step is to determine the range of cooler technology and type of equipment required at your facility. A simple method of accomplishing this is to categorize your needs into the following major areas in which coolers are utilized: bulk storage, interim storage, production requirements, service requirements, and specialty. Review each area of your facility in terms of use and physical attributes. Add to the process the application of your menu and production methodology. Then apply product/inventory turnover and product sourcing information, such as the frequency of deliveries.

The walk-in cooler application is extremely technical. Many individuals from varied disciplines are required to design and engineer a walk-in system. However, everyone involved in food-service management should understand and be able to determine capacity. Too often we hear, “Who designed this place? I need more cooler space.” This can be avoided by having more foodservice professionals understand the methodologies and formulas for sizing walk-in coolers.

Spacing out: A general rule of thumb for walk-in refrigeration is to allow about a one-half cubic foot of usable space per meal served. Let’s take a facility that serves approximately 400 meals per day. Using this rule, we would need about 200 cubic feet of walk-in space. With a 7′-6″ high walk-in, we need about 18 sq. ft. of usable cooler space. On smaller units such as this, we can assume that 60% of the space is usable; therefore, we would need approximately 30 sq. ft. of floor space. Extend this by the number of days storage–in this case, let’s say five days–and the total floor space required would be 150 sq. ft. With larger walk-in coolers, usable space drops down to approximately 45% of the total square feet.

The next step is to determine the cooler requirements for the remaining major areas of the facility–interim storage, production requirements, service requirements, and special needs. We can best break this down as follows:

* Interim storage: When primary storage coolers are located outside of the main kitchen (such as on a different floor), you may require an interim storage cooler (or “Day Cooler”) to stage the days or shifts cooler requirements within the actual kitchen.

* Production requirements: Refrigerated working coolers and prep coolers are always needed at the points of preparation, both cold and hot, within the kitchen and server areas. These may take the form of walk-in coolers or reach-in or roll-in refrigerators and provide a safe food supply to chefs and cooks at the point of preparation. Also, somewhere between the points of preparation and service, holding or “ready” refrigerators are required to safely hold the food products prior to serving.

* Service requirements: At the points of service, presumably in the cafe server and smaller retail venues, there are requirements for both ingredient coolers and finished product refrigeration. The ingredient units are typically reach-in and under counter refrigerators. Open ingredient rails or cold pans are utilized at sandwich, made-to-order, grill, pizza and salad and dessert stations. The use of both closed front and open-air refrigerated merchandisers is most evident; they increase merchandising opportunities as well as promote customer self-service. Open-air units require careful engineering to ensure proper food temperatures and safety concerns.

* Specialty needs: This category includes units such as blast chillers, temperature monitoring systems and food bank refrigerators designed for special temperature holding and refrigerated drink and condiment dispensing systems.

Cool rules: If designed properly, both water-cooled and air-cooled refrigeration systems will provide equal cooling results. In either case, the Food and Drug Administration’s Food Code requires that food is cooled from 140[degrees]F to 41[degrees]F within six hours. The more stringent Hazard Analysis Critical Control Point (HACCP) standard requires temperature reduction to 45[degrees]F within four hours. In addition, more health departments are requiring accurate recording of food temperatures through the food production and serving process.

New technologies, especially wireless networking, makes this easier than ever. In addition to having time and temperature information from every refrigeration system in the kitchen recorded on the central computer, the hardware itself can be monitored, allowing the operator to take care of service needs before they become critical.