Refrigeration technology has been with us so long that it is easy to take it for granted, or to assume there's not much R&D going on in terms of basic systems or the way they're applied to foodservice equipment. But in an era where managing temperature has become a critical part of managing HACCP programs, and the costs of maintenance and energy are rising, refrigeration systems are coming under increased scrutiny.
A good example of how the industry is responding is a new type of system design called “BLU” that was introduced by Kairak at the National Restaurant Association show in May. It moves a steady flow of low-pressure, food-grade, propylene glycol through hollow chiller plates or dividers that separate food storage areas in prep tables, drop-in pan chillers, custom counters and sauté stations.
The glycol solution then circulates back to be re-cooled in a heat exchanger attached to a conventional refrigeration system. (This is similar to the way closed loop systems use chilled water to provide cooling throughout large buildings from rooftop cooling units and cooling towers.)
The design has attracted much interest from chains like Steak ‘n Shake and Jimmy John's, which have already installed it, and high volume operations like colleges and universities, where some installations are planned or are underway.
Circulating glycol under low pressure has a number of advantages when compared to the way traditional systems use high pressure refrigerant lines do the same job. For one thing, the glycol's temperature can be constantly maintained near water's freezing point, eliminating frost or ice buildup which compromises heat transfer and reduces efficiency. The need for defrost cycles is eliminated, reducing maintenance.
Because glycol is fairly easy to pump long distances under low pressure, the design also makes it easier to implement so-called “remote refrigeration,” with the pumps and compressor and evaporator components placed in exterior, rooftop or other remote areas where they can be centrally maintained.
The same glycol loop can be lengthened to cool multiple display or prep units, walk-in coolers or reach-in equipment. The heat they produce can then be simply exhausted to the outside air, saving considerable energy.
For more information about the BLU systems, go to www.kairak.com/blu