Another is called secondary loop and involves HFCs or HCFCs and yet another coolant, such as brine or glycol. The idea here is to reduce the sheer amount of costly HCFCs or HFCs that have to be used to create adequate cooling for freezers and coolers.
Yet another approach is called distributed and virtually does away with a backroom in favor of mechanicals distributed throughout the store, thus lessening the amount of refrigerant lines, and also cutting down on the amount of HFCs and HCFCs needed.
Advocates of secondary loop and distributed technologies have been trying to gain a foothold versus DX for years now. I can remember going to Food Marketing Institute (FMI) Expos as far back as 10 years ago and seeing such technology displayed. Some years they had a higher profile than others, but they were most always present.
It has been slow moving them off of square one primarily because decision makers in supermarkets often don’t want their stores to be trial-ballooning new technologies when the tried and true of DX have worked so well for so long. And technicians often prefer to work on equipment they know, and prefer not to deal with the steep learning curve of new approaches.
But now things are changing on a number of fronts.
First, the Environmental Protection Agency (EPA) and FMI have launched a voluntary program called GreenChill. It is a partnership between the EPA and the supermarket industry to find ways to create refrigeration in as environmentally responsible a way as possible while still stressing energy efficiency. Some supermarkets had been signing on to try secondary loop and distributed long before GreenChill was announced one year ago. But it would seem that GreenChill will jump start that effort and, in fact, several supermarkets are already using the newer approaches in order to gain GreenChill recognition.
A second factor relates to efforts on the part of some store owners and engineers to introduce CO2 as a secondary refrigerant, again in an effort to lower HFC and HCFC charges. And research is underway to make CO2 work in refrigeration applications as a stand-alone refrigerant or in conjunction with glycol and brine - the idea being to do away with any need for HFCs or HCFCs.
On a third front is the trend in Europe for supermarkets to use secondary loop technology more and more, certainly at a much faster pace than in North America. Political pressures that often come from Europe regarding refrigerants may also be felt in terms of new directions for supermarket refrigeration.
GreenChill is on the plus side of the rapid technological shift in supermarket mechanicals. But there is also a negative motivation and that deals with the leak rate of refrigerants.
The EPA allows a maximum 35 percent leak rate, but is expected to require that leak rate to be much lower. At the time of this writing in late July, the EPA had not yet announced that magic number, but it will mean much, much tighter systems than we have these days.
There is a link to all this. Tighter leak rates may need to be attained not just by trying to seal up every leak in current systems. It may mean installing new technologies that address the leak issue as much as possible at the factory and/or make it easier to do so onsite.
The competitive nature of the supermarket industry means relatively frequent redesigns of stores or flat out new stores going up from scratch. That also means places to put these new, super, leak tight and technologically superior mechanical systems.
Contractors and technicians who have been happy campers dealing with leaking old DX systems may find themselves soon facing a whole new wave of tight, high-tech equipment.
Publication date: 09/03/2007