Awaiting the Natural Refrigerant Revolution
I should note that the event was held 6,000 feet above sea level in the Rocky Mountains in March, so the weather logically would have fit the topic of keeping things cold. But, go figure, temperatures were in the 60s.
What was interesting about the conference was how ammonia was no longer touted as only for the industrial refrigeration niche market. Nor was it the only refrigerant being talked about.
The first change had been coming about for a few years as the ammonia sector looked for ways to expand places that the environmentally correct and relatively inexpensive refrigerant could be used. The first major breakthrough came when R-717 (ammonia) was used with R-744 (CO2) in cascade systems in some large plants. The original idea was that that approach reduced the amount of ammonia needed on site, which in turn reduced the amount of supplemental equipment and components. Such installations were totally safe and up to code. It was just that the less ammonia, the less cumbersome the requirements.
For several years now, IIAR and other ammonia advocates have been looking at ways to bring their favorite refrigerant into commercial applications.
That’s why a report at the conference about a supermarket in Carpinteria, Calif., was so significant. The store had been using HCFC-22 in a direct expansion system, a familiar and long used approach. But when plans were made to double the size of the store to 40,000 square feet, the mechanical refrigerant system installed had ammonia and CO2 in a cascade configuration. The ammonia was on the roof. Prior to this store, CO2 had been used in some large supermarkets in conjunction with HFCs to lower the amount and cost of HFCs needed. But this is the first HFC-free supermarket in the U.S.
The significance of that should not be overlooked. The supermarket sector was the first to move from CFCs when the phase out of those refrigerants due to ozone depleting issues began more than 20 years ago. Even as supermarkets embraced HCFC-22 across the board, as a first move away from CFCs, stores were also the first (beyond the automotive sector) to use HFCs. Now supermarkets are starting to look at something other than HFCs.
The other point concerns all the ‘natural’ talk at the conference. It used to be that IIAR attendees talked solely about ammonia, spending most of their time discussing how to handle it safely so that it could gain more and more acceptance in industrial applications.
Well, the safety talk is still a primary focus, but now ammonia is being included in a basket of what’s being promoted as a ‘natural’ option. There was much talk in March about ammonia and CO2 as noted in the California supermarket example mentioned earlier. But presenters also referenced inroads being made by HCs such as propane and isobutene in smaller frozen food cases that contain food products. And several exhibitors at the expo were mentioning ways to make air- and water-viable refrigerants to create cooling.
The feeling was that natural refrigerants will continue to gain attention and applications. And for all the projects using them, naturals are still but small blips on the refrigerant radar screen. But, in time, they will continue to grow and gain, and, rest assured, The NEWS will offer the latest information as this evolution occurs.
HFCs still have the largest presence. Expect this to continue unless the still disorganized effort to phase down their usage ever gets in gear. But, that doesn’t mean natural refrigerants can be ignored. There is too much happening to let that happen.
Publication date: 4/15/2013