2017 RETA Breeze Nov-Dec

What goes around, comes around...

by Jim Price, RETA Education Manager

Almost everywhere we look these days we see something that is a retro. In sports, teams wear retro uniforms. Gardening stores offer heirloom plants. New car designs reflect classic styles. Architecture and interior designs have retro touches. We see it in fashion, movie remakes, and food. The classic style or technology is blended with the technology of the 21st century, and sometimes the results are stunning.

It is only natural we see that same trend in the refrigeration industry. Some of the “new” technologies are ones that were getting to be old timey when I started my career. A couple that come to mind are ice builders — thermal storage — refined direct expansion — to reduce refrigerant inventory — and Carbon Dioxide (CO2) — a natural refrigerant. Ammonia has been the refrigerant of choice for large industrial applications for the almost 50 years I have been in the business. And it goes further back than that into the mid to late 1800s. We all know ammonia is a great refrigerant, and I suspect it will continue to be on the design board for new refrigerated facilities, and in plants for many years to come. Carbon dioxide (CO2) is an heirloom refrigerant. Its history goes back with ammonia to the early days of mechanical refrigeration. In some respects, CO2 is a good refrigerant. I say good because like any other refrigerant it has pros and cons — there is, as of yet, no perfect refrigerant for every application. The use of CO2

peaked in the 1930s then declined to almost non- existent through the next several decades. What caused this decline? The rise of the chlorofluorocarbons (CFC), the hydrochlorofluorocarbons (HCFC) and so on, the so-called F refrigerants — Freons or synthetic refrigerants. They were cheap, easy to work with, “non-toxic”, not a fire hazard, and the newest thing, so they had to be the best. In a lot of applications, they were great. I still mourn the demise of some of the good old Freons. The problem was the industry was sloppy and not responsible. If we needed to work on a component, we did a quick pump down, and if there was still some pressure, we opened it up and vented it to the atmosphere. Other industries found uses for the CFCs as propellants and solvents. They were great for those applications as well, but again, large quantities were being released to the atmosphere. They were “safer” to use in applications where occupant exposure was a possibility, or in confined spaces. Sometimes the fact that these “safe” refrigerants displaced air

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