When I first started writing articles about R-717 Ammonia being used in ice rinks and in industrial refrigeration I tried to keep an open mind. However, over the past year or so I have become less and less confident with R-717 systems. I try to make my articles unbiased and to show the Pros and Cons to both sides but this is proving more difficult with R-717. Maybe I need some of you to re-convince me to the benefits of this refrigerant but as of today I am very skeptical of it’s practical applications.
Ammonia has been used as a refrigerant for nearly ninety years. While the applications have varied over the years it has always been around. It is highly regarded as the most efficient refrigerant available due to it’s low boiling point. To give an example R-717’s boiling point is -28 degrees Fahrenheit. While R-22’s boiling point is -41.62 degrees Fahrenheit and R-410A’s boiling point is -55.3 degrees Fahrenheit. Compare R-717 and R-22 and that’s a forty-eight percent difference in boiling point. Along with that low boiling point you also get no Ozone depletion and a very low Global Warming Potential. I can see why this refrigerant is used but we have to be aware of the downsides. R-717 is toxic and is also slightly flammable. It is rated as a B2L from the ASHRAE group.
Greenwood, South Carolina
Today, March 25th, the Department of Health and Human Services is on the scene of an Ammonia leak in Greenwood, South Carolina. Upon finding the leak and determining how large it was a half-mile radius was evacuated for precaution. Local citizens were awoken by police alerts on their phone and at their door to evacuate the area at two this morning. Later that morning police and firefighters walked through the affected areas taking samples to ensure that the air quality had returned to normal. The all clear was given this morning as well. Luckily, this leak was handled correctly.
While the exact cause of the leak has not been released I did find that it came from a food processing plant known as Carolina Pride Foods. This plant is a meat processing and manufacturing center. In the past I have toured a few meat processing plants and just as anyone would assume, they need to be refrigerated as well as have a freezer section. Heck, it’s so cold there you have to wear jackets, mittens, and hoods just to walk around for any matter of time. Using R-717 as their main refrigerant logically makes sense due to the energy efficiency. (In fact you’ll see these used in most industrial applications like this.)
Luckily, with this leak in South Carolina there were no fatalities. However, this latest incident was very familiar to a leak at an ice rink that occurred in Canada towards the end of 2017. A leak occurred and a large radius was evacuated just like in today’s story. The difference though was that proper precautions were not taken in Canada and it resulted in three fatalities. This tragic event has caused a lot of business owners and contractors to reconsider using Ammonia in future applications. I wrote a story about this event.
Conclusion
While today’s event ended well and with no injuries I still am quite skeptical on the reasonable application of R-717. If this stuff leaks, which all systems will at some point, then disaster can occur. Today Ammonia seems to have a monopoly on industrial refrigeration and a fair slice of the market on ice rinks especially over in the European Union. Here’s the thing though, even with it’s danger and risk to public safety the R-717 market isn’t expected to shrink over the next few years. In fact, just the opposite. With all of the pressure around the world to phase out or phase down Ozone depleting or high Global Warming Potential refrigerants the industry has only two options to turn two: HFO refrigerants from Chemours and Honeywell or Hydrocarbons such as Ammonia.
The question on my mind folks is when does saving the environment become more important then safety? Should we keep switching units over to Ammonia in an effort to reduce Global Warming, or should we begin switching to HFC alternatives until a more suitable refrigerant that provides low GWP and is non-toxic arrives into the market place?
I looked through Honeywell and Chemour’s website going over their Solstice and Opteon HFO lines but I did not see anything specifically referencing industrial applications. I’m wondering if the rush to find an alternative to R-717 is on the back burner because it doesn’t actually affect the climate whereas all of the other HFC refrigerants are affecting Global Warming. So, again, I feel like safety is taking a backseat to Global Warming.