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Changing Refrigerants and Why it Matters to You
Graphic Courtesy of Danfoss
During the week of 9/18/2017, Danfoss put out a lot of great information on global changes to refrigerants and their expected impact on equipment and the industry.
This a quick overview of the different types of refrigerants, the reasons for the changes, and some things to watch out for.
ODP & GWP
When I went to trade school in the '90s, all the talk about refrigerant regulation stemmed around the destruction of the Ozone layer by CFC (Chlorine, Fluorine, Carbon) refrigerants like R12 and HCFC (Hydrogen, Chlorine, Fluorine, Carbon) refrigerants like R22. The likelihood that a particular chemical would break down ozone in the stratosphere was designated by an ODP (ozone depletion potential) number. The worst offender was R11, and it was the benchmark for ODP with a rating of 1. Other refrigerants like R12 and R22 had a lower ODP than R11 but still had the potential for ozone depletion.
Over time, these CFC and HCFC refrigerants have slowly been phased out in the developed world, starting with Europe and moving on to the USA and many other countries.
The attention of the scientific and regulatory world has now shifted to considering the emission of greenhouse gases like methane and carbon. Scientists have studied the effects these gases have on global climate and have concluded that they contribute to global warming.
The term used to identify how much a particular gas contributes to global warming is GWP (Global Warming Potential). The number starts at 1 with carbon dioxide (CO2) and goes up from there with common modern HFC (Hydrogen, Fluorine, Carbon) refrigerants like R410a and R404a, which both have zero ODP but high GWP numbers.
Because of this, manufacturers like Danfoss have looked carefully at alternative refrigerants by looking at new technologies and some refrigerants that have been around for a very long time.
The hydrocarbon category contains FANTASTIC refrigerants with excellent heat transfer, pressure/temperature, and oil miscibility. The only problem is they are all flammable. These include R290 (Propane), R600a (Isobutane), R1270 (Propylene), and even some uses of butane and ethane in refrigerant blends. These refrigerants are already being used in some small self-contained units like soda machines and water fountains. They have zero ODP and very low GWP. Read more from Danfoss on HC refrigerants.
Natural refrigerants were the earliest refrigerants used. Starting with air and water and then moving on to ammonia and carbon dioxide. All of these refrigerants are inexpensive with little to no GWP, and they all can be used as a refrigerant.
Water and air have never been economically viable when compared to other refrigerants based on the power input to BTU output.
Carbon dioxide has a low critical point, making it fairly well-suited for colder climates and low-temperature equipment but posing some challenges in areas with higher outdoor temperatures.
Ammonia is arguably the best refrigerant available, but it is highly corrosive and toxic, making it a real safety risk.
HFO refrigerants have a similar makeup to HFCs, but they are formulated to break down more quickly, greatly reducing their chances of making it to the upper atmosphere. Because these refrigerants are new and still contain fluorine (a limited natural resource), the production costs are high. Currently, R1234YF is the most commercially available HFO and is being used as a replacement for R134a (HFC) in refrigeration and automotive applications.
Just last month, on 8/8/17, the United States court of appeals struck down an EPA phaseout of HFC refrigerants under the Clean Air Act on the basis that the Clean Air Act only gave the EPA the right to regulate ozone-depleting substances. The decision is likely to be appealed further. This case could have a wide-ranging impact on HFC regulations for the next several years, but those in the know suggest proceeding as planned due to the likelihood that HFC phaseout is still on the horizon.
Danfoss did some excellent interviews with Zack and Ralph from the HVAC Shop Talk podcast, which you can hear below: