|Jason Prenger | Refrigeration Engineering Director
Emerson Commercial & Residential Solutions
View our latest E360 webinar, “Understanding Applications for New Refrigerant Alternatives”.
Since the EPA’s 2015 rule that changed the listing status of certain hydrofluorocarbon (HFC) refrigerants to “unacceptable,” the commercial refrigeration industry has been closely evaluating new refrigerant alternatives. With a high global warming potential (GWP) of 3,922, R-404A was at the top of the list of those refrigerants scheduled for phase-out. Today, there are A1 refrigerants with GWPs below 1,500 that are available for use, such as R-448A and R-449A/B. But because they are largely unproven outside of manufacturer testing facilities, their reliability in specific applications is still in question.
In our recent E360 webinar, I examined these new A1 refrigerants by comparing their performance characteristics and operating envelopes to R-404A and R-134a. Emerson has been testing these new A1s across our compressor platforms for several years. So, from an engineering perspective, we have compiled significant data to help the commercial refrigeration industry address these questions and evaluate this emerging class of refrigerants.
I reviewed the extensive process required to qualify compressors with new refrigerants and discussed several important considerations when using A1s:
- R-404A alternatives have a higher heat of compression; R-134a alternatives have similar heat of compression
- Liquid injection allows compressors to run at full low temperature operating envelopes for the R-404A alternatives, albeit with higher power consumption
- Temperature glide is important to consider with R-404A alternatives
Per the first polling question posed in the webinar, nearly two-thirds of the audience is currently using or working with A1 replacement refrigerants. As I pointed out, some applications are more challenging to address with new A1s than others. For example, supermarket refrigeration systems have been trying non-R-404A options that are still allowable for many years, including R-407A and the natural refrigerant CO2. But, in medium-temperature, stand-alone units, the medium pressure A1 alternatives to R-404A — the R-407 series or lower GWP options like R-448A/R-449A — will either not be allowable or have yet to be listed by the EPA as acceptable for use. It’s also important to remember that these stand-alone applications are facing an EPA HFC phase-out date of Jan. 1, 2019 for the higher GWP refrigerants.
Aside from A1 alternatives, the industry is also evaluating A2L and A3 options, both of which fall into the flammable refrigerant classification. While the natural A3 refrigerant R-290 (propane) has gained acceptance by the EPA, many mildly flammable A2Ls are still going through the approval process. Both refrigerant types are the subject of numerous revisions to safety and building code standards.
Finally, I discussed the impacts of this transition to new refrigerant alternatives throughout the commercial refrigeration channel, from OEMs and wholesalers to contractors and end users; all will be impacted in one way or another over the coming years.
If you would like to view this webinar in its entirety, click here.