R-410A’s Replacement?

Earlier this year the Environmental Protection Agency announced that they were approving five new refrigerants for use in various applications across the United States. One of these refrigerants, HFC-32 (R-32), is a front runner for an alternative for R-410A. For a full description of the new approved refrigerants click here.

Why is R-410A being Replaced?

It seems like everyone is just getting used to R-410A from the 2010 switch over from R-22. Well, now 410A could be on the chopping block.

R-22 was phased out due to it damaging the O-Zone, while 410A does not damage the O-Zone it does have a very high Global Warming Potential. The GWP of 410A is a significant contributor to climate change and there is a big push across the world to phase out HFCs including 410A.

Now, 4101A is NOT being phased out… yet. The only steps that have been taken are strictly voluntary. However, in 2014 the three North American countries lobbied for an amendment to be added to the Montreal Protocol which would phase out all HFCs across the world. This would include R-134a, R-404A, and R-410A. The amendment has not been approved yet but I feel that it will be approved sometime in 2015.

Properties of HFC-32

I found a great detailed report that shows pros and cons as well as properties, tests, and other great information about HFC-32 versus R-410A. Ten pages worth of data!

A snippet of the article that I thought was worth reading was the pros and cons of HFC-32 versus 410:

“The relative merits of R32 can be summarized based on a comparison of theoretical properties as shown in Table 1 :
  • Considerably lower refrigerant cost than R410A and potentially better affordability
  • Available now in high volumes globally since it is 50% of R410A composition
  • 8% higher critical temperature, better performance at higher ambient conditions
  • Similar pressure and pressure ratio, a close drop in replacement for R410A without major system redesign
  • 9% lower liquid density, lower system charge requirement
  • 28% lower vapor density and lower system mass flow rate, about 50% lower pressure drop expected
  • Higher volumetric capacity despite the 28% lower mass flow due to 4350% higher latent heat
  • 41% higher liquid thermal conductivity, higher heat transfer coefficient at same mass flux
  • No glide and potential to optimize heat exchanger with smaller tube volume for further charge reduction
The disadvantages are cited below:
  •  A2L mild flammability rating (difficult to find a
  • LowGWP A1 nonflammable fluid)
  •  higher compressor discharge temperature from higher vapor specific heat
  •  New oil likely required since existing polyolester (POE) oil is not miscible with R32″

Is HFC-32 the Future?

The main push for new refrigerants is to lower the overall Global Warming Potential that refrigerants have on the environment. HFC-32’s Global Warming Potential is 675 compared to R-410A’s GWP of 1,725. While 675 is not an ideal GWP it is quite lower than 410A. Couple that with widespread use of HFC-32 in Asian countries, including Japan, and I could definitely foresee the United States transitioning over to R-32. (HFC-32)