2021 Webinar Series - 11 Lower GWP Refrigerants

Recent federal and state hydrofluorocarbon (HFC) refrigerant legislation will require the HVAC industry to meet the growing call for environmental protection. This transition will have significant direct and indirect impacts on the heat pump sector. There have been previous refrigerant phase outs, most notably a global effort to eliminate atmospheric ozone depletion. Now the focus has shifted to addressing the very high global warming potentials (GWP) of today’s commonly used refrigerants. This next transition looks a bit more complicated with multiple, mildly flammable, low-GWP refrigerants available as soon as building codes allow. The presentation provides perspectives on the next transition, leading low-GWP refrigerant candidates, timing and possible consequences for various stakeholders.



  • Richard Gerbe / Highmark
  • Joe Parsons / ClimateMaster
  • John Ciovacco / Aztech Geothermal







  1. Are you considering other strategies that will reduce the actual use of refrigerants?  Like distributing thermal energy in a building using water instead of refrigerants, reducing field assembled piping that's prone to leaks, and hermetically sealing condensing sections much like we do with refrigerators to eliminate leaks there?
    1. John Ciovacco - Most GSHPs are factory charged and sealed.  Like I showed from that chart from Steve Kavanaugh.  Then they carry the conditioned air or water to the spaces.
  2. Does the insulation effect that Richard describes also insulate the earth from solar gain?
    1. John Ciovacco - The mechanism for the sun to “heat” the earth with light and the ability for the atmosphere to trap heat that is no longer light is the key to a proper answer to this question.  From my reading, GHG don’t reflect much light but do trap heat.  A scan of this link provides a more detailed explanation. https://medium.com/the-philipendium/are-greenhouse-gases-a-myth-1a0bbc8aa89a 
  3. What is the scale of the refrigerant leak problem from heat pumps vs. refrigerators, window air conditioners and car air conditioning systems?
    1. There is a lot of research out there about this and I haven’t seen a real consensus. In my opinion, they are all a real problem. Refrigerators, window AC systems are usually well sealed, but become an issue after they’ve reached the end of their useful life and are moved to the scrap yard. Commercial systems are usually handled by technicians with EPA certifications, but also leak unknown to the operators. As such commercial HVAC systems usually leak about 2-3% of charge per year
  4. What are, if any, the local restrictions to using A2L refrigerants? Are there templates for local building codes to simplify and facilitate adoption of A2L refrigerants?
    1. There isn't really any code that says you can’t use A2L’s because it’s a new classification. The codes will need to be updated to include them. There are a number of organizations out there that are creating the guidelines and standards needed for the code officials to adopt their usages.  
    2. JC - As was discussed in Matt’s presentation there are a number of things from a code, UL, OSHA, DOT and others that need to be signed off on before A2L will be broadly permissible in residential and commercial occupied buildings. 
  5. Are there concerns about TFA (trifluoroacetic acid) as an atmospheric by-product of HFOs that will influence the adoption of R454B?
    1. my opinion, currently we are far from full f-gas elimination; as long we have f gases, TFA creation will occur. EPA considers all refrigerant options based on the entirety of their environmental impact. Im sure TFA is considered, but as end users of refrigerants, our main concern is efficiency and GWP is on the top of the list of concerns
  6. oil goes into a refrigerant? Why?
    1. To lubricate the moving parts - primarily the compressor and to some extent the reversing valve.  Kind of like a two-stroke engine, the oils are mixed with the refrigerant.
  7. Do refrigerant options change when talking about DGx systems? I've heard of CO2 as an option in these types of systems.
    1. JC- I’m not 100% sure what DGx refers to. Maybe Direct Exchange Geothermal systems?  Nevertheless, CO2 as a refrigerant will be covered in our next session.  Sign up and ask an expert! https://us02web.zoom.us/webinar/register/WN_DNXStq6lSn-wmjxcdUya8g 
  8. Is ClimateMaster leaning to R32 or R454B? Is there an industry standard that can be created so that all manufacturers can shift to the same refrigerants?
    1. ClimateMaster continues to investigate the ideal choice and is zeroing-in on the ideal solution to maximize application performance.  We are not ready at this time to announce our selection, however expect to do so in the near future.  In terms of creating a single standard that can be used for all manufacturers, that could be considered, however, this would remove the manufacturer from optimizing their product solutions based on their application... At this point, I am not aware of a regulation being pursued in this area.
  9. Given the flammability of A2L refrigerants what difference is there in danger from compressor burn out?
    1. that's not a concern. they are very stable compounds and you need a perfect storm of conditions for them to ignite
  10. What's the 20-year GWP of R454B?
    1. I looked quickly before the session but didn't find it right away.  I'm sure it's out there.  I'll look again!
    2. JC - I found it!  GWP100 = 490 and the GWP20 = 1,740 - so a lot higher. Here’s the link where I found that and other good information about next generation refrigerants: https://wedocs.unep.org/bitstream/handle/20.500.11822/14878/7740-e-SafeUseofHCFCAlternativesinRefrigerationandAir-conditioning.pdf?sequence=1&isAllowed=y
  11. Is the expectation that equipment weights & sizes with the newer refrigerants will increase over similar capacities with 410a - similar to the increase from R22?
    1. At this point, the low GWP refrigerant is not expected to have the larger weight change we saw with the change from R22 to R410A.   Much of that weight change was also related to an increase in the minimum efficiency requirements which required increases in efficiency.
  12. Best guess as to what percentage of the refrigerant charge does the average geothermal installation lose over the 25-30 year life of the heat pump.  
    1. JC for GSHP systems we install they fall in three categories at any given time.  1) don’t leak at all and that’s the vast majority. 2) Those that have a slow leak that we don’t know about yet - but that’s rare 3) those that have a big leak and need to be repaired or replaced - also rare.  I do think over 25 or 30 years a heat pump could fall into the second two categories before it’s replaced - but as we have discussed, if they have been displacing fossil fuels the net benefit is positive on the environment even with quite a bit of refrigerant escaping.  
  13. Is it expected that the working pressures for the newer refrigerants be similar to 410a? If not - higher or lower?
    1. Answered live.
    2. JC - Relative to R410A (today’s refrigerant), R32 is a little higher and R454B is a little lower.  They are in the same pressure range but that doesn’t mean that they can be a drop in replacement and certain components, including compressors, might need to be changed to accommodate the differences.   
  14. How far into the future is the industry looking at refrigerants and global warming? Is there a hypothetical perfect system conjectured that will neutralize the global warming impact that refrigerants have?
    1. Answered Live
    2. JC - There’s always a balance being sought for refrigerant of several factors.  GWP is a relatively new additional challenge.  Traditionally the changes have been to produce safer refrigerants - so lower toxicity to humans and lower flammability.  Reasonably pressures are good too.  But then there are performance factors that contribute to the efficiency of the refrigeration system which needs to be there.  Then you get into stability - like a mixture that stay’s mixed under expected operating conditions so it works as intended.  What lubricants can be added and also not separate out easily?  Is the refrigerant at all corrosive to the refrigerant system in the range of possible/expected conditions over time.  Will the refrigerant chemically break down over time based on expected use conditions?  So there are always trade offs - no refrigerant we know of is the best in every category.   Right now we are trading off lower GWP for more flammability.  When we talk about CO2 refrigerant next week, we’ll talk about a totally different set of performance curves and relatively high operating pressures.  There are trade offs.  Wish it was simpler.
  15. Since refrigerants have a higher GWP, should refrigeration recovery be incentivized to a point where it's free or we pay customers to reclaim? Who should be doing this?
    1. Answered live.
    2. JC - I think lots of work needs to be done here.  Especially since we will be moving to lower GWP refrigerant, which means we will be going out and removing/replacing existing systems with some of the highest GWP refrigerants.  We have an opportunity to do the right thing if we incent contractors / building owners to take care to contain, recapture, recycle or dispose of properly.  There are occasional refrigerator/freezer removal programs which are good but that thinking needs to be extended to HVAC installers when removing old AC and HP equipment too.  
  16. What, if any, incentives are there to recycle or reclaim refrigerant? There appear to be no incentives. If incentives are just avoiding punitive measures and fine we need to know if it is working at all. It would be interesting to know the effectiveness of current regulations in preventing release of ODP and GWP into the atmosphere. The threat of fines only is effective only if there is oversight of the industry and enforcement. It would be interesting to know the number of contractors fined or losing their certification since the laws went into effect. Further, what is the volume of ODP and GWP refrigerants recovered since the regulations went into effect.
    1. JC - I don’t have data on fines for violations.  Experience says there is very little tracking or oversight for systems below 50lbs charge - which is almost all residential systems.  Not looking for more regulation that adds time/cost but if there were incentives to recapture that would motivate the market to do the right thing.  I bet NYS would be receptive to provide funding for pilot programs that incent contractors to recapture/recycle.  So maybe think about what channels make the most sense and which NYS agencies would be open to funding such an effort.  I have suggested such things to the EE and Housing panel of the Climate Action Council. 
  17. Why aren’t new refrigerants better choices for HVACR equipment than CO2?
    1. Answered live.
    2. JC - We will talk about CO2 as a refrigerant in our next session - sign up! 
  18. How much retraining will be needed for technicians in the field to install the next generation of equipment? Does anyone know what kind of attitudes those technicians have regarding adopting the next generation?
    1. Answered live,
    2. JC - there will be training offered and it will not be a big change from current practice from what we can tell.
  19. How is the development of technology for heat pumps internally detecting refrigerant leaks?
    1. I know of a few manuf. who have a sensor solution, they currently exist
    2. JC - larger systems will have refrigerant monitoring as a secondary external system.  We do get low pressure alerts which are sometimes a sign of refrigerant loss presently on most of our systems.