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I decided to give NU-22 a shot in my brand new Freus A/C unit. It seems to be the perfect solution to the whole R-22 issue (much to the chagrin of the 410A folks.) It is marketed as a drop in for R-22. There are those in Europe who are giving 410A problems on the environmental front. Unfortunately, the copeland warranty is invalid as is stands now.

I haven't asked the Icor folks, but since is's a blend of hydrocarbons it should not need any recovery.

What are your thoughts?



  • Eugene Silberstein
    Eugene Silberstein Member Posts: 1,380

    Hi Jerry. A couple of things about NU-22 (R-417a).

    NU-22 is a blend of 2 HFC refrigerants (R-134a and R-125) and one hydrocarbon (butane). Since NU-22 is basically an HFC blend, it must be recovered under the requirements set forth in EPA SEction 608.

    I'm not sure what Icor has stated regarding its use, but I do know that HFC refrigerants and HFC refrigerant blens are to be used with Ester-based oils. R-22 systems, depending on the compressor manufacturer, can be equipped with mineral oils, alkylbenzene (AB) oils or ester-based oils. If the particular system contains mineral or AB oil, it must be changed as they are not compatible with ester-based oils. So, the answer to your question is this: YES and NO.

    Remember one thing about NU-22 though, when charging a syustem with NU-22, be sure that the total charge will be about 80% of the original R-22 charge.

    I have worked on a number of systems that have put back into service with NU-22 and have had no problems up to this point.

    Also, as you mentioned, the compressor manufacturer should be coonsulted as far as compressor warranty goes. Of course, on older equipment there is no waranty to worry about.

  • JeffD
    JeffD Member Posts: 41

    NU-22 can be used with mineral oil, alkyl benzene or ester oils. That's the reason they add the butane. The small amount of butane in the blend allows the refrigerant to dissolve into the mineral oil and promote proper oil return. All HFC's are compatible with mineral or alkyl benzene oils, it's just that pure HFC's will not dissolve into them, and this lack of solubility creates oil return issues. Adding a few percent of a hydrocarbon to the blend ensures that the oil that leaves the compressor will come back.
  • John Mills_5
    John Mills_5 Member Posts: 946
    Good guys

    I've been to ICORs plant a couple times. Good bunch of people. I have Hot Shot in my work car, talk about cold!

    Anyway, what was the reasoning for taking out R22 in a new unit? NU22 should be a good gas if the OEMs would give it a chance. Hard to compete with Honeywell pushing R410a though.
  • Eugene Silberstein
    Eugene Silberstein Member Posts: 1,380

    Interesting point, but one question for you, JeffD. It may just be a sticking point about the term "compatibility". You mention that, and I quote:

    "All HFC's are compatible with mineral or alkyl benzene oils, it's just that pure HFC's will not dissolve into them, and this lack of solubility creates oil return issues."

    Since there IS an oil return issue with mineral oil and HFC refrigerants, why whould we want to say that mineral oil and HFC refrigerants are "compatible?" I know that compressor manufacturers wouldn't.

    If possible, Jeff, could you please provide me with your source for this information, since all of the books at my disposal as well as the Federal Register, Volume 63 #112, state that HFCs are not compatible with mineral oils. I am definitely interested in researching the topic further and discussing the matter in more detail with the individual who provided this piece of info.

  • JeffD
    JeffD Member Posts: 41


    What I really meant was that they are chemically compatible, ie mineral oil mixed with an HFC won't cause either the oil or the refrigerant to breakdown. You are absolutely correct in that pure HFC's without a hydrocarbon are not compatible in mineral or alkylbenze oils in that these combinations will not allow for oil return. Sorry for the confusion on this one, sometimes my typing gets a head of the old brain:)
  • Eugene Silberstein
    Eugene Silberstein Member Posts: 1,380
    No problem

    No problem Jeff, I thought that I was missing something and I was going absolutely crazy going through every piece of literature I had in search of info.

    Thanks for your input. Keep it coming.

  • Kal Row
    Kal Row Member Posts: 1,520
    i am not so crazy about ICOR...

    HotShot is a rip off of 406a (there was a whole lawsuit) - except that it has less butane - so is doest NOT carry the oil around the system well - this makes hot-shot a big no-no for refrigerators with capillaries (they get oil-locked) – In a car with an expansion valve and an equalizer line – not so bad – but I would not recommend it for those orifice tube systems – as for NU-22 – I will wait to see if they cause systems to get oil locked, I would rather learn from other peoples experiences – also as R22 is readily available – why would you want to switch now

    PS just because I answered all the questions correctly on the EPA exam – doesn’t mean I buy it, I personally think that the ozone layer is cyclic, and as it thins out, the planetary wide thunderstorm rate goes up, which produces OZONE and rebalances it –

    especially those level 5 T-storms which produce those cool mushroom shaped lightning balls into the stratosphere – and those 6000 feet per minute updrafts, carry the stuff way up as well, much to the chagrin of “SledDrivers” (as SR-71 blackbird pilots are known), one of them recounts being over Hanoi at 60,000ft in a t-storm – and decides to do a lazy climbing turn to 80,000 figuring that by the time he travels the hundreds of miles it takes to do a 360 at those speeds, it will have passed, only to find himself in the soup at 80,000ft – so there – a well developed storm with tons of warm moist air feeding it (as it does from sides, the south-china-sea and the gulf of Tonkin) can really blow ski-high – if it weren’t for those, we would have lost the ozone layer millennia ago – so please – the EPA represents government out of control!! – no wonder the Chinese didn’t sign the Montreal protocol that banned CFC’s – they are smarter than us!!!
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