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Thread: Nu22 aka R422-B

  1. #1
    Join Date
    Sep 2008
    Posts
    586

    Nu22 aka R422-B

    I know this has been discussed to death (but not for my application). I've been happily using R-22 in the MT/HT 45°F coil temp (75# suction). Mostly fractional sized condensers with mineral oil, TXV.

    I've read and heard of some seal issues but that seems to affect retrofits.

    I've also heard of some oil return issues but that seems to affect LT systems more.

    I've got decent supplies of R-22 and plan to load up on some more before the pricing gets worse but it won't last forever

    Any thoughts, concerns, experience with this stuff?

    What would you do?

    PS...I've been using Tecumseh CU units and they do offer them in R134a and R404A but both suffer capacity loss and use POE


  2. #2
    Join Date
    Nov 2009
    Location
    West Yorkshire England
    Posts
    405
    I was also told about potential capacity problems regarding dropin/retro fits when I came back into refrigeration. To be honest I don't think they're as bad as I expected them to be. And the only alternative is to replace the whole system. Explain to your customer that there may be a problem with capacity, and tell them you can't guarantee the system to work as well as it did before but at least it will work, but their electric bill may be slightly higher. Offer them the alternative of a new system and I bet they go for the cheaper option.

    Can't say I've come across any refrigeration systems with R22 in them though, only air con. Most of the dropin/retrofits I've done have mainly been on R12 systems, and they really could do with replacing totally. They're old, rusty, and noisey, but as far as the customer is concerned they are working, and they won't have them changed because it keeps the food and beverage cold. And they know they can rely on me to make it work for them if they stop working.

    You said in your post that you've been having oil problems, the only thing you could do is flush out the system to clean it and use the correct oil for the gas. There are many new theories and methods regarding pot changing and retrofitting that don't include flushing with a flush chemical. I prefer to stick to my guns and use the chemical flushing method, then at least I know that they'll be no oil cross contamination and cap slugs.

    Just in case you don't know, if your using the said compressors then you will need to use whatever gas and oil is compatible with them. R22 will not work with pag or poe. And the said compressors will create major capacity problems if you don't use the compatible gas and oil with them.
    Martyn

    50 & 60 hz but 100's worse

  3. #3
    Join Date
    Jul 2007
    Location
    alexandria va
    Posts
    138
    Just in case you don't know, if your using the said compressors then you will need to use whatever gas and oil is compatible with them. R22 will not work with pag or poe. And the said compressors will create major capacity problems if you don't use the compatible gas and oil with them.[/QUOTE]

    not exactly sure what pag is but as far as i know 22 is compatible with poe. i may be wrong if i am please point it out for me. jbb

  4. #4
    Join Date
    Sep 2007
    Location
    NH
    Posts
    1,216
    Yep 22 will work fine with POE.. POE will work with pretty much any flavor.....

  5. #5
    Join Date
    Aug 2002
    Location
    Southold.calm
    Posts
    6,334
    For what it’s worth, POE oil will work with all refrigerants.

    But be advised POE acts as a cleaning solvent and will flush the line set. On older systems this may cause troubles.

  6. #6
    Join Date
    May 2000
    Location
    Indianapolis, IN, USA
    Posts
    34,599
    Talk to ICOR about the application. NU22b is most commonly used in air conditioning applications while One Shot which is 422C is more commonly used in refrigeration.

    http://www.icorinternational.com/oneshot.html

  7. #7
    Join Date
    May 2004
    Posts
    1,886
    I prefer Duponts MO79 (422A) for refrigeration.


    http://www2.dupont.com/Refrigerants/...CEON_MO79.html

  8. #8
    Join Date
    Sep 2008
    Posts
    586
    Thanks all.

    No oil return issues. These are small systems with relatively short <50' linesets with minimal rise/drop (<10').

    I'd like to limit myself to one gas for both retrofits and new systems.

    I'd also like to avoid POE because it's so hygroscopic and can be a PITA.

    A small 5-10% capacity loss would be acceptable in most applications.

    BaldLoonie, I'm sure ICOR will tell me it's great and will be happy to recommend a product, but I'm more interested in the boards collective experiences rather than manufacturer BS.

    270wsm, isn't 422a more for LT? looked at at PT chart and I'd have to run 115# suction...not happening

  9. #9
    Join Date
    May 2004
    Posts
    1,886
    Quote Originally Posted by CoolWine View Post
    Thanks all.

    No oil return issues. These are small systems with relatively short <50' linesets with minimal rise/drop (<10').

    I'd like to limit myself to one gas for both retrofits and new systems.

    I'd also like to avoid POE because it's so hygroscopic and can be a PITA.

    A small 5-10% capacity loss would be acceptable in most applications.

    BaldLoonie, I'm sure ICOR will tell me it's great and will be happy to recommend a product, but I'm more interested in the boards collective experiences rather than manufacturer BS.

    270wsm, isn't 422a more for LT? looked at at PT chart and I'd have to run 115# suction...not happening

    You must have looking at °C

    45° coil is about 92psi.

    Check out MO29 (422D) It is more for medium temp. 45° coil with this is about 73 Psi
    http://www2.dupont.com/Refrigerants/...CEON_MO29.html

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