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Thread: r22 conversions

  1. #14
    Join Date
    May 2009
    Location
    The Pas, Manitoba Canada
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    231
    Starting to sound like vehicle mpg ratings from the manufacturer. Does anyone out there feel like a volunteer refrigerant tester? Will there ever be a permanent replacement? I don't think so.

  2. #15
    Join Date
    Nov 2011
    Location
    North sweden, Umeε, Where the birches growing without limits.
    Posts
    98
    Actually.... a 18 year old Mitsubishi Aircond with scroll comp, that once had running on R22. Fixed minor leaks last summer, t'was 407C in the system, converted some years earlier, only the ref had been changed, nothing else.

    Well, as a answer on my earlier quest 'bout 404A vs. 507, 404A is more commonly used. Cheaper they say, my answer is... Bull****!... Same pricing for 404 as 507, but 507 has a li'l bit higher GWP value.

    Then... Dupont was first with 404A, then someone else came up with 507, it never "hitted" the market. Dupont ref is a type of DeFacto standard on the market. The "uppercuts" don't suceed in the same way.

  3. #16
    Join Date
    Jun 2001
    Location
    Michigan
    Posts
    12,077
    This conversion storm is about ready to launch here across the country with in the next 18 months. Great time to be in the refrigeration trade. There is gonna be so much work it's just incredible. I know that many chains are just now starting to put plans on the boards, starting to dream up budgets, starting to ask contractors about things. Remods and new stores have been going the alternative route for the last few years, but there is so much existing out there. I have heard guys say that a conversion won't happen till a catastrophic loss. When this stuff all began to be talked about I might have agreed. Now that I see what you gotta do to the system, changing gaskets, ect ect ect, there is too much to do to do it under duress. It must be intentionally executed. And the costs of 22, they are going to force the hand of all the chains. It's coming, it's gonna be a tsunami, sit back and enjoy the work.

  4. #17
    Join Date
    Sep 2008
    Location
    Western PA
    Posts
    25,952
    Quote Originally Posted by Dowadudda View Post
    This conversion storm is about ready to launch here across the country with in the next 18 months. Great time to be in the refrigeration trade. There is gonna be so much work it's just incredible. I know that many chains are just now starting to put plans on the boards, starting to dream up budgets, starting to ask contractors about things. Remods and new stores have been going the alternative route for the last few years, but there is so much existing out there. I have heard guys say that a conversion won't happen till a catastrophic loss. When this stuff all began to be talked about I might have agreed. Now that I see what you gotta do to the system, changing gaskets, ect ect ect, there is too much to do to do it under duress. It must be intentionally executed. And the costs of 22, they are going to force the hand of all the chains. It's coming, it's gonna be a tsunami, sit back and enjoy the work.
    Ya know, if you had the materials on hand, you could do a phase out on a catastrophic loss.

    Put two or three guys on the job. One changing oil and two changing the gaskets.

    Might not be a PERFECT job, but it'll run and you could clean up loose ends over the next day or so.

  5. #18
    Join Date
    Jun 2001
    Location
    Michigan
    Posts
    12,077
    I dunno. Thats a pretty optimistic look.

  6. #19
    Join Date
    Jul 2000
    Location
    Guayaquil EC
    Posts
    10,487
    As I see it, if the game plan is to eventually go to an replacement refrigerant which requires an oil change from MO and/or AB to POE, then the oil changes can be done at any time, but the gasket changing must be done at the same time as refrigerant switch, or no?

    I have little experience with the gasket issue. But 4-5 years ago I did a test (of sorts) on a small walk-in where I retrofitted from MP39 to MO49 Plus. It had one Alco 200RB LLS, so I intentionally did the retrofit without changing the seal, just to see what happened. It started leak like a SOB within an hour at a rate I estimated to be about 2 lbs per hour or so. I then quickly swapped out the seal and all has been well since.

    My question to those who have done such conversions is are there some seals or gaskets which are more prone to serious leaking than others? IOW, are there some which "must" be done and others which can afford you some time to do them after the fact?

    Also, I find it hard to believe that in this day and age, there isn't a seal compound which doesn't swell up with R22. If they were available to us, they could be change ahead of time as well, with minimal hassles.

  7. #20
    Join Date
    Jun 2001
    Location
    Michigan
    Posts
    12,077
    That's what I have been apart of doing. Oil done ahead of time. And it takes 3 changes to get to 98% I believe they want to see. I might have that % wrong. U have to use a refractometer to check it after each oil change.

    Then you start to do all seals that can be done live with old gas like schraders and llsvs gaskets. Then once you take the rack down you get the rest of the seals. Prior you have to also leak check a lot and try to get as tight as possible. You have to pull 500 microns before you put the new gas in. Then once you get new gas in, you still will find leaks.

    The way I understand it is the new gas has smaller molecular structure and this is the reason for all this work needed. Depending on the flavor of new gas, you will also be looking at new txv heads. I was a part of one here in Dallas. Did not do it all but was on the job helping. Did several up in MI before coming down here. Much of it depends on customers specs they set forth obviously. Recommision is the next step resetting all superheats and any valving manipulation. Bear in mind product will remain in fixtures and boxes, so the down time is critical. Its a lot of work in a short amount of time. Stage all material, plan the execution. This is critical to a smooth job. Just don't like the idea of doing such a task under the gone. The chains will most likely plan the work in a similair way as explained. Just too much to risk waiting for a loss.

  8. #21
    Join Date
    Feb 2008
    Location
    California
    Posts
    2,071
    We are going through 2 store conversions right now. R-22 MT/LT Racks to R-407F

    Leak check & fix existing leaks

    change oil, AB to POE, it took 2 changes to get well into the POE range with a refractometer reading ( http://www.nucalgon.com/products/oils/oil-refractometer )

    next up, recover the R-22, replace all high side ball valves vapor/liquid lines (per customer), replace gaskets, change filter driers liquid/suction/oil...add new R-407F.

    tweak all valve, pressure control, & EMS settings.

    Leak check

    It's a 2-3 day deal

  9. #22
    Join Date
    Mar 2013
    Location
    swan valley idaho
    Posts
    732
    i've read alot of stuff saying on small self contained/close coupled units like a reach in etc... you dont even need to change to POE. just evacuate, vacuum, re-charge to old ref head pressure, check sh,sc and call it good. Anyone having luck with this. Described in refrigeration for ac thechs book.

  10. #23
    I used MO99 (R438) on about a dozen empty systems last summer. All is well. As a drop in it reminds of R409 replacing R12 in the nineties. I knew they'd come up with a drop in at the right time (Dupont in charge here or what). Even with the problems of large Trane scrolls that came up (corrected with high wattage crankcase heaters) it's a bargain and easy.

    Use the blue can not the green one.

  11. #24
    Join Date
    Jul 2000
    Location
    Guayaquil EC
    Posts
    10,487
    Quote Originally Posted by Dowadudda View Post
    That's what I have been apart of doing. Oil done ahead of time. And it takes 3 changes to get to 98% I believe they want to see. I might have that % wrong. U have to use a refractometer to check it after each oil change.
    Doing the oil changes ahead only makes sense because you know you'll have to do it eventually...unless the store is closing or planning a major remodel. The old standard for POE concentration is still 95%, but that was established way back in the early 1990s when the manufacturers really didn't have a good handle on how much mineral oil could be tolerated in a system. RobY was involved in this at the time and has commented on this numerous times, adding that much higher MO concentrations will work well with HFC refrigerants and that they're shooting for a goal of 50%, so only a single oil change would be needed.

    Quote Originally Posted by Dowadudda View Post
    Then you start to do all seals that can be done live with old gas like schraders and llsvs gaskets. Then once you take the rack down you get the rest of the seals. Prior you have to also leak check a lot and try to get as tight as possible. You have to pull 500 microns before you put the new gas in. Then once you get new gas in, you still will find leaks.

    The way I understand it is the new gas has smaller molecular structure and this is the reason for all this work needed. Depending on the flavor of new gas, you will also be looking at new txv heads. I was a part of one here in Dallas. Did not do it all but was on the job helping. Did several up in MI before coming down here. Much of it depends on customers specs they set forth obviously. Recommision is the next step resetting all superheats and any valving manipulation. Bear in mind product will remain in fixtures and boxes, so the down time is critical. Its a lot of work in a short amount of time. Stage all material, plan the execution. This is critical to a smooth job. Just don't like the idea of doing such a task under the gone. The chains will most likely plan the work in a similair way as explained. Just too much to risk waiting for a loss.
    It's been widely discussed that the leaking seal issue is primarily due to their reaction to the presence of R22 (or any blend containing R22), causing them to swell. If the R22 is removed, they'll shrink and start to leak. I think changing seals before changing the gas might be taking a risk, but all I know is they will shrink quickly. I really don't have an idea of how long it takes them to swell up.

    So are we mainly talking about shraders and O-rings, or are other types of seals require replacing? IOW, On a typical market refrigerant retrofit, what seals are the main culprits?

  12. #25
    what sort of complete list of seal need to change for retrofit MO to POE in any system
    I've never done it so far.

    thanks

  13. #26
    what sort of complete list of seal need to change for retrofit MO to POE in any system.
    I've never done it so far.

    thanks

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