1. Welcome to Hvacproforums, an interactive community exclusively for HVAC professionals. The collective years of HVAC experience and the knowledge our forum members share make this an invaluable resource for those in the HVAC industry. We have a lot of fun, but make no mistake, we are pros. Hvacproforums is self supporting ...there are NO advertisers here. Do-it-yourselfers and Homeowners are encouraged to seek information elsewhere. Those involved in the HVAC industry are urged to register. its 100% free and easy, Once registered you will have access to the technical forums, Be sure to click over to the new members forum and introduce yourself after registering!

MO99 vs 407c

Discussion in 'Residential' started by jamesyarbrough, Jul 26, 2017.

  1. jamesyarbrough

    jamesyarbrough Amateur Gynecologist

    Messages:
    3,737
    Location:
    Denison TX
    bossman is finally interested in r22 replacements. he asked me what I think and I told him 407c is the way to go. the guy at the supply house told him mo99 is best....they don't sell 407c.


    do you guys have experience with both? what do u think?
     
  2. pecmsg

    pecmsg Junior my ASS

    Messages:
    21,192
    Location:
    Eastern LI
    About equil.

    Don't believe the crap No POE needed, add some or Supco 88

    Change all rubber seals.
     
    Mcool and Daryl_Dixon like this.
  3. R2D2-TX

    R2D2-TX New Member

    Messages:
    466
    Stick with R22 and price it accordingly... we will add R22 if the customer is wanting it with the understanding it won't last. This will make them think about upgrading to 410a... we advised a customer last Friday to not add 4lbs of R22.. but she was real adamant about it and was willing to pay several hundred bucks... so against our recommendation she had us add the refrigerant.. she called back on Sunday and said it is 85 degrees in her house.. we took her a portable unit to keep a bedroom cool while she is trying to secure financing.. she is a good example of a customer that think they know what is best for them. I feel sorry for her ... no one has a coffee can full of cash waiting on the ac system to fail.. heat seems to do something to peoples attitude... do or die..
    Another one bites the dust✌️


    We all will be better off when R22 is gone!!!!
     
    Last edited: Jul 26, 2017
  4. Texas-Tech

    Texas-Tech Official Geezer*

    Messages:
    17,734
    Location:
    duhh
    We have used both, more MO-99 than 407c. Haven't had any trouble yet
     
  5. Zman

    Zman Hanging by a Thread

    Messages:
    1,017
    Location:
    The "I know a Guy" State
    407C and 422B,both seem to be close to R22,slightly lower suction,little higher Head.All we have used so far.No oil change.
     
  6. Bustawrench

    Bustawrench Knucklehead

    Messages:
    10,949
    Location:
    South Jersey
    407c has been working just fine in Liebert Units for 20 years, but they use POE oil.

    We tried both MO99 and 422b and found that the 422b results in less problems for us, so that's what we use now.

    Be prepared to deal with oil return problems and loss of capacity, no matter which one you choose for retrofitting old 22 systems.
     
    Mcool and Texas-Tech like this.
  7. Swampfox

    Swampfox red tagged

    Messages:
    34,501
    Location:
    Hell Hole Swamp
    407C has the least capacity loss, but no isobutane like the others to help with oil return, so definitely add some POE at least or risk oil problems.
     
  8. Catpower

    Catpower The Crowd Pleaser

    Messages:
    22,334
    Location:
    in the Cabana
    I mix them 50/50 that way I get the best of both worlds:lachen::lachen::lachen::lachen:
     
  9. jamesyarbrough

    jamesyarbrough Amateur Gynecologist

    Messages:
    3,737
    Location:
    Denison TX
    pur install crew changed a compressor today and retrofitted mo99. I gave him my test 557 and showed him how to use it so he could get proper charge.

    he however, chose not to use it and googled a to chart. told him there were two sets of numbers. one for sh one for sc. he didn't know what I was talking about.



    this ain't gonna work out.
     
  10. 22blood

    22blood red wire nuts only

    Messages:
    1,756
    Go on strike until r22 comes back
     
    coldsnap, HMD, jamesyarbrough and 2 others like this.
  11. Texas-Tech

    Texas-Tech Official Geezer*

    Messages:
    17,734
    Location:
    duhh
    I'm guessing he couldn't do it even if it was r22
     
    Zman likes this.
  12. jamesyarbrough

    jamesyarbrough Amateur Gynecologist

    Messages:
    3,737
    Location:
    Denison TX
    he s a good tech. he just has 0 experience or education with drop ins and was pretty much set of for failure.
     
  13. knave

    knave Undeterred

    Messages:
    8,193
    Location:
    Out for a rip
    Tell him to get it right or go mulch your garden! No time for crazy callbacks eh?
     
    Mcool, jamesyarbrough and Catpower like this.
  14. Catpower

    Catpower The Crowd Pleaser

    Messages:
    22,334
    Location:
    in the Cabana

    Nah have him pull weeds,mulching is easy
     
    jamesyarbrough and knave like this.
  15. Joey791

    Joey791 New Member

    Messages:
    45
    Location:
    Louisiana
    Previous employer was using R407C in Trane scrolls, we were eating compressors like hotcakes and had to go back to R-22, if you even try it on a Trane scroll make sure to get ALL of the old oil out the system.............
     
  16. HMD

    HMD does it matter?

    Messages:
    93,400
    Location:
    here
    ahem................ i object!
     
    mike1020 likes this.
  17. HMD

    HMD does it matter?

    Messages:
    93,400
    Location:
    here
    i think they are discussing reefer, not drinks
    i like mine stronger
     
    Catpower likes this.
  18. HMD

    HMD does it matter?

    Messages:
    93,400
    Location:
    here
    and 11,12, 113, 114, 500, 502
     
    Rather B Riding and newtech like this.
  19. R/HVAC

    R/HVAC selfemployed

    Messages:
    470
    Location:
    W-S , NC
    I tried to make a rubber o-ring seal from a liquid line solenoid that started leaking after a conversion from r22 > r407c pop like I saw in a video. Pulled a vacuum on it like the video showed, nothing happened. We used a pint mason jar and took it to < 500 microns in 10 minutes. Guess we didn't do it right.
     
  20. jpb2

    jpb2 Dog Tard *

    Messages:
    47,385
    Location:
    within the bounds of reality
    This transition is good for business. I cant control at all what the dealers do. Some will go to the end of the earth to repair before even offering a common sense replacement. These blends suck even when put in propper.
     
    Rather B Riding likes this.