What kind of results have you had replacing R-22 with MO99 or some of the other "Drop IN" replacements for R-22? I have not used any of the replacements, the cost is not much different, plus I was told you loose 5-6% of the system capacity. Most of the info. I have is from some of the sales reps from different supply houses, have not actually talked to anyone who used the replacements that know what theyre doing. Was curious to see what others think of the new replacements. I believe there will be some that work well kind of like using 409a in place of R-12 which I have been using on a few walk-in coolers which seem to be functioning correctly now.
I haven't converted from 22 to MO99, but have talked to one of my suppliers that has a customer that did. One thing they did was change the seals on all their solenoid valves. They put the same type of seal in material wise, but apparently a seal that has been exposed to 22 will fail when then exposed to MO99-some kind of chemical reaction takes place. They kept mineral oil as a lubricant, but initially had return problems. They solved that by adding a bit of POE (how much I don't know). Price wise where I'm from, MO99 is almost half the price of 22.
You should check out DuPont's site-they have a tech manual on retrofit guidelines for MO99 that covers a lot of topics.
Gotta be tough when you're dumb!
Thanks for the input I will give the site a check and see what I can learn! I seem to remember something about seals going bad also with mo99.
I have done R22 to R407C swaps. The only real.pain.is.changing the oil and.flushing the system. Besides that it has gone well and I have yet to have any problems with a swapped system.
I used MO99 in a 5 ton Trane split. I replaced the drier, schrader cores, pulled a vacc, and charged to what it said, 95%? The pressures and temps looked exactly like R22.
Also, it sold for a lot less than R22.
Some literature suggests a certain percentage of POE oil be added to the mineral in the system for better oil return.
We looked at converting to MO 99, the Global Warming Potential is almost as bad a R22. 407C has a much lower Global Warming Potential, which made our Enviromential Affairs Department happy. We have done several on some DX unit with good results. We did the oil change on the first two, but checking with our supplier we found that Copeland is shipping R22 compressor with POE already in the compressor. The last few changed all seals and driers they were good to go. I think with the lower discharge perssures the compressor might last longer. We were told we might have to change the drier once or twice, so far, we have not had any problems.
MO99 = R438A
Global Warming Potential
MO 99 -- 2265
407C -- 1770
Critical elastomeric seals (o-rings) should be changed as part of any retrofit out of R-22. It is an issue of the seals swelling from the R-22 and causing the potential for leaks regardless of what gas is used to replace the R-22. If not replaced the old elastomers can shrink/move/dvelop pin holes etc.
Originally Posted by Toddbrewster
A number of posts have discussed MO99 retrofits over the past few years.