Retrofitting R22 In a split system

[marc5180]

I've been called to a job tomorrow that is faulting on "LP", luckily we can still get hold of reclaimed R22 from the suppliers but i'm wondering has anyone relaced R22 yet in a split system and if so what have they used? and is it a direct replacement.

Everyone that i ask doesn't seem to know and as of yet we haven't had to retrofit any.

[Andy AC]

Tried some R417a in a crappy old hitachi wall mount split, pressures were low - pressure was always low, before the leak, even on the R22. So can't really give you much info. Hopefully next time I use it, it will be on a more modern unit with a bit more quality to start with.
Andy

[thebigcheese]

yea have been using r417a as a replacement and it seems to be fine, have found it usaly runs around 50 - 60 on the suction

417 for cappillary device
422 for expansion valve

agas have a good sheet out on what replaces what etc

[hyperion]

R417A seems to work fine in split A/C systems. I have found that you often need to charge to about 90% by weight of refrigerant when compared to the R22 quantity. You might need to trim this charge amount slightly, but start at 90%. Pressures appear to be similar to R22, maybe slightly lower, but achieved temperatures seem to be OK.

[marc5180]

Good stuff, i'm prepared now when R22 runs out, thanks.

[al]

Any luck with 417 in a pack? Is it a good option as say converting to 404a?

Alec

[thebigcheese]

al we have been using 422d for most refrigeration aps, seems to be ok

aparently r407a is great if you can do an oil change

[al]

My only worry with the oil change is o rings leaking, otherwise i'd go with 404a.

alec

[Fri3Oil System]

If you change directly to 417a and not change the oil, you will also have lubricity problems, as it is not very miscible with the MO. Only 3% of it is a HC, miscible with MO, whereas 97% is a HFC.
A nice solution would be to clean the circuit out of MO and put 407 and POE. BEsides, you can earn some COP and CAP with the total cleaning of the plant.
check this link:
www.fri3oilsystem.com/june.zip
there you have the different retrofit options, so you can decide which one is more suitable for you.

[radekklimat]

I use R407C only mention on the synthetic oil and filter change (as is) no flushing system, and possibly if it is long and it is suspected that there remained a mineral oil, possibly under pressure of nitrogen blows.

[Fri3Oil System]

If you leave over 5% of remaining MO, you will end up having a phases separation, and a damage of the lubricity index, that will finally break the compressors, specially if there is a leak.
So the best solution is to clean entirely the system.