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fridge doctor
06-05-2011, 12:54 PM
Hi everyone, thanks for looking.

First thing to note. My location - Cyprus. Very small range of gases available here. R22 has disappeared and no drop-in is available.

My Q. A client has a 5HP Medium temp R22 condensing unit which is 7 years old but has been stored 5 years. He wants me to use it as the basis for an all new medium temp system (so new evap and new pipes). If I do this, I can obviously get the majoroty of the oil out of the R22 unit, and refill with synthetic. But given my poor choice of options as a replacement gas I am pretty much forced to consider 407c. Can anyone see a problem with this?

Thanks guys...this gas situation is a minefield, when I started in the business, there was just R12, R22, R502, Methyl Chloride, and Sulphur Dioxide (and we steered clear of that one I can tell you)!!

Regards, Trevor

taz24
06-05-2011, 03:27 PM
.

Hello Trevor.

If you are limited to 407 then that is the best option for him at the moment :)

But 407 has a wide glide due to the Zeotropic blend so you must make sure
the system is absolutly gas tight.

The gas will perform similar to 22 at the range you want.

Make sure you replace valves and other fittings that have the old seals in then
the newer refrigerants and oils eat through the old neopreen seals, so if you don't
replace them they will leak bad..

All the best

taz

.

monkey spanners
06-05-2011, 06:00 PM
I have some R22 stuff that has been converted to run on R404A which has a lower glide than R407C, would be worth having a word with you wholesalers tech department to see if the compressor is suitable after an oil change or two.

cadwaladr
06-05-2011, 08:09 PM
what about 134a

mikeref
06-05-2011, 10:43 PM
what about 134a Too much capacity loss on R134a. R22 at 2c is 430Kpa and R134a at 2c is 210Kpa.. Jon, R22 to R410a:confused:?? How did you pull that trick with thoes pressures?.. Mike.

mikeref
06-05-2011, 10:49 PM
Ahh, never mind, didn't read thread properly. Not R410, R404, still, gutsy move Jon;).

monkey spanners
06-05-2011, 11:08 PM
Ahh, never mind, didn't read thread properly. Not R410, R404, still, gutsy move Jon;).

The duties are very similar but it depends on the temperatures the system runs at, it needs a good technical guy at the wholesalers (with access to manufactures specs) to check everything is still working within its design paramitters.

Jon :)

Magoo
07-05-2011, 12:58 AM
I have done a couple of gas changes from 22 to 404a, on medium temp rooms, several oil changes and fitted a crankcase press reg., to limit FLA during pull down/ high load periods.

cadwaladr
07-05-2011, 02:57 AM
will be out there in october paphos, save some water 4 me and of course the keo brandy lol

fridge doctor
08-05-2011, 04:20 AM
Best time to come Cadwaladr, nice temperatures then.... me I just need to haul myself through the long hot summer which starts anytime now lol.

Thanks all for your replies, very helpful... As I will be fitting a new exp valve, cooler, pipework etc, it looks like replace the seals on the 5HP L'Unite comp, replace the oil and go for 407c. Thanks again, Trevor

D.D.KORANNE
09-05-2011, 06:58 AM
I HAVE A WRITE UP ON CONVERSION OF R-22 SYSTEMS TO R-407C ............. PRECAUTIONS AND HOW TO DO IT ETC ........ , CAN MAIL YOU THE PDF VERSION . SEND ME A pm to ddk0123@gmail.com

eliascom20
05-07-2011, 07:46 PM
Is much better for you to change to RS45. Im sure you can find in Cyprus.
Rs45 is a drop in for R22 and ozon friendly without any changes.Is working either with mineral and polyoester oil.

Fri3Oil System
06-07-2011, 06:55 AM
Without any changes?
RS45:
HFC 143a: 18.0 %
HFC 125: 63.2 %
HFC 134a: 16.0 %
Isobutane: 2.8 %
Do you think 2.8% of the blend is enough to bring back the MO to the compressors?
Pls, post back when compressors die :)

Regards,

Nando.

eliascom20
06-07-2011, 07:15 PM
Hello Nando
I used RS45 one year now and touch wood I have'nt any problems.
Of course and in some systems I change the oil to POE but most of them working with MO.

Fri3Oil System
07-07-2011, 07:06 AM
The plant design would affect, and also the size. In small units the problem is not big.
We get reports from our clients and other companies claiming they had lubricity problems when using new "drop in" blends, some last minutes, other days, and others 20months (this is the longest case we have checked).
Touch wood! I would change the oil instead. ;)

Regards,

Nando.

kayakalp
22-07-2011, 06:53 AM
Hello everyone.

zenen
25-07-2011, 01:17 PM
hello, I am in Cyprus too.

There is a refrigerant that replace R22, the R522, which does not require any flashing of the system either.