We are having domestic window acs and refrigerators working with R12 as refrigerant. How can I convert the same system to one which can work with R22 or R134A:confused:
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We are having domestic window acs and refrigerators working with R12 as refrigerant. How can I convert the same system to one which can work with R22 or R134A:confused:
Hi Dilip sahasrabu.
To convert it to R 22, you will need a smaller compressor with the same capacity.
The condenser will be too small though.
Using r 134a, you will have to replace the compressor and clean the system from all oil residues.
The units you refer to, are very old and inefficient.
Wouldn't it be wiser to replace them with modern R 410?
Chemi:)
Hi Chemi
What is the problem of using a R12 Compressor to R134A
if the oil in the compressor is changed. ? and the system
has been cleaned up as you said.
Best regards
Carlo Hansen
Hi there,Quote:
Originally Posted by Carlo Hansen
You can use the same compressor but the capacity will be lower.
In order to replace R12 with R134a the following procedure must be carefully followed:
1- Drain the system mineral oil.
2- Put appropriate synthetic oil in to the compressor.
3- Turn on the compressor and let it operate for a few minutes.
4- Turn off the compressor and drain the contaminated oil from the crankcase.
5- Again put new synthetic oil into the crankcase.
6- Turn on the compressor and let it operate for a few minutes.
7-Turn off the compressor and drain the contaminated oil from the crankcase. Test the oil for contamination with special test kit. If the contamination is less than 1% then you can recover R12 from th system.
8- If oil contamination is more than 1% then repeat from step4.
9- Change filter/drier,TEV, ...
10- Evacuate the system and change the oil again.
11- NOW YOU CAN CHARGE R134a.
Remember if the oil contamination is more than 1% then you can not charge R134a.
The synthetic oil is very hygroscopic i.e., absorbs moisture, be very careful.
I hope this helps a bit.
Cheers:)
G'day lanaQuote:
Originally Posted by lana
By the time you have done all this wouldnt it be cheaper to buy a new unit?
If it was a billable job to a customer they would be better off spending their money on a new system with warranty.
Unfortunately we are becoming a throw away society.
Agree, unless it is a 1000 RT Centrifugal chiller. :DQuote:
Originally Posted by Temprite
We don't give out D I Y advice to homeowners i hope !
Hi Fridg;
Velcome to this forum.
(We don't give out D I Y advice to homeowners i hope !)
I would like to know what you mean by this ?
Thx. Lana for the description of convert from R12 to R134A
This is what i have learn many eyars ago. In the meantime
it is normaly just to remain the oil to 5% in the system.
The main reason to reduce the oil to 1%, was to eleminate copper to atack the valves in the compressor.
Best regards
Carlo Hansen
Hi Carlo,
As you said, no problems at all, it is exactly the same inside the compressor and only oil changing and a quick system clean will do the job just fine.
a small window AC unit, is very simple, I agree.
Chemi:)
Just be aware that dropping R22 into an elderly R12 system is like putting a turbo on your mums 20 year old Ford escort at best it will leak like a sieve and die rapidly. At worst you will be pulling little bits of metal from your customers body......check your pressure tables....
CFC to HFC conversions (R12 to R134a) rarely suceed. The gaskets and seals go first followed by the compressor. Every brazed joint will develop a hole....
Then we have R11 to R123 conversions......
In any conversion remember to check the max working pressure of your system and validity all of the safety cutouts.
[QUOTE=Carlo Hansen]Hi Fridg;
Velcome to this forum.
(We don't give out D I Y advice to homeowners i hope !)
I would like to know what you mean by this ?
Thanks Carlo. I love this trade , i am a 2nd year apprentice.
We don't give out repair techniques to people who are not in the trade or not studying the trade do we ?
Just with all the new laws and dangers involved in this industry , i would hate to see someones advice land them in a civil suit.
And on the other side i would hate to see a poor hvac system suffer.
Remember the oil
this will have to be changed
at least.
Roger that tango !Quote:
Originally Posted by dogma
We seem to find each other in the most unusual places
:eek:
hiQuote:
Originally Posted by Dilip sahasrabu
over here in the uk we get away by using an drop in refrigerant like R409a this seem to work ok here.
You cheap ****, stop bothering engineers
with your chep ideas.
Buy a new fridge!!
Can anybody tell me about the Capillary size changes required in case of retrofitting from R-12 to R-134a? Is there any online chart for the same?