PDA

View Full Version : What to refill a R12 freeze with, R290, R600 or R134a?



Henry.
25-11-2010, 11:29 PM
Have a friend that had a freezer that didnt worked due to a leak but its small, unusual and very expensive new so he would very much like it to work again. Where i live R12 and similar gases is banned from all use quite some time ago so what could i fill this with to roughly get about the same capacity and temperature?

I have dirty bbq propane and clean butane as lighter gas to use for this and alot as well. I also have a smaller amount of R134a taken from a system but i dont know if it might be enough and the freezer should be filled with 80 grams of R12 but dont know what that would be in any of the mentioned gases.

I saw a ptchart of R134a that indicated that it might be ok in the way i read it to use compared to R12 but im not really sure.

So what do you think guys? And would i need to change the captube in any case? Just as long as it gets some degrees below say -14C so would it be ok but lower is always better.

Have read about propane butane mix but would that work better then a R134a and some propane in it for oil transport comparing for capacity and temperatures?

mikeref
26-11-2010, 01:10 AM
Hello Henry, i changed my own chest freezer from R12 to R134A some 4 years ago. Replaced spun drier and added 25cc synthetic oil. Vac out and recharge, no change in capillary. Cannot comment on R290 or R600a, though R600 is for R22 equipment(R600 not R600a). From what i have read, BBQ gas is no good, too much moisture.. mike.

Henry.
30-11-2010, 11:29 PM
Thanks for the info!

Although i just saw that i dont have oil to use with R134a so thats out. The original fill was 80 grams of R12 and i really dont think i have that much so it has to be a propane butane mix since i have read in a thread that this could work as well. And i just looked at a ptchart for R12, R600a and R290 and one are to low and the other to high but combined so could they very well be very close to R12 so it could be worth trying.

Yes bbq propane contains moisture but not more than the filter can handle what i have heard, at least if the filter are a little bigger then the very small ones but this is an old freezer anyway so it wouldnt really matter it would work anyway and quite some time as well i guess.

The best part is that i dont have to change the oil but i dont know yet if i would need to mess with the cap if i do fill it with this, but i will continue to read on about this.

Thanks the tip!

Brian_UK
30-11-2010, 11:57 PM
Dancap includes R600a in its' sizing programme.

Henry.
01-12-2010, 05:42 AM
Well yes but i dont have any captubes more then very big one that wont fit for sure and i dont know what power i would need to calculate a freezer for to get the right sized captube.

So to do it as easy as i can i think i will go with a R290 R600/R600a mix that are used to replace R12 in a 50/50 ratio fore some but i think i would need a little more R290 in a freezer.

Then i only need to see if can find any info if i might need to change the captube and if i would need more or less gas then the original 80 grams of R12 that was used.

However since the mix are ment to be a replacement for R12 my guess is that the cap would be fine as it is and i would need pretty much the same amount of gas in the system.

I have also seen interesting info about this now on the net that was hard to find and i found a ptchart of R290/R600x mixes and then it should be quite easy to get the right amount and the right mix in the freezer.

Henry.
05-01-2011, 03:11 AM
The only thing i have been able to get my hands on in enough amount was a mix of 35% Propane and 65% Butane. Could this be used as is in a freezer to get around -1F with or witout change the captube or i need to add propane due to the high amount of butane in this mix to be able to get down to this temperature?

mikeref
05-01-2011, 03:47 AM
Been on the phone while thread is up, Sadly, i have not had the luxury of working with these gasses yet so mixing them is beyond me. Surely someone works with R134a and synthetic oil there??

Henry.
05-01-2011, 05:22 AM
According to a PTchart i have a propane butane 60/40 mix is used to replace R12 however the mix i got as mentioned are pretty much the opposite mix. But add more propane should work but it would be hard to get the right amount i guess.

At work we mainly use R290 and R600a and others, we have used R134a some time ago but no more as far as i know. The guys here dont know anything about mixes they pretty much just put in whats needed in the systems and the old guys are just into R12 gases and such so they dont know that much about these "modern" gases they call it and especially not mixes but R12 and such gases are banned here several years back so no help from them.

charlie patt
05-01-2011, 07:53 PM
has anyone thought of the fact that you may be fitting a flammable refrigerant in a system with a leak if the leak is on a evap and something ignites it the mix will be the least of the problems changw oil and 134a or get a 49 drop in if available in yourcountry be lucky

install monkey
06-01-2011, 12:08 AM
dont use 290 or 600 too dodgy'
r134a can be used although it should be a synthetic oil.use can use the original oil but it will gurgle like a chip pan when it gets down to temp.u could always charge with isceon 49 a r12 drop in but again the oil should be changed-give it a go

Henry.
06-01-2011, 03:27 PM
has anyone thought of the fact that you may be fitting a flammable refrigerant in a system with a leak if the leak is on a evap and something ignites it the mix will be the least of the problems change oil and 134a or get a 49 drop in if available in yourcountry be lucky

I havent said anywhere that i wouldnt fix any leaks first before i would fill it, right? And to be able to ignite anything in a hermetic sealed system there has to be a source of an oxidizing agent like for example oxygen. This wont be present if made a proper vacuum before filled and thus no ignition could occur.

And where this freezer will be is in a big room so any eventual leak in the future would never be that concentrated that it would blow the room up or so in any matter not even if all gas would leak out in 1 sec which wont happen.


dont use 290 or 600 too dodgy

It works just fine if done right and handled right. We have used both gases at work as long as i have worked here and with no problems what so ever. I have also used it my self as well for several years in different homebuilt systems and same there no problems what so ever.

It all have to do if you at least have some little common sense and know what your doing and think before you do not the opposite around. I know very well how flammable gases should be handled and of course always take appropriate precautions before i fill anything.


I have spoken to ppl at work but they said that we dont build R134a anymore and they think it was back around 6 or 7 years the last time. R413a has never been used here since it is a replacement for R12 which we have never been dealing with. I dont think it would be illegal here based on its content but its nothing i can get my hands on anyway without buying a huge canister for big bucks.

So based on all this i will go with the R290/R600 mix since it the only thing i can get my hands on as a substitute for R12.

charlie patt
06-01-2011, 07:03 PM
i done a r600a course in bodnor at lec before they shut they had a r600a system with a simulated leak on a evap then they switched a internal light and blew the door right of its hinges approxten feet we are not talking about a possible explosion internally only if refrigerant is leaking which i believe was stated refrigerant was low on a hermetically sealed system then it has a leak? ah yes you say my freezer has no light but what if your friend has a fag in his mouth when getting a bag of peas? its your choice but convert to 134 use a drop in or bin it r 600 is fine and used for oil recovery in many blends and like you say used daily but can you take the risk ta charlie

chilliwilly
06-01-2011, 11:50 PM
Hey Charlie

When did Lec actually shutdown? I used to work there back in 85-86. I started on the general production line in the main factory, screwing feet on fridges. They came to me one morning after a week of being there, and I thought they were going to sack me. But they told me that they had looked at my application form and saw that I'd got aircon and fridge experience. And told me there was a job in the special products dept, making solar powered freezers and table top fridges for pensioners, and as I had kept my nose clean for a week, they offered it me.

I tried to get a reference from them just recently, but I didn't know they had closed. The company that owns them now didn't have any records that went back so far. I suppose the Purley family had made their money and sold up, shame though it was a good place to work if you were keen to get on and advance yourself. I liked the fact that you could cash your wage cheque anywhere in Bognor, as the company was so honourable. Did you attend their college then to do your training? I was all set to do it, but ended up having to move before the September of 86.

Henry.
07-01-2011, 02:19 AM
I dont see that as something commonly accuring based on all the R290/R600a freezers and fridges that are out there, i have never heard of anything like that happen.

And the chance that there would be a big enough leak that would fill the inside before its open and the light would turn on with the door closed and the bulb would either have an open filament or poorly put in place so a spark could be created then and all this at the same time are not very high as i see it but sure ok not totally impossible perhaps. But my friend takes the chance he said and he doesnt smoke.

The leak comes from a extra loop of condensor tubes down in the bottom of the fridge and the evap tubes are protected on top.

I would gladely use R134a but as i have said before i dont have any and neither the right oil. I might be able to get some from those airdusters if they still contain that here but i dont know if they do that anymore but then its the oil which i cant get so it really doesnt matter.

charlie patt
07-01-2011, 09:52 PM
the last course i done there was 2003 and all the staff new it was on the cards it was a very sad day in my view as the level of knowledge there was excellent they where already shipping goods in and out then and just shut the second line you could ring up for spares and it was never a problem i kept in touch with one of the trainers and he ended up working as a sainsbury driver he is happy with it but what a waste and i believe there is none of the old site left but unsure and reguarding problems with the flamable gases anyone seen the pictures of the explodeing fridges?