Can I add a little (1 lb) of R12 to a R22 system that is a little low?
What could it do to the compressor?
Jerry Tindle
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Can I add a little (1 lb) of R12 to a R22 system that is a little low?
What could it do to the compressor?
Jerry Tindle
Bad idea from 2 viewpoints: (1) One should refrain from mixing refrigerants whenever possible... The resulting concoction may give undesirable results; (2) R-12 is way more expensive than R-22. :)
Hello Jerry !
Of course the professor does not presume that you already have the R-12 in your possesion (which you discussed with me), but as he says, you are dealing with unknown results.
see ya' :)
Hi, Jerry:)
R12 will lower your condensing temperature, raise your evaporation, bring oil back better and also lower you discharge temperature. But the main draw back is it will lower the overall effeciency of the system, in effect reducing the size of you compressor in comparision to the other system components, leading you to perhaps struggle with capacity.
All the above depends on how much you add.
Regards. Andy:D
Andy, don't you mean it would decrease the condensing PRESSURE. The condensing "temperature" would be dependant on the ambient, superheat, heat of compression, etc.. would it not? :)Quote:
Originally posted by Andy
Hi, Jerry:)
R12 will lower your condensing temperature...
Hi, Herefishy:)
I am nearly certain that mixing R12 in the R22 system will both lower the discharge pressure as you pointed out and the temperature as I was suggesting. If I remember right when we added R12 to R502 and R22 flooded systems (to increase oil rectification, one of the side effects was a lowering of the discharge temperature, remember that it is R22 which has a high discharge temp not the R12.
The new gas with R12 in it will act differently than a single with Daltons law of partial pressures comming into play. By adding the R12 we are effectivly decreasing the compressor capacity and the system capacity and increasing the evaporator and condenser capacity.
I stand to be corrected by someone wiser than me, but what I have posted above I beleive to be correct.
:confused: Regards. Andy.
One would also like to ask where the R12 is coming from and are you legally allowed to use it ?
What sort of instructions would you leave for the next Tech who has to service the equipment ? Short charge it with the correct gas and then add about a 1lb of illegal gas :eek:
It is my understanding that it is the manufacture of the (R-12) not the [I]use[/] of.....
It is my understanding (through my distributor) that a major consumer of the R-12 still on the market is the medical industry (here in the States) which uses it for sterilization or some other purpose.
Hi, Herefishy,
We and we alone in Europe ban the use of a good gas R12, others like the US only ban manufacture and possibly import. If I go to site and find R12 in a system I have to decant it send it for destruction and replace it with a replacement that is not banned. Even R22 is on it's last legs with no new installations of any size allowed. If we move an existing R22 plant I have to replace the Refrigerant with a HFC, I can not reuse the system with R22 in it.
What about the US?
:) Regards. Andy.
In the U.S., we are actively imploying R-22 systems in replacement of R-12 systems !!!! "Class 2" refrigerants are still being manufactured and employed.
R-22 is still inexpensive and readily available.
We use, and buy R12 all the time, on small systems, one to two lbs only. There is no other gas out there like it. When it comes to oil return, compatability with either the internal parts or oil from the prior gas, the equipment dies prematurely. A thirty pounder is about $1200.00 US. Alot of the equipment are in kitchens that are over 100F, and the coils get any dust at all and they burn up from high temperatures or amp draw, or frequent failure.
Convert when the whole system is replaced only, R22 has done nicely and has only 5% of the ozone depleting chemical of R12. The real killer of the Ozone layer is that damn space shuttle.
They claim it takes 30 years for the chlorine to get up there, If thats true why don't we have a 30 year delay in the reverse effect of R12? Do you realize there is a volcano in either South America or Antarctica that is pouring millions of tons of Chlorine into the upper atmosphere every day?? They should concentrate their efforts in relieving that pressure instead.
My two cents!!!!
In the USA, we are not required to decomission a working system. I think that is a stupid idea. But I guess you people in Europe are rich and you can afford that.
R12 is readily available and the price is dropping. I do not use it, because it will not be here long. We will still be making R22 systems for another 8 years. R22 will be available for many years after that. Most of the medium temp systems I install are R22.
I would like to thank all you people in the rest of the "first world" for taking up our slack in the environmental issues of the day.
If we could just get you to invade Iraq for us, I would be extremely gratefull.
Hi, Superheat:)
Well you know us irish we will fight for anything, given a few potatoes.
I was listening to comentary from the commonwealth games (big sporting event), anyway it can to mentioning the Nothern Irish team and the comment was made that N. Ireland would agian do well this year as in previous years. At what I hear you ask? Why shooting and boxing.:p
So watch out USA and pray we are on your team when it comes to a war in Iraq. (Just kidding who else would want us):rolleyes:
Regards. Andy:cool:
I have heard that the best generals in the british army over the years were Irish. Drinking, fighting and boxing, well everybody has to be good at something. My great granddad was Irish. My wife is about half Irish and 1/4 american indian. That little red head can kick some serious butt when she gets upset.
I am getting the impression that America is taking over the British position of being the imperialist of the world, but hay somebody has to do it right. LOL I think Bush needs to invade the UN. Then he can do anything he wants and say it was the UN's idea.
i am in canada, not sure of laws, but on any supermarket (all company does), if we find a leak on an r12 or r502 system, it is retrofitted to mp39 (MT) or hp80 hp62 (LT)
we service for mostly one chain only and the ministry is on them hard, we leak check each store (50+) monthly. great in the winter when it is slow, a bitch this time of year with humidex above 40 C allot of days
also any leak of more than 45kg - 100 lbs has to be reported to ministry within 24 hrs
had it sunday, meat 5 dek cracked distributer 500 lb r12, nice way to spend a sunday doing a retrofit
on our new install we are using microtherm to control store, works good, monitors for leaks in machine room, monitors reciever level
Hi, Shaun,
I can't beleive that R12 is still being used in large supermarket chains, here in the UK we stopped using it 10 yrs ago, simply the supermarkets all refitted and drop-ins or new equipment was fitted.
It must be 5yrs since I posessed a bottle of R12 to have a bottle of R12 now is illegal (I think) and something we all keep quiet about. I personally can,t think of any system about with any quanity of R12 in it, even R502 is becomming very rare, with the only R502 about being large sxystems that have been topped up with drop-ins.:(
Andy et al. My installation manager has a 10-year-old 15-pounder of R12 in his garage to repair the a/c on old vans. That's it for R12 in Florida. I haven't seen a white jug in 10 years other than that one. As a company, we haven't used R12 for a decade.
As recently as 5 years ago, however, Nassau Bahamas was using R12 extensively. Buying it from Venezuela at darn near old R12 prices, when the US price was well above $10.00 a lb. I suspect there are some pockets in South America and elsewhere still using R12 in larger systems. In the USA, you will only see it in aging self-contained equipment.
"Topping Off" with any refrigerant other than the existing charge is definitely not a good idea! :)Quote:
Originally posted by Andy
...even R502 is becomming very rare, with the only R502 about being large sxystems that have been topped up with drop-ins.:(
Hi, Herefishy:)
It's an industrial thing, we (the company I work for) have developed refrigerant drop-ins to replace R12, R502. Commonly the drop-in is added to supliment an original charge, after a period of years either the system has been again topped up or it is decommisioned and the gas added to another system or finally destroyed, like all refrigerant should be at the end of it's useful life. The refrigerants we us are tested to be blended with existing
R502, R12.
I have not got a problem blending refrigerants of know composite, why chuck away 800lbs of R502 when all you need is a 100lbs to complete your charge, anyway the drop-ins inprove system performance ;)
There is also no crime in it as long as refrigerant is destroyed after final use. I have in the past added different drop-ins together in acase of emergency, with no detrimental effects, in all cases the systems performed better with less refrigerant charge.
Manufactures of refrigerant are bound to say not to mix purely on a comercial basis.
Ofcourse you are taking a chance the first time, but in my case the blending of refrigerant was tried out when we developed the refrigerants, so the eliment of chance is eliminated.
Try it and see you might like it.:D
Regards. Andy:)
okay, but what if you add 20% of a refrigerant which has an 11degF glide to an existing charge (w/o glide for instance), and the superheat setting is 8degF for a medium temp application? Who is re-writing your P/T charts? :)
Or are you assuming 20degf+ Sh at the compressor and simply ignoring it?
Hi, Herefishy:)
If I was to add 20% the change in the refrigerant mix wouldn't be that I would notice, as for a 8F superheat you would have problems setting that up matter what refrigerant you were using, as the valve would be inclined to hunt, 8c would be easier set up for a medium temp aplication.
Problems in determining superheat would occur more when the mix was 50-50%, then you would be writing your own charts.
Usually not a problem for us as our systems are flooded we go by our wet return temp, which would then determine our charge and metering control setting.
Valid point though, one which has caused me to use the gray matter on a few occasions.:confused: Fortunetly most of these plants are either now old and replaced or the gas is well dilute and nearer the drop-in properties.:)
Regards. Andy:cool: