Mixing refrigerants? (let the flames begin)

[mark beiser]

Out of all the dumb threads on this forum, this one is up there with the worst.

[ironpit]

Can I use gasoline instead of mineral oil with r22?

[captaincompressor]

I would like to set up a guinea pig in my warehouse and try propane....Mayne run some blue rhino.through a couple filter driers and see what happens.

[texasgentleman2]

I hope I never run into a situation where mixing refrigerants is required. I recently started servicing cooler/freezers/AC, and only had to repair r22 AC so far, but the guy that did it before didn't seem real big on labeling, I've found notes written in marker with 239,r404/408 etc written on equipment, sometimes the same equipment...

[VTP99]

I've found notes written in marker with 239 etc written on equipment, sometimes the same equipment...

R239 that's a new one to me. Must be what you get when you mix

[texasgentleman2]

Oops, that was supposed to be mp39, thats what I get for typing before I got my whole pot of coffee down.

[mrkool]

A local salesman told me he sold 8 - R-22 dry condensers to a contractor for some old condos, the next day, the contractor sent a guy in the buy some R-410a.

Later he ask the contractor how the units were working, he said better than the old ones.

Said he put 410 in all those dry R-22 condensers in May of this year and they're still cooling.

Now how can that be ?

[ICanHas]

I think the chance of being able to get away with HCFC in POE is better than HFC in MO

IIRC, POE is pretty much usable with any coolerant.

[VTP99]

Question I have is would that system be able to handle the higher operating pressures of R410a ?

[Freightshaker]

A farmer that I help outA/C on tractors, combines, and various other duties and repairs) called a while back. His home unit was down and needed some "freezon". When he called he was getting ready to gas it with some leakstop 134A. Glad he called me I told him the condensing unit would shoot off into space like a rocket and his home would burn down. He still believes that will happen I will not tell him any different. Now if I could get him to believe that 10lbs of 134A in a 4850 John Deere does not make it cool any better.

[Tommy knocker]

Wouldn't think a PT chart would help much. Once you mix them they become something different. No way to know what the heck your SST or SCT are so can't set TXV. Not saying it won't cool, obviously it does, but most cars will run on alcohol for a time as well.

[cy]

what an interesting topic ... no it's not a good idea, but what do you do when you find a unit marked with all sorts of different refrigerants?

no telling what's inside. even if one evacuates current charge, then refill with single refrigerant. one still doesn't know if prior charge contaminated oil, etc.

[jpsmith1cm]

what an interesting topic ... no it's not a good idea, but what do you do when you find a unit marked with all sorts of different refrigerants?

no telling what's inside. even if one evacuates current charge, then refill with single refrigerant. one still doesn't know if prior charge contaminated oil, etc.

Are you implying that a typical refrigerant charge ALONE can contaminate oil?

I'm curious as to the mechanism behind that.

[ironpit]

what an interesting topic ... no it's not a good idea, but what do you do when you find a unit marked with all sorts of different refrigerants?

no telling what's inside. even if one evacuates current charge, then refill with single refrigerant. one still doesn't know if prior charge contaminated oil, etc.

'

No problem! Just mix your oils! Let's see, there's uh...,canola oil, coconut oil ,corn oil, veggy oil, peanut oil....( no, allergies,)... and uh... oh yeah, there's Olive Oyle!

[Tool-Slinger]

Ok guys and gals... I KNOW it ain't right or what's taught or what they say ain't comtatible (so they say) HOWEVER!

I have come across units that have been marked by passed tech's "R-12/134A/409/hotshot.mix. And are working fine after I repaired a small leak and partially recharged with what I had on hand (134a).

I've also used R22 instead of 404a to get a WI freezer running after fixing a leak, havn't had to go back in 6 months and used 3lbs on a 8lb system.

The equipment,refrigerant,oil and other manufacturers adamantly proclaim that they WON'T mix but they will.

Now before you get your panties in a bunch! I don't do this all the time as a general practice, but only in a pinch. If the system pulls down to temp. then I leave it at that.


you can get as technical as you want but, R12,134a,409,hotshot,and a few others ALL have REALY close head pressure.. and the bottom line is protecting the compressor. R 502,404a,r22...ect are the same.


NO they are not intercomtatible with P.O.E. oil and Mineral oil. I know this but if it's a mix then as long as the majority is oil compatible it will work. Reduce performance and life???? maybe.


My proof I recently came across a 1 door upright freezer that was to be scrapped,marked 404a, The comp. worked so I fixed the evap. leaks and weighed in the 16 oz charge of as equal parts I could of 134a,404a,22,409a.

and also some recovered witches brew

Well it reached -10 F in 45 min. from 80 F.

Hmm?

Now let the beatings begin. (no I didn't make this up to provoke you guys...)

I have made my own mix for a walk-in box, but you have to understand that it was a medium temp coil, high temp condenser, and stuff like that. Nothing was matched and they wanted to run it as a low temp application. Seriously a disaster from the beginning, there were some other issues but I got it working with my own special blend of r-22 / r-12 components which was basically a 502 system when I finished. I added as needed to make my pressures go where I wanted them, it worked, but you could basically throw your pressure/temp chart out the window by the time I had finished.

[cy]

Are you implying that a typical refrigerant charge ALONE can contaminate oil?

I'm curious as to the mechanism behind that.

nope... I was asking ... so if I'm reading correctly. it's not possible for a wrong charge alone to contaminate oils?

[Tool-Slinger]

Out of all the dumb threads on this forum, this one is up there with the worst.

You have obviously not visited the "insulation wusses" thread,

[meplumber]

Alright. I have been reading this thread from the beginning and am ready to make my opinion known.

As JP stated very early, you wouldn't do this on a 1,000 lb system. That is where the two distinct branches of our trade differ. It is one thing to do this on some reach-in or walk-in that holds less than a lb of charge. But there is no way that I would do this on some of the larger HVAC systems that we work on. No way I am going to try and explain how we damaged something on a system with $25K worth of refrig in it.

[OldSchoolMech]

I have read this from the start and think that making a "Cocktail" Is dumb and unneeded. I can see the just a little bit when in a pinch. But to do it and Brag about it EPA anyone????

[jpsmith1cm]

nope... I was asking ... so if I'm reading correctly. it's not possible for a wrong charge alone to contaminate oils?

I don't see a way that it can happen.

POE oil is ALMOST universally compatible with the exception of R12 which is really a non-issue today.

Even if you added an HFC to mineral oil system, it won't damage the oil, there are just miscibility issues with HFCs and mineral oil.

Refrigerants, to my knowledge, do not chemically alter oils.