A/C upgrade gone wrong
- Thread starter okrobie
- Start date
dcg9381
Well-known member
I see used HVAC all the time on CL / Facebook - makes sense now.
Like others, I've seen the flammable refrigerants listed as compatible with R12 and associated base oils. I have a few cans in the garage waiting on a project...
Like others, I've seen the flammable refrigerants listed as compatible with R12 and associated base oils. I have a few cans in the garage waiting on a project...
LS6 Tommy
Well-known member
Keep in mind, once you open a system up, you need to replace the accumulator/drier, too and pull a vacuum on it ASAP after you leak check.
Tommy
Tommy
kapnkirk
Member
After your well and check the gasket and repair, pull another vacuum with a vacuum gage in line, after a couple hours turn the pump off and check the vacuum gage to ensure it holds a good vacuum.
The system is good if it holds 500 microns for 30 minutes or so.
Keith
The system is good if it holds 500 microns for 30 minutes or so.
Keith
Just because I haven’t seen anybody else post this… There’s a pressure switch in the system. Low Freon levels will cause low pressure which will drop the compressor out of line. One can of Freon isn’t nearly enough, probably two or three at least. Start by checking to see if the compressor clutch is engaged when you don’t have pressure. Perhaps the only thing wrong is that you didn’t put enough Freon in yet and didn’t understand why the compressor stopped.
Thanks Tommy. I don't have an economical access to dried Nitrogen, so wen't against your prior advice and used compressed air. My compressor has a pretty good dryer on it and I vacuumed it extra long before I charged it.
With respect to flammable gasses. I am now 77 years young, and I have been working with flammable and explosive gasses since I was 24. In the Natural Gas and Steel industries. I do respect where you are coming from but I would not do anything that would endanger me or others. I wouldn't advise anyone with less experience to try this at home. And in the end I opted to not do it anyway because I didn't have proper fittings to do it safely.
Don't ask me why I was stupid enough to leave out the receiver/dryer gaskets. No excuse.
With all due respect for your opinion, I found several YouTube video's that recommended compressed air for pressure testing and took your opinion under advisement by being extra careful to use dry air (as dry as possible) and to evacuate it for over 2 hours before charging it.
You sound full of wisdom and experience and I do respect that very much. Regards, Jim
rlitman
Well-known member
Clearly your survival is a coincidence. Pressure testing with acetylene is actually more dangerous than what got this guy killed:
https://www.odt.co.nz/news/national/fatal-explosion-when-i-turned-around-shed-was-flat
But hey, you found some information on YouTube. See anything good from the Flat Earthers lately? They're really becoming a global movement.
Tommy, with respect to UL Approval, I'll tell a little story from my personal experience. Years ago I worked for an instrumentation company. I made service calls on my companies products. One day I got an assignment to service one of our temperature testing ovens at the UL Laboratories lab near Chicago. I show up and they lead me to the instrument and I began my work. Well, that was about 10AM. For the next two hours I heard nothing from the technicians but which clients would be taking them to lunch that day. That was their whole focus for the morning. I saw no one lift a finger to test a product or do any other work while I was there. Fortunately I was done with my work before dinner time because I felt in real danger of being trampled on their way to the door. For some reason since that experience I have lost confidence in the UL Label.
Just sayin. But I'm sure they have more integrity than the brief encounter I experienced.
Just sayin. But I'm sure they have more integrity than the brief encounter I experienced.
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Board, please accept my apologies for my arrogant and know it all attitude. Clearly I have no experience with acetylene and I appreciate your collective input on the matter. I'm really not sure if I would ever have tried it, but by the Grace of God I didn't. Thanks for your concern for my safety.
P.S. My recent behavior does not represent the kind of sobriety that a person with 33 years should have. But as we say, it is one day at a time. And progress not perfection.
P.S. My recent behavior does not represent the kind of sobriety that a person with 33 years should have. But as we say, it is one day at a time. And progress not perfection.
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rlitman
Well-known member
I guess you missed where I say that flat earthers are becoming a global movement. But yeah, I have cats. Mine are weird though, and they don't really fit that mold. One thinks it's a tribble (or maybe I'm just an evil supervillian) and just snuggles and purrs, and the other likes to perch on things and stare at you (probably waiting for you to die) and also thinks that my wife is a chew toy.
I really don't want to come off as harsh, and I want to be clear that I see no ill will directed towards you by anyone in this thread. We're all just trying to prevent you from first and foremost hurting yourself, and next, damaging what you're trying to fix. And, well, youtube (and google) simply has no such filter.
Lassen Forge
Well-known member
Wait - I want to see the results of his putting Acetylene in his refrigeration system and pressurizing it. I bet that would be the first time the fire marshall saw an AC system take out an entire neighborhood... from someone not understanding what they were doing and faking it because, hey, what can it hurt?...
I thin maybe the OP should sell his welding tanks as well.
I thin maybe the OP should sell his welding tanks as well.
rlitman
Well-known member
Most FSMs have a table that explains how much oil to add for the each of the components that have changed (say, x ounces for a hose, and y ounces for an evaporator). At a minimum, you'll be changing the receiver/dryer.
But you've got a much bigger issue, which is that having a system that was originally R12, it is still filled with mineral oil that is incompatible with both the PAG and the R134a you intend to fill it with. You can't just top it off with new oil and hope for the best. ALL of the old oil and any residue must be removed.
Also, there are many types of PAG oil. In the very least, it comes in three viscosity ranges, and using the wrong one WILL be the short end to your compressor. Plus, I suggest that you use "double-end-capped" PAG.
I have been told (maybe wrongly) that extensive vacuum pump action will evaporate off old oil. I have been relying on that because when I first started evacuating, I was getting a lot of vapor from the vacuum exhaust pipe then after a few hours it stopped.
Nevertheless, for better or worse, (before your latest post arrived) I put in a 3oz. can of PAG oil and then two cans of R134A. The compressor kicked in just after I started the first can and after the second can was empty, I measured the chilled air and it was 34.5 deg. F. and the compressor was running quietly. Purred like a kitten. I don't know how long it will last, but for now seems OK. Fools rush in where angels fear to tread.
Nevertheless, for better or worse, (before your latest post arrived) I put in a 3oz. can of PAG oil and then two cans of R134A. The compressor kicked in just after I started the first can and after the second can was empty, I measured the chilled air and it was 34.5 deg. F. and the compressor was running quietly. Purred like a kitten. I don't know how long it will last, but for now seems OK. Fools rush in where angels fear to tread.
rlitman
Well-known member
That is flat out wrong.
Jeepster04
Well-known member
- Joined
- Jun 25, 2013
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You can read endless threads on R12 to R134a conversions. From what I remember, the mineral oil wont be carried about by the R134a... It may last a long time just putting the PAG oil in there.. You can buy a flush on amazon then borrow the flush kit from autozone. That was a my plan when I had a vehicle that took R12 that evidently had a leak... No longer have the vehicle so dont need to worry about that. Never heard of using compressed air to check for leaks, Ill have to keep that in mind since I too do not have Nitrogen. If I did have Nitrogen and couldve fixed the leak I would keep it R12. I've always pulled a vacuum overnight then ran the pump again the next day.
https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/1193907/Re:_Why_are_R134a_and_mineral_
https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/1193907/Re:_Why_are_R134a_and_mineral_
As was said don't use any fuel gasses in refrigeration systems. Nitrogen is your best and safest bet. But I agree with LS6 Tommy. Hire someone you trust to do the work. I work on home hvac so it wasn't a problem for me to replace compressor filter drier and expansion valve on my car. Part of doing the job is having the right tools. I speak from experience when I say having all the right hvac tools costs a good bit of cash.
Falcon67
Well-known member
I'll add that in my experience, if you didn't pull and flush the condenser and flush the evap coil, then have your hoses re-done with "barrier hose" then you've spent a bunch of $$$ for nothing. Also, since R-134 is less efficient than R-12, if you don't or can't update the condenser to something bigger, better or more efficient than some of the older units you will have somewhat reduced cooling capacity.
Also - in my experience - if you DIY a system like this with a replacement compressor, unless you have a licenses shop do the pressure, test and load - your warranty on the compressor is void. Last one I did the compressor warranty REQUIRED that a filter be installed in front of the compressor to protect it from potential debris issues.