I mean why are they welded shut and all that, why not just screw them together like car engines or whatever so if there's a problem they can be opened up and fixed? Is it planned obsolescence?
why are residential compressors hermetically sealed?
taiwanluthiers
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I am 6'4". I reach over and take out the old and braze in the new. I even did a service valve by climbing into the condenser and brazing it. I wore a 3M organic vapor cartridge mask, though.
Sincerely,
Wiliam McCormick
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I'm thinking of building a refrigerated cooler for my laser cutter. The commercial ones are very expensive, even Chinese made ones. I can just scrounge up old fridge that don't work quite so well for this job.
Worst thing invented for air conditioning installs. They will leak.
Recalled the congressional review on space shuttle Challenger explosion, with demo of O-rings clamped down in glass of ice water.
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Semi-hermetic compressors I've dealt with aren't repaired, they are re-manufactured. People in the field aren't equipped to do this. The facility I've been to that does this are essentially new when out the door.
The price of hermetic's is low enough that no one could afford to even open one up let alone fix it.
I did this once with a 20 ton semi-hermetic. The connecting rod broke. I obtained a new one, located some plastigauge to check bearing clearance and put it back together. The cost exceeded the cost of a re-manufactured one. It's hard to beat the efficiency of a facility set up to do a job.
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6,240 Posts
Yes and no. You can buy and replace stuff like a valve plate kit or oil sightglass yourself, but if you have a catastrophic failure it's not practical to rebuild it in the field. Copeland won't sell you stuff like pistons, rods, etc anyway even if you wanted to fix it.
Copeland is big on pointing out the difference between "rebuilt" and "remanufactured". It's usually a few hundred dollars or more :grin2:
As for the original question, residential AC compressors are designed to be disposable. By welding them shut they keep most people from goofing around trying to repair them. Compressor go boom, replace it or the unit.
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39,604 Posts
An American company is rebuilding welded hermetics.
AARCO - out of Tennessee. Very nice to deal with.
PHM
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AARCO - out of Tennessee. Very nice to deal with.
PHM
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I hope there better than A1 remanufactured Semis of the 80's!
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39,604 Posts
I do too. I just bought an AARCO ZR24 rebuild to test in my own unit. <g>
I hope they're better than A1 remanufactured Semis of the 80's!
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694 Posts
I have guys who tells me that R22 is unethical like they murdered baby seals to make the stuff.
And it's almost like governments wants us to throw away perfectly good R22 systems in favor of R32 or whatever system, like that's going to save the planet, and what happens to the old systems, sit in a landfill? All this environmental and green whatever doesn't really do what it sets out to do.
And it's almost like governments wants us to throw away perfectly good R22 systems in favor of R32 or whatever system, like that's going to save the planet, and what happens to the old systems, sit in a landfill? All this environmental and green whatever doesn't really do what it sets out to do.
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694 Posts
In a lot of ways communist China seems more free, as R22 is freely available and cheap too. Not sure if they signed the Montreal protocol but it sure as hell looks like they don't care.
Though in hindsight I should have just used R417a when I swapped compressor, to satisfy those guys who sees R22 as unethical, but that meant spending money waiting on another can of refrigerant (as I don't have any R417a handy).
And honestly I'm not a huge fan of R410a (and supposedly those are getting phased out) because the mini split that I have that's R410a doesn't cool all that well, either because the compressor is weak, or that it had leaked at some point in the past and so the mixture ratio has been upset. Only way to fix that is recover everything and then re-add everything by weight. That and it seems everything's just harder with 410a, needing micron gauge and all that.
Almost like there's a conspiracy to make HVAC trade more and more difficult.
Though in hindsight I should have just used R417a when I swapped compressor, to satisfy those guys who sees R22 as unethical, but that meant spending money waiting on another can of refrigerant (as I don't have any R417a handy).
And honestly I'm not a huge fan of R410a (and supposedly those are getting phased out) because the mini split that I have that's R410a doesn't cool all that well, either because the compressor is weak, or that it had leaked at some point in the past and so the mixture ratio has been upset. Only way to fix that is recover everything and then re-add everything by weight. That and it seems everything's just harder with 410a, needing micron gauge and all that.
Almost like there's a conspiracy to make HVAC trade more and more difficult.
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What a joke. You should see their industrial cities. Only idiots like us would allow that status.
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Back on the subject as why smaller compressors are welded and not bolted together. The compressor shell of a hermetic compressor is technically a certified pressure vessel that has gone through a myriad of tests to assure it will not burst under certain conditions. To achieve the same standards on a small unit that two halves were bolted together would require much thicker construction, making it heavier, larger, and much more expensive. Many older tin can compressors bodies had a certification tag spot welded to them with BOM or other backup reference information. The NFPA and UL regulate the standards for construction and testing of these vessels in here in the USA.
For example, here is testing performed by Carrier back in 2000 on the new rotary compressors hitting the market intended for R410a to verify integrity of the "pressure vessel". Short read, but goes in to depth how the just the design of the encapsulating vessel is heavily engineered.
For example, here is testing performed by Carrier back in 2000 on the new rotary compressors hitting the market intended for R410a to verify integrity of the "pressure vessel". Short read, but goes in to depth how the just the design of the encapsulating vessel is heavily engineered.
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3,454 Posts
Back in 72' I went on a Factory Tour for the Carrier Compressor, Carlyle. And they bragged about being the 'most' hands free comp builder at the time. Damn near everything was automated, from pressing the steel shell to adding the dry air charge.
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1,629 Posts
everything!
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Wow, that high? I will have to take a look at the max pressures on a condensing unit next time.
If I can put that much pressure on a system it would help with finding leaks.
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