Call Me a Pessimist, But I Can See This Coming...

[man from trane]

I live in the US Virgin Islands. Skills are generally lacking here (I'm being polite :rolleyes: :D).

The reason I'm concerned is that because of salt air, lack of vacuum pumps used by others at install, and power company issues the average lifespan of a condensing unit here is about 5 years. The AHUs last much longer so they are usually left in place when the condensing unit is replaced. The EPA has thrown a wrench in the way we do things.

After all the R-22 equipment is gone, I'm sure some guys around here are going to start sticking new R-410A condensing units on older AHUs with R-22 coils. So here's what I'm wondering about:

What would happen if you did that? Will the coil hold the pressure in the off cycle? It's like 275 psi I think. Most R-22 evaps say 150 psi test pressure.

Then, what would happen if you sucked the R-410A out of the new unit and replaced it with R-22? R-22 is usually compatible with POE oil in refrigeration equipment. I would think that might actually work, but I've never tried it. The only R-410A equipment I've put in yet has been mini splits.

[Senior Tech]

Dude...you live in the Virgin Islands, don't worry...






















Be Happy :D

[man from trane]

^ That's exactly what I'm afraid of. You must be from here. :D

[fixitguy]

410 with 22 coils doesnt work..Its been proven when accidently installed!!
orifices in TXV's or pistons are different, An old r22 coil will come apart very soon. But there will be big business in coil replacement!! Cant the tecs afford vacuum pumps there???

So if 410 is removed and you now have r22 at 410 pressures...
110 on the low and 285 on the high... the coil temp will be high too...

[man from trane]

Cant the tecs afford vacuum pumps there???
So if 410 is removed and you now have r22 at 410 pressures...
110 on the low and 285 on the high... the coil temp will be high too...

Apparently not, re. the vac pumps.

You wouldn't charge it to those pressures, you'd charge it to normal R-22 pressures. The compressor probably moves about the same cfm, I would think.

[inf_sys]

Sounds like a mess that I am sure will be happening not just in your area in the near future. I see service call $$ in the future. It depends on the manufacturer as far as the coils go but they would need to be newer. Some mfg are now making coils that will run both R-22 or R-410A to reduce the mfg models of air handlers they are putting out. So if the air hander is new and then the condenser goes it may be possible if the coil was mfg for both. If someone is trying to run R-410A on an old coil that was not dual designed then it will not work and will have leaks quickly. As far as running R-410A in a R-22 system, no that will not work. There are no current R-22 condensers for residential applications that can be converted to R-410A. R-410A compressors and coils are manufacured with thicker walls to contain the higher pressures of the R-410A. There are drop ins for R-22 that have been on the market for a long time and I expect those will increase in volume as the R-22 supply is depleted. Right now they are not worth it as the cost is more than R-22 in most all cases. Either way without proper line and system flushing it is just going to be replacement time.

[fixitguy]

410 with 22 coils doesnt work..Its been proven when accidently installed!!
orifices in TXV's or pistons are different, An old r22 coil will come apart very soon. But there will be big business in coil replacement!! Cant the tecs afford vacuum pumps there???

So if 410 is removed and you now have r22 at 410 pressures...
110 on the low and 285 on the high... the coil temp will be high too...

[catmanacman]

time will tell what works and what dont i would guess that in the Virgin Island you use mostly electric air handlers no gas furnaces witch makes changing the coil only with the condensor a little tougher

[man from trane]

410 with 22 coils doesnt work..Its been proven when accidently installed!!
orifices in TXV's or pistons are different, An old r22 coil will come apart very soon. But there will be big business in coil replacement!! Cant the tecs afford vacuum pumps there???

So if 410 is removed and you now have r22 at 410 pressures...
110 on the low and 285 on the high... the coil temp will be high too...

But you wouldn't charge it to those pressures, you would charge it to the normal pressures for R-22.

Oh well, someone will soon try it here and then I'll let you know what happened. :D

[man from trane]

time will tell what works and what dont i would guess that in the Virgin Island you use mostly electric air handlers no gas furnaces witch makes changing the coil only with the condensor a little tougher

The worst part is that they always stick the AHUs up in an attic where it's almost impossible to work on them.

[dash]

When Carrier started with Puron/R410a,many coils that wer built for R22 were approved and used with Puron,by changing the TXV only,no issues.

Just did one in my neighbors house last year!

Not saying all will be okay, I'd go with the mfrs apporoval.

[gremlor]

you can use some r-410a coils with r-22, lennox has a coil that says r22 and r-410 A.

The txv was on the line going into the cabinet rather then inside the cabinet kinda like a retrofit. i just assume they made the coil to handle the pressure for 410A and put a different metering device so it can be used for both refrigerents.

[stonefly]

its a good question. get enough of the oil out of the lineset & coil, change the txv. can anyone here say for sure if the manufacturers had to build a stronger coil because 410-a was one the horizon? my guess is that the older coils were stronger knowing how thin they've been made for efficiency sake. anyone ever pop one with nitro? come on you know you do it.:D