Ok to convert existing coil from R22 to R410?

[soupcxan]

I live in Dallas and depend on my AC. Our house was built in 1996 and we have a 15 year old 4 ton York compressor that is starting to die. It's hooked up to a 5 ton Lenox coil that is substantially newer, though it must be at least 5 years old because that is when we bought the house. The system is on r22 now. We are looking at options to replace either the compressor (stay on r22) or replace both the compressor and coil (switch to r410).

One company checked the serial number of the Lenox coil and said that it was r410 compatible, they just need to flush it a couple of times and change the expansion valve. This would bring the cost of switching to r410 down because I was expecting that we would have to buy a brand new coil. He said the existing coil was in good shape, not too old, and well installed, so would be good to reuse it with a new r410 compressor (from American Standard).

I know that linesets are routinely cleaned and reused when switching from r22 to r410. Is it safe to do this with a coil? I did a quick search and some techs said that "you should never reuse a r22 coil with r410 because you can't flush all the gunk out of it" and that will lead to the death of your new compressor.

[Integrity Aire]

yes it is safe, and works well if matched up like your tech did. all proper installation standards should be used.

[handrichardson]

That is the correct way, all too many times, the line sets dont get flushed which in turn makes the compressor to fail! So who ever is doing this knows there stuff! seems like your in good hands!

[BaldLoonie]

Why not match a Lennox coil with a Lennox A/C? Best performance that way.

American Standard units are looking for an expansion valve inside. Hopefully the dealer is smart enough to put on a 410 valve.

[SkyHeating]

I personally don't flush and reuse systems to save a few dollars. It can costs thousands if done wrong and your paying labor to replace a compressor and then potentially upgrade the coil later. Why not match everything up now and have a new system instead of a 15 year old furnace with 5 year old coil with new AC?

If you were buying a car that was 15 years old with a 5 year old motor and a new transmission would this scare you? I am not saying it can't be done, just be cautious as it can be done right but most of the time I see it done wrong and costing more in the long term. Good luck with whatever decision you make.

[R123]

Ive flushed out the coil and lineset and replaced the TXV without any problems on several units and they've been running fine for several years. Just make sure he flushes it thoroughly! Sky, I see your point but not everybody can afford a complete new system.

[heaterman]

It is do able, the question is why? You will not get the warranty that is available because of a mismatched system and most likely not get the maximum efficiency either. Flushing the line set is one thing (we don't reuse those either) but keeping a 5 year plus coil and replacing an old condenser just is not good use of your hard earned dollars.

[SkyHeating]

Ive flushed out the coil and lineset and replaced the TXV without any problems on several units and they've been running fine for several years. Just make sure he flushes it thoroughly! Sky, I see your point but not everybody can afford a complete new system.

I just reread what I posted and it sounds like I am saying replace the furnace too, but I only meant replace the coil and AC. The coil can't be a huge percentage of costs for the benefits that would be received.

[Gib's Son]

The reason why I recommend against it is the higher operating pressures of 410A vs 22. If you got a week coil to begin with the added pressure can push it over the edge.:.02:

There is a reason why 410A components need to be rated at 600 PSI vs 450.

[catmanacman]

I am not a fan of flushing evap coils as I do not think you can get all the flush out of it I would rather just blow it out with nitrogen while the metering device is removed . that being said I would just replace it and match the outdoor unit and coil

[pwg11386]

yeah, lets get that straight:
NEVER use any line flush chemical to flush an evap coil. Pure r11 would work, but no rx11 or pro flush. Pure nitrogen through the coil will work, just remove the old metering device first so there is no restriction.

Seriously... NEVER!

[BaldLoonie]

Exactly. Hard to flush a multi-circuited device completely. Probably have some flush left in the bottom to dilute the POE oil of the new unit.