Use R410a condenser with Rheem R22 evaporator?

[apb]

I have a similar question as the original poster in this thread: http://hvac-talk.com/vbb/showthread.php?p=13078631 .

I have a split system, and need to replace my condenser unit. This system and house is about 20 years old, and uses R-22. I would like to replace the condenser with an R-410a unit, but I don't know if that is possible with my evaporator.

The model of my evaporator is a Rheem RCLB-A036S. The nameplate also says low side test pressure 150PSI. I was not able to find any published pressure specs for this model (other than specs relating to the air handler).

I gather from reading the referenced thread that I would for sure need a new TXV, but I'm not sure if the evaporator can take the different pressure used with an R-410a compressor?

Also, someone mentioned that the two different refrigerants take different lubricating oils, but does that matter? I mean, can the existing lines be cleaned?

And, another mention was made of the type of tubing used. That is two issues: 1. Is the coil tubing usable with R-410a? and 2. Is the connection tubing between the condenser and evaporator (that probably runs through my slab) usable with R-410a? This is important even with a new evaporator, which I might also do to be able to use R-410a.

It might or might not matter that I am located in California (in case we have some extra regs here, as is often the case).

Thanks.

[jmac00]

If you change the outdoor unit to R410, you MUST replace the indoor coil with a matching coil.

[BaldLoonie]

RCLB is an old cap tube coil. Not meant for the pressures of R410a. Not meant for the pressures of 13 SEER. Reusing that old think is ASKING for trouble. I wouldn't even put a 13 SEER dry 22 unit on it.

[apb]

RCLB is an old cap tube coil. Not meant for the pressures of R410a. Not meant for the pressures of 13 SEER. Reusing that old think is ASKING for trouble. I wouldn't even put a 13 SEER dry 22 unit on it.

Hmm, that's very worrisome. I thought that 13 SEER is the minimum on the market these days? Meaning, I will need to replace the evaporator no matter what.

(My tech is proposing to replace only the R22 condenser with a new R22 condenser, btw.)

So, if I replace the RCLB evaporator, and go to an all R410a system, will I need to replace the house pipes connecting the evaporator to the condenser?

[apb]

BTW, thanks to jmac00 and BaldLoonie for the quick very helpful replies.

[mark beiser]

I've got a little bit broader range of "things I would be comfortable with doing" than the average on this forum when it comes to reusing existing coils, but I would not even consider reusing that coil with a new 13 SEER R-22 unit, and an R-410a unit on that coil is not even in the realm of possibility.

[darctangent]

apb:

Please do yourself a favor and ditch this guy and your plans. you aren't saving money, you're wasting it.

Stick around and learn how to hire a quality contractor and pay for something worth having from a contractor that will stand behind their work. That's the smart buy.

[bobboan]

So, if I replace the RCLB evaporator, and go to an all R410a system, will I need to replace the house pipes connecting the evaporator to the condenser?

That depends on their sizes and condition. If they are the right sizes and in good condition, they would have to be chemically flushed and purged with nitrogen.

If it's reasonably possible, you're better off with new lines.

[darctangent]

That depends on their sizes and condition. If they are the right sizes and in good condition, they would have to be chemically flushed and purged with nitrogen.

If it's reasonably possible, you're better off with new lines.

+1

but to the horse in front of the cart, learn how to find a good contractor.

[apb]

Well, ok, other than the two contractors that are members of this site and like an hour's drive away, how do I find a good contractor?
(Thanks to Mark, darctangent, bobboan for replies.)

[Wheelbaron]

See I think this is funny, (strange, not ha ha). I mean what contractor writes a quote for just a condensing unit on residential?? I write the quote for the whole ball of wax; Condensing unit, coil, txv, lineset, pad whip disconnect... And if their t-stat looks like a pile of crap I replace that as well, so I don't get nuisance call backs. If they don't want all new lineset and coil, then who knows what kind of crud could be in that old stuff, and even with a rx11 flush there could be issues.

[darctangent]

Well, ok, other than the two contractors that are members of this site and like an hour's drive away, how do I find a good contractor?
(Thanks to Mark, darctangent, bobboan for replies.)

hmmm....

anybody got a good thread to reference?


ok... here's a start.

a contractor that is willing to spend hours, not minutes assessing the old system, the house and the duct work.

Can perform a Manual J load calculation, and present it to you at time of install.

Can test the existing ducting.

Commissions the equipment at the end of the install, and adjusting airflow, refrigerant charge, and refrigerant metering device for proper operation.

and willing to put in some kind of decent filter access!

oh.... forgot.


brazes with nitrogen.

evacuates the refrigerant system properly and tests with a micron gauge and standing pressure test.

and uses cased coils whenever possible!


I guess that makes for an ok start, but others will add or debate.