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Any coils compatible with both R-22 and R-410?

I have a leak in the evaporator coil of my HVAC unit. Are there any coils (and regulators) on the market that are compatible with both R-22 and R-410? I can’t afford to switch out the AC unit now. But expect it to go bad in a few years. One tech. recommended a coil that is compatible with both gases, another said that wasn’t possible and a third just didn’t know about that. [Before Irishmist gets started, I have consulted with licensed (as in professional), certified, full-time HVAC contractors (3 to be exact) and I am getting slightly different stories from each. I am looking here for additional information and educated assumptions. Not iron-clad answers.]

Re: Any coils compatible with both R-22 and R-410?

Kevin, most if not all your evaporator coils are compatible with either R-22 or R410a. The problem with mixing them up is two-fold. First of all, if you are replacing an outdoor unit (formerly R22) with a new 410a unit, and keeping the same indoor coil (as long as it is a match) you have to be able to eliminate (in its entirity!) the residual R22 that is in the system. The 'flushing' techniques work pretty well, but if you let even a slight amount of residual R22 remain in the system, it will not mix with the R410a, and catostrophic results can occur.

The second problem is the metering device. The R410a unit that you are using (outdoor) may require a different metering device than is what is on the existing R22 coil. Even if it is a TXV, the R410a unit matched with that coil, may use a differnt expansion valve.

It is not worth the potential problems and failures that can very likely occur to try to salvage and re-use EITHER the indoor coil or the refrigeration line set. All should be replaced so that you have a pristine environment for the new refrigerant.

The ONLY exception that we allow is if the refrigeration lines are in a finished space, i.e. wall or ceiling and cannot be accessed to run new lines. ONLY in those cases will we even consider flushing the lines and reusing them, and even then, we qualify the results of the flushing by indicating problems could occur. The indoor coil is usually a non-issue as the equipment can be accessed and therefore the replacement of the indoor coil is not prohibitive. Dont' forget the line sets!!!

All the best, Irishmist

Re: Any coils compatible with both R-22 and R-410?

Thank you Irishmist. A most informative response. I have a much better prospective now. I haven't been able to get good answers from the companies that have looked at my system. I haven't been able to talk directly to the tech only the office folks. Thanks again I have a great deal more info now to have those conversations.

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