What to do-replace seer 10 evap coil with 13

[pcumming]

Have 2 10 year old Comfortmaker (ugh) residential units-2 ton and 2.5 ton with gas Comfortmaker furnace on top.
No ice on coils. Last year my great and trusty hvac guy had to top off the R22. This year he has been out 2x to top off. One needed more R22 than the other.

This time he got out his leak detection meter (for R22) and found a leak in both evap coils, one more than the other. I was interested and watched him do this. *Tomorrow he will come out and check the outside condenser for any leaks-we ran out of time today.

A. Also tomorrow, he will get me a price on 2 replacement uncased downstream Seer 10 Comfortmaker coils.

B. He also mentioned that Seer 13 uncased evap coils (Goodman/Aspen) could work with my Seer 10 condenser unit assuming they fit in the evap case. He said we would need a TXV valve and would need a 3/4 to 7/8 adapter or something. He also said that this would not make my units operate at a seer 13 level. These Seer 13 evap coils can handle R22 or R410A per Alpine: http://www.alpinehomeair.com/viewpro...ctID=453063169

Since I am not working currently and been out of work for a while. I do not have the money to replace both AC units (and condenser) in their entirety-ie: 2 completely new systems.
But I was thinking that if I used seer 13 coils with R22, that if the condenser went out in the future, perhaps I could go to a Seer 13 condenser and run R410A making things more compatible
Would this give me a Seer 13 unit or are there more factors???

Whats best to do-=A B and any comments you might have?

Thanks so much
Peter

[classical]

Evaporator coils DO NOT HAVE SEER ratings, they affect the SEER of condensing units and they affect the percentage of sensible and latent heat removal capacity of a system.

Strictly speaking even if a coil is capable of being used with either refrigerant, once it is used with either rerigerant it should not be switched to the other refrigerant. The oils used in the refrigerants are not compatiable and it is unlikely that a coil can be sufficently flushed to remove the old oil.

[pcumming]

Duh, what a dope I was. I should have figured that out. My fault, not my HVAC guy.
So I guess the question is would an aftermarket evap coil from Alpine like a Goodman or Aspen work just as well as the original maker-Comfortmaker. Has 10 year warranty. Only issue if it is one is that the replacement coil will have about 1/2 inch clearance on depth (front to rear).

And then that leads me to the question. If one were to change the condenser to a seer 13 and evap coil and use R410a does that make it seer 13 or is there more to it?
I can ask my HVAC guy tomorrow if you rather not reply

Thanks
Peter