R410A Retrofit from R-22

[jborges]

What is your opinion on retrofitting a York R-22 split system with a R-410 condenser? The evaporator min test pressure is 150 PSI. The evaporator model is K3eu180.

[passintyme]

bad idea. coil surface area will be larger. metering device will not be the same, flush will be required.

[jborges]

How come the surface area is different
If the evaporator size has not changed in at least 6 years. And I understand the work that it has to be done for the retrofit including line flush and txv replacement.

[passintyme]

Surface area is larger due to increased seer rating requirements by uncle Sam and company... R-22 coils were max 350# I believe and the 410a is somewhwere in the neighborhood of 5-600# . If space is the issue and not cost they do make some lower profile coils. There would be n obig issue you couldn't overcome (txv,flush,saturation points etc.) Other thatn the test pressure and matching seer rating.

[jborges]

I am sorry did not specified that retrofit is for a 15 and 20 ton system seer does not matter and the condensing unit will be replaced and the pressure does mot go over 160# in the evaporator.

[passintyme]

In that case... Only issue is correct pressure test... All others would be good..

[welling service]

I would never try to flush the evap coil. You just can't get all of the oil out of the coil. Replace the evap coil. Armstrong Air will not honor the warranty if you do not replace the evap coil when you change to a 410A condenser.

[BaldLoonie]

If you insist on reusing the coil, I'd skip the flush. You have that oil diluter left in the coil. NO WAY of blowing it all out of the coil like there is a lineset since coils have multiple passes. Nobody making uncharged units that big? Rheem stops at 10 ton.

Obviously remember to change the TXV.