To flush or replace coils

[rs77063]

I need to replace my R22 condenser. I had my evaporator coil replaced (the whole air handler unit actually) just a few years ago and it can handle R410. I've so far gotten 2 bids (waiting on #3 right now). Both techs agree that the coil can handle R410. But one says they can flush out the oil from the R22, while other claims the flush can't get the all the oil out of the coil and I'm looking at problems down the line unless I replace the coil. Who's right?

My searches so far SEEM to indicate, if the flushing is done correctly, it will work:

"...the R22 refrigerant can be evacuated from the evaporator coil, the thermal expansion valve can be replaced with one designed to work with R410A refrigerant, and all traces of R22 flushed from the refrigerant lines so that the entire system can be converted to R410A..." from one site

and

"...The oil for R22 and the oil for R410a isn't compatible. Just trace amounts of oil such as what is left over after flushing is OK, but the oil in the inside coil isn't easily removed without using a flushing agent such as R11..." from another site (I can't put the URL's in due to forum rules)

[HayZee518]

replace coil

I think you are looking for problems if you flush and put in R-410. The oil from R-22 is or has infiltrated the pores of the copper tubing and is difficult, if not impossible to completely remove. it is of a different viscosity than r-22. Next you have to think about the compressor. this is nearly as bad as the condenser coil with regards to the different oils. it seems even more difficult to remove because the oil would have worked its way in between the coil windings of the motor.

[rs77063]

compressor

I think you are looking for problems if you flush and put in R-410. The oil from R-22 is or has infiltrated the pores of the copper tubing and is difficult, if not impossible to completely remove. it is of a different viscosity than r-22. Next you have to think about the compressor. this is nearly as bad as the condenser coil with regards to the different oils. it seems even more difficult to remove because the oil would have worked its way in between the coil windings of the motor.

I'm replacing the compressor anyway, so that's not going to be an issue. It's the condensor coil I'm worried about. BTW, I got bid #3 in the meantime, and they claim I can flush too. So the vote is 2 for flushing, one for replacing. Of course, the majority isn't always right...

[HayZee518]

a/c

you've gone this far, change everything. 410 is a little more ecological friendly than 22