Is it me, or is there conflicting information on the conversion of R22 to R422? This is going into a residential 3 ton Heat Pump. I have selected R422B as the suitor as this most closely resembles the R22 characteristics for HVAC. The unit has a TEV with a Receiver. From the Tecumseh document RD-0003-E section A3, I would need to flush the system and replace with POE. Information from the National Refrigerants, Inc., blends tutorial pg. 86 indicates that I might need to just add a little POE.

Thoughts on this?

Some seems to state the unit needs to be evacuated, dryer replaced and possibly use a larger expansion valve. Other information seems to indicate that you can just evacuate and recharge with no changes at all. It’s like Voodoo and Black Magic.

Any other thoughts?

Thanks. You guys are the Greatest!