R22 Recirculated system

Hello everyone,
I am faced with the same old question again. I have a customer that has bought a shut down cold storage that has an empty R22 recirculated system . He has asked me what is the right thing to do. For me it would be convert to ammonia. All the pipe and coils are steel. All the compressors are Frick. He is a little nervous about this. I guess Ammonia has a bad rap for some reason. Has anyone done a conversion of a recirculated system to one of the new refrigerants? Lowest room temp will be 39 deg F.

You probably will get every side of the issue on this one. I have done this, without any major problems, but others will probably have bad stories.
Need to check out the evaporators for copper
The screws and condenser and vessels should be Ok With a good plan I think it is possible but probably will take some time and baby sitting .
Probably have to get new chips for the screw controllers etc.

Let me know how it goes
Bruce

Check closely for any non-compatible pressure controls.