Refrigerant Questions, Straight Answers

Not banned — production of new 410A steps down, but the installed base runs for another 15+ years on virgin and reclaimed supply, same story as R-22. Nobody should scrap a working system over refrigerant headlines. Prices will drift up slowly; that's the whole drama.

No. Different refrigerants, different pressures, and a mixed charge is unrecoverable — you'd be signing up for a full recovery, deep vacuum, and recharge. Every system gets its nameplate refrigerant, period.

Yes — federal rule, not store policy. Section 608 certification is required for purchase of regulated refrigerants, and any counter that skips checking is risking fines for both sides. Bring the card once; a good counter keeps it on file.

It's printed in the unit's install manual as ounces per foot of liquid line beyond the rated length — commonly around 0.6 oz/ft for 3/8" liquid lines, but use the table for your exact model. Weigh it in on long runs; chasing subcooling from a wrong factory charge wastes an afternoon.

Necessary. Brazing copper in open air lines the pipe with black oxide scale that ends up in the TXV and the compressor. A lazy 2-3 SCFH nitrogen purge while you braze keeps the inside clean — it's the cheapest system protection there is.