I've posted a few times about an aging Lennox ZoneMaster system at my father's house. He's researching all kinds of crazy ideas to improve on or replace parts of that system while he waits for variable speed compressor technology to meet multi-zone (if that EVER happens).

He's asked me to do some research for him on the Goodman MS20 line of mini-splits, which have variable speed compressors. The question is: Is it possible to marry one of these (presumably the larger 24k btu model) with his existing traditional air handler/furnaces? What would be the challenges?

Thanks for any info, or pointers to resources I can use to help him (or help convince him to go another way).

Secondary questions: Does anybody know the specific model number of the compressor used in those mini-split condensers? Also, if you were looking at a home with two zone master systems (each 5 tons, one supporting two air handlers, the other supporting three) what would be your first thought about how to update/replace?