> As far as I can tell, it's also illegal to install split systems in the US when it's not done by a professional Split systems are sold OTC in chain home impr

> As far as I can tell, it's also illegal to install split systems in the US when it's not done by a professional Split systems are sold OTC in chain home improvement stores here in California, and are ordinarily self installed. Perhaps there is some regulation somewhere in the US god knows, but if so there is little to no enforcement of it.