@AmeliesUncle
25Cf2 is in regards to joint ownership. For example, a boiler installed in a two family home where each family owns their own unit. It doesn't seem to apply to (or limit) the case where one person owns two home and installs a system in each home, or where one person owns a large home that requires two separate systems.
I suppose it could be argued that Congress meant to allow one "system" per home, and that if you have a very large house that requires two condensers and two evaporators, that is one central air conditioning "system". But the law doesn't say system, it says "item." Or it could be argued that "per item" really means "per category". But if you ever read any appellate court decisions, you will find that when the words mean something, they mean what they mean. Only when the word are ambiguous do courts sometimes turn to intent. I think it could be argued that "per item" means "per item" and if Congress had wanted to say "per category" or "per system" they could have done so.
Anyway, all this falls back to the fact that any taxpayer can't claim two AC units in Turbotax, because Turbotax follows the forms, even if they are (possibly, arguably) incorrect. The taxpayer would have to find some other way to circumvent the form and claim two credits and take the risk of what happens next.
