“As I mentioned before that oneg shabbos might be considered a mitzva.”
OK, now you’re just being silly. The rationale of using “oneg Shabbos” to get around issurim has been employed by the Reforms for decades; it’s not going to hold any water here. I’m not accusing you of being like them, but surely you should be able to see the slippery slope you’re going down. If you say oneg shabbos mattirs a Shabbos goy, then why not have him turn on your TV? Drive you 45 minutes to shul?
We hear you saying that this issur doesn’t apply to AC, what we aren’t hearing is your reasoning. You can keep repeating over and over that “circumstances change;” nobody here is disputing that. The question is WHAT circumstance changed in regard to AC units since the psak of Reb Moshe was given? Oneg Shabbos existed back then too, so you can’t use that.