So what your saying that if the ac had a built in timer (which are available on the market) then reb moshe would be ok with it just like a built in t-stat on shsbbos
No, I don’t think a timer being built into the appliance would make it muttar according to R’ Moshe. If you programmed a built in timer to turn on the a/c at 11pm Friday night, for example, the a/c’s operation is beginning at 11pm.
If, however, you turn on the a/c before Shabbos, and the compressor happens to cycle on at 11pm, that is considered a result of what you did on erev Shabbos.