i’m using a couple of Homekit automations and Homebridge virtual switches to archive something similar to this.
As a trigger I‘m using two virtual switches configured over homebridge-dummy (one called Hourly timer and one called Restart timer) and have two automations, where one turns on the other and then turns it back off after a specific amount of time.
Next a Homekit automation runs every time the Hourly timer turns on, this was converted into a shortcut and uses an if statement to open/close the roof windows and blinds according to the levels of a temperature sensor. I‘m sure you can set it up yourself, but in case anybody is wondering i can send you screenshots of the shortcut itself.
Additionally, in order to cover some edgecases when i restart Homebridge (mainly when i was working on the Raspberry Pi running the Homebridge server), I’m starting the Hourly timer every time Homebridge restarts, i archive this by using a Homebridge plugin called homebridge-delay-switch, which turns on yet another virtual switch called Homebridge restart 10 after Homebridge is restarted.
Homebridge restart then starts the Hourly timer and turns it off in an hour.
This does the trick for me and could probably be modified to turn on/off your AC.
Let me know if this helps.