So I haven't done this (and I am actually following this thread, hoping that someone who has will reply and confirm), but my strategy would be as follows.
Scene Event: Armed Sensor is tripped
Luup logic:
*Sleep for 5 minutes
* then check status of sensor.
* If sensor is no longer tripped
* end.
* otherwise
* continue to execute
Essentially what you would have here is the scene firing when the door is opened, but all the scene will do for 5 minutes is sit there watching the clock. Once the 5 minutes has expired, it'll manually (via luup code) check the status of the sensor again, and if it is still in a tripped state, then it'll execute the commands. In your case, it'd be to turn off the AC appliance control module (which is a very good idea btw). In my case, it'd be to send me an email saying you left the door open again.
I think this'll work, and the LUUP code would be pretty straightforward. I could write it up, but I'm sure someone has done it before.
Any comments from those that have done it?
Thanks