Thanks Hawk,
I'll check the sensors since that looks easiest to do and a sensor probably isn't too much.
It's little inconvenient when I park my car and the fans are roaring for 10 minutes. Can be heard from inside the house...

yeah, Bitcoin. I have a small solar array I built as a project and it's connected to some gear that generates Bitcoin that I then use on an EFTPOS card.
The address there is a donation kind of thing.