TonySue, if that question was for me, I am going to get my timers and have them fitted by the contact Barry & Di have posted. The timers I was looking at in the UK ranged from £30 - £50 each, and I was far from confident I could get anyone to understand how to fit them correctly in Turkey. I probably could have fitted them myself but didn't really want to !
Yes it's still a fair bit of money to get them fitted to each ACU. Some people would rather charge guests more money and just accept the rental will cover the electricity bill. We decided we wanted try and conserve energy without making life difficult for guests. We think it's a good middle ground. I can't say we have worked out the cost/payback timescale .... but when you factor in further savage electricity increases, pale "greenness", and extended ACU life-span, it just "feels" the right thing to do.
We did look at a different system which had a movement sensor and would turn off ACU's if there was no movement in the room, but They were £50 per unit, ran on batteries and looked like the COULD be more problematic. The idea was good if only they weren't so expensive.
I haven't been able to find a better option