Thank you all for your thoughts. Indeed I probably do not hear much complaints because the people who want AC never came. So obvious that I did not think about that
. We always tried to use a little energy as possible. And we get much power from our solar power installation. But we are connected to the grid since last year as well. My idea was to built the sleeping compartiments in 5 of our cottages only. I think that if I can limit the space of the sleeping part to 15m3, a 500W AC, set a 40% power would be more than enough. If we would want to cool the whole cottage it would use indeed lots of energy, and it would be very hard to isolate it aginst sound and insects. We will put an adjustable thermostate in the compartiment. I really like the idea of getting fresh dry air in lower to the floor and letting the warmer (used) air flow out at the ceiling. Thi would prevent the problems which people describe who do not want to have AC. What I like too is the idea that you can adjust the brightness and the temperature of the light. The indoor unit would be placed outside the sleeping compartiment and the outdoor unit outside the cottage. The cottage are rather far from each other, but anyway we have to prevent they disturb the guests next door. Our restaurant is very spacious and open without getting direct sunlight inside. I think that the ceiling fans with an extra standing fan still will do. More feedback is very welcome. We still have plenty of time to expiriment and adjust our ideas. One of the most difficult things is how to keep the low frequency out. The period around New Year was rather disturbing last year because of the parties in the villages. I think to build 40 cm thick stone walls and a thick coconut wooden ceiling. No windows and only one heavy wooden door. But again, advice more than welcome.