As I do have the Raspberry Pi installed in the rooms for multi-room audio, and have added the LIRC support there for infra remotes, I kind of thought it might be cool to use the opposite way (IR transmit) to control A/C units. That way I'll be able to centrally control the operating mode, shutdown on exit and basically everything what the supplied infra remote does.

Sounds simple, not an easy task though. I have started some research and landed on an interesting article summarizing why LIRC is not easily capable doing this. See here: http://blog.bschwind.com/2016/05/29/sending-infrared-commands-from-a-raspberry-pi-without-lirc/ (thanks Brian Schwind)

There are obviously other methods how to centrally manage home A/C like Modbus of KNX, but just the extension boards for such connection costs almost similar price as the external inverter unit. 🙁

I am going to explore this a bit more later and probably summarize my findings in an article here later on.