Fan for Room Air

[storm shale]

Is there a good fan with Wi-Fi or Zigbee to control via Home Assistant (zigbee2mqtt)? I have a 120mm hole in the wall, and I'm looking for a fan that fits inside... It needs to blow air in and out depending on the calendar date for the server room.

Fan for Room Air

[topaz magnet]

I'm not sure you will find a fan that will blow both in and out, since most are designed for optimum air flow in one direction. If you only want one direction then it should be straight forward to DIY a solution using an ESP and a 120mm PC FAN - could add PWM so that it speed increases as needed.

[storm shale]

not everyone like building staff as DIY most time it just looks crap if you dont have all tools like 3d print and co ...

[elfin fern]

the "correct" solution is probably to make a second hole and have 2 fans, one facing each way.

[storm shale]

thats not a "correct" solution thats just a i dont now how solution ...

as an example
https://shop.siegenia.ch/siegenia-ch/de/Lüftungssysteme/Wandlüfter/AEROTUBE/AEROTUBE/p/AEROTUBE
or
https://acinfinity.com/hvac-home-ventilation/home-comfort/room-to-room-fans/room-to-room-fan-two-way-airflow-temperature-controller-8-inch/

just searching for something like this that is control by homeassistant

[topaz magnet]

Your original post stated you have a 120mm hole, which is why I mentioned that you wouldn't find a fan that will provide optimum airflow. Both the links you posted seem to be bigger than 120mm.

DIY is also a matter of opinion and potentially skill level.