Let’s be honest, commercially-available soldering fume extractors are cheap enough that you probably don’t need to build one yourself. But it still makes for a good starter project ...
A Wemos D1 Mini is used to run a pair of the valves, which are paired with a Y-adapter to connect both a soldering station and 3D printer to the fume extraction system. As a nice touch ...
They are indoor air quality devices that draw-down air and do not require external ventilation. Often, downdraft tables are used as workstation fume extractors and dust collectors in welding, sanding, ...