Thanks for the idea!

I might just do something like this. My paddle workshop is the third bedroom in my rented apartment. My computer shares the same room, as my wife prefers to organize (shove) everything useful (somehow related to "man activities") in it. Dust is a concern, as it coats the electronics as well as introducing asthma related issues with the wife.

I might just use some plywood to make a spacer for the window... redirect the output from the fan to the air outside. We've got something similar for our portable dryer.

: I find a dust mask less than satisfactory although I do wear one. I
: finally found one that doesn't fog up my glasses! When I wear
: the whole kit - eye and hearing
: protectors and dust mask - I feel like an old-time knight ready for
: the joust.

: You may be interested in what I did for my workshop. I attached a
: 20" box fan to the ceiling, with aluminum brackets added to
: it to hold a 20 x 20 (500 mm) furnace filter on the intake side.
: I wired it into the lighting circuit, but it is mounted
: upside-down so I can reach the switch to change speed.

: It does an excellent job; on LOW it silently recirculates the air
: and extracts dust as a background task, HIGH creates enough of a
: breeze to move the dust from around me so it doesn't accumulate,
: and it's still not too noisy. The workshop stays cleaner as a
: result and my dust masks stay clean and last longer. It does a
: better job on the ceiling than at floor level, where it mostly
: stirred up the dust from the floor.

: Another idea: when installing my regular dust extractor system I
: added an outlet at head height over the boat-building location;
: this allows me to connect a hose to a portable tool as well as
: the fixed tools. Most of the time it is used with a 1-1/4 (?)
: hose because that's what the portable tools usually accept - if
: there is any provision at all.