As mentioned on the Guild of Makers Conference post, I picked up an extractor fan at the swap meet. This was a powerful dual blower style fan with a timer and an external trigger. There’s also a microswitch that controls the second fan, which kicks in when the primary is not pushing out so much air.
The control circuit is interesting as it is pluggable so I could potentially add my own board there in the future.
Given the large size of the fan, I wanted to get it attached to the wall as soon as possible so that it was not taking up precious bench space. So I located a suitable section of the wall and cut out a space. To give the fan some support I found some old hardwood offcuts and made a simple frame, then cut some plywood to fit.
My first attempt at fitting the fan was a failure as I’d not allowed space for the small plastic backdraft doors to open so they would have clashed with my supports. So I took another plywood offcut and patched that up
Some small wooden pillars were cut to form the corners and the original case was flipped around so that I could use it to attach a hose. I need to mount an external vent and complete the wiring but otherwise it’s ready to go, and most importantly it is not on the bench.