Window-mounted solder fume extractor (not just for RVs!)

Step 5 Make foam mounting for computer fan

Cut a piece of compressible, open-cell foam at least as thick as the computer fan (I used some polyurethane packing foam) to fit snugly inside the dryer vent (make it a little bigger than the vent diameter). I traced around the tube from the other end of the dryer hose for this. Then cut out a square opening for the computer fan; make it a bit smaller than the fan's dimensions so that the fan will fit snugly.