Window-mounted Solder Fume Extractor (not Just for RVs!)

This is my solution for solder fume extraction for my home (RV) workbench. It uses a dryer hose, a computer fan, and some insulation board to make a removable solder venting system that blows fumes outside. You can even use it for regular houses, too!

Step 1: Get Parts Together

You'll need the following:
- Piece of rigid foam insulation material or wood 5 or 6 inches (125-150mm) wide by almost the width of your window (minus a gap for weatherstripping). I used 1/2" (12mm) polyisocyanurate insulation board (the stuff with foil on both sides and rigid yellow material inside).
- Outside clothes dryer vent (I used a 4" (100mm) diameter vent kit) with inside trim ring
- Two pieces of sheet-metal dryer hose tubing for ends
- Piece of flexible dryer hose long enough to go from window to soldering area plus some extra length
- Computer fan (12VDC) small enough to fit inside the dryer hose tubing. If you're using 4" (100mm) dryer hose, you should probably use a 60mm fan. You'll want the highest flow fan you can find.
- Power cable for computer fan, and either a 12V lighter plug (if you're using this in an RV and have 12V power handy like I do) or a 12V power supply capable of powering the fan.
- Open-cell foam, at least 1" (2.5cm) thick and bigger than dryer hose
- Weatherstripping (1/2"/12mm) for edge of panel
- Bendable wire for legs (I used 0.105"/2.7mm suspended ceiling wire)
- Rubber bands
- hot melt glue, contact cement, duct tape, or other adhesive/tape to put everything together with

Look at what's included in the "dryer vent kit" in your local hardware store; it might contain all the dryer hose related parts.

Step 2: Cut Window Insert Panel to Size

Cut a piece of rigid insulation or wood to fit in your partially opened window. In the second photo, it's the light blue piece that's jammed into the window. I used foil-covered 1/2 inch thick polyisocyanurate insulation board; this is much quicker to work with than wood, and is a better insulator. Avoid the polystyrene foam insulation board if you can, as it'll make a mess.

Step 3: Add Weatherstripping on Edges of Window Panel

Add strips of weatherstripping or other compressible foam material around the edge of the window insert panel to seal out the weather. You'll probably find that the self-adhesive weather stripping doesn't attach too well to the crumbly foam edges, so you might want to put tape around the edges first so that the weatherstripping's adhesive can stick to it.

I used strips of Gorilla Tape to hold the foam down on mine.

Step 4: Attach Dryer Vent to Window Panel

Cut a hole in the panel to hold the pipe from the outside dryer vent. It's easiest to just trace around the pipe and cut it with a razor knife. Then assemble the dryer vent to the pipe, and insert the pipe through the panel. Attach it somehow (hot melt, etc.), and make sure that it's sealed so that the outside air doesn't seep through around the edges. Here I used more Gorilla Tape to hold the tube in. I also used tape on the edge of the pipe, since the metal is sharp and I didn't want to cut myself or the dryer vent hose on it.

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.

Step 6: Connect Fan to Power Cord

Make a hole in the metal vent tubing just inside the window panel to pass the cord through. Put a rubber or plastic grommet in the hole to keep the cord from getting cut (or use hot-melt glue after you put the cord through). Solder or crimp-connect a cord to the fan terminals (make sure to pass the wires through first if you're crimping!) and stick the cord through the hole.

Step 7: Insert Fan Into Foam

Now put the fan into the square hole in the foam, and then put both together into the dryer vent tubing. Use hot melt glue if necessary to keep the foam from sliding around.

Step 8: Make 'vent Hood' Out of Trim Ring and Stiff Wire

Use the inside trim ring from the dryer vent, the other piece of metal vent tubing, and some stiff wire to make the "vent hood". Even better: make a larger hood with better capture area out of cardboard, coroplast, aluminum roof flashing, gallon plastic milk jug, or other rigid material. The stiff wire I used was the sort that is used for hanging suspended ceilings; it measures 0.105" (2.7mm) in diameter and is easy to form. I bent hooks at the ends to go through the holes in the trim ring (which I had to drill out a bit). I also used rubber bands to hold the legs together.

I used rubber adhesive stuff (like blu-tack) to hold the corners of the legs down and keep them from sliding.

Step 9: Put Panel in Window and Attach Dryer Hose

Now you're ready to go! Open your window, put in the panel, and then close the window so the panel is held snugly. Then attach the dryer hose between the vent tubing and the hood tubing.

Step 10: Plug in Power and Start Soldering!

Now plug in your power supply (or 12V lighter plug if you're in an RV; I used an old cell phone charger cable from the thrift shop) and you're ready to go. Adjust the hood so that it is as close as possible to where you're soldering and make sure that it's capturing the fumes OK. Make the hood bigger if you need to.