Someone on the Milwaukee Makerspace mailing list posted an email with the subject line Laser cutter expert, so I could not ignore it. The person was specifically asking about exhaust systems. Above is a photo of what I built for the 40 watt laser cutter in my basement, and below is most of my reply.
The exhaust from my laser cutter is a 4″ diameter vent hose, which I connect to a 6″ hose with an adapter I got from Home Depot. (In this photo you can sort of see the while plastic piece that attaches to the back of the laser cutter. It has a small and inadequate fan that came with it.)
The vent hose coming out the back of the laser cutter connects to an inline fan that is mounted to the ceiling…
The output of the inline fan goes to another step down adapter and then a quick connector that twists to lock into place.
I’ve also got an AC Variable Voltage Converter which allows me to run the blower at lower speeds if desired. (I sometimes dial down for paper, thinner material, etc. to reduce suction and noise.)
I then have a basement window that I replaced with a piece of wood on the outside and pink foam on the inside which has a hole in it (covered with a laser cut screen) on the outside, and on the inside the quick connect that I connect up when I use the laser cutter.
This just gets all the fumes out of the tiny room the laser cutter is in. It doesn’t scrub the air. I am not cutting for hours at a time. My main goal was to not have my spouse come home and say “why does the whole house smell like melted plastic!?” and I think I’ve achieved that goal.
Here’s the list of all the components I could remember:
- iPower 6 Inch 442 CFM Inline Duct Ventilation Fan
- iPower 6 Inch 8 Feet Non-Insulated Flex Air Aluminum Ducting Vent Hose
- Two-Piece Dryer Hose Quick-Connect
- AC Variable Voltage Converter
- 6 in. to 4 in. Round Reducer (QTY 2)
Oh, and if you want to see a real laser cutter exhaust system, or at least the details of building one over many years, check out lasercutterventingsystem on the Milwaukee Makerspace wiki.
Note: As I understand it you want the exhaust fan as close to the exit of the building as possible, which I could not easily do, but I think this is a good compromise.
Update: I did add a HEPA Air Purifier to this setup about six months later, just to help with any residual smells in the air.