Homebrew Laser Cutter made by Zach Radding

Step 9 Airflow and Smoke Eater

The hose that sucked smoke away from the lens used to go to a blower that blew it out of the building through a vent. The fumes from cutting plexiglass were so malodorous that the stink drifting back in from outside was unpleasant. So Zach bought this unit. It blows the rank fumes through a charcoal filter which soaks up all the nastiness. It's a RSU12-CCHR "Space Saver" model made by Electrocorp. He says it gives him better air quality than an exhaust fan.

I asked Zach about the possibility of a laser cutter that held the workpiece vertically to save floorspace, whether he thought convection would cause fires. He said no, every laser cutter has to have lots of airflow past the cut, so that problem wouldn't be any different.
In his opinion, the big problem with a vertical workpiece is that cut parts would fall out, shift around, slump, and possibly fall into the cut and glue themselves back together.