Laser cutters produce fumes and particles from the materials they cut. To make sure these fumes are removed from spaces where people occupy, an exhaust system is used, which works much like a typical clothes dry exhaust. Of course, big production shops could have vastly larger and more complicated exhaust systems, but the concept is the same.
What Exhaust Fans Do
Exhaust fans have a simple, but important job, to remove fumes and fine particle from spaces were people breath and blow them to a safe place, usually outside. This is generally done with a fan that sucks the fumes from the laser cutter bed and then pushes them through ducting to a port that leads outside the building. Dedicated manufacturing spaces often have these ducts as permanent fixtures with multiple exhaust ports, however the set-up for smaller spaces can be as simple as porting the fumes out an open window.
Why Exhaust Fans Are Important
Improperly exhausted fumes and particles can be a health issue. Concentrations of laser cut material fumes can irritate the throat and chest, or worse, depending on the material being cut. Remember, exhaust fans are not designed to prevent toxic fume exposure and certain materials, such as PVC should never be cut with a laser, no matter how good the exhaust system is. Always check with the manufacturer or the That said, even non-toxic fume can accumulate creating breathing and even fire hazards.
Proper Set-Up & Usage
Individual needs for exhaust fan size and power will vary. In general, be sure you have a powerful enough exhaust fan to successfully push air through the ducting to reach the outside exhaust port. The further away the exhaust port is from the exhaust fajn, the more power it will need to get the job done. It is also important that your exhaust fan is configured to pull air and fumes out of the laser bed and not blow air into it. Finally, It is important that either rigid or ﬂexible metal ducting be used in the exhaust system. Any type of “soft” ducting is potentially ﬂammable and should not be used under any circumstance.
Check your instruction manual and be sure your fan is properly set up. You can also take a certification course to understand how all the accessories are set up and work together.
Exhaust Fan Maintenance
Exhaust fans pull dust and small particles, as well as fumes and smoke, from the laser workbed. Over time, these minute particles will accumulate in the ducting and on the blades and interior of the exhaust fan, just like a normal room fan used for cool breezes in a home. Depending on usage, the ducting and the fan should be inspected weekly to monthly and thoroughly cleaned. If these particles are left to accumulate too long, they can become a fire hazard. Check your machine's user manual for complete maintenance procedures for your laser cutter.
Fume extractors do the same thing as an outside exhaust port, however, instead of releasing the fumes outdoors, they pull the fumes through a complex filter system that catches the particles and purifies the fumes to safe levels of contact. It works remarkably well because of the three different types of filters. Different fume extractors may have different configurations of this filter types, but they all work the same way. To learn more about fume extractors, explore our blog How Fume Extractors Work.