Cleaning the Air for Future Welders

In 2012, Green River Community College and the State of Washington initiated a plan to build a new state-of-the-art community college focused on training skilled metalworking welders. This program was created to not only provide students with the skills and knowledge needed to produce high quality welds, but to also provide hands on training in the welding booths.

Of critical importance for the welding classroom was the need to maintain a high level of indoor air quality by reducing hazardous air pollutants such as Manganese and Hexavalent Chromium. These toxins, listed in the Environmental Protection Agency’s (EPA) regulations for nine metal fabrication and finishing source categories, can cause several health hazards after prolonged exposure.

Since hazardous fumes and gases are invisible, it is impossible to visually gauge the effectiveness of ventilation. For this reason, an exhaust ventilation system is needed to remove fumes, and gases from the welders’ breathing zone. Green River Community College contacted AAF to help design, and install a collection system for filtering weld fumes in their metalworking classroom.


The metalworking classroom had several welding stations that needed fume/smoke collection. As a working class environment, attention had to be paid to both the hood/duct design as well as the collector design flexibility. The classroom layout and collection system had to be designed to ensure safety of both students, and instructors as they moved throughout the class as well as adapt to multiple pick-up points, and allow for significant turndown of airflow when class size was low.


For the metalworking classroom AAF’s applications engineering team recommended the OptiFlo® 5RC80 cartridge collector utilizing REDClean® media, filtration return air is 99.99+% efficient on 0.5 micron (MERV15/F9). Additionally, utilizing a variable frequency drive control system to maintain proper velocity in the ductwork takes advantage of AAF’s REDClean® media’s low pressure drop (typically below 0.5”/125Pa on initial startup) to reduce energy consumption and provide the necessary turndown flexibility for the classroom.


The school now has an industrial dust collection system that keeps students and instructors safe, maintains good housekeeping, while also complying with OSHA, NFPA and EPA regulations in the US and CE, Machinery directive and Atex directive in Europe. The AAF provided solution reduces metal fabrication hazards of Manganese and Hexavalent Chromium which are often present in welding applications.