This was a unique design and fabrication project. An industrial laboratory had a dilution tunnel that was very loud inside the lab. The requirements for my solution were substantial noise attenuation, while still flowing 1200 cubic feet per minute with only several inches of water in differential pressure loss. You can see 2 halves which were on roller trollies to allow servicing of the HEPA filters that were installed in the system. I designed and built this and as you can see, had to build tilting and hoisting fixtures for transport and installation. This was a lot of work.