For noise reduction in outdoor environments, UNITECNA INDUSTRY produces silencers that reduce noise in the exhaust gas ducts of engines, vent valves, and ducts carrying high-speed fluids.

The silencers can be of the reactive type, which work by dissipating and damping sound power through a series of passages with specially designed sections and shapes. Alternatively, they can be of the mixed type, where an absorbent section is added to the reactive section, further increasing the level of acoustic attenuation.