Engineering controls eliminate, or engineer out the noise, by using noise control solutions: sound absorbers, sound blocking, composite sound absorbers/blocking, and ventilation silencing.
OSHA's Noise Standard (29 CFR 1910.95) requires employers to have a hearing conservation program in place if workers are exposed to a time-weighted average (TWA) noise level of 85 decibels (dBA) or higher over an 8-hour work shift. Noise control is accomplished through three different modes: sound absorption, sound blocking, and silencing.
|90-95||hearing loss from sustained exposure|
|125||start to experience pain|
|140||quickly causes irreversible hearing damage|
If it is not possible to reduce noise at its source, then sound absorption in the space should be considered. Sound absorption occurs when a material takes in sound energy as opposed to reflecting the energy. Part of the absorbed energy is transformed into heat and part is transmitted through the absorbing body. Noise reduction targets of 10 dBA or less are suitably obtained using sound absorption techniques.
A significant amount of noise can be reduced by using blocking. Some sound energy is reflected while some is blocked. The magnitude of sound energy blocked is in direct relation to the mass of the material (lb./ft2). Noise reduction targets range from 18 dBA - 45 dBA.
A significant amount of noise can be reduced by combining sound absorption and sound blocking. Sound absorbing material takes in sound energy as opposed to reflecting it. Part of the absorbed energy is transformed into heat and part is transmitted through the absorbing body. A portion of the remaining sound energy is blocked by the solid mass material. Noise reduction targets range from 18 dBA - 45 dBA.
Fans used to move processes (i.e., dust collection, particulate conveying) or cool equipment and personnel all make noise. Noise is generated by the fan blades imparting upon air molecules or bad flow conditions. Silencers & acoustic louvers can be tuned to balance pressure loss and noise reduction are a great method of solving noise issues.
Silencers come in many shapes, sizes, and performance
Fixed-blade acoustic louvers, many models, many thicknesses
Learn more about Kinetics Engineering Controls to Reduce Noise Exposure by calling us at 1-800-959-1229, or email us at email@example.com.