Noise control Acoustic Enclosures

Acoustic Enclosures

Noise reduction is required by law in working areas in industrial plants as well as residential areas in the vicinity of plants. Acoustic enclosures are installed to absorb sound produced by noisy machines and equipment, thus minimizing the noise affecting the outside environment. The sound-insulation properties of enclosures are mostly dependent on the density of their outer shells. The most efficient insertion loss is produced by a soft material with a high specific mass. Such a soft material cannot be used due to the lack of its structural strength. Thin steel plates, in combination with mineral wool, are used instead.
The enclosure consists of an outer and inner wall with the mineral wool in between. The inner wall is needed to keep the mineral wool in place, but perforated to allow the mineral wool to absorb the noise.
Diesel and gas operated internal combustion engines, refrigerating machines, and compressors generate low frequency noise – partly with significant single tones – and maximum levels of up to approx. 200 Hz. In case of gas and steam turbines, high-frequency noise prevails with level peaks of approx. 1,000 to 4,000 Hz. Consequently, our acoustic enclosures must have an optimum design for both frequency ranges.
However, high noise reduction can only be achieved if the casing consists of solid components and if it is possible to design and mount it carefully without gaps or leaks.
With our enclosure system, we have specially concentrated on the requirements of heat pump systems, compressors, and high noise engines. It is a modern and flexible system with the following advantages:
- Highest possible insertion loss, even in the low frequency range to reduce low-frequency noise caused by induction, ignition and compression. Our enclosure system is conceived in such a way that, for example, at a third-band centre frequency of 63 Hz an insertion loss of 25 dB can be obtained.

  • For the frequency range of 100 to 4000 Hz, we guarantee an insertion loss, of 30 dB(A), a value that can only be reached in dismountable enclosures by major constructive efforts.
  • Despite having high insertion losses, our system is designed as a modular system. Wall panels are fixed to a steel structure by quick locks. Assembly and dismantling can easily be done by one person without special tools.
  • Our enclosures are resistant against all weather conditions and therefore can be installed inside or outside.
  • Specially designed inlet and exhaust silencers together with high performance fans, provide ventilation of the enclosure. Doors, windows, and transmissions for pipes are integrated in the design.
  • By means of an appropriate single element assembly system, the costs for this high-quality noise protection can be reduced to a minimum for each individual application