For Ventilation Systems of all Types
The standard range of rectangular splitter type sound attenuators/silencers have been developed to give virtually any attenuation required in normal practice, in any air handling situation. They are designed for use in industrial ventilation systems, where axial or centrifugal fan noise must be reduced.
They are also ideally suited for use as cooling air inlet and outlet silencers for diesel generator sets, compressors, etc. , where they can simply fitted into builders work openings or mounted onto acoustic enclosure.
When an installation has external facing walls, our range of fixed blade weatherlouvres, motorised weatherlouvres or gravity operated louvres, can be readily incorporated, to give maximum protection against ingress of rain and to prevent through draughts when the plant is not in operation.
Acoustic and Aerodynamic Performance.
Acoustic and aerodynamic performance is determined in accordance with the recommendations of BS 4718 1971 "Method of Test for Silencers in Air Distribution Systems." The attenuation is calculated by comparing the sound levels from a sound source, with and without the silencer installed in the duct work between the source and the point of measurement.
Acoustic measurements are carried out without airflow and the attenuation which is measured in dB, in the octave bands from 63Hz to 8KHz, is termed the 'Static Insertion Loss (S.I.L.) . The acoustic performances of our standard range of silencers are shown below.
Types 244, 264 and 284 are each 600mm overall length
Types 344, 364 and 384 are each 900mm overall length
Types 444, 464 and 484 are each 1200mm overall length
Types 544, 564 and 584 are each 1500mm overall length
Types 644, 664 and 684 are each 1800mm overall length
Types 744, 764 and 784 are each 2100mm overall length
Types 844, 864 and 884 are each 2400mm overall length
The aerodynamic performance is determined by calculating the airflow velocity through the silencer. We will be pleased to advise on individual applications.
Constructional Specification.
The silencers are constructed with a 1.6mm thick welded galvanised or zinc coated steel outer skin, with pre drilled, 50 x 50 x 5mm thick rolled steel angle flanges. The internal acoustic splitters are constructed using 1.6mm thick steel casings, with a heavy density rockfibre acoustic infill having a scrim cloth facing to prevent fibre erosion, in turn being retained in place behind 0.7mm thick perforated galvanised sheet steel. The complete assembly can have an external primer/undercoated paint finish, suitable for additional paint treatment if required. The heavy density rockfibre acoustic infill is inert, vermin proof and non-hygroscopic. It has a Class 1 Spread of Flame Certificate to BS 476, part 6.
Where arduous conditions prevail, such as with chemically contaminated processes or offshore applications, the range of silencers can be modified in construction by using heavier gauges of materials, stainless steel materials, hot dip galvanising, specialist paint finishes, etc.
Selection of Attenuators
The information given on this web page is for guidance only and it should be remembered that, if a silencer is situated in a system in close proximity to bends, filters, louvres, dampers, etc. , an increase in system pressure loss, apparently due to the silencer, may be produced.
We will be pleased to asses the particular acoustic requirements and system resistances of an installation upon receipt of full details.
For further information please contact CES at