With increased demands of living comfort, ‘aural comfort’ is becoming as important as thermal comfort for all building services applications – hotels, hospitals, schools, residential complexes, commercial complexes and all Energy-Saving Buildings. Poor aural comfort relates to presence of noise (unwanted sound) as well as to the quality of sound in the room. One of the major sources of these nuisance sounds in almost all central cooling/heating buildings is the ‘duct noise’. Both structure-borne and air-borne noise within the HVAC system travels along the connecting duct network and emerges at the system outlets or vents. Noise can also ‘break into’ ductwork through the duct wall in one room and propagate along the duct into adjacent rooms. If left untreated, there will be little attenuation of this duct noise, even over large distances, ruining an otherwise acceptable acoustical construction.
Up to now, it has been necessary to use relatively thick acoustic insulation materials in the frequency range between 500 and 5000 hertz in order to achieve the desired noise absorption. Armasound Super-Silence Ductliner with Microban (active anti-microbial protection 24X7), through its engineered pore geometry, formulation & composition, can offer substantially higher acoustic energy absorption.
The benefit for designers and users lies in the fact that they can apply lower insulation thicknesses – often half as thick – to achieve the same performance. Alternatively, considerably greater sound ab-sorption can be achieved if the same insulation thicknesses are applied. High NRC (Noise Reduction Coefficient) and High Insertion Loss reduce noise generated by airside equipment (fan generated noise), air movement (air rush) & cross talk, giving more productive work environment. Propagation noise and breakout/in noise is often worsened by the fact that the duct wall panels vibrate very easily. This resonance behaviour is similar to what one might observe with a loudspeaker and amplifies the noise both inside and outside of the air-conditioning system.
The ductliner, owing to its high density (140kg/m3) and visco-elastic properties, helps deaden these resonance effects in metal panel work and thus reduces re-radiation effects. It also acts as a sound deadener by reducing the transmission of structure-borne noise. Anti-Microbial Protection is built into Armasound Super-Silence Ductliner during the manufacturing process, giving continuous active protection against microbial growth and provides the basis for continuous system hygiene.
As a comparatively heavy material, the Super-Silence ductliner has very good noise barrier properties. The relatively high density and high air-flow resistance reduce the passage of noise. Traditionally noise barrier and noise absorption could only be achieved with the use of combined material layers.
The product can be installed quickly and easily even in tight spots. It does not need to be fixed mechanically or additionally clad, but can simply be glued directly onto various surfaces. Although the material is open-celled like all acoustic foams, it is hydrophobic and therefore does not absorb water or other liquids as easily as many other acoustic products. Armasound Super-Silence is manufactured in two different grades: alongside the standard material Armasound (140 kg/m3), an acoustic foam with a density of 240kg/m³ has also now been added to the range.