Acoustic Ventilation...

Ventilators have a natural attenuation to minimise the intrusion of noise from outside the ventilated area to inside. There will be an Acoustic loss due to noise from surrounding sources (such as passing road traffic, rail, aircraft and children at play) trying to squeeze through the small apertures in the ventilation.

This is called the Reflection loss of the ventilation aperture and is dependent on the size of the aperture: Smaller apertures will give a higher reflection loss and will particularly limit low frequency noise intrusion such as a low rumble. There will be a further small loss, at the higher frequencies, caused by reflections within the ventilation.

However if the ventilated space is near a high noise source (such as a busy road, a nearby railway, a low aircraft flight path, or a noisy air-conditioning plant ) there may be a need for higher attenuation within the ventilation system. If this is the case then attenuators may be installed within the unit, which can be achieved within the thickness of a double masonry wall.

The amount of attenuation required will be dependent upon how high the external noise level is and this should be measured if deemed critical. We are able to offer a consultancy to carry out an Acoustic survey to assess the background noise level around the ventilated area and offer an Acoustic ventilation system.