Marshall Day Acoustics - Building services noise assessment and attenuator specification

Whether listening to a symphony in a concert hall or having a telephone conversation in an office, we need an appropriate balance of noise from the building's mechanical services system.

A noisy air conditioning system can render a music auditorium useless and therefore detailed design and analysis is required. To this end Marshall Day have developed unique specialist software that interacts the mechanical services CAD drawings and identifies problem areas causing excess downduct or regenerated noise.

Conversely, it is often found that offices that are too quiet are worse for speech privacy than offices that provide an appropriate level of "ambient" noise. A properly designed office air conditioning system can provide acoustic masking that will reduce the required sound transmission loss provided by partitions.

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Mechanical Services Projects

	THEATRES ON THE BAY, Singapore: In order to achieve a very low noise criterion of N-1 (which is about 12dB lower than NR15), Marshall Day developed software called COGEN to identify and track areas of noise generation. The duct layouts were labrynthine and the task of assessing the duct layouts was extensive but there was no other way to evaluate the complex supply and return networks.
	RADIO NEW ZEALAND STUDIOS, Wellington, New Zealand: The relocation of Radio NZ studios to an existing office block in central Wellington presented many challenges in providing low noise air conditioning system to studios and control rooms. Marshall Day worked closely with the mechanical services consultant to ensure that appropriate noise control measures were employed.