Chill Hill

The flats overlooking the railway are consequently exposed to significant levels of environmental noise.

Our aim was to develop a passive ventilation strategy for the flats to allow residents to control summertime overheating without being exposed to unacceptable levels of noise break-in.

The client was presented with various design options for the ventilator. To help evaluate the internal noise levels associated with each option an audio recording of a passing train was processed to simulate the acoustic performance of each ventilator. Considerations of space, architectural impact, as well as noise levels led to a final choice.

The audio file below demonstrates a simulation that was presented to the client - first with the windows open and then with the windows closed and the ventilator open. The open ventilator simulation corresponds to the ventilator that was actually installed. The levels you hear will depend on your volume settings but allow a relative comparison to be made. The sound is best listened to on headphones.

On completion of the first phase of the development, we made video and sound recordings in a flat to demonstrate the actual improvement achieved by the acoustic vent.

The measured sound attenuation improvement was up to 15 dB which is consistent with the performance expected during the design phase.

The benefit of auralizing the noise levels was an immediate understanding by all involved of the relative advantages of each attenuated vent option. This led to a quick decision on which to adopt with everyone involved committed to achieve the agreed design target.

For further information on this project or on auralization at Max Fordham's 3D Ambisonics lab - SoundSpace - please contact p.novo@maxfordham.com.