Natural ventilation without noise transfer
Cross ventilation between internal spaces in a building and good acoustic performance is provided by WhispAir devices installed at high level in the partition between the two spaces. Developed by Passivent and Arup, WhispAir provides the low-resistance to airflow that is essential in naturally ventilated buildings. Accredited laboratory testing has demonstrated that an acoustic performance of up to Dnew 44 can be realised.
Design features include a patented sound-absorbing lining optimised to attenuate mid-frequency sound, typically the most problematic.
The design is based on an ABS sleeve with foam lining, so it can be packed flat for easy transport. There are 16 models. The smallest is 300 x 300 x 300 mm; with standard acoustic foam it achieves Dnew 31 and an average attenuation of 34 dB at mid frequencies. The largest unit is 600 x 600 x 1200 mm, which with high-specification foam can achieve Dnew 42 and an average attenuation of 51 dB at mid frequencies.