Tackling traffic noise through plenum windows - An application in Hong Kong

Hong Kong is a very small but hyper-dense city with over 7 million living in 1,100 sq km in which 85% of land is hilly area. Like other metropolitan cities, Hong Kong is facing significant road traffic noise problems. The Government of Hong Kong is committed to addressing road traffic noise problems and has adopted proactive actions like preventing the problems through land use planning and environmental impact assessment process for new roads, implementation of appropriate mitigation measures on existing roads etc. In most cases, measures like roadside barriers / enclosures would be required. However, the majority of residents live in high-rise buildings and such compact urban forms setting would easily be susceptible to road traffic noise problem. To make Hong Kong a livable place with a good acoustic environment, examining other measures on building façade design is necessary. This paper will discuss on the actual application and in-situ tests conducted for plenum type windows in its application at a housing development next to a heavily trafficked road. With careful design and use of absorptive materials, a noise reduction of up to 8 dB(A) can be achieved without compromising sufficient air ventilations meeting local regulations.