Air vents inside the National Indoor Stadium

(BEIJING, November 25) -- To control noise, the National Indoor Stadium applies a 25-cm-thick, nine-layer multi-functional design that is rarely seen in China. The "sandwiched" layers are composed of cement planks, glass fiber, a waterproof layer, and sound-insulating materials, topped off with a sound-insulating outer coating. The resulting product minimizes the effect of noises from the outside and solves a problem faced by many of the Olympic venues -- that of noise from falling rain.

Meanwhile, Low-E glass curtain walls combined with metal composite boards surround the stadium on all four sides. The glass curtain walls are made of double-layer glass, which not only provides heat insulation but also provides excellent sound insulation. And the stadium's air conditioning equipment is specially designed to contain noise. All these measures result in an environment free from excessive noise so spectators can simply enjoy the competition.

According to chief project engineer Zhang Guoqiang, the National Indoor Stadium will serve as a top-grade artistic performance venue after the Games. Therefore, not only must the building be waterproof and insulate heat, but acoustics and sound insulation are also important considerations.

Noise from heavy rain is no longer a concern at the venue, he added.