Armacell in the World’s Largest Bird’s Nest


In August 2008 China hosted the Olympic Games for the first time in history. The world´s greatest sporting event took place in a distinctive building, which is affectionately known as the ‘Bird’s Nest’ due to its intricate steel construction.

The Olympic stadium is an architectural sensation and received the Brit Insurance Designs of the Year Award in the category Architecture even before it was completed. The 330-metre-long, 220-metre-wide and almost 70-metre-high building was used as venue for the Olympic opening and closing ceremonies,as well as the football and athletic competitions.

The insulation material made by Armacell is more energy efficient than traditional elastomeric products – a fact that is true for the whole service life.

In spite of its 42,000 tonnes of steel, the national stadium appears light – the steel beams were interwoven like twigs in a bird’s nest and due to the use of a translucent membrane the rooms remain transparent. The impressive steel skeleton both frames the tiers of spectator seating and at the same time acts as a roof. All facilities are self-contained construction elements and, like the reinforced concrete bowl with the seating, are not connected to the façade. The open construction allows natural ventilation thus ensuring a pleasant indoor climate. Nevertheless, air-conditioning was still needed in many parts of the building.

An important requirement for the design of the national stadium was that natural resources should be conserved and energy consumption should be kept as low as possible through the use of modern technology. Armacell was able to beat numerous competitors to win the contract to provide the insulation material for the chilled-water lines and air-ducts of the air-conditioning systems. With a thermal conductivity of λ 0° C ≤ 0.034 W/ (m•K), a resistance to water vapour transmission of µ ≥ 10,000 and an oxygen index of L.O.I. > 35, installations insulated with Class 1 Armaflex have long-term protection against condensation and energy losses.

The four cooling units of the air-conditioning system have a capacity of around 13 MW and provide cool air in the service area of the Olympic stadium. Apart from the reception hall, offices, restaurants and other facilities, the rooms for the athletes and the luxury boxes for spectators are, of course, also air-conditioned.

The chilled-water lines of the air-conditioning system have a line temperature of +7 °C and diameters ranging from 15 to 500 mm. Armaflex tubes in an insulation thickness of 24 to 32 mm were installed on pipes with diameters below 100 mm, 32-mm-thick sheet material was used on larger diameters. Air-ducts were insulated with 25-mm-thick Armaflex sheets. In total, approximately 65,000 m of Armaflex tubes and 87,000 m² of Armaflex sheet material have been installed in the Bird´s Nest.