Tower rises to the energy challenge

Any developer embarking on a project as ambitious as the 490-metre 118-floor International Commerce Centre in West Kowloon knows that the building will serve as both a physical landmark and a gilt-edged opportunity to set new standards in design, technology and the incorporation of the latest environmentally friendly features.

From when the tower was first conceived as one half of Hong Kong's 21st-century 'harbour gateway', mirroring Two IFC in Central, Sun Hung Kai Properties made a point of adopting green concepts and the most energy-efficient practices.

Au Yeung Shiu-keung, a manager with Sun Hung Kai's project management department, said this approach anticipated the expectations of major institutions and catered to their needs. As office tenants, they would naturally benchmark against the highest European and North American standards when choosing new headquarters in Asia. And committing to take space in what, when fully completed in 2010, will rank at least for a while as the world's third-tallest building, they expected to have hi-tech installations, tailor-made layouts and environmental thinking innovatively applied.

The company's basic target was to achieve the HK-Beam (Building Environmental Assessment Method) platinum standard. By a rough count, the ICC now has more than 100 advanced green features.

A good example, according to Pau Wai-keung, project manager with the Sun Hung Kai Properties Group, was the energy optimiser air-conditioning system. Developed during a two-year research project with Polytechnic University, it has an intelligent central control system, which monitors energy consumption and allows for efficient 24-hour 'housekeeping'.

By collecting and analysing data on day and night temperatures plus seasonal variations, the system creates a baseline for optimum settings. A digital control on every floor enables zoning, variable air volume and automatic adjustments in line with average occupancy, and each box can be reset remotely through the building management system. 'Property managers and academics have been studying usual office practices to design software and make sure [it is] working at maximum operational efficiency,' Mr Pau said. 'With the temperature and occupancy controls, we can achieve an estimated 15 per cent reduction in power consumption compared to conventional grade A office buildings.'

Hundreds of sensors help to monitor indoor air quality and modulate fresh air supply. They measure carbon dioxide levels, to maintain them at international standards and provide a healthy work environment, while independent exhaust outlets on typical floors improve ventilation and reduce indoor pollutants.

Mr Au Yeung emphasised that it was essential to make such systems adaptable. Tenants had specific requirements depending on their use of space and varying office routines, and there had to be scope for upgrades, with the possible use of wireless technology in future.

'Our technical team specifies open protocols, and all monitoring and evaluation specifications ask for open connectivity according to international standards, so the company is at no point locked into the use of certain products,' he said. Noting the need for the planning of environmental features to be holistic, he said that condensed water from the ICC's air-conditioning system was reused twice. It was first recycled through the main cooling towers and then used to flush toilets.

There were double-glazed curtain walls with low-emittance coating to ensure good thermal insulation, and all the major mechanical and electrical systems were equipped with power analysers. These made it possible to conduct energy audits, see which parts of the building consumed the most power, and identify solutions or make suggestions to tenants.

Mr Pau was keen to see the initial reports, in particular on the 'vertical transport' or lift system. He was confident that new technology developed with manufacturer Schindler, combining access control, security functions and means to eliminate unnecessary energy consumption, would give a power saving of around 12 per cent compared with other high-rise structures.

The key, he said, was an intelligent system which read staff smart cards at security turnstiles in the lobby. This checked identities and authorisations, immediately assigned a lift number on the display panel, and automatically grouped passengers for the same or nearby floors in the same lift. The system was also able to 'learn' user practices if, for example, individuals regularly moved between different floors occupied by the same company during the day.

'This will significantly reduce the number of lift trips and the travelling time, and will also consume less energy by cutting the number of stops lifts make,' Mr Pau said.

He added that, in off-peak hours, lights and certain lift cars would automatically go into 'sleep' mode, while gearless motors and low-friction mechanics would allow higher efficiency and better acoustic performance.

The company had made a commitment to use extra low sulphur diesel for emergency generators and variable frequency drives for pumps and fans. The firm had also recognised the importance of education about specifics and in the broader context.