SOM designs world's greenest sckyscraper.

The air inside the Skidmore Owings and Merrill-designed 69-story Pearl River Tower currently under construction in Ghangzhou, may eventually be cleaner than the air inside any other office tower in China. That is, unless you take a toke of one of the products the building's office residents produce.

The first skyscraper hoping to claim "zero energy" that will produce at least as much energy as it consumes will be the new headquarters of, China's largest cigarette manufacturer, the China National Tobacco Corporation.

Roger Frechette, SOM director of MEP engineering speaking at a panel discussion at 7 World Trade Center this week, conceded that their client's presence at Pearl River may seem ironic. However the team is confident that the design of their $300 million building will have a healthy impact on both the environment and future projects throughout the industry, Frechette said.

"I think it is the responsibility of the industry to consider zero energy projects throughout the world. There is no technical reason it can't be done," Frechette said. "Architects and designers can take advantage of these features, plus, in any other part of the world."

The fact that the building is in China, where people joke that the national bird is the construction crane, and is currently the world's leader in construction projects, makes it a good testing ground for comparable projects that could take place in New: York as the boom continues to gather momentum, Frechette said.

Americans can take these concepts further as our environment does not contain some of the limitations as those in China, like polluted groundwater, that make it uncondusive to black water systems.

The engineers used the concept of biomimicry, mimicking plant and animal systems in building designs, and studied sponges for the towers design. They examined the way sponges, which have survived over 600 billion years, exist in relatively shallow water, can capture rainwater and hold sunlight absorbed from their skin in their bodies. Accordingly, they studied how much sun energy is absorbed by the sun on different parts of the building's double walled skin and put photovoltaic cells on those places. That energy is then naturally transferred to the building's mechanical floors, and used to power generators and a dehumidification system. The team is furthering this concept to relate to the wind. The building will attempt to capture the wind through its body to generate power inside. To do this, SOM -which was also responsible for the Gold LEED certified 7 WTC--has angled the building so that its long side is facing directly into the wind, rather than being turned away from the wind like most other buildings.

Three openings are cut into the building on its mechanical floors, making it appear to be segmented, which are used to reduce the pressure on the building caused by the direct wind and to capture the wind which push turbines that generate energy for the buildings heating and air conditioning systems.

"A small increase in wind velocity can yield a large increase in power," he said.

An radiant, under-floor cooling and ventilating system that takes the relationship between the body temperatures of humans and objects such as glass and metal into account as they are regulated, can also set a good example for projects in the states, Frechette said.

Though these systems are in use throughout Europe and Asia, the idea has not really caught on in the United States yet, Frechette said.

These factors will combine to reduce Pearl River Towers energy consumption by 60%, making it the most "energy efficient building of this height in the world," Frechette said.

The tower is slated to be completed late in 2009.