x Abu Dhabi, UAEWednesday 26 July 2017

Masdar Tower is a big experiment

The 45-metre Masdar Tower may provide effective cooling by updating antique Arabian methods -- or not

Masdar's colossal wind tower has been touted as a symbol of the institute's zero-energy concept, a simple modern version of the traditional Arabian cooling system.

But officials admit that the 45-metre high passive ventilation system - designed to capture the desert's breezes and cool the air in Masdar's plazas by as much as 20°C - is, like everything else in the green city, an experiment.

One researcher directly involved with customising the tower's functions is sceptical about how useful the system will be in the summer or in crowded courtyards.

"It is premature to say whether this is working or not, but the results suggest the amount of cooling or energy from this is minimal," said Isam Janajreh, an associate professor of mechanical engineering at the university.

"To use this for energy harnessing especially, by our initial calculation, is not promising."

Dr Janajreh was asked by the institute to research whether planting tiny turbines inside the stainless steel tower would be worth the effort. It would not, he found.

He is more optimistic about installing small water jets to make the air heavy with moisture so that it falls, mimicking an old tradition of hanging water-soaked blankets high in architectural structures.

The basic science of the tower's current design is fairly simple. Louvres at the top trap the air and funnel it down into the campus's narrow, shaded walkways.

On hot days, caps at the top of the tower can be used to create negative pressure at the opening and suck hot air from underneath.

The tower will incorporate solar-powered LED screens that will flash green, pink or red lights to give those on campus an idea of how much energy they are consuming. It is the first of what will become a system of wind towers by 2016, once Masdar City, planned to be the world's first large-scale carbon-neutral development, accommodates an estimated 90,000 people.

According to the most recent estimate, the entire project will cost about US$16bn (Dh59bn). That is down 27 per cent from the original cost announced three years ago.

Another way to make the tower more energy efficient, Dr Janajreh said, would be to paint it black, to create what he calls a "solar chimney". That would heat the air inside, causing it to quickly rise and create an updraft strong enough to power microturbines.

Testing these ideas, though, will take months or even years. And the results will change as Masdar Institute and then Masdar City expand.

"As the space gets more congested, that will change the fluidity of the air flow," he said. "It is in an unsteady and experimental stage right now."

Gerard Evenden, a senior partner at Foster + Partners in charge of Masdar's design, said the tower and the institute were built with the idea that they might be altered or enhanced in some way down the road.

"The university has always had to be flexible in its development, because nobody really knows where the research is going to take people," he said.

"We want to make the structure itself a laboratory and get people talking about other possibilities, and hopefully, get that to influence the next phase. We see it as an ongoing learning process."

The second of four phases of construction recently began at the university, and will add 75,000 square metres of space to the 43,000-square-metre campus.

The design has been tweaked based on feedback from faculty, Mr Evenden said. The residential floor-to-ceiling height, for instance, will be about half a metre higher than had been planned originally.

"People are conditioned to feel cooler in rooms with higher volume," he said.

"Still, because nobody has done these things before, nobody can accurately say, yes, this works better. You can only build a picture of what's working well and what is not working so well, and in that way this is an experiment."

 

econroy@thenational.ae