Andrew Watts of Newtecnic tells Jonathan Newell about a new approach to tall building design to overcome solar heating problems in hot climates
Set to rise from the banks of the River Tigris in Baghdad, the new headquarters of the Central Bank of Iraq is already creating waves in architectural and construction circles with its innovative design and its new approach to managing heat and light in the powerful climate of the Middle East.
Designed by Zaha Hadid architects, the 170m high tower will benefit from the technical expertise of Newtecnic, a company whose modern approach has already set it firmly in the list of key engineering companies in the construction industry.
To find out more about the problems of building design in hot climates and the possibilities of solving them, I spoke to Newtecnic’s CEO, Andrew Watts.
A blend of transparency and opacity
The creation of towers as “glass boxes” with toned or solar reactive glazing is a trend that Newtecnic very much wants to buck. With such disadvantages as light attenuation and solar heating effects, such designs have their drawbacks even in moderate climates but in the unremitting climate of the Middle East, these drawbacks become serious flaws.
According to Newtecnic, there is the opportunity to create the means to provide lighting where it’s needed without the drawbacks through a combination of glazing, shutters and adaptive air conditioning. Such glazed areas can be blended with opaque zones on the building facade placed in areas where natural lighting isn’t a reqirement. This is exactly the approach the company took with its designs for the Central Bank of Iraq tower.
Solar control panels
For the glazed areas, the design incorporates solar control panels on the inside of the glass. “Usually, these are fixed and external but in the Central Bank of Iraq’s case, these are like blinds between the glazing,” Watts explains.
This gap which houses the blinds is about 300mm between the outer double glazing and the inner layer of opening panels. “This gap is also used for cooling. Blowing air through it provides another layer of protection against the build-up of heat,” Watts continues.
Newtecnic employs Computational Fluid Dynamics (CFD) analysis to model the building performance in different environmental circumstances and to ensure that the Building Management system can adequately orchestrate the complex interaction of solar control panel operation, HVAC and lighting in order to maintain the best environment for the occupants whilst minimising energy consumption.
Not all facades on the building need to be transparent and an important aspect of the tower’s design is the creation of opacity where appropriate, whilst still allowing the adequate passage of daylight. “The correct design and placement of opaque facades with adequate access to daylight is important to reduce the levels of electrical lighting needed during the day,” Watts says.
For the future, Newtecnic sees such facades as providing more than structural support and opacity. Changes to the composition of the concrete can enable them to be used for absorbing atmospheric carbon. However, such changes aren’t quite on the horizon. “The industry has a century of experience with concrete so you can’t just change the chemical composition of it without research into its long term safety,” concludes Watts.