BAHAR TOWERS
A quick glimpse at the upcoming weather for Abu
Dhabi will show a week of intense sunshine, temperatures steadily above 100
degrees Fahrenheit with 0% chance of rain. In such extreme weather conditions,
even architects listing environmental design as their top priority are up
against a tough battle. Never mind that the sand can compromise the structural integrity of the building, the
intense heat and glare can render a comfortable indoor environment relatively
impossible if not properly addressed. For Abu Dhabi’s newest pair of
towers,
Aedas Architects have designed a responsive facade
which takes cultural cues from the “mashrabiya”, a traditional Islamic lattice
shading device.
Completed in June 2012, the 145 meter towers’ Masharabiya
shading system was developed by the computational design team at Aedas. Using a
parametric description for the geometry of the actuated facade panels, the team
was able to simulate their operation in response to sun exposure and changing
incidence angles during the different days of the year.
The screen opperates as a curtain wall, sitting two meters
outside the buildings’ exterior on an independent frame. Each triangle
is coated with fiberglass and programmed to respond to the movement of the sun
as a way to reduce solar gain and glare. In the evening, all the screens will
close.
At night they will all fold, so they will all close, so you’ll see more of the
facade. As the sun rises in the morning in the east, the mashrabiya along the
east of the building will all begin to close and as the sun moves round the
building, then that whole vertical strip of mashrabiya will move with the
sun,” said Peter Oborn, the deputy chairman of Aedas.
It is estimated that such a screen will reducing solar gain by more than 50
percent, and reduce the building’s need for energy-draining air conditioning.
Plus, the shade’s ability to filter the light has allowed the architects to be
more selective in glass finished. ”It (the screen) allows us to use more
naturally tinted glass, which lets more light in so you have better views and
less need of artificial light. It’s using an old technique in a modern way,
which also responds to the aspiration of the emirate to take a leadership role
in the area of sustainability,” added Oborn.