Vodaworld’s Unique, Rotating Sunshade.

Visitors to Vodaworld’s five-storey glass building in Midrand, Gauteng will see a sunshade with a difference spanning the building along the western side.

Because the west front of the building, in particular the ground floor restaurant, catches the full impact of the afternoon sun a rotating sunshade has been designed to move with the angle of the sun, thus keeping the building on that side in constant shade.

The sunshade is 13 metres wide, 20 metres long and weighs 11 tons. Built of stainless steel, the movement of this giant sunshade is driven by two 22kW geared motors operating from a variable speed drive, which is controlled by a PLC drive. Information of the angle of the sunshade is constantly fed back to the PLC, using an encoder.

Autocon Systems was responsible for the design and installation of the automation system. The engineering had to take into consideration the changes of the sun’s passage through the year, from summer solstice to winter solstice. The sunshade is also programmed to close after sunset and open again into the horizontal position the following morning.

An added safety factor comes in the form of an anemometer, which measures wind velocities. This has been incorporated into the system, to ensure that the sunshade automatically returns to a safe position once wind speeds in excess of 60 kilometers per hour are detected. The system has also been fitted with a manual override so that building management personnel can close the shade in emergency conditions or for maintenance purposes.

“A great deal of research was done before writing the programme”, explains Autocon’s Allan Marnitz, “as we had to be sure that the right formulas were being used to achieve the correct calculations”.

The Vodacom sunshade project has once again proved Autocon’s flexibility and ability to work successfully with other contractors on complex projects.