A combined system for the Department of Environmental Affairs HQ in Pretoria
29 October 2014
Designed by architects Boogertman & Partners, the DEA is the first government building in South Africa to be awarded a 6 Star Green rating from the Green Building Council of South Africa (GBCSA). It also achieved the highest score for a large commercial office space of this scale, due to the highly energy efficient sustainable design and the extensive use of ‘green’ technologies.
The three-storey head office provides more than 27,000 m² of floor space and uses solar shading, water recycling and extensive photo-voltaic arrays in the north car park and on the roof, which provide more than 10% of the building’s annual energy load. An energy efficient mixed mode natural ventilation system is also installed to manage indoor air quality and temperature, which provides a comfortable working environment for staff.
The building’s internal space is separated into several self-contained ‘pods’ each of which is naturally ventilated by atrium vents and automatically opening windows. The vents and windows are operated by 104 SE Controls’ SECO N 24 40 600mm stroke length chain actuators and controlled by 20 OS2 Type 21 control panels supplied by SE Controls’ South African operation, which has offices in Durban and Johannesburg.
In addition, SE Controls Africa also supplied PIR sensors for each automatically opening window to avoid the risk of finger entrapment during operation. The complete system was installed and commissioned by specialist contractor, Robertson Ventilation Industries (RVI), to ensure it met the necessary safety and environmental specifications.
The natural ventilation system, which also operates in ‘night purging’ mode to cool the building and reduce the need for artificial cooling during summer months, is linked to both the supplementary evaporative cooling system and the smoke control system via the central BMS.
This integrated approach not only allows the ventilation system to operate in different modes, to maintain cooling and comfort, but also provides effective smoke control to ensure escape routes are kept smoke free, if a fire should occur.
Russell Cramb of SE Controls Africa, explained: “The DEA building breaks new ground in what can be achieved from an environmental management and sustainability perspective, when all of the latest green technologies are combined within a highly effective and energy efficient design.”
He added: “Natural ventilation is a highly energy efficient solution for cooling and ventilating buildings to maintain indoor air quality and temperatures and in the DEA building, it has proven to be a key element in it achieving such a high environmental rating from the GBCSA as part of an excellent integrated design from the architects.”