Project support openness , chance interactions , teamwork , and increased collaboration . The office promises improved efficiency , integration and sustainability which is good for our business , our people , our clients and the environment , as well as our long-term capacity needs .”
UNIQUE ENGINEERED FEATURES Tessa Brunette , the lead project engineer from Arup says , “ Together with the buildings ’ intrinsic thermal mass , the façade is the most important ‘ machine ’ ( controlling indoor environment ) in the building . We reached our design response using first principles , in close collaboration with studioMAS , the architects .
“ These design responses were then tested and refined by using advanced computer modelling methods . These included the testing of different glazing types , orientations , and shading types . Thus , we identified the optimum combination of orientation vs shading vs glazing type .
“ Through an iterative process with many stages of analysis , modelling and interpretation initial modelling , the various options were refined to assess which combinations worked best in conjunction with the architecture and budget .
“ Modelling confirmed that the zigzag ( pleated ) façade that we adopted for building levels 2 and 3 performs as well as a straight deeply shaded façade and allows for more glazing without external shading devices that could obstruct views to the outside and reduce the amount of internal natural light .
“ So , the design significantly reduces the amount of direct sunlight entering the building , which in turn means that the internal spaces can largely rely on the mixed mode system and not need air conditioning to remain comfortable .
The building is designed to be as comfortable as possible without needing air conditioning to heat or cool . Occupants can control their personal comfort by adding or removing outer layers of clothing . If that is not enough , the controls can be adjusted to suit what the user prefers .”
The TABS operates continuously throughout warmer months , cooling the internal environment using chilled water circulating through the floor slabs . This complements the operation of the natural ventilation system and HVAC , meaning that the building ’ s possible use of fresh air ventilation rises from 60 % to 80 % of the year .
It is all done on a controlled basis . Traffic lights installed around the building perimeter indicate to the occupants when they should open and close the windows , based on outside conditions .
When the windows are open , the active ventilation system is switched off . When the weather outside is not suitable for natural ventilation , the building management system ( BMS )
Arup
activates HVAC ( air conditioning ), provided that the windows have been manually closed .
Air from the HVAC system , when switched on by the BMS , enters the office spaces via a low energy usage displacement ventilation system via air grilles that are in the floor .
Special custom-designed acoustic panels are suspended underneath the exposed slabs to provide appropriate levels of sound absorption for a comfortable work environment , whilst leaving sufficient exposed thermal mass for the TABS to provide benefit to the occupants .
ARCHITECTURAL CRITERIA Sean Mahoney , the Ridge project lead architect , Studio MAS , says their role as the architect is to combine the logic and practicalities of engineering with the creative arts . “ I think of the climate control systems in use at the Ridge as the ( Toyota ) Prius of the built environment – a veritable hybrid ,” he says .
This was a collaborative process with Arup best illustrated on the Ridge by the zigzag timber façade and the ‘ central street ’ with its roof light drums . Both these design elements have a strong engineering and design rationale backing them up , but at the same time managed to create beauty and joy out of them . They are key to the building ' s identity and aesthetic and create memorable experiences . These include natural light , natural timber in the case of façade , wonderful views out of the windows , connection with the outdoors and identity .
TR014 . jpg < Caption > There are 8 pumps in total , located on the roof . They pump water through the whole building , to the on-floor AHU ’ s , as well as the TABS system . < Credit > Arup
There are 8 pumps in total , located on the roof . They pump water through the whole building , to the on-floor AHU ’ s , as well as the TABS system .
www . hvacronline . co . za RACA Journal I November 2021 37