Project
Arup
In one of the on-floor plant rooms , this DB controls the fans / AHUs on depending on the indoor conditions .
standout features , some of which are firsts for South Africa .” Some of these features : Air quality : The building operates on mixed mode interior climate control system , which includes Natural ventilation , which significantly raises the indoor air quality and is controlled by the occupants . This means that office workers may open the windows to let in fresh air for up to 80 % of the year round . An impressive atrium runs from ground to the third level of the building . Referred to as the ‘ central street ’, it helps to pull air through the building , in through the windows and out through the rooflights , while also bringing many other benefits to workers and visitors inside the building .
Minimal HVAC ( air conditioning ) usage : The building incorporates passive ( non-energy consuming ) temperature control mechanisms several of which are unique , a virtual sum of parts that leads to a greater whole .
The zigzag shaped engineered timber façade ingeniously orientates the glass windows towards the north or south , which prevents lower angle sun from the east or west from entering the office spaces . This provides natural daylight while reducing glare and patches of hot sunlight . This has a major impact in promoting both fresh air quality and the saving of energy .
Thermally Activated Building System Technology ( TABS ): TABS is installed into the soffits ( ceilings ) above the working areas of the building , and this cools the concrete structure by means of water circulating from the chiller and heat pumps on the roof . The cooler soffit hence cools the air below , which circulates around the workspace . TABS is another important contributor to the mixed mode climate control system at work inside the building .
“ All these measures mean that people inside the building will experience steady indoor ambient temperatures which respond slowly to outdoor temperature variations . The mixedmode system design aims for the building ’ s conventional air conditioning system to be active for only 20 % of the year . This is in line with international standards such as WELL , in promoting occupant productivity and thermal comfort ,” Noble adds .
THE RIDGE ’ S FURTHER SUSTAINABILITY FEATURES Power : The building has a specific energy strategy . Passive energy efficient features are incorporated , to reduce base energy load . Active energy efficient designs include lowenergy lighting systems . A solar array on the roof harvests additional power when the sun is shining . Ultimately , in the case of a grid failure , vital systems in the building are kept going by means of a standby generator . Water resources : The building employs the normal low water flow devices in sympathy with Cape Town ’ s growing status
www . hvacronline . co . za RACA Journal I November 2021 35