Mechanical Technology February 2015

⎪ Heating, cooling, ventilation and air conditioning ⎪

Above: Nearing completion is an office building for a Swiss pharmaceutical giant targeting an LEED Silver rating. HVAC features include: partial ice storage; heat recovery wheels and very high efficiency multi-energy air-cooled chillers. Top right: The Atrium on 5 th has a new glass facade, air conditioning system and other services and is the first-ever refurbished building to be awarded a 4-Star Green star rating from the GBCSA. Right: One of WSP’s most notable references is the Vodafone Site Solution Innovation Centre, South Africa’s first 6-Star rated building to be officially certified by the Green Building Council of South Africa (GBCSA). Bottom right: WSP has pioneered the use of the more advanced Kyoto energy recovery wheels in data centres in South Africa. This is one of the first operational Kyoto cooling cells in the world and features: chilled water coils; absorption chillers; primary and secondary filters on the ambient air intake; evaporative wet packs in the outside air stream for adiabatic free cooling; and more. Photo: Deon Nadasen. use of VSDs (variable speed drives) to avoid having to run a system at maximum capacity if the demand does not require it,” De Bod tells MechTech . “A prime example is the old Twin Tower, part of Liberty Properties’ Sandton City complex, which, following refurbish- ment, has been renamed Atrium on 5 th . The building now has a massive glass facade that looks down onto 5 th Avenue, the Sandton Convention Centre and the Michael Angelo Towers. The 24 000 m 2 12-story Atrium was stripped down to concrete and a brand new glass facade, air conditioning system and other ser- vices were installed. Basically, all of the internal systems are being replaced. “Atrium on 5 th is the first-ever refur-

bished building to be awarded a 4-Star Green star rating from the GBCSA. It has air-cooled ammonia chillers and is only the second building in the country to use ammonia as the refrigerant for office air-conditioning, which is a ‘green’ refrigerant with both zero global warm-

ing potential (GWP) and ozone depletion potential (ODP).” The building also has a host of pas- sive green features and its old facade has been replaced with an air tight, modern glass equivalent to keep infiltration to a minimum. Two heat recovery wheels

Mechanical Technology — February 2015

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