Mechanical Technology February 2015

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⎪ Heating, cooling, ventilation and air conditioning ⎪
Mechanical Technology — February 2015 27
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 5th 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 5th.
The building now has a massive glass
facade that looks down onto 5th Avenue,
the Sandton Convention Centre and the
Michael Angelo Towers. The 24 000 m2
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 5th 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