Architect and Builder Magazine South Africa March/April 2014 | Page 24

Panoramic views of the
landscaping from all
offices and open plan
workspaces unite the
exterior with the interior

Toilet extraction is achieved by mechanical
axial fans located in the rooftop plant area and
sheet metal ducting from each toilet core.
The relative humidity is not positively
controlled but would be indirectly controlled
within the comfort range as a result of the
design and selection of the cooling plant.
Chilled Water Generation & Distribution
The series of air cooled chillers generate the
required chilled water. The chillers utilise
environmentally friendly refrigerants. The chilled
water is distributed to the terminal air handling
units by mechanical pumps and thermally
insulated steel piping. The pump arrangement
is duty-standby to ensure continuous operation
during system maintenance.

When required, the chilled water is distributed
horizontally through the co-ordinated ceiling
void to in ceiling mounted fan coil units serving
dedicated spaces (cellular offices, boardrooms).
Conditioned Air Distribution:
Open Plan Spaces
The open plan office space is conditioned by
means of floor standing variable air volume
(VAV) AHU’s located in various mechanical plant
rooms, located on each floor. The open plan
areas are zoned, as necessary, to ensure optimal
thermal comfort for the occupants.
Conditioned air is supplied to the space
by means of externally insulated sheet metal
ducting and ceiling mounted diffusers (constant
and variable volume type as required). Air is
returned to the units via ceiling mounted ceiling
curved blade return air grilles.
The outdoor air (fresh air) is delivered to the
space via external weather louvres located on
the façade of the building within the mechanical
plant room. Heating in winter will be by means
of electric resistance elements located in the
AHU’s, FCU’s and at the terminal diffusers
as required. The AHU’s maintain the desired
internal conditions automatically.
Conditioned Air Distribution:
Cellular Offices and Boardrooms
The cellular offices and boardrooms are
conditioned by means of dedicated FCU’s
allowing full individual control to these spaces.
These areas have been identified as requiring
dedicated units due to their unique heat load
profiles; this ensures optimal thermal comfort
for the occupants within these areas.
The outdoor air (fresh air) is delivered to
each unit by means of uninsulated sheet metal

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Cell C Head Office