Architect and Builder Magazine South Africa March/April 2014 | Page 26

Cell C’s new home in
Midrand comprises
of 46,000m2 of under
cover space with
14,000m2 planned for
future development

ducting, mechanical fans and attenuators.
The outdoor air supply equipment is located
either within the nearest mechanical plant
room on floor or within the ceiling void of
the space.
Toilet & Basement Ventilation
The toilets are mechanically ventilated by
means of ceiling mounted extract disc valves,
uninsulated sheet metal ducting and axial fans
located in the rooftop open air plant area.
The basements are naturally ventilated with
adequate openings, available and suitable.
Stairwell & Lift Shaft Pressurization
The escape stairs are pressurized in accordance
with EN12101.

HVAC - CUSTOMER CARE & REPAIR CENTRE
Air Conditioned Spaces
These areas are served by a separate
plant, comprising packaged, air cooled air
conditioning units, situated in open plant areas.
Conditioned air from each unit is supplied
by means of externally insulated sheet metal
ducting and distributed to the space through
constant volume ceiling type diffusers.
Re-circulated air is returned through grilles
positioned at the rear of the space and shall be
ducted back to the plant area.
The required quantity of fresh air is
introduced through louvres mounted on the
sides of the return air ducts before they connect
to the units.
Heating in Winter is provided by means of
electric resistance type heaters mounted in
the units.
The plants are automatically controlled to
provide the required temperature conditions
in Summer and Winter and shall be switched on
and off automatically at the plant control.
Toilet Ventilation
The toilets are proposed to be mechanically
ventilated by means of ceiling mounted extract
disc valves, uninsulated sheet metal ducting
and axial fans located in the rooftop open air
plant area.
Basement Ventilation
The basements are mechanically ventilated
by means of fans located in agreed positions
extracting to atmosphere. These fans are dual
purpose, providing everyday ventilation and
smoke extract in fire conditions. They are operated
by variable speed drives and carbon monoxide
sensors, located throughout the basement.

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Cell C Head Office