Architect and Builder Magazine South Africa March/April 2015 | Page 32

• Reduce – Bring less material into the building that will
become waste
• Reuse – Wherever possible, reuse the materials within
the building or elsewhere
• Dedicated recycling storeroom that allows all waste to
be sorted and stored for collection.
• 70% of all waste generated during the construction
project to be recycled or reused on site.
Sophisticated lighting control was installed - known
as DALI (Digital Addressable Lighting Interface). This
system is energy efficient and allows the user to have the
ability to control each light individually. The DALI sensors
can be controlled by a switch and/or by infrared readers
that sense if there are people in the room and switch off
if the area is not used.
The lights sense daylight in a specific area and can
automatically dim to reduce energy usage; this is known
as daylight harvesting.
The lights are controlled by ballasts which have a
high frequency control that produces no flicker and
white noise. This prevents the occupant from suffering
eyestrain and headaches experienced with older
magnetic ballast type installations. The added benefit is
a 50 % reduction in energy losses in the ballasts.
The actual lamps used are known as T5s (high efficiency
small diameter fluorescent lamps) which provide the
highest industry standards in terms of lighting quality,
colour, energy efficiency, with reduced maintenance
costs and an extended life span per fluorescent.
The dimming of the lights can be reduced to 10%
of total capacity when necessary and also provide
optimised efficiency and a lifespan of about 4 years.
While energy efficient, the design still prioritises the
comfort, productivity and health of the occupants. The
heating and cooling systems were designed to provide
comfortable conditions in the building throughout
the year.
Economy Cycle technology is used for the air
conditioning fans (HVAC), which calculates a quantity
of fresh air needed and then also recycles a quantity of
cooler return air which reduces the energy used to cool

32

the air. When outside air temperatures are favourable,
100% of fresh air can possibly be supplied to the building,
thus reducing the need to chill the air mechanically which
will, in turn, reduce energy consumption. A spin-off is
the improvement of the air quality within the building.
The process is continuously controlled by the Building
Management System (BMS).
Due to the long east and west façades of the
building, at certain times during the day, the building will
experience heat loss and heat gain at the same time in
different areas of the building. The HVAC system reads
this through the BMS and adjusts the cycle and optimises
usage by means of heat reclaim chilled/hot water plant.
Building heating will be produced by the chillers acting
as heat pumps, eliminating the need for less energy
efficient electrical heating.
The fresh air ventilation rates delivered from the
HVAC system are a 100% improvement on the SANS 204
(2008) that states that 5 litres/second/person must be
supplied to the occupants. The Chevron HQ will achieve
a minimum of 10l/s/p and higher.
There is also variable speed control for the fans
delivering the air to the building. This enables the system
to adjust the fan speed to the amount of air entering the
building and is calculated by the BMS. This prevents
energy wastage.
The chillers use an air cooled system and not water to
cool the air.
The structure of the building has been constructed
using 40% less cement in the concrete. Cement has a
high embodied energy and, by using recycled slag from
the steel manufacturing plants, the usage of virgin raw
materials is reduced.
All reinforcing steel in the building was obtained
from SA Metal which supplies 100% recycled reinforcement bars.
Due to the nature of the structural design and the
implementation of post tensioned slabs, the absolute
quantity of reinforcing steel has been reduced by more
than 30% and concrete by 7%.
20% of the projects total value was sourced from within
400km, meaning that the local economy has benefited.

Chevron