The mixed use building of an international project "East Gate Harare" was built by the concept of passive cooling.

1. ARCHITECTURAL
D E S I G N - V
M I X E D - U S E H I G H R I S E C O M P L E X

2. East Gate
Harare
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3. The east gate centre’s design is a delibrate move away from the “big glass
block”. Glass office blocks are typically expensive to maintain at a
comfortable temperature, needing substaintial heating in the winter and
cooling in the summer. They tend to recycle air, in an attempt to keep the
expensively conditioned atmosphere inside, leading to high level of air
pollution in the building.
Artificial air-conditioning systems are high maintainence, and Zimbabwe has
the additional problem that the original system and most spare parts have to
be imported, squandering foreign echange reserves.

4. Interior Veiw Concept Exterior Veiw

5. • Mick Pearce, the architect, therefore took an alternstive approach
• Because of its altitude, Harare has a temperate climate despite being in the
tropics, and the typical daily temperature swing 20 or 24 C
• This makes a mechanical or passive cooling system a vitable alternative to
artifical air-conditioning
• No direct sunlight must fall on the external walls at the north facde (direction
of summer sun)
• window-to-wall area must not exceed 25%
• balance between artificial and external light to minimize enegry
consumption
Working
To Work well, the building must be very carefully designed. After computer
simulation and analysis, the engineering from Ove Arup, gave Pearce a set of
rules

6. Termite mound
each creature radiates a certian amount of heat in the process of releasing
energy from sugar molecules. to be exact 2805kj/mol of energy from
combustion, this heat is radiated in from the skin. in a termite mound they
have a high density of organism living together underground that too in the
hot deserts Africa, but these termites created an indegenious way of
regulating heat.

7. Passive cooling
Passive cooling works by storing heat in the day and venting it at night as temperatures drop.
Start of day: the building is cool.
During day: machines and people generate heat, and the sun shines. Heat is absorbed by the
fabric of the building, which has a high heat capacity, so that the temperature inside increases but
not greatly.
Evening: temperatures outside drop. The warm internal air is vented through chimneys, assisted
by fans but also rising naturally because it is less dense, and drawing in denser cool air at the
bottom of the building.
Night: this process continues, cold air flowing through cavities in the floor slabs until the building's
fabric has reached the ideal temperature to start the next day

8. p

9. Eastgate comprises two buildings side by side linked together by a glass roof.
Below this, steel bridges and lifts suspended on cables from steel lattice beams
span over the atrium below. The lifts connect with a suspended glass skywalk which
runs the length of the atrium at level 2. The centre of the skywalk is connected to
street level by escalators and the street leads to the city’s web

10. Along the ridge of the red tiled roof are 48 brick
funnels topping internal stacks which pull the
exhaust air out of the seven floors of offices
below. Under the office floors is a mezzanine
plant room behind the cross chevron screen
where 32 banks of low and high volume fans
draw air from the atrium through filters. This air is
pushed up through the supply section of vertical
ducts in the central spine core of each office
wing. From the duct the air is fed through the
hollow floors to low level grilles under the
windows. As it is warmed by human activity it
rises to the vaulted ceiling where it is sucked out
via the exhaust ports at the end of each vault
through a system of masonry ducts to the
exhaust sections of the central vertical stacks. In
the office space uplighters use the concrete
vaulted ceiling to reflect light downwards and to
absorb their heat.

11. Roof Scape
• chimneys for air extract
• solar panels for water heating
• windows hood for sun sheilding
• glass roof with open sides over the atrium
it has a facade correctly to exclude direct sunlight between the hours of 9am &
5pm for energy efficiency.
the special sun screens( sun breakers)
windows alleviate the effects of the climate with a 75% savings on air
conditioning requirment for the office floors. the building is dark at the bottom
and light at the top

13. T H A N K S
FATHIMA TABASSUM S
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D E S I G N S T U D I O