The encyclopedia · Engineering & Operations · Technical decision · 1996
Eastgate Centre beat the Harare heat by ventilating like a termite mound
A nine-storey office cools itself with concrete mass and air flow, using about 5% of a conventional AC's energy.
Old Mutual Properties · Eastgate Centre
the move
Old Mutual Properties wanted a large Harare office and shopping complex that did not rely on expensive, imported air-conditioning, in a hot country short of hydroelectric power.
Architect Mick Pearce, long intrigued by termite mounds, worked with Ove Arup to design an alternative ventilation system using air flows and the building's own concrete mass.
The result kept the interior between about 18 and 25C on roughly 5% of the energy a conventional air-conditioned building would use, with a capital cost far below a glass-towered, AC-dependent design.
why it works
- It uses the building's own mass as the battery, so no refrigeration is needed to bridge day and night.
- Natural buoyancy drives the flow, so there are no fans or chillers to power and maintain.
- It uses local climate and cheap concrete instead of imported chillers in a foreign-exchange-constrained market.
- Lower running cost and build cost translate into lower rents, which sold out the space before completion.
what transfers
Store hot daylight in a mass you cool for free overnight, and you cut the air-conditioning bill.
what came after
Eastgate became the world's first large-scale commercial use of the termite-mound ventilation principle and is cited as a model of passive and biomimetic design; it generated fresh interest in termite-mound-inspired cooling for hot climates.
references
- ARCHITECTURE-ZIMBABWE: Termites Inspire New Office Complex
- The architectural design of smart ventilation and drainage systems in termite nests
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