Solar Chimney & Cool Towers
…………………………SUBSIDENCE TOWERS
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Introduction
The Visitor Centre at Monarto Zoological Park uses three subsidence towers for cooling the public and administrative spaces. The subsidence towers are 3.6m x 3.6m with an overall height above floor level of 9.4m.
The subsidence towers at Monarto are believed to be the first installed in Australia and will demonstrate an alternative low energy, low water consumption model for cooling in hot arid climates.
Purpose
The purpose of incorporating the towers into building designs is for space, air, comfort condition in arid climate locations.
Subsidence towers introduce moisture at tower top by air filtration through controlled rate wetted perimeter pads, the increased air mass within the tower propelling the air volume into the building.
Tower operation utilises these naturally occurring air movement forces and thereby minimises both water and energy demand. Energy demand is limited to water pumping from storage to the tower head. Water use is regulated to maintain wetting of pads released by evaporation with minimum excess water discharge. As the tower is large in duct volume, significant air changes are generated with low perceptible air movement speeds which avoids the chill cooling more common with duct and fan forced systems.
Background
Similar evaporative systems have been used at times over the centuries in Middle East and Asian locations with arid climates. In modern mechanised societies, fan forced, package evaporative air conditioners have become standard.
In the mid-1980s the University of Arizona, U.S.A. through its Environmental Research Laboratory, trialed a formal tower construction which was subsequently installed on successful trial for space conditioning of a public shopping centre pedestrian plaza in Phoenix.
In the late 1980s a detached residence was built (Thompson & Cunningham) incorporating both a thermal chimney and a downdraft tower. This tower was monitored for performance, and this was subsequently computer-modelled at UCLA. The University of Arizona has published a number of abstracts on their work and the Thompson & Cunningham installation. This is summarised and extended on by Professor Baruch Givoni of UCLA in his book Passive and Low Energy Cooling of Buildings.
Phillips and Pilkington Architects together with a consultant architect for the Monarto Visitor Centre, Emilis Prelgauskas, designed and documented the towers using knowledge and expertise drawn from his previous work and study. The result is a modern, practical application for an ancient climate control design.
The Monarto Visitor Centre subsidence or “cool towers” are believed to be the first to be constructed and used in a commercial application anywhere in Australia.
Click to see ->Solar Chimney
Sources:http://www.green-trust.org/chimney.htm