[ASC-media] Mercury rising! Offices to stay cool and save dollars

Sarah Brooker sarah at scienceinpublic.com
Wed Aug 30 07:20:17 CEST 2006

A Sydney research team has developed a sun and wind driven ventilation
system to cool commercial buildings on the hottest summer days. They hope
that the new system will reduce the power requirements of a commercial
ventilation system by 15 to 20 per cent. 

The new system, designed by Simon Shun, working under the supervision of
Associate Professor N.A. Ahmed at the University of New South Wales, relies
on solar and wind power when it can. When the wind drops or there is not
enough sun, the ventilation system automatically switches to mains
electricity. This ensures that the building gets adequate ventilation, and
meets the ventilation standards legally required for health, safety and

Commercial ventilation systems use significant amounts of electrical power,
enough to cause blackouts in some states during the hottest summer days.
This new system has the potential to assist the wider community by reducing
peak energy demands and greenhouse gas emissions. 

"At present, devices based on renewable energy cannot be used for constant
flow ventilation because of the unpredictable nature of the wind and sun,"
Shun says. "The challenge, therefore, was to design a system that uses clean
energy to the maximum possible effect. Our device has a smart switching
module that selects mains electricity as a back-up power source."

The new ventilation system was designed from the outset to use both wind and
solar energy. A horizontal spin-axis design was developed to increase the
effectiveness at which energy was extracted from low-speed wind. This
configuration more than doubled the ventilation output at wind speeds
between 0 and 10 metres a second. 

The horizontal axis design gave the team the freedom to introduce
advantageous design features that were more difficult to incorporate with
conventional configurations. Under zero wind speed conditions, an electric
motor powered by a stand alone solar panel powers the system. If wind and
sun conditions are both less than ideal, mains electricity is often the only
solution to maintain a constant ventilation flow rate.

An electronic control module was designed as a smart solution to switch
between the energy sources of wind, sun and mains electricity. The module
has adjustable inputs for wind speed and solar intensity. This allows a user
to adjust the point at which the system switches over to mains electricity. 

Shun plans to turn his prototype into a working trial system and install it
on a purpose- built test building within the next six months. The industrial
partner, Edmonds, a business unit of CSR Limited, which has supported the
development of the concept, stands ready to assess the advantages of the
system with the view of possibly taking the concept to market.

Simon Shun is one of 16 young scientists presenting their research to the
public for the first time thanks to Fresh Science, a national program
sponsored by the Federal and Victorian Governments. One of the Fresh
Scientists will win a trip to the UK courtesy of British Council Australia
to present his or her work to the Royal Institution.

For interview or more information contact: contact Simon Shun on (02) 9451
5011 or 0411 057 241, s.shun at hotmail.com, or Dan Gaffney, Journalist,
Science Faculty, UNSW on 0411 156 015, dgaffney at science.unsw.edu.au

For Fresh Science contact: Sarah Brooker on 0413 332 489,
sarah at freshscience.org	

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