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Climate
and urban design - the rewards!
When climate expertise
is part of the urban design team's skills: -
- the full potential
for using solar energy is realised;
- air drainage
patterns carry pollutants away from residential areas;
- city-dwellers
enjoy improved levels of climatic comfort; and
- the site of
a new town is chosen to lessen danger from natural hazards.
In the climatically
optimum city, the thermal comfort and even the health of some city-dwellers
improves. Less energy is needed for indoor temperature control. Peak power
demand and peak stormwater run-off are reduced, saving on the cost of
city infrastructure.
Designing
with the climate.
Some of the things which can be done: -
- In a hot
dry climate, sun protection is essential (we need shade,
and pale surfaces to reflect the sun's radiation). Glare and reflected
heat from these pale surfaces can be reduced by shading from eaves,
verandahs and from vegetation. Trees are Nature's own evaporative
coolers - perfect for the dry climate, if water supply permits. Trees
will also filter blowing dust from the air.
- In a warm
humid climate, we need air movement to keep us comfortable.
Streets and buildings are oriented to catch the breezes. A mix of
building heights promotes ventilation. Vegetation must not impede
air movement: trees with branches far from the ground, such as palms,
would be ideal. Rainfall may be heavy, so permeable surfaces are needed,
to reduce urban stormwater runoff.
What
to do when summer is too hot and winter is too cold?
In a temperate climate, the
wind direction usually changes with the season. It may be possible
to choose a street layout which will block the winter wind, yet allow
cooling summer breezes through the city. As an example, have a look
at a suggested street layout modelled
on Coolangatta.
In cooler
parts of the temperate zone, or on exposed sites, we need maximum
wind protection (tree shelter belts, closely spaced buildings of constant
height, main streets perpendicular to the prevailing wind).
Have a look at
a map showing where these climate zones
occur.
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