Cool buildings lead to green city

Cool buildings lead to green city

By Tri Harso Karyono

JAKARTA (JP): Economic growth has brought higher living
standards, but has also had a negative impact in Indonesia.
Cities were developed, infrastructure laid, high-rise buildings
erected, but all this is being paid for by devastating the
country's energy resources.

Because cities are being developed along western models,
particularly American designs, there is a massive waste of
energy.

A 1993 study done by the writer found that nine times more
energy was used to cool each square meter in selected air-
conditioned office buildings than in one naturally ventilated
building.

It was also found that the comfort range for office workers
was between 23.5 degrees and 29.9 degrees Celsius, which is wider
and higher than the American standard of between 22.5 degrees and
25.4 degrees C. Indonesian building engineers use the American
standard.

The Indonesian comfort figures are close to Jakarta's average
outdoor temperature of between 23 degrees and 33 degrees C. There
is therefore much potential for engineers to manipulate a
building's indoor temperature to be within the comfort range
without installing any mechanical means. Even if mechanical means
are used, the amount of energy used for cooling could be lower if
the building is designed correctly.

The city has more than 450 high-rise buildings and about half
were office buildings.

Conserving energy requires new designs, open spaces and
gardens because naturally ventilated buildings must be surrounded
by open space. A city designed in accordance to the climate would
have a unique shape.

A study of the radiant heat above different surface coverings
revealed that air temperature above the concrete surfaces was
significantly higher than above the grass. In Jakarta, this makes
walking a short distance a chore because grassy areas have been
concreted, the trees cut down and any open areas built upon. This
makes the city even more claustrophobic.

The problem stems from Indonesian architects and urban
designers trained abroad copying western ideas without proper
interpretation or selection. Designers who have never been
abroad, also mindlessly imitate the designs they see in films and
magazines.

Concreting a square and planting a few trees is only
necessary for people in cold or temperate climates. It allows the
sun's radiation to warm the air above the ground. Copying this in
tropical Indonesia is a huge mistake and could lead to disaster.

As a result of copying the West, most of Jakarta's buildings
are simple steel column boxes covered by glass walls. Most of the
new buildings, no doubt, are air conditioned. The climate is
hardly considered in the design, causing huge amounts of energy
to be wasted in cooling the massive greenhouses.

The naturally ventilated former Ministry of Religious Affairs
building on Jl. Thamrin consumed one-twelfth of the energy used
by the air-conditioned Agency for the Assessment and Application
of Technology next door. On average, the former Ministry of
Religious building consumed one-ninth of the energy the air-
conditioned buildings of the Bank Central Asia, the Ministry of
Education and Culture, the Indonesian Institute of Sciences and
the Widjojo Center did.

The massive energy loss in air-conditioned buildings
illustrates the problem of blindly copying western designs. Many
buildings are designed with air conditioning just for prestige.
The climate is almost ignored, causing the massive consumption of
fossil fuels and, in turn, air pollution.

A city's identity should be based on its climate, culture
and economy. Considering the local climate in energy conservation
is crucial.

Trees must be planted within Jakarta to absorb the sun's
radiant heat and shade roads and other concrete spaces. Grass is
the ideal ground covering. Shaded sidewalks will encourage people
to walk short and medium distances, decreasing the number of cars
and therefore pollution. Tree-lined roads would keep vehicle
passengers cool without the need for air conditioning.

By conserving energy, Indonesian cities will be greener not
grayer.

The writer is an architect currently studying for his Ph.D in
architecture in the United Kingdom.