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Vishal Thakur
Before
the advent of artificial air conditioning, people used many different ways to
cool their houses.
Some
of these techniques included designing houses with respect to the surrounding
environment, using evaporative cooling, wind-catchers, etc.
Summers
can become an unbearable mess sometimes.
Rising
temperatures in the afternoon, sun beating down on top of your head, roads
filled with traffic and pollution… it all feels like a bad and very sweaty
drag.
Fortunately,
we now have the option of cushioning ourselves in an enclosed room with the
temperature turned way down on the AC unit, effectively detaching ourselves
from the heatwave going on outside.
This,
of course, wasn’t always an option. The first air conditioning systems were
powered back in 1902, meaning that artificial cooling is a relatively new
phenomenon.
Just
imagine how miserable it would have been for folks in the scorching summer when
their only option would be to vigorously wave a paper fan with their hands.
Fortunately,
they had more options then handheld fans, as people found plenty of natural methods to keep their houses cooler than the
temperature outside.
They
employed methods of passive cooling to design houses in a way that is in
accordance with the climate, enabling them to lower the temperature inside the
house.
Let’s
look at some of the ways people naturally cooled their homes.
Ways
in which houses were cooled naturally
Without
modern technology, people relied heavily on the way houses were built in
accordance with the local climate to maximize heat dissipation and thermal
insulation.
Many
buildings constructed today completely disregard this, as it is easy to simply
build a box and slap electric air conditioning on the side.
In
the past, people did not have this option, so they had to learn techniques to
make houses as site-friendly and aligned with the climate as possible, making
it completely natural.
These
tricks were used to make their houses cooler:
House
layout based on the climate of the site
As
stated before, the climate of a site is one of the most important aspects of
deciding how a building should be constructed.
This
must be done by taking into account the movement of the sun and wind on the site.
The
information that this provides determines the location of the rooms in the
houses, so placing rooms in the opposite direction of the sun’s path would make
the room naturally cooler than the others.
Wind
direction also plays an important role, as the flow of natural wind in a room
would help keep it ventilated and cooler.
Some
very interesting examples include Indian step wells, which were dug underground
in the shape of stairs.
The
level underneath has water and as is away from sunlight, making it much cooler
than the rooms above.
Shading
of the house
Well-designed
exterior shading of the house cuts off the harsh sunlight coming in during the
afternoon.
This
reduces the heat gain on the exterior surfaces of the house (windows and blank
walls) and also ensures ambient temperatures in semi-open and outdoor areas of
the house.
Initially,
this shading was done with trees, but as techniques evolved, the shading could
be achieved by an opaque slab running through the house (seen above modern
windows), extended balconies, and perforated wooden shades called pergolas.
Examples
of this are seen in Mughal architecture with jharokhas, which provide a
separation of space, reducing the temperature of the room inside.
Thermal
insulation
The
thickness of the walls and the roof of the house plays an important role in
transferring heat from the exterior to the interior.
Many
materials are used to insulate this transfer, making the interior rooms much
cooler.
These
materials are stacked between the walls; some of the common ones are wool,
cellulose fiber and glass fiber.
Thermal
insulation boards are drilled on the back of the roof to avoid heat transfer.
Earth
walls help a lot in insulating the houses, as it is a cooler material; adding
splashes to the walls makes the incoming air cool and pleasant.
Natural
Ventilation
Keeping
windows facing the direction of the wind helps cool down rooms with the breeze.
Having
two windows on two opposite walls or having a courtyard on one side helps this
even further, as there is a constant flow of wind in the room, giving no time
for the hot air to linger.
Innovative
window-making techniques also help get rid of warm air. As warm air moves
higher than cooler air, small vents were placed on the windows for its
elimination, thus making the room cooler.
Black
openings are also placed on the roof for the suctioning of warm air, with a
wind tunnel on the ground to cool the incoming air.
Windcatcher
In
use for thousands of years, a windcatcher is a small tower with an opening on
the top.
The
tower ‘catches’ the wind flowing above and forces it to enter the houses, thus
cooling the interior. This is the simplest type of windcatcher.
Another
type is used with a qanat, which is the opposite of the one described above. A
qanat is an underground tunnel with a water body for the warm air to cool down.
The
air then flows into the room and goes out of the opening on top of the tower,
thus completing the ventilation cycle.
Evaporative
Cooling
Our
bodies cool through evaporation. As we exert energy and perspire (sweat), the
evaporation cools our body down.
This
same principle is used in making a room cooler through evaporation. Wet
khas-mats hung on a window on a windy day will make the room cooler inside.
This
method is so effective, in fact, that modern coolers use the same principles to
operate.
The
earliest example of this is the Egyptians using wet reeds on their windows to
cool down their rooms.
Aqueducts
Romans
gave us many engineering marvels and aqueducts are one of them.
Aqueducts
are an underground network linked to a water supply and used to connect clear
sources of water to community spaces and individual houses.
They
were also used to take heat away from houses by pumping into the walls.
However,
this was just for the elite, as it was an expensive system to develop and use.
These
aqueducts were also used to fill Roman fountains, which were used to cool down
the common public.
Conclusion
We’ve
come a long way, from sprinkling water on our walls to installing electric air
conditioners without a second thought.
People
have always found ingenious ways to get some relief in the heat and identified
ways to create a balance with the local environment.
As
artificial air conditioning is not very environmentally friendly, we can still
use some of these clever approaches when designing new buildings to reduce the
need for artificial cooling!
Vishal is an Architect and a design aficionado. He likes
making trippy patterns in his computer. Fascinated by technology’s role in
humanity’s evolution, he is constantly thinking about how the future of our
species would turn out – sometimes at the peril of what’s currently going on
around him.
Stepwells make the room on the lower floors cooler. |
Jarokha’s help shade rooms from the penetrating sunlight. |
Thermal insulation on roofs to reduce heat gain. |
Earth walls with openings for airflow |
Windcatcher |
Windcatcher with qanat |
Egyptians used wet reeds for evaporative cooling |
Three-tier aqueduct |
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