When the scorching sun beats down mercilessly and you wipe the sweat off your tired brow, don’t you wish you were inside the cool confines of an air-conditioned room? Find out how our ancestors kept themselves cool long before modern air-conditioning was invented.
Trust the ancient Romans to conceive the first mode of air conditioning. The master builders constructed aqueducts — long stone channels which carried drinking water from the nearby hills to the towns. Wealthy Romans arranged to have pipes from these aqueducts circulating the brick walls of their houses. This effectively kept the rooms cool. The same concept was also used by Indian palace builders, notably the Mughals.
In 747 AD, an Emperor of the Tang dynasty installed a ‘Cool Room’ in his Imperial Palace. It used water-powered fan wheels and rising jets of water from fountains to lower the room’s temperature.
Iran is known for its dry climate. So its ancient rulers devised effective ways to escape the harsh summers. Their ‘cool’ designs were best displayed in the classic Persian gardens in which water played a vital role. Features like cooling fountains and water channels not only added to their beauty, but also offered visitors a soothing retreat from the heat.
How do people living in hot places survive the heat? Since olden times, they have adopted natural methods to cool their homes. These passive cooling strategies are great energy savers.
Traditional Indian houses are built around courtyards. A courtyard facilitates natural ventilation, working on the principle of convection of air. Acting like a chimney, it allows warm air to escape while the dense cool air sinks below and circulates around the rooms surrounding it.
Building earth-air tunnels is an economical method to cool houses without air-conditioning. Unlike air temperature which varies with seasons, the ground temperature at a depth of four metres remains constant at around 20oC. Earth-air tunnels use this feature to cool residential as well as agricultural and industrial units.
Pipes embedded four metres below the surface draw in air and cool it before circulating it through the home. Earth-air tunnels are used in conjunction with solar chimneys which enable hot air to escape, creating space for cool air.
If you thought that people in deserts and villages live in mud houses because they cannot afford better building materials, you couldn’t be more wrong. Walk into a mud hut and you will immediately notice a distinct drop in temperature. Mud helps to insulate the interiors from the heat of the sun.
Indigenous peoples of the Americas, Spain and parts of Africa have lived in adobe houses for centuries. These regions have hot days and cool nights. In such conditions, adobe is the perfect choice as a building material.
Adobe bricks are made from sand, clay, water and straw and then baked in the sun for several days. A well-built adobe wall delays the transfer of outside heat into the home during the day. After sunset, the warmed wall keeps the inner living space toasty for many hours.