Air conditioning in buildings implies high energy use and high utility bills. Today while we are devising sustainable heating and cooling methods to comply with the green architecture movement, it is pertinent to know that natural heating and cooling techniques have been used for as long as humans have been building homes. Mughal architecture in India offers unique active and passive air conditioning methods, which can be easily adopted in contemporary architecture.
The Mughals came up with some ingenious ways to beat the summer heat in the arid desert areas. Each design element was a response to the climate of the area.
Mughal Gardens: One of the hallmarks of Persian gardens is the four-part garden laid out with axial paths or water channels that intersect at the centre. This highly geometric garden layout travelled to India with the Mughals. They controlled the microclimate around the building with the help of two elements — vegetation and water. The vegetation not only made the surroundings aesthetically pleasing but enhanced cooling by facilitating evapotranspiration. They designed water channels and fountains, which improved the humidity in hot and dry regions. Oftentimes, these water channels and fountains were extended into the interiors of buildings. Nahar-i- Bahisht (Canal of Paradise) at the Red Fort Complex is one such example. Here the canal connected the imperial apartments, running through the centre of each. Water was drawn from the river Yamuna through a tower in the corner of the fort. The palace was designed to emulate paradise as described in the Quran.
Courtyards, Verandahs, Shading and Ventilation Devices: Architect Le Corbusier remarked, ‘Comfort is in the shades, it is in the coolness of currents of air, and in shaded naves of Mughal palaces.’ Mughals introduced unique layered spaces to Indian architecture. They realised that rooms should not be flooded with direct daylight. They used intermediary spaces like courtyards and verandahs in relation to the climate of the place, to buffer and to protect interiors from extreme weather conditions. The courtyard was the heart of the Mughal buildings, socially as well as environmentally. It prevented interior spaces from being exposed to solar radiation and the hot winds. Mughals added vegetation and water design elements to these courtyards to further enhance the microclimate and for better humidity control. They shaded the doors and walls with stone chajjas (cantilevers). A stone jaali (latticed screen) is another Mughal feature. While offering privacy it allows diffused light and controls air flow in interiors. These would often be placed near the ceilings to allow hot air to escape from the rooms.
Building Envelope: Mughals used thermal mass or thick walls of masonry or other materials with low thermal conductivity that have low transmittance value of heat. During the day, heat will get absorbed in these thick walls, keeping the interiors cool. During the night, due to high emissivity of these walls the absorbed heat will dissipate, thus facilitating further cooling of interiors. Shaded walls, moistened reed or bamboo screens over windows in summer of thick quilts in winters, high vaulted or domed ceilings are some other elements used to control temperature and humidity.
Many modern architects successfully adopted environmental features of Mughal architecture and knitted them into contemporary designs.
Le Corbusier in Chandigarh and Edward Lutyens at Rashtrapati Bhavan in New Delhi, H V Lanchester at Umaid Bhavan in Jodhpur are some prominent examples where the architects demonstrated how to knit this tradition into contemporary design.