Eishan Jain, associate director at our Delhi studio, explains his innovative proposal to tackle hot Delhi summers using traditional techniques.
Anyone who’s visited our Delhi studio in the scorching summer or chilly winter months will know that the climate can be pretty unforgiving. At its hottest, the city is hit by temperatures as high as 50°C (122°F), while dust storms accompanying heatwaves can make conditions even more unbearable. It’s hardly surprising that people have become dependent on air conditioning, sealing buildings off from heat and dust; but this response comes at a significant cost, both in terms of electricity usage and greenhouse gas emissions.
It’s a growing problem, with population and construction works increasing across the city. And it’s a problem which we’ve been seeking to fix with our entry for the Clean Energy Challenge, proposing a solution which is more economical, greener, more adaptive, and easy for anyone to construct. Our concept works on the idea of passive cooling, achieving a comfortable, dust-free environment at minimal cost or damage to the environment. And it was inspired not by high-tech, cutting-edge science or hyper-modern building practices, but by a local Indian tradition.
It was once common practice for Indian people to cover the windows of their houses with handmade grass-weed or cane-based blinds, which could be made retractable using a simple pulley and string mechanism. They would regularly spray water onto these blinds – giving the double benefit of cooling the air as it entered and filtering out any dust – while the blinds themselves protected from the harsh sun. It’s a simple principle, now largely forgotten – but it’s one which can be easily modified and updated to suit modern buildings.
Our adapted design sticks with local, easily accessible materials, using khus (vetiver roots, native to India) tied to bamboo flats to give the blind rigidity and weight. Bamboo is not only strong, cheap, and recyclable: its round stems provide the perfect shape for rolling up the blind when it’s not needed.
The question then became how to introduce water to the blinds in a controlled, energy-efficient way. This time, we turned not to traditional Indian practices but to the traditions of our own architectural practice: ADP has undertaken bike rides to raise money for Marudyan, a charity providing teaching facilities for children below the poverty line in India.
Our design equips a bicycle with a Pedal Power Water Pump (PPWP*), consisting of a regenerative turbine pump operated by pedal power. The shaft of this pump is connected to the bicycle’s wheel using a belt, while the pump itself sits on a stand. As the bicycle is pedalled and the wheel turns, the centrifugal pump discharges water from an underground storage tank, pumping it along flexible PVC pipes hidden in the immediate structure of the building. Eventually the water reaches the bamboo blinds – perforated with pin holes – where it falls along the khus mat, providing crucial protection from the heat and dust outside.
It’s a solution which is hugely adaptable. The concept can be tailored to any kind of building, from housing and shops to offices and industrial units; and the bicycle can be placed anywhere in the building. It also has far-reaching benefits: the bicycle itself can be used for exercise, and the system improves air quality. To cap things off, the bicycle can be disconnected for a ride into town or to work, then reconnected and pedalled to set the whole system going again.
It’s also an efficient solution, with every aspect geared (no pun intended) towards reducing waste. For instance, any excess water which drips from the khus mat falls into a drain channel, where it flows back into the underground storage tank it came from – and the process begins again. This tank can be drained, cleaned, and refilled at any time; and when the weather gets cooler, the turbine can be used to generate and store electricity for buildings and appliances.
The result is a considerably more comfortable summer for those using the system, without the need for expensive and damaging air conditioning. Cool, moisture-laden air enters the building through cross-ventilation, while the water molecules in the khus mat reduce dust and other particles in the air. We’re excited by the possibilities of this approach – having already been shortlisted to the top 57 entries (from a total of 452 submissions), we’re looking forward to seeing how it fares in the Clean Energy Challenge on the 10th February.
* For an explanation of the PWPP system, see this article in the Open Journal of Technology & Engineering Disciplines (OJTED): https://www.researchgate.net/publication/317521302_DESIGN_AND_FABRICATION_OF_PEDAL_OPERATOR_CENTRIFUGAL_PUMP
Written by:
Deputy Director
Eishan Jain
