issue: May 2009 APPLIANCE Magazine
Web-Exclusive: Engineering a Life-Saving Stove
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It's made of concrete and clay. It burns biomass fuels like wood or dung. And the design? Philips is just giving it away.
The story of the Chulha stove began in September 2005 at a Philips Design global community workshop in Eindhoven, entitled ‘A Sustainable Design Vision – Design for Sense & Simplicity’. The event goal was to envision products to support NGOs in relieving the suffering of people in emergencies (e.g. earthquakes) or enhancing individual empowerment and local communities’ socio-economic development. Some 80 design ideas emerged and after the workshop these were filtered by criteria such as compliance with Philips corporate strategy, social investment policy alignment, technological feasibility, and Millennium Development Goals.
Five Months To Prototype
In the end, the chosen proposal was for a smokeless wood-burning stove, initially intended for rural and semi-urban India.
“This idea seemed to have the best chance of helping the socially disadvantaged through leveraging our expertise and capabilities without involving sophisticated and expensive technologies,” says Simona Rocchi, director of Sustainable Design at Philips Design in Eindhoven.
The stove would be simple to use/maintain, locally manufactured, relatively inexpensive, easily produced, and able to significantly reduce indoor pollution. Indoor air pollution was a major factor in the choice. Respiratory illness affects the health of large populations that live in developing societies and cook indoors with biomass fuels like wood or dung. Philips reports estimates that over 1.6 million people die as a result each year of these illnesses – 25% of those in India.
A three-person team from Philips Design Pune turned the initial design idea into two, field-tested prototypes within 5 months. The collaborative effort included local NGOs, entrepreneurs, self-help groups, and Indian families.
Insight into the potential users' culinary habits and cooking behavior came from research in several villages in India's Maharashtra state, where the design team held introductory meetings, observations, and in-depth interviews. The focus was on women aged 23-45, as they are traditionally the ones who do the cooking.
The research made it clear the new stove would have to be flexible enough to use different kinds of biomass fuels. It would also need to be adaptable for use in different seasons and for many different foods, such as cooking chapatti (bread), steaming rice, and boiling water. It would also need to accept non-standard cooking vessels.
The Crucial Piece
Crucial to the design would be the chimney – the most important component for reducing indoor air pollution.
"The feedback we got was that conventional chimneys, which were made from a single length of pipe, were difficult to transport, often requiring a small truck or cart. They were also often damaged in transit, and were extremely difficult to clean," explains Unmesh Kulkarni, senior design/account manager at Philips Design in Pune.
The Chulha stove was engineered with a chimney that is in several sections, so it is easier to produce and to transport.
During testing, feedback convinced the design team to look into a vermiculite material for the chimney to reduce stove’s weight and improve thermal efficiency.
Philips is also making the intellectual property of the design available to manufacturers as a way of bringing the stove to market rapidly. “We allow local stakeholders to use the IP and design for free as our philanthropic contribution to sustainable development,” says Rocchi. “In this way we make it much easier to achieve widespread distribution of the stoves and help keep costs down. This will not only create better living conditions for the users, but also stimulate local entrepreneurial activities with a low environmental impact."
In fact, a support package is being created which includes the stove’s design details as well as marketing information for entrepreneurs, communication materials for NGOs, and installation instructions. A training program is also being developed.
The end product will be made largely of concrete and coated with local clay. "It is definitely ‘advanced’," says Rocchi. "Not in a high-tech way, but purely because the proposed technology is considerably more effective and sophisticated than the one currently available. This simple stove demonstrates that we can clearly improve the quality of many people’s lives through design.”
“It is all about appropriate technology,” adds Kulkarni. “We tackled a huge problem using a minimum amount of resources. In many ways this is more challenging than designing a very advanced, high-tech solution."
Two Versions of the Chulha
The Chulha smokeless stove was designed in two models.
One, called Sampoorna, is an all-in-one unit for cooking/boiling with an integrated steamer that prepares rice, lentils, etc.
The second model, Saral, is a modular system with a basic cooking block that allows the addition of various other blocks to accommodate extra pots, steaming, or a hot box for keeping food warm or heating it up.
In the end, the stoves reduce indoor smoke pollution by 90% compared to traditional cooking fires. The concrete-and-clay construction helps keep costs low. The estimated cost for the Sampoorna is roughly €8; the Saral will be roughly €5. Kulkarni estimates the stoves will be affordable by half of the 700 to 800 million people in rural India who currently cook on traditional biomass fuel fires.