Monday, February 23, 2009


INSULATION-The rocket elbow and its surrounds should be made with good insulating material;Good insulation is made of tiny pockets of air separated by lightweight non-conducting material.Soil or clay used in traditional stoves is dense and heavy and does not make for good material for stoves;a lot of the heat is absorbed by the stove itself.Using bricks made from a mixture of clay and saw-dust/ rice-husk / hay from paddy stocks will make a good material for rural areas;mix clay and saw-dust,knead saw-dust into the clay thoroughly,then add water;the bricks from the kiln should float in water.
RURAL AREAS-A fixed model with in the house;this can be done with fire bricks made as described above;the stove can be made with sixteen bricks as shown in the video-

Or with available local material-

URBAN AREAS-A portable stove which can be used indoors or outdoors as shown in the videos here can be made with used tin cans and insulation of facing/surface fire tiles/bricks available in the market.

The Envirofit models in the market can be seen here-

Saturday, February 21, 2009


By Dr. Larry Winiarski
1. Insulate around the fire using lightweight, heat-resistant
2. Place an insulated short chimney right above the fire to burn up
the smoke and speed up the draft.
3. Heat and burn the tips of the sticks as they enter the fire to make
flame, not smoke.
4. High and low heat are created by how many sticks are pushed
into the fire.
5. Maintain a good fast draft from under the fire, up through the
coals. Avoid allowing too much extra air in above the fire to cool it.
6. Too little draft being pulled into the fire will result in smoke
and excess charcoal.
7. Keep unrestricted airflow by maintaining constant cross sectional
area through the stove. The opening into the fire, the size of
the spaces within the stove through which hot air flows, and the
chimney should all be about the same size.
8. Use a grate under the fire.
9. Insulate the heat flow path, from the fire, to and around the
pot(s) or griddle.
10. Maximize heat transfer to the pot with properly sized gaps.

Friday, February 20, 2009


Figures from AricMcBay:

"It is easy to construct, and it uses low-cost materials. The rocket stove's main components are:

  • Chimney: a metal box (such as a 5-gallon tin can) or pipe standing vertically and supporting the cooking vessel
  • Fuel magazine: a short length of steel or ceramic pipe fitted horizontally into the base of a chimney
  • Fuel shelf: a flat plate to hold the fuel clear of the bottom of the magazine to allow air to flow underneath
  • Heat exchanger: a tubular metal shield that forces hot gases from the chimney to pass over the sides of the cooking vessel

The chimney and magazine are joined at a right angle, forming the 'rocket elbow', and it is at this junction that primary combustion occurs."

-The heart of the stove is the rocket elbow;small pieces of wood/ twigs are fed on to the fuel shelf in the fuel magazine;wood burning occurs only at the elbow aided by the air flow as shown in the figure;this ensures complete burning of the wood and prevents production of smoke ;smoke is formed when adequate air[oxygen]is not available for burning;
-complete burning results in full release of heat energy from wood and high temperatures in the combustion chamber;the heat energy is conserved by the insulation around the combustion chamber and directly transferred to the vessel on the grate as shown in the figure to the right.;
-the pot skirt ensures heat transfer to the pot both at the bottom and the sides.

-A long combustion chamber prevents smoke but reduces heat to the pot; a short chamber provides more heat but may generate some smoke.
-the gap between the pot and the skirt should be around twelve millimeters to ensure efficient transfer of heat to the pot;heat escapes with a large gap;if the gap is too narrow it restricts air flow.
- wood burns only at the inner end and it should be pushed in as it gets whittled down in burning.
"This stove operates on about half as much fuel, and produces substantially less smoke., compared to the traditional stoves;the stove requires small diameter lengths of wood, small branches or twigs; sufficient fuel for cooking tasks can be gathered in less time, without the benefit of tools, and ideally without the destruction of forested areas."[wikipedia]
The insulation of the combustion chamber is crucial for conservation of the heat generated and several types of materials have been used to achieve this;
Based on these principles several stoves have been designed to cater to all segments of the users;a ready-made stove ENVIROFIT is available in souther states for prices varying from Rs.700 to 2800.we could also build stoves for as low Rs.50 to 100 using local material like in 'Good-stove' ; after a survey of improved stoves the World Bank stated that models that can be constructed by the people with local materials are the ones that are easy for adoption.Stand-alone models are the best for urban poor and for all rural areas.

Thursday, February 19, 2009


The stove seen in the picture is made from a tin can;a 4"x4" window is made on the side near the bottom to place the firewood and a grate on the top to hold the pot all for Rs.6 !cooking is done in the open to avoid smoke in the hut.
For the poor in urban areas and most people living in rural areas, there's little alternative to burning wood and other biomass for cooking food,particularly for theBPL[Below the poverty level]families;biomass is readily available; kerosene and LPG are expensive and not available easily in rural areas; require an investment poor cannot afford;they involve a long transport for delivery to the over 600,000 villages in India;they are non-renewable and likely to exhaust one day;in contrast properly planned, wood can be grown where it is needed,near the villages and being renewable it is inexhaustible;our long term security lies in developing our wood can also be carbon neutral when compensatory planting is done
However biomass burning creates indoor air pollution which kills one person every twenty seconds[WHO];India accounts for 80% of the 600,000 premature deaths that occur in south-east Asia annually due to exposure to IAP.The World Health Organisation estimates that pollution levels in rural Indian kitchens are 30 times higher than recommended levels and six times higher than air pollution levels found in New Delhi. secondly the traditional open stoves are very inefficient and consume high quantity of wood or other biomass.
Tremendous amount of research has gone into making of improved stoves with superior cooking efficiency and no or less smoke; almost all these innovations follow the basic design of the ROCKET STOVE invented by Dr.Winiarski of Aprovecho.The salient features of the design are-
1.complete burning of the wood is achieved by providing for adequate air supply into the combustion chamber;proper burning of wood reduces or eliminates smoke.
2.By providing good insulation to the combustion chamber loss of heat is prevented.
3.The heat is efficiently transferred to the vessel/pot by providing a skirt round the vessel.
these details are presented in the figure in the next posting.

Wednesday, February 18, 2009


Here you can see the pot water filter;the filter candle is placed in the top pot and the filtered water collects in the bottom pot which has a tap to draw the water.The filter element should be cleaned regularly using a soft brush;it is easy to clean and poses no danger of loosing the nano silver coating.Maintained properly it may serve for two years or more .it can purify water of high bacterial content from well and pond.
Similat filters called Matka filters were used in Gujarat floods by society for environmental protection[SEP] and peoples health and development trust[PHDT].
HWTS is not a substitute to infrastructure development for water supply;it ensures safe water at the household;the vessels used for storage should have narrow mouth; hands should not be dipped in the storage pot.
Benefits of Pot water filter
1.It is a stand-alone facility and empowers the household to safe water at home.
2.Low cost.The filter candle is the only item to be obtained from the market once in two or three years.
3.Long life.
4.Assured elimination of pathogens.
5.simple to maintain.

Tuesday, February 17, 2009


DRUMSTICK SEED-drumstick seed powder added to water removes turbidity .
STRYCHNOS POTATORUM,NIRMALI,CHILLA-The seed are very hard;the seed may be rubbed on a rough stone with addition of small quantity of water and the seed extract added to water removes turbidity.
While drumstick is grown as a vegetable in most homes,Strychnos potatorum occurs in forest areas in most tribal tracts.


Generally water filter prices range from Rs500 to 2000 in the market;the heart of the filter is the ceramic filter candle;by fixing the candle in the clay pot used in most rural households for storage of water, a low cost water filter can be made as shown in the picture .such filters have been used in flood effected areas of Gujarat and Bihar.
Nano silver ceramic filter candle
The International Advanced Research Centre for Powder Metallurgy and New Materials (ARCI) is an autonomous R&D Centre of Government of India‘s Department of Science and Technology (DST) located in Hyderabad. ARCI has designed a ceramic filter with nano silver coating of millions of fine silver partcles .;these effectively destroy all the pathogens in the water with the silver acting as a catalyst.Field testing done in forty villages in Andhra Pradesh has shown that maximum probable number[MPN] of E.coli ranging from 30 to 1600 has decreased to zero MPN by these candles.These filter candles are being manufactured by SBP Aquatechnology,Hyderabad under the trade name PURITECH for
For ARCI see-

Monday, February 16, 2009


"Every year there are 1.6 million diarrhoeal deaths related to unsafe water, sanitation, and hygiene—the vast majority among children under 5. More than one billion people lack access to an improved water source.
Numerous studies have clearly shown that improving the microbiological quality of household water by on-site or point-of-use treatment and safe storage in improved vessels reduces diarrhea and other waterborne diseases in communities and households of developing as well as developed countries.
Household water treatment and safe storage (HWTS) interventions can lead to dramatic improvements in drinking water quality and reductions in diarrhoeal disease making an immediate difference to the lives of those who rely on water from polluted rivers, lakes and, in some cases, unsafe wells or piped water supplies.The most promising and accessible of the technologies for household water treatment are filtration with ceramic filters, chlorination with storage in an improved vessel, solar disinfection in clear bottles by the combined action of UV radiation and heat, thermal disinfection (pasteurization) in opaque vessels with sunlight from solar cookers or reflectors and combination systems employing chemical coagulation-flocculation, sedimentation, filtration and chlorination. All of these systems have been shown to dramatically improve the microbiological quality of water".[WHO]

Sunday, February 15, 2009


Washing hands is the simplest way of protecting ourselves from several infections;"Worldwide, surveys have shown that handwashing alone reduces the instance of diarrhoea by as much as 43 percent.IT also prevents the spread of other communicable diseases. Proper hand washing is not just a quick cold rinse of the hands. It requires 20 seconds of your time, warm water, soap (liquid is best) and some devoted scrubbing. This means washing around tips of fingers, fingernails, and the web, as well as the front and back of your hands. The dirtier the hands, the longer the wash time. Use the towel to turn off the faucet handle. This reduces the risk of picking up bacteria from the handle.


- after defecation/using toilet

-after cleaning children's faeces

-before taking/eating food

-after playing

-after doing any work that soils the hands

Poster from-

Saturday, February 14, 2009


These families have come from Nalgonda district to Hyderabad in search of employment. Presently they are working on a construction site as daily wagers.They are living in the temporary huts seen here, constructed near the work-spot.
What are the bare necessities for a family?
Good, clean, safe water for cooking and drinking; an efficient stove for cooking food; a light in the hut in the evening for two or three hours including for children to study.

SAFE WATER,the first priority:These families get their water from a municipal tap in a nearby housing complex; the quality of the water depends on the supply source, its collection and transport and storage container used;often even treated water gets contaminated in transport or storage;after a study of these issues WHO strongly recommends HOUSEHOLD WATER TREATMENT at point of use[POU] as the best measure to ensure safe water for homes..A simple POT WATER-FILTER for Rs100 is described in this blog.
The Rajiv Gandhi Drinking Water Mission has been working on providing drinking water to all villages in India;its focus is on infrastructure development;while it is a laudable objective, household water treatment should also be included in its program to ensure safe water at home as recommended by WHO.
STOVE:The poor use biomass based stoves for cooking food;these are generally inefficient both in quantity of wood use and quality of fire as it produces more smoke than heat;indoor air pollution kills one person every 20 seconds according to WHO. Improved stoves for below Rs.100 are described.
LIGHT:The family in the photo uses a kerosene lantern like most poor in rural areas;several solar lanterns with CFLs[compact fluorescent tubes] or with LEDs[light emiting diodes]are in the market in price ranges of Rs 700 to Rs3000;A LED light for Rs.100 is described !.