Get our free book (in Spanish or English) on rainwater now - To Catch the Rain.

Category:Improved cook stoves

From Appropedia
Jump to navigation Jump to search

Template:Wikipedia p

This page refers to stoves using a fuel, usually solid. For solar versions, see Solar cooking
Subcategories and articles are linked from the bottom of this page.

Cook stove is a general term for stoves used in developing countries, often of a very simple designs.

Efforts have been made in recent years to design and promote more efficient stoves. These are known by various names: improved cook stoves, improved stoves, improved cookstoves, improved cook stoves, smokeless stoves and wood conserving stoves. These designs, when they work as intended, don't fill the home with harmful smoke (through more efficient burning to reduce smoke, and a chimney or venting to remove that smoke), and use less fuel. Several designs have been developed.

Health impact

Cooking and heating with solid fuels such as wood, dung, coal or crop waste over open fires or stoves without chimneys can lead to indoor air pollution. This indoor smoke contains carbon monoxide, benzenes, aldehydes, small soot and dust particles and other health-damaging pollutants.

A WHO assessment found indoor air pollution to be the 8th most important risk factor for disease. It is a particularly important risk factor for acute respiratory tract infections (ARI) including bronchitis and pneumonia. Each year, IAP is implicated in the deaths of 1.6 million people ( a death every 20 seconds). Because women and children spend the most time near the domestic hearth, they are especially vulnerable [1].

Use of cleaner burning fuels, access to improved stoves and/or behavior changes could substantially reduce exposure to indoor smoke and associated diseases [2].

Key design features

Some or all of these design features help make a stove more efficient and lower in health impact:

  • Chimney or vent - to remove smoke to outdoors, and improve airflow through the fire.
  • Controllable air inflow - requires the fire to be in an enclosure with an adjustable inlet - allows reduction of burning rate to match needs.
  • Use of a material with good insulating properties, for the inside walls of the stove - usually ceramic.
  • Afterburning - mixing the flue (exhaust gas) with a small amount of new air, to allow the last remaining hydrocarbons and carbon monoxide to burn without a flame.
  • Use of the flue gas heat for space heating (in cold climates) and/or water heating. To avoid leakage of flue gas into the room, a heat exchanger is needed. In an expensive product this may be a complex stainless steel device, or in a developing nation a simple metal flue pipe.[Suggested project]

Ongoing research and development

Groups including the Kobus Venter's Vuthisa Technologies[3] and EWB San Francisco Professionals Chapter[4] are doing research into optimizing such stoves, including using briquettes made from waste biomass (e.g. agricultural waste) with a simple briquette press.

The fuel used can have a great impact on the smoke produced, as well as affecting the environmental impact. CharcoalDEPRECATED TEMPLATE - PLEASE USE {{W}} INSTEAD. is much cleaner burning than wood or dung, but is usually made from wood.

Amy SmithDEPRECATED TEMPLATE - PLEASE USE {{W}} INSTEAD. has done work on producing charcoal from other forms of biomass. To make the biomass stick together, a binder is used. (Another method of making briquettes more cohesive is to leave the biomass in water for a couple of days to decompose slightly.) The choice of biomass depends on what is widely available, but includes bagasseDEPRECATED TEMPLATE - PLEASE USE {{W}} INSTEAD. (sugar cane waste) bound with a paste of cassavaDEPRECATED TEMPLATE - PLEASE USE {{W}} INSTEAD. root (also called manioc or tapioca); and wheat or rice straw bound with a small amount of dung, in areas where pure dung is normally burnt.[5]

Footnotes and references

  1. World Health Organization
  2. Randomized Exposure Study of Pollution Indoors and Respiratory Effects (RESPIRE) Trial
  3. Vuthisa Technologies is a small company in Pietermaritsburg, Kwa Zulu Natal, South Africa, and Kobus Venter discussed (or discusses) the development of the design on the Biomass cooking stoves lists.please expand
  4. EWB-SFP Appropriate Technology Design Team's blog, with a strong focus on improved stoves. See also Darfur Cookstoves - Updates May-December 2006
  5. MIT's Amy Smith on third-world engineering: TEDTalks - Video on YouTube.

See also

External links