Last edited: 1 December 2015
The Rocket Stove, a popular variety of improved combustion stoves, is an integral part of the Integrated Cooking Method. It is easy to construct, with low-cost materials. These are low-mass stoves designed to burn small pieces of wood very efficiently. Cooking is done on top of a short insulated chimney. A skirt around the pot will help hold heat in, increasing the efficiency.
Rocket Stoves use branches, twigs, small wood scraps, or just about any small combustible material. The pieces of wood or other material burn at their tips, increasing combustion efficiency, creating a very hot fire, and eliminating smoke. The low-mass stove body and insulated chimney ensure that the heat goes into the cooking pot, not into the stove. Rocket stoves used in conjunction with hayboxes can save enormous amounts of fuel, cooking complete meals while using very few resources.
A related design, the Rocket Bread Oven, is constructed using two 55 gallon drums, one inside the other. The outer drum is split open to create an insulated chimney space between the two drums and to allow for a doorway. Baking is done inside the inner drum--in a sealed compartment within the chimney, above the firebox.
Rocket Stoves operates roughly twice as efficiently, and substantially more cleanly, than the open fire cooking methods still used in many areas of the world. Furthermore, the design of the stove requires small diameter lengths of wood, which can generally be satisfied with small branches. As such, sufficient fuel for cooking tasks can be gathered in less time, without the benefit of tools, and ideally without the destruction of forested areas.
Because these qualities improve local air quality, and discourage deforestation, the rocket stove has attracted the attention of a number of Appropriate Technology concerns, which have deployed it in numerous third-world locales (notably, the Rwandan refugee camps). This attention has resulted in a number of adaptations intended to improve convenience and safety, and thus the size of the target audience. The Justa Stove, for example, is a cousin of the rocket stove adapted for indoor use and family cooking needs.
Key features[edit | edit source]
The Rocket stove's main components are as follows:
- Fuel magazine - a short length of steel or ceramic pipe fitted horizontally into the base of the chimney
- Fuel shelf - holds the fuel clear of the bottom of the magazine to allow air to flow underneath
- Chimney - a metal box (such as a 5-gallon tin can) or pipe standing vertically and supporting the cooking vessel
- Heat exchanger - a tubular metal shield that forces hot gases from the chimney to pass over the sides of the cooking vessel
Problems[edit | edit source]
Overview: Fire based solutions, such as the Rocket Stove, allow cooks to make meals when the sun isn't shining or achieve temperatures that would be difficult without expensive parabolic cookers. However, they do have drawbacks:
- Pollution When biomass, such as wood, is consumed completely in the burning process, it produces carbon dioxide (C02) and water vapor (H20) alone. However, according to Joel S. Levine of the Atmospheric Sciences Competency NASA Langley Research Center in Hampton, Virginia, '[s]ince complete combustion is not achieved under any conditions of biomass burning, other carbon species, including carbon monoxide (CO), methane (CH4) nonmethane hydrocarbons (NMHCs), and particulate carbon, result through the incomplete combustion of biomass material. In addition, nitrogen and sulfur species are produced from the combustion of nitrogen and sulfur in the biomass material.' Further, it is possibly the most injurious common form of generating heat in terms of particulate emissions and other pollutants.
- Efficiency The book, "Capturing Heat II" by the Aprovecho Research Center suggests that without a skirt the Rocket Stove is only about as efficient as a well-run open fire. With the addition of a skirt that efficiency rises, but is still less than the 40% that is sometimes cited.
- Maintainability Tin can stoves may disintegrated due to rust after 3 to 6 months and the constant heating and cooling of other materials can cause these to break down.
Alternatives/Variations[edit | edit source]
- The Global Alliance for Clean Cookstoves provides these descriptive summaries of the different fuel-efficient stove technologies currently in use. fuel-effcient stove catalog, including solar cookers.
Sierra Zip Stove[edit | edit source]
An interesting alternative -- at least in the developed world -- is the Sierra Zip stove. By pumping heated air into the combustion chamber quick high temperatures can be achieved with little energy wasted on thermal mass or warm-up time. Ensconced in a cooking system which skirts the cooking vessel, 4 oz of wood will give 2-3 minutes of gas-like cooking.
Two-Door Rocket Stove[edit | edit source]
The Two-Door Rocket Stove can burn both wood and charcoal. It saves a lot of both! Wood fuels are fed into the big door. The small lower door controls the flow of air into the fire which lowers emissions. When burning charcoal, the big door is closed, and the rate of burn is also controlled by opening and closing the lower door.
Adding adjustable doors to a Rocket stove allows for control of the air that enters the fire to speed up or slow down the rate of combustion. More air is needed to start a cold fire and to create a hot fire initially. Once the fire is going, the bottom door is partially closed. Limiting the air increases heat transfer to the pot and reduces harmful emissions.
The popular EcoZoom Versa Two-Door Rocket stove efficiently uses charcoal to cook food.
Carbon monoxide is reduced when it is burned up in the enclosed space above the fire. Frequently, enough charcoal is made when burning wood so that simmering can be done using only the made charcoal. After boiling food, the big door is closed and air from the lower door keeps the made charcoal burning. The interior grate and dual doors make the EcoZoom Versa Two-Door Rocket stove slightly more expensive than the one door EcoZoom Dura stove.
Dimensions: Stove D-11 in H-11 in (Dimensions above are as packed for shipment) Upper Door: W-4 3/4 in H-2 3/8 in Lower Door: W-2 3/8 in H-1 1/8 in
Rocket stoves are commercially available in some developed countries, and often cross subsidise projects in developing countries.
Features of EcoZoom Versa rocket cookstove:
- Insulating, abrasion-resistant combustion chamber
- Grate to hold both wood and charcoal
- Two doors with sliding covers
- Cast iron stove top
- Stick support
- Adjustable galvanized steel pot skirt
- Painted sheet metal body
- Wooden and painted steel handle
Click here for the EcoZoom homepage.
Audio and video[edit | edit source]
|How to Make a Tin Can Rocket Stove|
|How to make a 16 brick rocket stove|
|How to make a rocket stove from vermiculite|
Articles in the media[edit | edit source]
- May 2014: Global health: Deadly dinners Polluting biomass stoves, used by one-third of the global population, take a terrible toll. But efforts to clean them up are failing - Nature
- April 2013: Study finds improved cookstoves solve one emissions problem, but create another - E&E Publishing
- February 2011: Aprovecho Research Center's Rocket stoves This article recognizes the Aprovecho Research Center for 35 years of work on Rocket Stoves, and notes worldwide initiatives to fund and develop fuel efficient stoves. - The Oregonian
- September 2010: Developing Nations to Get Clean-Burning Stoves - The New York Times
- Success Story: Reforesting Guatemala - the careful way - PeopleAndPlanet.net
See also[edit | edit source]
- Other improved combustion stoves on this site
- Estufas en Imágenes
- Integrated Cooking Method
- September 2007: Report on Oaxaca, Mexico Project With Photos Showing the Construction of Rocket Stoves From Various Materials
- Cookstove Fuel Consumption Evaluation Guidelines
- Biomass briquettes
- Photovoltaic cooking
[edit | edit source]
- ENVIROFIT - Winter 2015 Product Overview
- Rocket Stoves, Boilers and Patsari cookstove - Haiti Reconstruction
- Papers presented at the ETHOS Conferences (2004-2013)
- A long list of organizations (with links) that work with improved biomass cookstoves - Aprovecho Research Center
- Possible Stove Options for Haiti A review of the Lucia, Stove Team International, and Stovetec stoves.
- Aprovecho Research Center.
- Video showing how to build a Rocket stove.
- Video showing how to build an institutional-size Rocket stove made from barrels.
- Institutional Rocket Stove Manual
- Design principles for wood-burning stoves, describes in full details the design principles on which all stoves talked about here are based, and compares all common materials for building one. 40 pages.
- The Institutional Rocket Stove Design Tool allows you to produce detailed designs for three different types of institutional rocket stoves. You specify pot and material dimensions, and the tool generates a custom set of Rocket Stove plans.
- Campus Center for Appropriate Technology (CCAT) demonstration rocket stove, Humboldt State University, California.
- Sierra Zip on zzstove site.
- How to make a simple type of rocket stove on Pyro-energen site.
- Grover Rocket Stove, Stockstorage selling site.
- Improved Cooking Stove(ICS) use in Nepal. From the Nepalese Centre for Rural Technology. A historic of the development of these stoves in Nepal, and succinct technical specifications. 5 pages.