Hexayurts[edit | edit source]
- Summary
The hexayurt is a simple shelter suitable for both on-site manufacture from basic materials (cardboard, hexacomb, polyisocyanurate insulation boards like Thermax HD) or prefabrication in a factory context.
The Hexayurt Project includes a sample infrastructure solution which seems to represent a "sweet spot" of easily available tools, technologies and best practices to provide a really effective package for about $40 to $100 per head.
- Advantages and Disadvantages of this solution.
Hexayurts are untested in the field at this time.
Hexayurts are quite costly when measured against a typical relief budget for a developing world emergency.
Hexayurts encode a lot of assumptions and presumptions, and are not culturally appropriate for all situations in all liklihood.
Hexayurts, while lighter than tents, have a much larger cube, and the low-cube, high-density shipping approaches are still theoretical.
- Success Story (use vignettes)
File:Big sa hexayurt.jpg:800px
This is one of the hexayurts built at Strong Angel 3, a US DOD demonstration in San Diego in 2006. It was assembled in only a few hours
- Safety Considerations
- Source (where did this come from)
- Investment
- Approximate Cost
- Needed Materials (Parts List)
- Labor
- Lifecycle Cost
- Logistics for this Solution
- Transportation specifics (size, weight, special handling, etc)
- Maintenance
- Sources of supply
- Instructions to Build/Deploy
- Summary and description (with figures and diagrams)
Build a Durable Shelter for Your Family (One Page Flyer)
- Step-by-step instructions
All hexayurts cut neatly from 4' x 8' sheets, the standard size for most construction goods.
The large sizes require only one kind of cut - diagonal cutting straight across six boards to form the roof triangles. Six 4'x8' boards are cut along the diagonal, three right-to-left, and three left-to-right. From these twelve right-angled triangles, six equilateral triangles are formed, making the roof cone. The vertical walls are formed from whole 4'x8' sheets.
The smaller sizes require a somewhat more complex cutting pattern for efficiency but all details are below.
If you are cutting angles:
The angle between vertical boards and other vertical boards at the corners is 60° so you cut 30° on each edge. The angle between the vertical boards and the roof is also 60°. The angle between the boards on the roof cone is 29.5° so you might as well cut a 15° angle on each board. All boards which meet flat should have no angle cut on them at all, of course.
Angle cutting is not required for a perfectly good hexayurt of any size, as long as one is using wide enough tape. 3" will do, 6" is better.
- Training Resources, Weblinks and Points of Contact.
- Implementation Guidance (hints and warnings)
- Cultural sensitivities
- Tricks and tips
- Interdependencies (Relationship to other SPs and needed Infrastructure)
- Disposal or reuse
Trailiers[edit | edit source]
- Summary
- Advantages and Disadvantages of this solution.
- Success Story (use vignettes)
- Safety Considerations
- Source (where did this come from)
- Investment
- Approximate Cost
- Needed Materials (Parts List)
- Labor
- Lifecycle Cost
- Logistics for this Solution
- Transportation specifics (size, weight, special handling, etc)
- Maintenance
- Sources of supply
- Instructions to Build/Deploy
- Summary and description (with figures and diagrams)
- Step-by-step instructions
- Training Resources, Weblinks and Points of Contact.
- Implementation Guidance (hints and warnings)
- Cultural sensitivities
- Tricks and tips
- Interdependencies (Relationship to other SPs and needed Infrastructure)
- Disposal or reuse
Prefabricated Buildings[edit | edit source]
- Summary
- Advantages and Disadvantages of this solution.
- Success Story (use vignettes)
- Safety Considerations
- Source (where did this come from)
- Investment
- Approximate Cost
- Needed Materials (Parts List)
- Labor
- Lifecycle Cost
- Logistics for this Solution
- Transportation specifics (size, weight, special handling, etc)
- Maintenance
- Sources of supply
- Instructions to Build/Deploy
- Summary and description (with figures and diagrams)
- Step-by-step instructions
- Training Resources, Weblinks and Points of Contact.
- Implementation Guidance (hints and warnings)
- Cultural sensitivities
- Tricks and tips
- Interdependencies (Relationship to other SPs and needed Infrastructure)
- Disposal or reuse
Heating[edit | edit source]
Cooling[edit | edit source]
Ventilation and Air Filtering[edit | edit source]
Drinking Water[edit | edit source]
Food – Transport[edit | edit source]
Food – Preparation[edit | edit source]
Kearny Improvised Grain Mill[edit | edit source]
- Summary
- Advantages and Disadvantages of this solution.
- Success Story (use vignettes)
- Safety Considerations
- Source (where did this come from)
- Investment
- Approximate Cost
- Needed Materials (Parts List)
- Labor
- Lifecycle Cost
- Logistics for this Solution
- Transportation specifics (size, weight, special handling, etc)
- Maintenance
- Sources of supply
- Instructions to Build/Deploy
- Summary and description (with figures and diagrams)
- Step-by-step instructions
- Training Resources, Weblinks and Points of Contact.
- Implementation Guidance (hints and warnings)
- Cultural sensitivities
- Tricks and tips
- Interdependencies (Relationship to other SPs and needed Infrastructure)
- Disposal or reuse
Food – Cooking Stoves[edit | edit source]
Integrated Solar Cooking [[1]] This method combines the use of: 1. An appropriate solar cooker model whenever the sun is shining, 2. A retained heat (fireless) cooker or hay basket to continue the cooking process [[2]], 3. A rocket stove or other efficient cook stove for use after sunset or on cloudy days. The combined use of these three simple technologies can reduce fuel consumption by more than 75%.
Integrated cooking Wiki [cooking method]
Darfur refugees in Chad using solar cookers and hay baskets
SOLAR COOKER BASICS
THE THREE TYPES OF SOLAR COOKERS AND HOW THEY WORK
Box cookers, which can be made of cardboard, metal or plastic, with glass lids and aluminum foil or metal reflectors, trap heat from sunlight inside a sealed, insulated box and cook food in 2-3 hours at between 250-350 F. and often accommodate multiple pots. They are the most common solar cooker used worldwide. There are several hundred thousand in India, which has developed an official rating system for solar cookers. All solar cookers work with varying degrees of efficiency in hot or cool weather as long as the sun is shining.
Curved concentrator cookers or "parabolic cookers," cook fast at high temperatures and are excellent for boiling and frying. They require frequent adjustment and supervision for safe operation. Several hundred thousand exist, mainly in China. They are used in large rooftop arrays in India for institutional steam kitchens. The two most common types of parabolic cookers are the SK model that resembles a satellite dish and the two panel Chinese, or "butterfly" model. Other models are made by hand using small vanity mirrors. These cookers are also used for indoor cooking by focusing sunlight through a hole in the wall on cooking pots or burners inside a kitchen.
Panel cookers incorporate elements of box and curved concentrator cookers. They are small, lightweight, foldable, portable and relatively inexpensive to buy or make by hand. They work like a crock-pot, with temperatures ranging between 225 and 275 F. Most panel cookers are made from cardboard and aluminum foil. They require a lightweight cooking pot painted black with non-toxic paint. Raw food is placed in the pot, which is put inside a heat resistant plastic bag and placed in the cooker. Food cooks in 2-3 hours.
TRAINING AND INTRODUCTION OF SOLAR COOKER TECHNOLOGY: The introduction of solar cooker technology in the developing world requires a culturally sensitive approach. The technology is so radically different from traditional three stone cooking that it is sometimes perceived as magic or trickery the first time it is demonstrated. Trainers must work closely with respected females in the community to demonstrate the cookers and then test and refine local recipes produced in solar cookers before presenting the technology to the wider community. When financially possible solar cookers should be presented as an opportunity for income generation involving men and women. The manufacture and sale of the cookers, maintenance and repairs, spare parts, food drying and food preparation and sales can all provide new sources of income. Once solar cooks develop a "feel" for the intensity of available sunlight, depending upon the time of day, time of year, their latitude and the food being cooked, solar cooking is easy, healthy and fun. Solar cooking, when combined with efficient cook stoves and retained heat cookers dramatically reduces deforestation, indoor and outdoor air pollution and improves the health of women and children who gather wood and breath in the smoke of cooking fires on a daily basis.
SOLAR INSOLATION: Most countries located between 40 degrees north and south of the equator with at least six months a year of sunny dry weather have a high potential for successful solar cooking. The sun is most intense between 10:00 a.m. and 2:00 p.m., which is when breads and pastries should be baked. Several years ago, NASA created this link to their solar insolation database for use by solar cooker advocates: http://web.archive.org/web/20171223090218/https://eosweb.larc.nasa.gov/sse/. You can log on and create your own password to access data on the intensity of sunlight in selected regions.
SAFETY: Harmful food microbes, including bacteria and viruses, are killed when pasteurized (heated to 65ºC or 150ºF). Food cooks at 82ºC (180ºF) to 91ºC (195ºF), and is free from disease-causing organisms when fully cooked. Panel and box solar cookers cook food gently at temperatures just above these, so foods cook thoroughly, maintain moisture and nutrients, and rarely burn or overcook. With all cooking methods, certain bacteria can produce heat-resistant spores that germinate after food has been cooked and cooled. Cooked food should be kept at temperatures above 52ºC (125ºF). If cooked food is allowed to drop to temperatures between 52ºC (125ºF) and 10ºC (50ºF), these bacteria can spoil the food. Food that stays in this temperature range for more than four hours should be heated again to cooking temperatures before consumption or discarded. Cooks should always wash their hands before and after handling food. Utensils and pots should be washed with soap and water after each use.
SOLAR WATER PASTEURIZATION: Water can heated and made safe to drink in all types of solar cookers. Disease-causing organisms in water including Escherichia coli, Rotaviruses, Giardia and the Hepatitis A virus are killed by pasteurization—heating water to 65ºC (150ºF) for a short period of time. At around 70ºC (160ºF), milk and other foods are pasteurized. The WAPI (Water Pasteurization Indicator) a simple, reusable plastic tube containing a special soy wax that melts at 65 degrees centigrade can be used to indicate when water is safe to drink.
EXAMPLES OF COMMERCIALLY AVAILABLE SOLAR COOKER MODELS
Cookit - A low cost, low-tech, PANEL SOLAR COOKER developed by Solar Cookers International of Sacramento, California. It is made of cardboard and aluminum foil. It works like a crock pot and cooks food in 2-3 hours at between 225 and 275 f. Thousands of CooKits have been manufactured by female refugees in Iridimi Camp, eastern Chad. Projects in Kenya, Ethiopia and Sudan are also training women to make and use CooKits. Plans for the CooKit are available on line at the solar cooking archive (http://www.solarcooking.org/). CooKits can be purchased on-line from Solar Cookers International. Food is cooked in a low-cost, light-weight aluminum or steel pot widely available in the developing world. The pot is placed inside a heat resistant plastic bag (oven cooking bag) to retain the heat. If cared for properly a CooKit can last one to two years. The oven-proof cooking bags last about 30 days. Two used bags can be placed one inside the other to extend their usable life. The CooKit needs little attention, food will not burn. The user should rotate it once or twice during the cooking process to keep it facing the sun. It is easy and safe to use, only the black pot gets hot, the reflector does not. It is most convenient for the aged and handicapped. It never reaches a temperature high enough to burn wood, cloth or paper. Placing it a table keeps it away from animals. The cooking pot and lid must be painted black on the outside with non-toxic "blackboard paint" which is readily available in the developing world (in the U.S. we would use barbecue paint or just buy a black enameled pot).
Solar Hot Pot - A more efficient, durable, user friendly panel cooker inspired by the CooKit. It is currently manufactured in Mexico. Solar Household Energy, Inc.(SHE), a DC-based non-profit organization contracted the Florida Solar Energy Center to develop it. The Hot Pot can last for 5-10 years. It consists of 3 parts: a durable exterior glass bowl and lid, an interior black enameled steel bowl that is suspended inside the glass bowl and a reflector. The transparent glass lid allows the cook to see the food cooking; it can be lifted to add ingredients. There are two different reflectors available: (a) a cardboard one similar, but slightly larger than that of the CooKit; (b)a more durable one made from polished aluminum that folds up like a Japanese fan. The latter is more costly. The HotPot works like a crock pot, it reaches 275-300 F. It is easy and safe to use, nothing is hot to the touch except the black pot. Food will not burn, it needs little attention. The user should re-orient it towards the sun once or twice during the cooking period. It is more efficient than the CooKit.
Global Sun Oven -- This is a SOLAR BOX COOKER. The two models described above are panel cookers. The Sun Oven is manufactured in Illinois and can be used by campers and even ice fishermen in the winter. Some retirees use them in desert communities to roast, stew and bake during the summer months so they don't have to turn on their ovens. This box cooker model provides more insulation and is less affected by the ambient temperature or the wind than are the panel cookers described above. (Note that solar cookers work in cold weather--all they need is direct sun light). The box cooker can (depending on its size) hold more than one pot. You can see the food cooking if the pot inside has a transparent lid. The box cooker reaches temperatures between 325-375 f. in bright sun. The Sun Oven is relatively expensive-- $229 if ordered on line, but similar designs (which can be made of cardboard, wood, or other locally available materials) are available in the public domain on the solar cooking archive.
Villager Sun Oven – This is the mother of all solar cookers. It can bake up to 300 loaves of bread a day. The Villager is for large operations and is completely reliable, because it has a propane back-up. It is portable (it comes with its own trailer), durable and when used as a bakery, can save 150 tons of wood a year. Villagers are made to order in Illinois by Sun Ovens International and are10-12 thousand dollars. The donation of Villagers to community-based micro-enterprises in Afghanistan, South Africa and elsewhere have been funded primarily by Rotary Clubs.
SOS Sport -- This is another type of BOX COOKER. It is made of recycled soda bottles. Coca Cola donated the money to the Solar Oven Society to buy a mold to press out the black boxes and the clear lids. This one can hold two pots or a sheet of cookies. The Sport is relatively inexpensive--$149 with two pots. It is lightweight, easy to use. After a few years of extensive use, the plastic eventually begins to show signs of wear from sunlight.
Tulsi Hybrid -- This high-end HYBRID SOLAR BOX COOKER (which has electric back-up) is made in India and marketed in the U.S. with a few modifications. The Tulsi is very reliable because a thermostat can be set at a desired temperature. If the sun goes behind a cloud and the temp drops, the electric power kicks in to keep the temp steady. It is fairly expensive--$275 on-line. The box is designed to hold several small pots (designed for Indian cooking).
SK-14 This is a PARABOLIC SOLAR COOKER, it concentrates light on a small area at the bottom of the pot. The parabolic cooker generates as much heat as a stove top or an open fire at 400-500 degrees F. It can be used for boiling and frying. It cooks as fast as a wood fire. Versions of this model can be assembled locally; the reflective panels made from polished aluminum are made in Germany. Millions are used in South and East Asia, especially in China, which along with Tibet also use a modified parabolic cooker called a butterfly cooker. This model has also been successfully introduced in Somalia by a California non-profit called Sun Fire Cooking. Since only the pot gets hot and not the reflective dish, there is less likehood of burning than when boiling or frying over a flame. Parabolic cookers require continuous adjusting (about every ten to fifteen minutes) as the sun moves across the sky. They cannot be left unattended (but then neither can an open fire or a gas burner). People need more training in how to use these because of the possible risk from sun glare, burns and the requirement to adjust the angle every few minutes.
