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Revision as of 04:01, 28 March 2020

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Solar hot water system for a hotel in Parras de la Fuente, Mexico
Hotel Perote solar pool heating system. Parras de la Fuente is a desert oasis town of about 44,000 residents located in the south of the Mexican state of Coahuila. Along with textile manufacturing, tourism is one of the main industries in Parras. Tourism has become increasingly emphasized after Parras's designation as the "primer pueblo mágico del Norte de México." Parras is warm in the summer, and cooler in the winter, but temperatures rarely fall below freezing, snow falls once every several years.

Antiqua Hacienda de Perote is a hotel, restaurant, nuez (pecan) ranch, vineyard, and winery. It sits on about 500 acres on the western-most edge of Parras. According to Igancio (Nacho) Chacon, Perote's owner, Perote's hotel business has been growing rapidly, and in 2006, the hotel was constructing rooms to meet demand.

Parras Program students Heather Kuoppamaki and Rowan Steele built a rooftop solar hot water system for Hotel Perote in the summer of 2005. Intended as prototype for a larger system to heat a spring-fed swimming pool (alberca), then being constructed, the system was sized to provide heated water for a single hotel bathroom. The 2005 system is no longer located at Perote, and has been moved to the residence of someone afiliated with the local city government. Igancio has requested a system to keep the pool at 28° centigrade from October to March. The design problem revolves on this performance parameter and several state variables. Read more...


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Selected pages

1 through 20

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The Full Belly Project Universal Nut Sheller
What makes "appropriate technology" is determined by context. Therefore, none of these are absolute - they are simply common features that make a technology "appropriate" to a world where many suffer a lack of basic necessities, a lack of money, and lack of equipment and technological expertise. They are also technologies that have a gentle impact on the earth:
  • Small, as in Small is Beautiful. Small often means affordable and adaptable, and puts the control in the hands of the users. Small also means local, which offers benefits in resilience;
  • Few moving parts - less to go wrong (similar to the KISS principle).
  • Can be built locally;
  • Easily repaired, by local people with locally available equipment;
  • Affordable; and
  • Made with locally available materials.

Welcome to Appropedia/Selected page/2

There are four basic Hexayurt sizes which cover a variety of needs.
What is it? The Hexayurt is a refugee shelter system based on work done at the Rocky Mountain Institute. It uses an approach based on "autonomous building" to provide not just a shelter, but a comprehensive family support unit which includes drinking water purification, composting toilets, fuel-efficient stoves and solar electric lighting. Other systems can be added in a modular fashion.

Is this for real? Yes. Both the American Red Cross and the US Department of Defense have examined the Hexayurt system in detail and found that it has considerable merit and utility. I hope that we will see it in use by international agencies within two years.

The best place to get started is to read the slides from the presentation Vinay Gupta gave at the Pentagon in December 2006: Pentagon Presentation (pdf) - 20 pages, not much text, and the best summary of the system we currently have online. Read more...

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Rope pump upper construction
Rope pumps. Industrial hand pumps, such as the Indian Mark II, for communal wells donated by development projects often break down after two years. If maintenance costs are the responsibility of the users, then this cost is too high when repairs prove necessary and the pump is left nonfunctional.

An alternative reliable hand pump is needed for communal and private use to supply clean drinking water and irrigation. These pumps will raise the standard of living if they are low cost, reliable and pump water effectively. Efficiency is critical to irrigate a garden in the dry season due to the relatively large amount of water involved. Such gardens provide food and increased income.

Local affordability, maintenance and good pump efficiency are required features. Local affordability means a twenty-to-hundred-fold cost reduction compared to imported industrial goods. Local maintenance is only possible when made with local resources and skills. Read more...

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A treadle pump being demonstrated in Malawi.
A treadle pump is a human-powered Pump designed to lift water from a depth of seven meters or less. A Treadle is a lever device pressed by the foot to drive a machine, in this case a pump. The treadle pump can do most of the work of a motorized pump, but costs considerably less (75%) to purchase. Because it needs no Fossil fuel (it is driven by the operator's body weight and Leg Muscl]s), it can also cost less (50%) to operate than a motorized pump. It can lift five to seven cubic meters of water per hour from wells and Boreholes up to seven meters deep and can also be used to draw water from Lakes and Rivers. Many treadle pumps are manufactured locally, but they can be challenging to produce consistently without highly skilled welders and production hardware. Compared to bucket irrigation, the treadle pump can greatly increase the income that farmers generate from their land by increasing the number of growing seasons, by expanding the types of crops that can be cultivated, and improving on the quality of grown crops. Read more...

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Small Scale Vegetable Oil Extraction
Small Scale Vegetable Oil Extraction. Oilseeds are the major source of edible oils. The oil-cake remaining after the greater part of the oil has been extracted is a valuable source of protein for animal feeds. Nutritionally, oils provide the calories, vitamins, and essential fatty acids in the human diet in an easily digested form. Oils are used in cooking to enhance the flavour and texture of food. It has been estimated that while 30% of malnourished children in developing countries suffer from a lack of both energy-producing and protein foods, the other 70% suffer from a lack of calories which could be obtained largely from oils and fats. The per caput consumption of fats in tropical Africa is roughly one-quarter of that in North America. Only a small number of developing countries have surpluses of vegetable oils for export. Malaysia and Indonesia export palm oil, the Philippines export coconut oil, and Brazil and Argentina export soy-bean oil. In most developing countries, vegetable oils are in short supply with the rising demand due largely to population growth. The need to import uses up scarce foreign exchange. Read more...

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Awsome thermal curtains
How to make awesome thermal curtains.

Step 1. Measure the windows to be treated with thermal curtains. Be careful on how you convert your measurements into the fabric yard.

Step 2. Obtain the batting material and decorative fabric material. It is best if you can use recycled or sustainable material. Keep in mind that you want sturdy material that is not going to stretch or rip easily. Twill works best, while jersey is impractical.

Step 3. Wash the decorative fabric material before you fabricate your thermal curtains.

Step 4. Cut the batting material and the fabric out according to the measurements of the window, giving an allowance of 2 inches around the perimeter of the decorative fabric material. Remember, it is better to be a little over than too short.

Step 5. Pin the fabric on to the batting material so that it makes sewing easier. With the Warm Windows batting material, the fabric-side of the batting material must face the decorative-side of the fabric material. (more steps follow) Read more...

Welcome to Appropedia/Selected page/7

Surrey Hills house
Surrey Hills house. In 2001, my partner Lena and I were faced with the prospect of living in a dark and dingy 1930’s duplex “one of a pair” solid brick dwelling built in 1930, renovating it, or buying another house. The old house had a maze of small pokey rooms. We viewed the high cost of selling and buying property, where a lot of money goes to the “middlemen and the taxman”, as a waste of money. We were really keen to make maximum use of the sun for heating and natural lighting, and decided to go ahead with renovating. We prepared a detailed brief covering our requirements, with a strong focus on low environmental impact features. After discussing the project with Andreas and Judy Sederof from Sunpower Design, we felt confident that we could achieve what we wanted, although the site and the existing dwelling presented challenges. It soon became clear to us that the expertise and ideas that experienced “sustainable and solar efficient” architects provide is invaluable. Read more...

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After being hung up overnight in a breezy location, shirts worn once (even in the tropics!) smell quite fresh enough to wear again.
Washing and drying clothes. Washing and drying clothing are common activities that can use a lot of energy - if we aren't careful. But there are a lot of things, most importantly washing in cold water and line drying, which are not only greener, but will make your clothes last longer (as long as you don't leave them outside too long, to fade).

Why does it matter? - Energy usage: We need to use less energy with efficient washers and cold water (unless there is abundant solar hot water), and use renewable energy where possible.

Water usage: The more water we use, the harder it is to process the waste water, and the more strain we place on the water supply.

Water pollution: Minimize the use of detergent. Consider these words about the chemicals you use. Once people appreciate that they make other things dirty when they make their clothes clean, they think differently about what they're doing. Read more...

Welcome to Appropedia/Selected page/9

You can have a Green Christmas.
You can have a Green Christmas. Often the best time of year for catching up with family and friends, it's also the biggest time of spending - on presents, food, alcohol, parties and holidays. Unfortunately, all of our spending and consumption results in significant environmental damage and carbon pollution. However, you don't have to be a scrooge to reduce your carbon footprint at Christmas. Here are tips for a more sustainable festive season.

Buy a service, not a product: To reduce embodied carbon pollution and water consumption, think about buying someone a service - say a voucher for a massage, rather than a massaging appliance. Vouchers for other services, (such as gardening or housecleaning) or film and theatre tickets are also good. Beware gifts that will increase the recipient's motor travel.

Buy gift vouchers: Gift vouchers are a good thing for the environment. People use them to get exactly what they want. And they can use its value for a purchase in the store at any time after christmas. Make sure the validity is at least 6 months or a year, so that recipient will not forget to use it before it expires. (more tips follow) Read more...

Welcome to Appropedia/Selected page/10

CSA participants in New Hampshire
Community Supported Agriculture consists of a community of individuals who pledge support to a farm operation so that the farmland becomes, either legally or spiritually, the community's farm, with the growers and consumers providing mutual support and sharing the risks and benefits of food production. Typically, members or "share-holders" of the farm or garden pledge in advance to cover the anticipated costs of the farm operation and farmer's salary. In return, they receive shares in the farm's bounty throughout the growing season, as well as satisfaction gained from reconnecting to the land and participating directly in food production. Members also share in the risks of farming, including poor harvests due to unfavorable weather or pests. By direct sales to community members, who have provided the farmer with working capital in advance, growers receive better prices for their crops, gain some financial security, and are relieved of much of the burden of marketing. It is a form of local support for agriculture. Subscribers pre-pay a farmer to grow the desired produce. Sometimes the farmer will select what is to be grown, sometimes the buyer selects what they want to buy, more often it is a cooperative arrangement between the two parties. Read more...

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Arcata Educational Farm
Local food (also regional food or food patriotism) or the local food movement is a "collaborative effort to build more locally based, self-reliant food economies - one in which sustainable food production, processing, distribution, and consumption is integrated to enhance the economic, environmental and social health of a particular place" and is considered to be a part of the broader sustainability movement. It is part of the concept of local purchasing and local economies, a preference to buy locally produced goods and services. Those who prefer to eat locally grown/produced food sometimes call themselves "localvores" or locavores. Local food systems are an alternative to the global corporate models where producers and consumers are separated through a chain of processors/manufacturers, shippers and retailers. With an increasing scale of industrial food systems the control of quality is increasingly decided by the middlemen while a local food system redevelops these relationships and encourage a return of quality control to the consumer and the producer respectively. These quality characteristics are not only in the product but in the method of producing. Read more...

Welcome to Appropedia/Selected page/12

Arcata Educational Farm
Organic farming is the form of agriculture that relies on crop rotation, compost, biological pest control, mechanical cultivation, and other techniques using natural processes, to maintain soil productivity and control pests. Organic farming excludes or strictly limits the use of synthetic fertilizers, pesticides, and livestock feed additives. Genetically modified organisms are excluded, and organic standards in Britain and Australia exclude engineered nanoparticles.



Welcome to Appropedia/Selected page/13

Home made jelly on the window sill.
When I first thought of making jelly, I didn't realize that it was a definite challenge and art. When I visited with Eppel Beard, she made it look so easy. She gave no hint that it might be hard to make a perfect clear jelly with the colors vivid and beautiful that when taken from the jar would hold its shape. But when I tried to make jelly on my own for the first time, I chose a fruit low in pectin, put too much sugar in it and didn't cook it long enough. It turned out like syrup. I tried again and cooked it too long. When it hardened it made a very good candy. Soon I found my mistakes and tried again and it turned out all right. Like most people, I had thought that it wouldn't be very hard to make jelly because I reasoned, all I'd have to do was follow the recipe on the box of pectin. But Eppel said the real challenge is to make jelly like women did before the age of packaged products and commercial pectin, when they depended on the natural pectin and acid in the fruit. Read more...

Welcome to Appropedia/Selected page/14

Yeast Cakes from Hops
Yeasts for Baking. Generally when one mentions yeast, aromatic loaves of fresh homemade light bread come to mind. And so they should. Aside from acting as a leavening agent in bakery products, yeast is also the ingredient responsible for the tantalizing aroma that arises during baking.

Though probably today the most commonly known and used are store-bought packages of dried yeast, there are several other different kinds. The recipes that follow show two examples of different ways to make yeast--dry yeast cakes made from hops and an everlasting yeast "starter"--and also how the yeasts are used in making bread.

The dry yeast cakes are made in part by boiling the blossoms of the hop vine. These flowers contain a fragrant yellowish oil called lupulin. The use of this oil as a preservative in beer and as a narcotic drug originated in Germany before Charlemagne. Since then its use has become widespread and the vine cultivated in other nations, including America. Read more...

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Bathroom Toilet Unit
Bathroom Toilet Unit. Why? This is about the construction of Bathroom Toilet units affordably. It aims at improving sanitation in rural settings. This method is meant to be used in a communal project where inhabitants of a village can be motivated to build a private bathroom for every family around. To achieve this each family works on its own bathroom facility concurrently while sharing experience and guidance. A special construction method is used to permit this.

How? Properties of the Bathroom Toilet-unit:

  1. A comfortable space for bathing, also to be used for sanitation, nice looking, decorated, easy to clean.
  2. Sufficient space for a parent to bath a small child and to teach it the proper use of a toilet. (more steps follow)

Welcome to Appropedia/Selected page/16

Monolithic dome office
Monolithic domes are constructed following a method that requires a tough, inflatable Airform, steel-reinforced concrete and a polyurethane foam insulation. Each of these ingredients is used in a technologically specific way. This technology was developed by the Monolithic Dome Institute (MDI). The domes can be designed to fit any architectural need: homes, cabins, churches, schools, gymnasiums, arenas and stadiums, bulk storages, landlord dwellings and various other privately or publicly owned facilities. The dome, when finished, is earthquake, tornado and hurricane resistant (FEMA rates them as "near-absolute protection" from F5 tornadoes and Category 5 Hurricanes). MDI has also developed the technology to build so-called "EcoShells". These are simple structures to provide for the basic needs of a family. They are designed specifically to answer the needs of shelterless people worldwide. They are strong structures that can withstand natural disasters, fire, termites and rot. In underdeveloped areas with hot climates, EcoShells make affordable, low maintenance, sturdy housing. In industrialized nations, EcoShells make superior workshops, garages, storage sheds, etc. Read more...

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Monolithic dome office

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The First Rice Hull House
Rice Hulls in Construction. The rice hulls are unique within nature. They contain approximately 20% opaline silica in combination with a large amount of the phenyl propanoid structural polymer called lignin. This abundant agricultural waste has all of the properties one could ever expect of some of the best insulating materials. Recent ASTM testing conducted R&D Services of Cookville, Tennessee, reveals that rice hulls do not flame or smolder very easily, they are highly resistant to moisture penetration and fungal decomposition, they do not transfer heat very well, they do not smell or emit gases, and they are not corrosive with respect to aluminum, copper or steel. In their raw and unprocessed state, rice hulls constitute a Class A or Class I insulation material, and therefore, they can be used very economically to insulate the wall, floor and roof cavities of a super-insulated Rice Hull House. This paper also explains how the structure of such a house can be fashioned out of a variety of engineered lumber products derived from sugarcane rind. Read more...

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This is what it looks like when finished.
Welding wood. This is a technique to join wood using scrap tin, such as that from a used can. Needed materials include:

1. Two sticks of wood to be joined.

  • Make sure the wood is in good condition where the connection is to be made. It should be clean, no bits of bark or loose paint, and no knots, as they are too hard for nails.

2. Two pieces of thin tin.

  • For the first bond, use a knife for cutting the tin from a small can for example.
  • Length and width equal to the stick diameter. (more steps follow)

Welcome to Appropedia/Selected page/20

Solar heater
Solar hot water describes active and passive solar technologies that utilize the sun’s freely abundant solar thermal energy in order to heat water for a desired application. It is one of the most efficient ways to heat water (in terms of energy/waste), as it requires no energy conversion, unlike electric-resistance heating or fuel burning. It is a simple transfer and concentration of heat energy from one place to another. Another interpretation of the efficiency of the practice is that the solar energy is free, and only dependent on the extent of the technology used, and its cost and efficiency. In other words, the energy is free, only the collection, conversion, and storage devices cost. If you have ever felt hot water trickle out of a garden hose that’s been sitting in the sun, you’ve experienced solar hot water in action. Essentially, a solar hot water system is made up of a solar thermal collector, a well-insulated storage container, and a system for transferring the heat from the collector to the container vis-à-vis a fluid medium, which in some circumstances is the water to be used itself. Read more...

21 through 40

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The finished greenhouse!
Construction of an Affordable Greenhouse. The capstone project for Queen’s University 4th Year Mechanical Engineering Class,"Engineering for Sustainable Development", is to design and construct an Appropriate Technology with a quantifiable engineering result. This project is to construct a greenhouse, review the heat requirement on the system for the whole year; then, based on the materials and conditions selected, review costs associated with this and build a scaled model.

This project is the first step to easy community greenhouse development - the goal of the affordable greenhouse is to:

  1. Improve greenhose design and awareness for residential application.
  2. Demonstrate the feasibility (i.e costs) of a greenhouse in the winter months and determine the best time to install such a system for optimal crop yield.
Due to the materials selected and the cold Canadian Spring, it is not effective to construct until late April. But with better material selection and innovative greenhouse designs, it is hoped that constructing miniature greenhouses will become common practice. Read more...

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Passive water heater diagram
Thermosiphoning is considered to be an appropriate technology. This process utilizes natural, renewable resources and the basic laws of thermodynamics to create movement of a heated supply of air or water. The energy source for this process is solar radiation: the energy of the sun is captured in a solar collection device and is transferred to either air or water via conduction. The entire process may be explained by the thermosiphoning effect: When air or water is heated, it gains kinetic energy from the heating source and becomes excited. As a result, the water becomes less dense, expands, and thus rises. In contrast, when water or air is cooled, energy is extracted from the molecules and the water becomes less active. It also becomes more dense, and tends to "sink." Thermosiphoning harnesses the natural density differences between cold and hot fluids, and controls them in a system that produces natural fluid movement. The passive thermosiphoning of water is the process of heating and moving water within a system without the need or use of electricity. This process functions by utilizing natual phenomena such as solar energy, gravity, and an available water source. Read more...

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Earth bound radiation losses
The solar resource. Solar energy is the source of all energy on earth, available to us in a number of derivatives. Plant matter for example, which relies on solar energy for nutrition, experiences natural compression and decomposition over millions of years to form the the fossil fuels we use today for electrical generation and transportation. Other examples of this can be seen in use of biomass for fuel or the harvesting of wind energy which is reliant on solar heated air for the formation of currents. We are also able to utilize the solar resource directly. Solar thermal technologies take advantage of this resource to heat a working fluid that can transfer energy to an air stream or water for domestic or commercial use. Solar Photovoltaic or PV devices exploit various materials (principally Silicon) that experience sub-atomic variations when exposed to solar energy in order to induce an electric current. Both solar PV and thermal technologies provide a useful source of energy with little to no moving parts, no pollution and very little embodied energy. Read more...

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Direct and diffuse solar radiation (Practical Action)
Solar thermal energy. The sun is the source of the vast majority of the energy we use on earth. Most of the energy we use has undergone various transformations before it is finally utilized, but it is also possible to tap this source of solar energy as it arrives on the earth’s surface.

There are many applications for the direct use of solar thermal energy, space heating and cooling, water heating, crop drying and solar cooking. It is a technology which is well understood and widely used in many countries throughout the world. Most solar thermal technologies have been in existence in one form or another for centuries and have a well-established manufacturing base in most sun-rich developed countries.

The most common use for solar thermal technology is for domestic water heating. Hundreds of thousands of domestic hot water systems are in use throughout the world, especially in areas such as the Mediterranean and Australia where there is high solar insolation (the total energy per unit area received from the sun). As world oil prices vary, it is a technology which is rapidly gaining acceptance as an energy saving measure in both domestic and commercial water heating applications. Presently, domestic water heaters are usually only found amongst wealthier sections of the community in developing countries. Read more...

Welcome to Appropedia/Selected page/25

The Kitjito Windpump
Windpumps. Windpower technology dates back many centuries. There are historical claims that wind machines which harness the power of the wind date back to the time of the ancient Egyptians. In Europe the first windmills were seen much later, probably having been introduced by the English on their return from the crusades in the middle east or possibly transferred to Southern Europe by the Muslims after their conquest of the Iberian Peninsula.

The first half of the 20th saw further development, particularly a move toward propeller type wind machines for electricity production. By the 1920's 6 million windpumps were being used in the USA alone and their manufacture and use had become commonplace on every continent.But the glory of the windpump was short-lived. With the advent of cheap fossil fuels in the 1950's and 1960's and the development of pumping technology the windpump became almost obsolete in the USA.

There are manufacturers in several developing countries now producing windpumps. The uptake of wind machines for water pumping, however, has been generally very slow even though the technology is well suited to the demand of many regions of Africa, Asia and Latin America. Read more...

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DC circuit analogy: 1 Tank 2 Parallel Blenders

Electricity basics. Some basic definitions, equations and analogies of electricity. Read more...

Welcome to Appropedia/Selected page/27

Micro hydro scheme showing the power house, the penstock and the transmission lines
Microhydro power. Water power can be harnessed in many ways; tidal flows can be utilized to produce power by building a barrage across an estuary and releasing water in a controlled manner through a turbine; large dams hold water which can be used to provide large quantities of electricity; wave power is also harnessed in various ways. It is a technology that has been utilized throughout the world, by a diverse range of societies and cultures, for many centuries. Water can be harnessed on a large or a small scale. Micro-hydro power is the small-scale harnessing of energy from falling water; for example, harnessing enough water from a local river to power a small factory or village. This fact sheet will concentrate mainly at micro-hydro power. In the UK, water mills are known to have been in use 900 years ago. Their numbers grew steadily and by the 19th century, there were over 20,000 in operation in England alone. In Europe, Asia and parts of Africa, water wheels were used to drive a variety of industrial machinery, such as mills and pumps. The first effective water turbines appeared in the mid 19th century and it was not long before they were replacing water wheels in many applications. In contrast to water wheels and the early turbines, modern turbines are compact, highly efficient and capable of turning at very high speed. Hydropower is a well-proven technology, relying on a non-polluting, renewable and indigenous resource, which can integrate easily with irrigation and water supply projects. Read more...

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The Geysers in Northern California.
Geothermal power is generated from the high temperatures that can be found in various parts of the earth's crust such as volcanoes, hot springs, and geysers. The water that surrounds and fills the gaps between the rocks in the crust is raised in temperature by these natural processes. This hot water is then pumped to the surface and its steam is captured and used to create electrical power through a turbine system.

There are three common types of geothermal power: dry steam, flash steam, and binary cycle. Dry steam is rare and uses the steam directly from the earth, flash steam pumps the hot water that naturally occurs in the earth to the surface and utilizes its steam, and binary cycle uses a secondary fluid and its vapor to power a generator.

Dry stream geothermal plants use natural steam directly from the Earth. Once the steam pocket is tapped, the steam is channeled directly into a turbine which converts the thermal energy into electrical power. (more types follow) Read more...

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Preparing the trap
GEM mosquito control. This method of mosquito control involves the use of water containers inside/outside households as well as other buildings, regularly replaced to kill mosquito larvae. It is well known that mosquitoes lay eggs in water where ever it be. It is also equally true that they visit human dwellings as well as cattle/bird sheds for feeding usually from dusk to dawn and they cannot complete their reproductive cycle without animal protein. Exploiting these weaknesses one could achieve mosquito control. For that provide a few micro water bodies around the building using household utensils. Destroy larvae as & when they appear.

By two months one gets tangible reduction in mosquito problem. This experience has repeated at many sites. Further research unearthed the reasons for the magnificent result produced in a short span of two months.

This can be easily extended to larger areas with people’s participation as well as cooperation & guidance from concerned agencies like the WHO and the perennial & apparently unsurmountable problems like Mosquito menace & Malaria, Dengue fever & a host of other problems can be solved once for all. See also Some history. This tall claim is based on the confidence given by the three decade long experience in the matter. Read more...

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The chief medicinal property of horsetail is its high silica content. The best dietary source of silica is whole grains-meaning much of our dietary silica is lost in the refining process. In addition to silica, horsetail contains large amounts of potassium as well as aconitic acid, equiaitinee, starch and many fatty acids. Horsetail is often used for mending broken bones. Our hair, skin, nails, and bones all need silica. Silica gives our cells strength, durability, and flexibility.

Think about walking outdoors on the grass. You put a lot of weight on the little blades of grass, but they spring right back up again. This is because of the high silica content in the grass. Silica enables the blades of grass to be resilient and bend, yet not be broken. Without silica, our bones would be very brittle and break easily. The same is true of hair, skin, and nails. Without enough silica in our diet, our hair can be brittle and break easily, causing split ends.

Without enough silica, our skin loses its elasticity. Without enough silica, our nails become very brittle and split. As horsetail is very, very high in silica, it feeds our hair, skin, and nails along with our bones and keep the cells in these systems strong and resilient. Read more...

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Fixed dome digester
Biogas and liquid biofuels. Biomass residues can also be converted into various non-solid fuel forms. These fuels are referred to as biogas and liquid biofuels. The aim of this conversion process is to improve the quality, specific energy content, transportability, etc., of the raw biomass source or to capture gases which are naturally produced as biomass is micro biologically degraded or when biomass is partially combusted. Biogas is a well-established fuel for cooking and lighting in a number of countries, whilst a major motivating factor in the development of liquid biofuels has been the drive to replace petroleum fuels. In this fact sheet we will be looking at some of these fuels, their applications and the conversion technologies used to derive them. In Europe and the United States, as well as in several developing countries, there is a move toward cultivating energy crops specifically for the production of biomass as a fuel. The potential for energy production from biomass throughout the world is enormous and as fossil-based fuels become scarcer and more expensive, as carbon emission levels are becoming of greater concern and as people realise the benefits of developing integrated energy supply options, then biomass could begin to realise its full potential as an energy source. Read more...

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Luggage carrier for transport bicycle
Luggage carrier for transport bicycle. Bicycles are used for transporting bulky and heavy loads. It is trickey to do this in a way that it is still possibe to pedal the bicycle. In practice sometimes special racks are permanently attached to the bicycle. Such racks may hinder the more normal use of this bicycle. Moreover normal bicycles are not build to take heavy loads over rough roads. Special bicycles for heavy loads are not generally available. An alternative could be a load carrier characterized with the following: the load does not rest on the frame of the bicycle, but is transferred directly to the wheelaxles; it is easy to mount and remove the load rack; such a load rack can be made by the user and adapted to the load to be transported. The load rack should not be in the way to push the loaded bicycle or to ride it. To make sure that the load put on the bicycle is mainly transferred to the wheel axle, straps are attached where the wheel axles are bolted to the bicycle frame. These straps are made by winding some thin wire around frame and axle and twisting it into a loop. In each strap fits the tapered end of a straight stick roughly one and half a meter long. Read more...

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Covered bike racks at Fabrica La Estrella
Parras transportation gallery. There appear to be hundreds of bicycles hung on a series of covered bike racks at Fabrica La Estrella, just inside the entrance to the fabrica (factory). The bicycles are unlocked. The racks were manufactured in Torreón. Active non-motorized transportation offers benefits to its users' health, the community at large, and earth's climate. Covered bike racks, specifically, offer bicyclists greater status (as people worthy of finding a dry seat when they go to use their bike), and make bicycle parking a more emphasized part of the landscape. Improving the status of bicyclists is particularly important in Parras, as the bicycle is identified as a poor person's vehicle, and they are afforded little respect on the road. Drunk driving is rampant on weekends. It happens that on the morning of 4 June 2006, a bicyclist was run over early in the morning. In such accidents, as in this case, the driver most frequently does not stop. If covered bike racks are to truly improve the status of bicycles, however, they must be installed outside of the factory, as in this location they are intended to serve the the lower-class labor force of the factory exclusively, and are invisible to the greater community. Issues include the factory labor practices, waste water, etc. Long distance travel using bikes can be difficult. Also, bikes require frequent maintenance, whereas cars require less frequent but more costly maintenance. Read more...

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The new and improved Marsh
AEF greywater. For our final project we rebuilt a greywater system at the CSA, Arcata Educational Farm. Greywater consists of all used water produced at a particular site, except for water coming from the toilet, which is known as blackwater. When building a greywater system you first separate the greywater from the blackwater and send the greywater through a separate treatment system. Ideally, after the greywater passes through the purification process it will then be able to be reused. Greywater systems are an appropriate use of technology for many reasons. Some of them being: they reduce the use of fresh water, there is less stress on existing more conventional septic tanks, it is a highly effective purification process, and there is less chemical and energy use required. In our case the majority of water used on the farm is to water vegetables, herbs, flowers and fruits, and the source of greywater comes from the outdoor kitchen, used by the farmers and volunteers to cook and wash vegetables or dishes. Read more...

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Aerial view of the marsh.
Arcata Marsh overview. The Arcata Wastewater Treatment Plant is responsible for the treatment of the sewage for the city of Arcata. The Arcata Marsh and Wildlife Sanctuary is a part of the system that cleans our waste in preparation to be released back into the water cycle. The system as a whole is the wastewater treatment plant (WWTP). The Arcata Wastewater Treatment Plant personnel maintain 11 wastewater pump stations as well as all of the equipment, motors, and pumps associated with the plant. They also are responsible for the operation and maintenance, of the 55 acres of oxidation ponds and 154 acres of treatment and enhancement marshes. The Arcata Marsh and Wildlife Sanctuary is a constructed wetland and is part of the Arcata Wastewater Treatment Plant. This use of constructed wetlands is what separates the Arcata Wastewater Treatment Plant from other Wastewater Treatment Plants. The first treatment plant was built in 1946 and discharged unchlorinated primary treated wastewater into the bay. Read more...

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Sarah the hardest worker who is always chuggin' away.
CCAT yurt rainwater catchment. The long history of rainwater collection, can be traced (in recorded history) as far back as ancient times some 3,000 years ago (850 BC) if not even farther. The need for water is a basic human essential for maintaining life, without it, no civilization could have prospered. Rainwater collection in ancient Constantinople is one of the last megalithic structures of its kind. The CCAT Rainwater Catchment Group consists of: Sean Colley, Matt de Young, Jessica Radtkey, Sarah Shimizu, and Tiesha Whittaker. Our project for ENGR 114 was to build a rainwater catchment system around the yurt at CCAT on campus at Humboldt State University. The purpose of the rainwater catchment system is to capture and store rainwater in a large storage drum for use to water plants on the CCAT grounds. Water is a resource that is always present around us but not always in an immediately useful form. Therefore, it is necessary that we use innovative and appropriate techniques to capture and transform the water that we have into a useful form of water for our needs. Read more...

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Sectional view of sand dam

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Foundation of the underground tank (copyleft Practical Action/Douglas Gumbo)
Underground rainwater storage facilities. Rainwater storage tanks are more important in semi arid areas than any other areas because they are useful in storing limited water supplies for agricultural purposes. In semiarid regions, where precipitation is low or infrequent during the dry season, it is necessary to store the maximum amount of rainwater during the wet season for use at a later time, especially for agricultural supply. One of the methods frequently used is the underground storage tanks. The in situ technology consists of making storage available in areas where the water is going to be utilised. All rainfall-harvesting systems have three components: a collection area, a conveyance system, and a storage area. In this application, collection and storage is provided within the landscape.

Consider five main factors when designing your underground tank.

  1. Seepage
  2. Evaporation
  3. Length of the dry spell
  4. Daily usage
  5. Construction costs

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Kiva's straw bale greenhouse
Kiva's straw bale greenhouse. Welcome to our straw bale greenhouse. The following page will take you with us on our greenhouse building adventure. We will discuss the process, what worked best and did not work, problems we had, how much time it took to build, and the money spent on the project. Over all we hope that this is a fun and comprehensive look at what we did to make this project come together. The reason that we chose to build a straw bales greenhouse is that both Scott (my building partner) and I would like to get into alternative building as a career and we thought that this would be a good place to start and learn from. To build a straw bale greenhouse where Kiva can grow chili peppers, tomatoes, and lots of other yummy warm weather plants. The reason we decided to build with straw bale was to gain experience with this material and the great insulative value of it. Scott and I decided to have two of the walls straw bale and the other two wood and glass. Where we live no permits are required for a 10' x 12' greenhouse, so we decided these would be the inside dimensions. To receive optimal year-round sun in our area the glass on the south facing wall is at a 40 degree angle. At the building site there is plenty of morning sun and not much evening sun so we opted to have our east side be glass and our west side be straw bale. Read more...

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41 through 60

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Appropriate Technology Engineering 305 class
Parabolic basket and tin can solar cooker. The objective of this project is to create a solar cooker out of local invasive species and waste materials. We want to create a device that can pasteurize water and be an alternative to the use of fossil fuels for cooking food. Our criteria for evaluating the appropriateness of technology are: use of local materials, efficiency, durability, ease of use, ease of construction, cost, impact on environment, impact on culture/lifestyle, education or expertise needed for construction. Overall this was a successful project. We were able to meet our goal of pasteurizing water. The solar basket can pasteurize water in a quart container in about an hour with optimal conditions. If we were to make the solar basket version 2.0, here are some changes we would make: 1. double up the blackberry runners so that the ribs of the basket are stronger; 2. use another material instead of pampas grass because it causes lumps on the basket's surface, maybe something softer; 3. use all large can lids, of the shiniest quality; and 4.construct the rings that hold the parabolic shape out of a less flexible material than the aluminum and wire that we found. Read more...

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The Earthen Ox Oven at the Blue Ox Mill
Blue ox earthen oven. The earthen oven at the Blue Ox Millworks in Eureka, California was constructed in 2004 by Appropriate Technology (Engr305) students at Humboldt State University. The project took four, three-hour work sessions to complete over a total of four weeks. As of 2007 it is still standing, is in immaculate condition and retains nearly the same heating efficiency as when it was first constructed. This page includes information on the construction of the Blue Ox earthen oven and information and updates on its current condition.

Earthen Ovens have been used for thousands of years by cultures all over the world and they are still built today by people all over. Earthen ovens are made up of just that, EARTH! Sand, clay and straw are used in building these versatile ovens.

An earthen oven can be used to cook the same things cooked in a normal household oven, so long as you can fit it through the door! Often Earthen Ovens are somewhat unique from other ovens in that they don’t have a fire burning continuously to cook with. The oven is heated before any cooking is going to take place. Generally Earthen Ovens are fired for a few hours and the hot coals are then scraped out of the interior. Once the coals are scraped out, the oven is ready to cook in. Read more...

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CCAT natural paint project
CCAT natural paint project. The Campus Center for Appropriate Technology (CCAT) at Humboldt State University in Arcata, CaliforniaW is completely remodeling the inside of their building. When all of the construction is finished the entire interior of the house will need to be painted. As an ENGR 305 project, Spring 2007, Andrea Lanctot and Jill Anderson have decided to make all the interior paints from scratch using safe natural ingredients. The project has four main goals. The first is to research natural paint ingredients, recipes, and techniques. The second is to make several of the recipes and test the paints for color, durability, and texture. The third is to choose paints from the tests for the new CCAT house and apply them to the interior. The last goal is to test the final application with the test of time. See natural paint basics for background research on ingredients, types and advantages/disadvantages of natural paint. Read more...

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Homemade ethanol still to compare ethanol from local organic sugar beets and from imported refined cane sugar
Ethanol from organic sugar beets versus refined cane sugar. The purpose of my project is to determine the cost inputs and energy outputs of small scale ethanol production from local and conventional sources. I decided to use local grown organic sugar beets farmed with bio-fueled agricultural equipment. In comparison to the costs of a local source, I also used conventional sugar transported from Mexico and sold at a local restaurant supply company. In addition, I made Amal's ethanol still to do the testing. Ethanol is a grain alcohol that can be used as fuel in most four cycle spark ignition engines. The process of making ethanol begins by extracting the sugars from a sugar crop such as sugar beets, or converting the starches of crops such as corn or potatoes to sugars. Crops used for ethanol production are titled "feed stocks". Starch and sugar crops both have their benefits depending on the region that they are produced in. The benefit of sugar crops is that they require less energy input since no starches need to be converted. The benefit of corn is that it can store much longer than sugar beets before rotting. I am using sugar beets since they were the most appropriate crop for the season and region. The sugars are extracted by juicing the beets and boiling with water. Now the solution is called "mash" and it can be fermented and then distilled to extract the ethanol. Read more...

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Finished Vermicomposting System
CCAT's Vermicomposting Bin. I am very excited to be posting directions for building your very own home vermiculture bin! The methods employed will produce a bin appropriate for a household of 3-5 people and should last a number of years if constructed properly. There of course are many types of bin designs out there and I wanted the creative opportunity to design my own. In looking for ideas in a gardening magazine, I noticed a pentagon shaped planter for gardens whose shape I really liked. A pentagon is also practical because compost is less likely to get stuck in the corners as often happens in normal square shaped boxes, preventing the organic materials from cycling properly. I decided to make a two-part stackable bin so that using the finished compost would be easier. Once the compost is processed it is easy to take off the top section, dump the compost in the garden, and put it on top to be filled again. The partitioned design is also improves aeration to speed up the composting process. Aeration is also provided by the holes drilled in the sides of the bin. The bottom of each bin section is finished with wire mesh to keep the compost in place. The holes of the wire mesh are large enough to allow worms and microbes to enter the system and speed up decomposition. The top is simple plywood cut to size with a brass handle and L-brackets to keep the lid in place. The bin was lastly finished with natural organic linseed oil as a sealer for endurance in the elements and general durability. I hope you enjoy! Read more...

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Prototype of Nutsy
FBP Nutsy. The Full Belly Project (FBP), has designed a Universal Nut Sheller (UNS) that are distributing throughout West Africa and Haiti. The UNS shells large amounts of nuts in a fraction of the time that it would take a single person.

Our Engr215 Introduction to Design class from Humboldt State University was divided into seven teams, each consisting of four members. Each team was given one of three assignments:

  • Create a smaller version of the UNS to be marketed in the US in order to fund FBP's efforts abroad.
  • Find a way to make a UNS out of cheaper, lighter and more sustainable materials for the countries of West Africa.
  • Find a way to make molds out of recycled plastic bags for the working parts of the UNS using extremely limited resources in Haiti.
Our team worked on the first of these assignments by redesigning the UNS to be marketable in the United States. Read more...

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Wild Chick Farm
Wild Chick Farm. In the fall of 2005 Sarah Brunner and Shail Pec-Crouse, started a commercial pastured chicken operation in Arcata, California. The first four months see update of business were spent learning from other successful models, experimenting with different equipment, suffering through trials and tribulations, getting our hands bloody and planning improvements to our system. Throughout it all we have been guided by our core values of humane husbandry and sustainability. We began with a very small flock of 175 birds and decided to try two different models of raising them on pasture to see which model worked the best for our situation. We compared the two models by looking at efficiency, loss to predators, land impact cost, fossil fuel use and mobility which strongly effects efficiency, land impact and fossil fuel use. After working with both models for a couple of months we came to the conclusion that the Chicken Tractor (CT) model is most appropriate for raising meat chickens and the Hoop House (HH) model is more appropriate for raising laying hens. The CT is better for meat production because it is more cost effective and mobile and there is less predation. The CT is also important for pasturing laying hens for their first few months since there are less predator risks. The Hoop House is better for egg production because it accommodates nest boxes and roosts. Read more...

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Building a very hot parabolic solar cooker using pedal power tools.
Notice how the focus is the same for the various parabolas.
Aleiha's parabolic solar cooker. The paraboloid is an interesting shape with some amazing qualities. It has the power to concentrate light, electronic waves, sound, etc. to its focus at the center. To find the focal point of a paraboloid, one must use the formula, [math]y=p*x^2[/math], where p is a constant. The variable y is the depth of the dish, and x measures the distance from the center axis to the maximum circumference of the dish. You have to pretend that there is an x axis going through the center of the base of the dish and a perpendicular y-axis passing from the center of the base of the dish to the focal point. The two numbers, x and y, represent a point on the paraboloid, and from that, you are able to determine where the focus is. Parabolic cookers have been used for centuries now. The idea to concentrate light using curved mirrors was developed by the Greeks, Aztecs, Incas, Romans and Chinese. The Incas used bronze and gold for their mirrors and they built structures that were several stories high. This technology seems to have appeared around the same time for each of the civilizations. It is thought that Archimedes harnessed the technologyW to defend Syracuse from invading Roman fleets in 212 BC. Read more...

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RFVB large.jpg

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Solar Charged Lawnmower
Solar Charged Lawnmower. An electric lawnmower that utilizes solar power as an energy source will address a number of issues that standard internal combustion engine mowers do not. An electric lawnmower with a solar charger will be easier to use. There is no messy dangerous gasoline to deal with. It will eliminate those pesky trips to the gas station for fill-ups. Just plug the mower into the charging station when not in use and it will be charged and ready for your next mow! Most importantly it eliminates the emissions of an internal combustion mower.

The basic idea is to convert an older non-working gas mower into an electric powered mower by replacing the gas engine with an electric motor that runs from a 12 volt battery. This battery will be charged using photovoltaic panel (A.K.A. - solar panel). I chose to convert an old gas mower rather than just starting with an electric mower due to cost and so I could design the power output. I also planned on using as many used materials as I can. This will help to save these materials from ending up in our already over filled landfills.

I would like to claim that I came up with this solar charged electric mower idea on my own but the truth is I came across an article about one in a "Home Power" magazine (Issue 107) a while back and have wanted to build one ever since. When the opportunity arose to use it as a project in my Engineering 305 class at Humboldt State University I jumped at the chance. Read more...

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The CCAT Wash n' Flush
Painstakingly photoshopped diagram of the Wash n' Flush
CCAT Wash n Flush. The Wash n' Flush is a Humboldt State University environmental science 410 senior project implemented by Jeffrey Steuben, Annie Welbes and Tim Dower which is located in the downstairs bathroom at CCAT. This is a toilet modification that allows users to save water by utilizing the wastewater from handwashing to flush the Toilet.

If you think of this project as a way of doing a DIY version of an Aqus Toilet, you'd be mostly right. These are also commercially popular in Japan.

The goals of our project were: conserve drinkable water by eliminating the use of clean, potable water to flush toilets; break down social stigma around toilet water pre-use; build awareness of creative water conservation; make toilet modification replicable, accessible, and affordable to low income households; and conserve water at CCAT.

We thought about the fact that clean, drinkable water is being used to flush human waste down the toilet. We consider this to be environmentally and socially irresponsible. Therefore, we took action. Read more...

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M2-B2 Rocket Stove
Concept Art of The WaterPod (thewaterpod.org)
WaterPod Rocket Stove. The M2-B2 Rocket Stove promotes sustainability through demonstration and education while on the WaterPod in New York City. The stove is designed to provide a reliable and sustainable means of cooking by minimizing fuel use and optimizing efficiency. The WaterPod is a project being put together by a group of artists and engineers. This project is going to take place in New York City, in which a group of artists are going to live on a barge for six months traveling down the Hudson River promoting sustainability. The WaterPod will stop off in the five boroughs of New York and allow the public to tour the barge. The WaterPod has worked with the Engineering 215 - Intro to Design class at Humboldt State University to create sustainable projects for the WaterPod. Team Mel Brooks was assigned the task of creating an efficient means of cooking that can be utilized for the duration of the project. Team Mel Brooks created a rocket stove, which will optimize biomass as a fuel source to cook for The WaterPod. Read more...

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An LED traffic light
LED traffic light FAQ. Here are a number of frequently asked questions concerning retrofitting street lights with LEDs. For full information see LED.

What does an LED traffic light look like? An LED traffic light looks very similar to a regular traffic light. It still gets the job done and is actually brighter. An LED is actually very small and therefore the traffic light is made up of a bunch of smaller lights, this is apparent when you look closely. The color of the light depends on the exact composition inside the bulb.
Who Invented the LED? It all began when Oleg Vladimirovich created the first LED in 1927. There was no practical use for it until 1962 when it was discovered that the infrared LED could be changed into a visible red LED.
How does an LED work? An LED is basically a tiny light bulb with a semiconductor diode in place of a filament. Inside the diode, there are positively and negatively charged areas. When a voltage is applied to the diode with the positive end hooked up to the negative area and the negative end hooked up to the positive area the electrons inside become excited and jump from the positively charged to negatively charged areas. This interaction produces light.

What is a diode? A diode is a component that restricts the directional flow of charge carriers. In other words, a diode allows an electric current to flow in one direction, but blocks it in the opposite direction.

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Sustain to the music! :-)
Environmental songs. Below is a list of Songs with and Environmental Theme - something to listen to while you are working on Appropedia:

Blues: Global Warming Blues

Country: Jimmy Buffet - Wheather with YOU · Jimmy Buffet- Volcano · Jimmy Buffet - A salty Piece of LAnd

Folk Rock: Big Yellow Taxi by Joni Mitchell · Politik by Coldplay · Hagen - Mother Nature · Dave Matthews Band - Too Much · Antarctica by Joanne Rand · Fire and Rain by James Taylor · Waiting on the World to Change by John Mayer · Hearts And Hands by Stele Ely · On The Clothesline by Stele Ely

Funk: Jamiroquai - Emergency on Planet Earth

Heavy metal: Biotech is Godzilla by Sepultura · Steel Prophet- Environmental Revolt · Sepultura - Old Earth

Hip hop: New World Water by Mos Def · Atmosphere · Michael Franti & Spearhead - Is It Love Enough? · Ozomatli- Coming War · Earth Song by Michael Jackson · Ice MC - Look After Nature

Ja: Spirit- "Fresh Garbage"

Indie: Lay Me on the Water by Gavin DeGraw, from the indie album "Gavin Live" ·

Nature Anthem

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Open source 3-D printing of OSAT. There have been a number of open source 3D printers, such as the RepRap developed. The basic idea for this project is to use them as tools to create OSAT in the field to help the goals of sustainable development. Prices on 3D printers are dropping rapidly.

An example of how these 3D printers can be used to meet these goals is the DremelFuge. The Dremelfuge is brilliant Open Source Hardware project developed by Cathal Garvey in Ireland. The DremelFuge is a printable rotor for centrifuging standard microcentrifuge tubes and miniprep columns. It is at least 10 times less expensive than a standard centrifuge and can be used by field workers in doing things like blood tests, but also by DYI biologists and educators. It requires industry standard 1.5ml/2ml Eppendorf/Microcentrifuge tubes.

  • Used with a drill at 3000 RPM, the Dremelfuge will deliver over 400g, enough to comfortably spin down Miniprep samples (proven personally). It will likely achieve acceptable results at lower speeds, too.
  • Used at 10krpm, on a Rotary tool for instance, a Dremelfuge should deliver over 4400g, more than enough to spin down bacterial cells.
  • At 16krpm, Dremelfuge matches commercial centrifuges.
  • On a Dremel 300, a maximum speed of 33krpm equates to a force of over 50,000 times earth's gravity, which puts it into so-called "Ultracentrifuge" territory. The latest version (as printed by Shapeways) has successfully spun tubes at this speed. Read more...

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Chicken tractors
The name "chicken tractor" is somewhat misleading, since no conventional motorized devices are used. A chicken tractor is little more than an open-bottom cage for chickens, which is light enough to be moved on the ground from location to another.

The chickens live in the chicken tractor and scratch, eat, and defecate on the ground surface. This process turns over the shallow surface, hence the 'tractor' reference. As the surface is sufficiently worked by the chickens, the tractor is moved to another space, repeating the process. The consumption of plants, seeds, and insects reduces plant growth and insect population, and the defecation nourishes the soil. Conventional chicken houses produce a volume of chicken waste with very high Nitrate concentration, which will burn many plants if used directly and therefore must be composted. The chicken tractor eliminates these handling and processing needs.

A chicken tractor will work on any flat surface with a substrate that supports plants and insects. Its main benefits are that it is a means of having free-range chickens and its attended benefits, but with better control/protection of the chickens. Moving it around permits more localized vegetation management, and keeps chickens out of gardens. Read more...

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Human-powered nebulizer
In remote areas and resource-limited settings, clinics may lack expensive, electric nebulizers to induce sputum samples for tuberculosis diagnosis and respiratory treatments. We have developed two versions of the Human Powered Nebulizer. One is hand-cranked; the other is pedaled like a bicycle. The health care provider operates the HPN while the patient induces a sputum sample or receives treatment. This technology is inexpensive and portable, putting respiratory treatment and diagnostics in the hands of even the most remote clinics. Read more...

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