On September 10, 2009 and showing the marvel of technological inventions that are already an essential part of the life of the social being in the face of global needs and that are, in addition, if they are used appropriately, friendly with the environment and the environment, the group “Engineers without Borders” proposed the celebration of a world day dedicated to appropriate technologies, which has been celebrated every July 15 since 2010, AIM registered.
When talking about appropriate technologies, reference is made to the appropriate use of certain technologies, that is, to the application in the specific functions for which they were developed. Appropriate technologies are also those that are developed according to the availability of resources where it will be used and their sustainability to avoid unnecessary expenses, prioritize needs and improve the standard of living according to the cost-benefit of each technology.
Appropriate technologies are also the ways of doing, learning and solving problems, adapting to people's abilities. What is sought with appropriate technologies is to provide each population with the appropriate instruments for the performance of their daily tasks, to avoid the importation of expensive models or technologies that are not adapted to the needs of the regions.
The Appropriate Technology concept emerged in the 1970s in response to the limitations of traditional technologies and the problems for poor countries due to the importation of expensive technologies.
These technologies must be adapted to the economic, social and environmental conditions of the region, using materials found there to facilitate their maintenance and repair.
In many cases, hand in hand with appropriate technologies, there are problems due to the scarce knowledge about the region and the damages that it can present to the environment or to society, a specific technology, therefore, an analysis of the impact must be carried out. that its introduction will have in the social, economic and environmental field.
Characteristics of appropriate technologies
- Little investment of money
- Use of materials available in the region
- More productive than traditional technologies
- They can be done without the need for a high level of education
- They can be produced on a small scale
- They are flexible, they adapt to the context in which they are carried out
Adobe (including the variation called Super Adobe), embedded earth, Dutch brick, and cobs can be considered suitable technologies for many developing countries, as they use materials that are widely available locally and relatively cheap. Consideration should be given to the local context, such as with mud bricks which may not last long in an area of heavy rainfall (although a large roof and cement stabilization may be used to correct this), and if the materials are not are readily available, the method may be inappropriate. Other forms of natural construction can be considered suitable technologies, although in many cases they may place more emphasis on their sustainability than on their cost or suitability.
The Architecture for Humanity organization also incorporates the principles of appropriate technology, dedicating itself to meeting the needs of impoverished and disaster-affected populations.
“Right” energy technologies are especially well suited for small-scale and / or isolated needs. In any case, the high capital investment must be taken into account.
Electricity can be supplied from solar panels (which are initially expensive, but simple), windmills or micro-hydro installations, with energy storage in batteries.
Biobutanol, biodiesel, and straight vegetable oil may be suitable as direct biofuels in areas where vegetable oil is readily available and cheaper than fossil fuels.
A generator (running on biofuels) can work more efficiently if it is combined with batteries and an inverter; This significantly increases the capital cost but reduces operating costs, and can potentially represent a cheaper option than wind, solar and micro-hydro.
Biogas is another potential source of energy, especially where there is an abundant supply of organic waste.
The term soft energy technology was coined by Amory Lovins to describe suitable renewable energy.
The Light Up the World Foundation uses white led lights and renewable energy sources such as solar panels to provide lighting to impoverished populations in remote areas, representing significant advantages compared to the kerosene lamps they replace.
The Safe Bottle Lamp is a safer kerosene lamp designed in Sri Lanka. Its greatest security consists of a screw-on metal cap, and two flat extensions on the sides that prevent it from rolling if it is tipped over.
Ventilation and air conditioning
Natural ventilation can be created by creating grilles in the upper part of the building to allow warm air to rise by convection and escape to the outside, while cold air is drawn in through other grilles in the lower parts.
The solar fireplace often referred to as a heated fireplace enhances this natural ventilation by using passive solar heated air convection. To maximize the cooling effect, the incoming air can be led through underground ducts prior to entering the building.
A wind catcher (Badgir; ??????) is an Iranian architectural device used for centuries to create natural ventilation in buildings. It is unknown who invented the wind catcher, but it can still be seen in many countries today. Wind catchers can have various designs, such as unidirectional, bidirectional and multidirectional.
The passive downdraft cold tower can be used in arid and hot climates to provide air conditioning in a sustainable way. The water is evaporated at the top of the tower, by means of evaporative cooling holes or by spraying water. Evaporation cools the incoming air, causing a drop of cool air that reduces the temperature inside the building.
According to its supporters, Right Technology can greatly reduce the tasks of preparing food, compared to traditional methods, while still being much simpler and cheaper than the processes used in Western countries. This reflects E. F. Schumacher's concept of “intermediate technology,” that is, technology that is significantly more efficient and expensive than traditional methods, but is still an order of magnitude (10 times) cheaper than technology in the developed world. Some key examples are the Malian peanut sheller, the fonio sheller machine, and the unscreened beater mill.
Smoke-free and wood-saving stoves promise higher efficiencies and less smoke, resulting in savings in time and labor, reducing deforestation, and with significant health benefits. Briquettes can convert organic waste into fuel, saving money and / or collection time, thus preserving forests.
Solar cookers are suitable for various situations, depending on the climate and cooking style.
Rocket burners improve energy efficiency and reduce indoor air pollution.
The phase change incubator, developed in the late 1990s, represents a low-cost way to incubate microbial samples for healthcare workers.
Note that many appropriate technologies benefit public health, especially by providing safe drinking water and sanitation. Refrigeration can also provide health benefits.
The Jaipur leg was developed by Dr. P.K. Sethi and Masterji Ram Chander in 1968 as an inexpensive prosthetic leg for victims of landmine explosions.
The pot-in-a-boat refrigerator is an African invention that keeps you cool without electricity. It facilitates the preservation of food and the production of cold in the longest possible way. This can be of great benefit to the families who use it. For example, it is said that young women who had to sell perishable fresh produce can now go to school instead, since it is less urgent for them to sell their produce before they spoil.
The right technology for water supply includes the hippo water roller, which allows you to carry more water with less effort; the collection of rainwater (which requires an adequate method of storage, especially in areas with marked dry seasons); and mist harvesting, suitable for areas where mists abound even when rain is scarce.
Developed and used in southern Africa, the round play pump harnesses the energy of children when playing to pump water, although its cost of thousands of dollars does not make it a low-cost option.
Hand pumps and pedal pumps are more suitable for the developing world than motor pumps, in general, and can provide better quality water with less transport time than surface water sources; although, even handpumps often give problems, failing and falling into disuse due to lack of maintenance. Pedal pumps for domestic irrigation are now widely distributed in developing countries. The principle of Local Maintenance and Operation is important for hand pumps, but can be difficult in application.
Water generally needs treatment before being used, depending on the source and the desired use (with high requirements for drinking water). The water quality of domestic connections and community waters suggests that in low-income countries they are not reliable for direct human consumption. Water drawn directly from surface waters and from shallow wells drawn by hand almost always requires treatment.
The appropriate technology options for water treatment include both community-scale and domestic-scale designs of the place of use.
The most reliable way to kill microbial pathogens is to heat the water to a boil. Other techniques, ranging from filtration, chemical disinfection, and exposure to ultraviolet radiation (including solar UV) have been shown, in a series of randomized controlled trials, to significantly reduce the levels of waterborne diseases in low-income countries. income.
Over the past decade, [when?] An increasing number of field studies have been undertaken to determine the effect of site-of-use measures to reduce waterborne diseases. The ability of site-of-use options to reduce disease is a function of both their ability to eliminate microbial pathogens if properly applied, and social factors such as ease of use and cultural appropriateness. These technologies may generate greater (or less) health benefits than the results of laboratory-based microbial kill might suggest.
The current priority of supporters of site-of-use treatments is to reach large numbers of low-income users on a sustainable basis. Few measures of place of use have reached a significant scale, although efforts to promote them and the commercial distribution of these products in the impoverished world has only been developed in a few years.
On the other hand, small-scale water treatments are reaching significant fractions of the population in low-income countries, especially in South and Southeast Asia, in the form of water treatment kiosks (also known as water treatment stations). water refill or packaged water producers). While quality control and certification at these locations can be varied, sophisticated technologies (such as multi-stage particulate filtration, UV irradiation, ozonation, or membrane filtration) are increasingly being applied. These microenterprises are able to sell water at extremely low prices, with increasing government regulations. Initial monitoring of the quality of the water sold is being encouraged.
Some examples of specific treatment processes, both applied at the domestic and community levels, are:
- Porous ceramic filtration, using both clays and diatomaceous sands, and carried out both by means of cylinders, pots or discs, with feeding systems by gravity fall or based on siphons. Silver is often added to provide an antimicrobial enhancement.
- slow sand filtration intermittently operated, also known as biosand filtration.
- chlorine disinfection, using calcium hypochlorite powder, sodium hypochlorite solutions, or sodium dichloroisocyanurate tablets (NaDCC).
- chemical flocculation, using either commercial forms of iron or aluminum salts or through the crushed seeds of certain plants, such as Moringa oleifera
- mixing flocculation and disinfection using commercial powder mixes
- irradiation with ultraviolet light, both produced by electric lamps and by direct sunlight
- membrane filtration, using vacuum fiber ultrafiltration or reverse osmosis filters preceded by pretreatment.
BiPu is a portable system suitable for disaster management, while other forms of latrines represent safe ways to deposit human excrement at low cost. The Orangi Pilot Project was designed on the basis of an urban sanitation crisis in shanty towns. Kamal Kar has documented latrines developed by Bangladeshi farmers once they became aware of the health problems of open defecation.
The reed bed can help purify sanitation and greywater.
Ecological sanitation can be seen as a three-step process that deals with human excreta:
(3) Recycling. The goal is to protect human health and the environment by limiting the use of water from salty systems for hand (and anal) cleaning, washing alone, and recycling nutrients to help reduce the need for synthetic fertilizers in the farming.
The SanPlat is a simple plate that is used to cover the hole in the ground of a pit latrine.
The whirlwind wheelchair provides mobility to people with reduced mobility who cannot afford the expensive wheelchairs used in developed countries.
The bicycle provides human-powered transportation for all purposes, at a lower cost to its owners than motorized vehicles, with many benefits over walking.