Saturday, January 23, 2010
Beginning Stages Chicken Pox
bioclimatic architecture.
The use of solar energy through passive elements is nothing that the recovery of planning and construction in line with the climate. The fundamentals of the construction under the sun simply coincide with the physical laws of radiation, uptake, accumulation and distribution of heat. Historical examples-emerged at a time without an excess supply of technical aids, and show us many times those principles which unfortunately we have forgotten and now we strive to rediscover as the passive use of solar energy.
The use of solar energy through passive elements is nothing that the recovery of planning and construction in line with the climate. The fundamentals of the construction under the sun simply coincide with the physical laws of radiation, uptake, accumulation and distribution of heat. Historical examples-emerged at a time without an excess supply of technical aids, and show us many times those principles which unfortunately we have forgotten and now we strive to rediscover as the passive use of solar energy.
The Passive Solar Architecture , also known as bioclimatic includes modeling, selection and proper use of passive solar technology , to maintain a home environment at a comfortable temperature through the sun, every day of year. As a result, minimizing the use of active solar technology, renewable energy and especially the fossil fuel technologies.
passive solar architecture is only a small part of the design of energy efficient buildings, which in turn, is another part of sustainable design , although these terms often erroneously used interchangeably.
A bit of history.
What is now called passive solar heating systems were used for the first time in Greece 2500 years ago. Systematic foundation for the Greek cities and residential home was carefully designed according to the cardinal points and designed with the aim of ensuring both summer and winter, optimal microclimate conditions and a comfortable climate inside.
A few centuries later, in Rome, using solar energy for heating villas and bathhouses. The Greeks and Romans were obliged to apply the hot sun as provider to mitigate the energy crisis of his time. The use of wood for fuel has led to deforestation of many regions and that, therefore, serious environmental damage occur.
In 1940, architect George Fred Keck, designed what is now considered the first modern passive solar house ( Sloan House ) in Chicago. Keck had designed a house fully glazed to the Century of Progress exposition and marveled that, on sunny days in winter, the temperature was very pleasant inside, even before you have installed heating. Other solar houses were built also in this decade, but the passive use of solar energy is not found wide acceptance or assessment.
In the last decade, however, the need to seek an alternative to oil and natural gas, has led the national interest about solar heating in many European countries.
Elements of passive solar heating system.
A passive solar heating system is completely determined by five elements. Each serves a separate function, but the five elements must work together and be harmonized so that the system can work.
-collector collectors are large areas of glass (or plastic) through which sunlight enters the building. The collectors should face south (in the northern hemisphere and north in the southern hemisphere), with a maximum deviation of + / - 30 ° of the exact address and during the heating period should not be in the shade other buildings or trees, at least for a time between 9 and 15 hours.
-absorber absorber is the dark surface of the accumulation element. This surface, which can be a facing, the ground or a container of water, is located in the place of incidence of sunlight. Solar radiation reaches the surface and is transformed into heat.
-accumulator accumulator acting as materials or construction materials those items that by its high specific gravity absorb heat that is produced on the absorber due to solar radiation. These materials are called accumulating mass (thermal mass ). The difference between the accumulator and the absorber, which are often together on the same system of construction-absorber is that it can only function as a free surface, illuminated by the sun, while storage mass that acts as a constructive element from the absorber can be heated by thermal conduction.
-Distribution is the method by which solar heat is conducted from the place of recruitment and accumulation at different parts of the house. A purely passive system uses only three natural methods of heat transfer: conduction, convection and radiation. In some systems, the heat distribution is aided by fans, pipes and compressors (hybrid systems).
-Regulation
In principle, the adjustment is made by heat shock moving parts, it depends on the performance capabilities of the entire system. The moving parts prevent heat shock during the night heat losses by those surfaces of glass through which, day, it produced heat radiation. Other elements that have both a cooling and prevent overheating, for example:
electronic measuring devices, for example, a differential thermostat that connects a fan.
openings adjustable dampers that allow or choking the flow of heat or facilitate ventilation natural.
overhanging eaves or awnings that shade the collector surface during the summer months.
physical configurations.
solar system is called a passive one in which heat energy flow is by natural means, ie using radiation , thermal conduction and convection natural. Passive systems are distinguished from the assets of the lack of mechanical pumps or fans, which are needed to maintain the flow of fluid through heat exchanger forced. Many times the elements of the system have a great relationship with the elements architecture can perform several functions at once. For example, a window facing south, is used to capture heat, while providing exterior views, natural lighting and ventilation (control). The building's walls also serve to both heat accumulation and supportive construction.
solar system is called a passive one in which heat energy flow is by natural means, ie using radiation , thermal conduction and convection natural. Passive systems are distinguished from the assets of the lack of mechanical pumps or fans, which are needed to maintain the flow of fluid through heat exchanger forced. Many times the elements of the system have a great relationship with the elements architecture can perform several functions at once. For example, a window facing south, is used to capture heat, while providing exterior views, natural lighting and ventilation (control). The building's walls also serve to both heat accumulation and supportive construction.
direct solar gain.
sunlight entering the space to be heated, is transformed into heat absorbent surfaces and is dispersed to different surfaces and volumes delimiting space. The direct solar gain involves the use of windows, skylights and shutters to control amount of solar radiation reaching the direct inside a house. Use sun screens with high floor combined mass is a simple example of such use.
Traditionally, these direct solar gain systems have not been well considered, especially by the high cost of the crystals were well insulated with R-values \u200b\u200bcomparable to the isolation of the walls. This is radically changing in Europe, where there are windows superaislantes to help implement the standard German passive solar house.
indirect solar gain.
indirect solar gain is obtained through the skin of the building, which has been designed with a thermal mass (such as a water tank or a solid wall covered with glass). The heat accumulated by this mass is transferred into the building indirectly by driving or convection . Examples of this technique are: Trombe wall, water walls, or installing small pond on a roof. The roof garden is also a representative example.
In practice, these systems are often critical of which are difficult to control, besides the high price of insulating glass.
Isolated solar gain
isolated gain passive involves capturing heat from the sun, and later transported within or outside the home using to do a liquid (such as a thermal sensor equipped with thermosyphon ) or air (a solar chimney) or both (a heat store ).
The solariums, greenhouses and solar cabinets are alternatives to achieve an isolated heat gain we can harness the hot air.
passive solar design strategies.
guidance in construction. Taking into account the weather local, you can build a house facing so that it receives as much annual solar radiation, avoiding shadows in winter and protecting it from excess radiation in summer. You can also use techniques based on vegetation cover.
Construction Features. The shape of the building and its surrounding determine the amount of surface exposed to solar radiation, adjusting it to the desired needs. The properties of selected construction materials, serve to regulate the absorption, reflection or transmission of the captured energy. Using
environment. The use of natural elements like trees and plants can be useful to create zones of cooling in summer and a wind shield in winter.
Although not classified into passive solar technologies, the use of thermal insulation materials are widely used for reducing the losses or gains unwanted heat.
The evolution of Passive Solar Architecture
design constructs based on passive solar architecture comes from the ancient times and has been linked to the traditional architecture of many countries. In the developed world, although they have continued to be used in rural communities or by enthusiastic people have been ignored by industry construction until the end of s. XX.
Despite the lack of interest, passive solar technologies were taken up and improved in the last third of the twentieth century coincided with the 1973 oil crisis. The introduction of technology computer aided design and appearance of buildings also helped pioneer.
In the early twenty-first century, the issue has gained renewed interest, mainly due to the already visible consequences of global warming.
levels of use of passive solar design.
Pragmatist: A house could save the order 30% or more in heating costs without modify its appearance, comfort or usability. This can be achieved through proper status of windows, small contributions of thermal mass and good insulation. A south-facing wall can receive the rays of the sun during the day, accumulating heat and loosen it at night. Seasonal
Pragmatist: A house could save the order 30% or more in heating costs without modify its appearance, comfort or usability. This can be achieved through proper status of windows, small contributions of thermal mass and good insulation. A south-facing wall can receive the rays of the sun during the day, accumulating heat and loosen it at night. Seasonal
Traditionally, passive solar technology has focused on daily cycles of accumulation / radiation heat to maintain optimum temperature can be maintained for several days even in the absence of sunshine. Recent research has developed techniques to build up the heat in hot or detach months later in cold seasons. These techniques require large amounts of thermal mass usually located in the ground about 7 feet deep and well insulated to prevent heat loss by weather or water. In the cold months to retrieve the heat conducted through plastic pipe by inserting it into the heating housing.
minimum Machinery: A pure passive solar home should not incorporate any mechanical or electrical element to be considered as such. You should only use the energy radiated by the sun and receive only indirectly to the heat produced by elements such as light bulbs, candles, stoves, household appliances, showers, people or animals. The use of natural ventilation mechanisms not involving fans or other devices, are typically included within these techniques, although not considered strictly passive solar design. References
Passive solar building design (Wikipedia)
Building with the sun. Using passive solar energy
A brief history of solar architecture
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