- Passive solar
: "For the application of passive solar technologies in buildings, see
passive solar building design ."Passive solar technologies are means of using sunlight for useful energy without use of active mechanical systems (as contrasted to
active solar ). Such technologies convert sunlight into usable heat (water, air, thermal mass), cause air-movement forventilating , or store heat for future use, with little use of other energy sources. A common example is asolarium on theequator -side of a building.Passive cooling is the use of the same design principles to reduce summer cooling requirements. [http://www.PassiveSolarEnergy.info]Technologies that use a significant amount of conventional energy to power pumps or fans are
active solar technologies. Some passive systems use a small amount of conventional energy to control dampers, shutters, night insulation, and other devices that enhance solar energy collection, storage, use, and reduce undesirableheat transfer .Passive solar technologies include direct and indirect
solar gain for space heating, solar water heating systems based on thethermosiphon , use ofthermal mass and phase-change materials for slowing indoor air temperature swings,solar cooker s, thesolar chimney for enhancing natural ventilation, andearth sheltering .More widely, passive solar technologies include the
solar furnace andsolar forge , but these typically require some external energy for aligning their concentrating mirrors or receivers, and historically have not proven to be practical or cost effective for wide-spread use. 'Low-grade' energy needs, such as space and water heating, have proven, over time, to be better applications for passive use of solar energy.Advantages and comparisons to active solar
Passive solar systems have little to no operating costs, often have low maintenance costs, and emit no
greenhouse gases in operation. They do, however, need to be optimized to yield the best performance and economics.Energy conservation reduces the needed size of any renewable or conventional energy system, and greatly enhances the economics, so it must be performed first. Passive solar technologies often yield highsolar savings fraction s, especially for space heating; when combined with active solar technologies orphotovoltaics (for example, to power pumps or fans), even higher conventional energy savings can be achieved.fact|date=July 2008See also
External links
* [http://www.eere.energy.gov/de/passive_solar_design.html Passive Solar Design]
* [http://www.solarbuildings.ca/ Canadian Solar Buildings Research Network]
* [http://www.greenbuilder.com/sourcebook/PassiveSol.html www.greenbuilder.com Passive Solar Design]
* [http://www.eere.energy.gov/de/passive_solar_design.html www.eere.energy.gov US Department of Energy (DOE) Guidelines]
* [http://www.ornl.gov/sci/btc/apps/ www.ornl.gov Oak Ridge National Laboratory (ORNL) Building Technology]
* [http://doerr.org/services/residential-checklist.html Residential Green Building Checklist]
* [http://doerr.org/services/commercial-checklist.html Commercial Green Building Checklist]
* [http://nmsea.org/Curriculum/Courses/Passive_Solar_Design/Guidelines/Guidelines.htm Passive Solar Design Guidelines]
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