archopotamus: November 2011

Sunday, November 20, 2011

NREL Passive Solar Homes Case Studies

A "passive" solar house keeps the home warm in the winter by storing and distributing the sun's heat and cool in the summer by blocking the sun's ray. A comfortable indoor temperature is maintained without the use of mechanical equipment. For passive heating and cooling, the plan of the house, careful site selection and planning, construction materials, building features and other aspects of the home must be carefully considered before design even begins. Passive solar houses can be built in any architectural style and in any part of the country.
More: http://www.nrel.gov/buildings/passive_solar.html

NREL Commerical Case Studies of Low-Energy buildings

NREL studied six commercial buildings in detail over a four-year period to understand the issues related to the design, construction, operation, and evaluation of the current generation of low-energy commercial buildings. These buildings and the lessons learned from them helped inform a set of best practices—beneficial design elements, technologies, and techniques that should be encouraged in future buildings, as well as pitfalls to be avoided. The lessons learned from these six buildings are also used to guide future research on commercial buildings to meet DOE's goals for the development of highly energy-efficient buildings. For more information, read "Lessons Learned from Case Studies of Six High-Performance Buildings PDF

." Detailed research reports are available on the High Performance Buildings Database for the case study project buildings.

StoCoat Lotusan

StoCorp picked up on the cleaning-power of a lotus—a plant with a unique hydrophobic microstructure that forces water droplets to bead and roll off its leaves—to improve the lifespan of numerous hard-to-clean materials such as stucco, concrete and other exterior wall finishes. The company’s Solit Lotusan exterior coating paint, with its patented “Lotus Effect” has super-hydrophobic properties and miniscule peaks and valleys on the its surface, making it highly resistant to water, dirt, mold, mildew, chalk and even UV rays. Stolit Lotusan paint can help surfaces stay dry and clean, and could help decrease maintenance cleaning and water costs for building owners.
The StoCorp’s “Lotus Effect” coating, coined by botanist Dr. Wilhelm Barthlott, was introduced into the European market in 1999 and has now been applied to more than 300 million square feet of façade surfaces. Available in more than 38 colors and custom tints, Stolit Lotusan can be used to coat over prepared vertical concrete, masonry or plaster substrates. More info: www.stocorp.com

Dyesol solar cells

Dye Solar Cell
Using a dye similar to the chlorophyll found in green leaves, the Dye Solar Cell (DSC) prototype by Dyesol departs from the more traditional silicon-based solar cells by working to mimic the photosynthetic processes of plants. Dyesol’s technology creates an artificial photosynthetic process by inducing a charge between a titanium dioxide semiconductor and an electrolyte solution. Then it builds the technology into small tiles that compose panels, which can be installed anywhere that might accommodate the conventional photovoltaic panels. Dyesol argues that the DSC is a sustainable answer to the commonly used silicon-based solar cells, which require large amounts of energy to produce.
The Australia-based company has a working prototype and is aiming to license its technology. It reported in June 2009 that it received an order for more than $788,500 of Dye Solar Cells to a subsidiary of Malaysia-based Petronas, a Fortune Global 500 company. Dyesol also sells the photosynthetic dyes and other components on its Web site. More info: www.dyesol.com

Pioneering Solar Buildings | via wikipedia

http://en.wikipedia.org/wiki/List_of_pioneering_solar_buildings

Trombe wall / solar chimney / passive heating

via Wikipedia - Common modifications to the Trombe wall include:

Exhaust vent near the top that is opened to vent to the outside during the summer. Such venting makes the Trombe wall act as a solar chimney pumping fresh air through the house during the day, even if there is no breeze.
Windows in the trombe wall. This lowers the efficiency but may be done for natural lighting or aesthetic reasons. If the outer glazing has high ultraviolet transmittance, and the window in the trombe wall is normal glass, this allows efficient use of the ultraviolet light for heating. At the same time, it protects people and furnishings from ultraviolet radiation more than do windows with high ultraviolet transmittance.
Electric blowers controlled by thermostats, to improve air and heat flow.
Fixed or movable shades, which can reduce night-time heat losses.
Trellises to shade the solar collector during summer months.
Insulating covering used at night on the glazing surface.
Tubes or water tanks as part of a solar hot water system.
Fish tanks as thermal mass.
Using a selective surface to increase the absorption of solar radiation by the thermal mass.
Also: Barra System

Panelite ClearShade Insulating Glass Unit

Just as the hub of a bee hive is the honeycomb, the hub of New York-based Panelite’s ClearShade insulating glass unit is its “tubular polycarbonate” core. Modeled after the hexagonal structure of a honeycomb, ClearShade’s core limits sunlight coming through glass thereby reducing heat gains as well as energy costs. Because light rays can only make it through when they hit the glass perpendicularly, the sun is most obscured when it is highest in the sky. At midday, ClearShade has a low shading coeffcient and a low solar heat gain coefficient—which Panelite touts as “four times better than a typical insulating glass unit.”

The honeycombed glass glaze was first used in the entryway of the McCormick Tribune Campus Center at the Illinois Institute of Technology, and was last year installed in the new JetBlue terminal at JFK International Airport. The ClearShade insulating glass unit can be glazed different colors, and its unique structure can give logos or patterns a three-dimensional effect.
More info:
www.e-panelite.com
IGU Catalogue.pdf
Bonded Catalogue.pdf

Eastgate Centre, Harare - Mick Pearce

The "termite mound building".
Eastgate Centre, Harare - Wikipedia, the free encyclopedia

http://inhabitat.com/building-modelled-on-termites-eastgate-centre-in-zimbabwe/
Because of its altitude, Harare has a temperate climate despite being in the tropics, and the typical daily temperature swing is 10 or 40 °C. This makes a mechanical or passive cooling system a viable alternative to artificial air-conditioning.