From the outside, there is nothing unusual about the stylish new gray
and orange row houses in the Kranichstein District, with wreaths on the
doors and Christmas lights twinkling through a freezing drizzle. But
these houses are part of a revolution in building design: There are no
drafts, no cold tile floors, no snuggling under blankets until the
furnace kicks in. There is, in fact, no furnace.
I didn't have a chance to see the inside of their solar home. There were long lines every day I was there. Anyway, a couple of excellent features of this solar home. Not only they have incorporated high-tech, but also low-tech using the passive energyof the sun to condition and conserve energy of the house.
The louvers on east, west, and south sides planted with solar cells that provides energy while shading. It even have a tracking system that according to the Solar Decathlon booklet "..automatically tilts the louvers to follow the sun during the day, maximizing the shading and power from the louvers."
The first time I saw University of Maryland solar home, I knew it that they would somehow win something. For a regular consumer like me (not a solar geek), their architectural design is what attracted me the most. The concept they use LEAF house system using off-the-shelf energy efficient technology today.
Their idea is that - this is something that could easily be mass produced. The analysis shown that through mass production, a typical 2 or 3 bedroom up to garden apartment could be had for $228 per s.f. for the competition version [800 s.f.] and larger for $180 per s.f. for larger version.
LIQUID DESICCANT SYSTEM
The most innovative feature for University of Maryland is the liquid desiccant wall system or indoor waterfall that acts as dehumidifier. The answer for dealing with DC famous 'humidity' problems in the summertime.
The basic idea is to use a material called a desiccant (in our case a type of salt called calcium chloride) to absorb water directly from the air without all the complicated machinery and energy requirements of conventional AC. As the desiccant absorbs water, it becomes diluted and its ability to dry the air declines. The desiccant needs to be regenerated. This can be done by simply heating up the desiccant and letting the water evaporate to the outside air. Thus, the desiccant is concentrated and ready to return to its job of drying the indoor air. LEAFHouse uses heat from the Solar Hot Water collectors to regenerate the desiccant.
I also like the fact that they use a flexible series of movable, translucent panels that transform a small house to larger space. You don't really feel cramped living in a small space. It gives you that flexibility whenever you want it to create a bigger room. This idea can be applied in a loft style home.
SANTA CLARA UNIVERSITY
A cute little house, California style. Big porch. They're one of the five teams that received 100 points for energy balance and hot water contest. The team uses eletrochromic windows. These are windows that can be darkened or lightened electronically with the use of a switch. Another innovation is a combination of solar thermal unit that can be used for space, water heating and air-conditioning and PV panels that are integrated to the siding of the house to charge batteries for this event.
BAMBOO I JOIST
I think their most innovative idea is bamboo I joist. This is the only house that uses bamboo, a sustainable building material. Information on their website is quoted as "on average bamboo I-joists can support up to 10,390 lbs before bending or breaking; making bamboo by far the strongest grass we have ever heard of."
In addition to being strong, bamboo is an exceptional sustainable building material for multiple reasons: 1) As a grass, bamboo replenishes itself in 5-7 years, compared to the 30-50 needed by hardwood 2) Some bamboo species can grow up to 2 feet each day 3) Bamboo produces 4 times as much lumber as an equivalent plot of hardwood 4) Bamboo retains its root structure when harvested, meaning new shoots regrow from the old stalk 5) This root structure controls water flow and alleviates soil erosion through bamboo forests and farmlands
Other sustainable building materials they use, bamboo floors and finishes. It's all renewable, sustainable material bamboo.
All of the teams, twenty of them, deserves a 'standing ovation.' Each of the team brings cool ideas that we all can adapt into daily uses. A simple idea like using fan ceiling to help circulate the cool air in the house. That doesn't cost a fortune, right?
By the way, all of the decathlon homes were designed to be off-grid. Of course, they have the option to tie it to the grid.. after the completion of the competition.