ABE Contributes to Winning Design of the "Gable House"

Published Oct 20, 2009

The Gable House 2009 U of IL Solar Decathlon 2009 2nd Place Team

You can read more about the competition and the University of Illinois team at their website:

http://www.solardecathlon.uiuc.edu/

Members of the Department of Agricultural and Biological Engineering (ABE) played an important role in the design and construction of the “Gable House,” the University of Illinois solar house that took second place in the 2009 Solar Decathlon design competition sponsored by the U.S. Department of Energy.

The DOE hosts 20 college and university teams from around the world and challenges the students to design, build and operate the most attractive and energy-efficient solar home. The competition took place on the National Mall in Washington, D.C. from October 8th through October 18th.

Xinlei Wang, an associate professor in ABE, was the mechanical systems adviser for the 2009 competition. Mark Adams, a graduate student in ABE, was the student lead for all mechanical systems in the house, such as hot water, appliances, and heating, ventilation and cooling systems. Adams personally constructed the HVAC system from scratch.

When designing and constructing the home Adams said, “The team wanted to focus on simple design concepts and simple engineering. That’s not to say simple is easier. Many times it’s actually harder to take the simple approach. But we really wanted to stress conservation, reliability and cost-effectiveness.”

Adams said most people think of solar panels when they think of energy efficient homes. “Solar panels focus on generation and they are very expensive, so they don’t have the quickest payback. There are other, smaller systems that focus on conservation, such as the heat pump hot water heater we used in the house. It has a very quick payback. You can save a few hundred dollars every year, and the system only costs about $700, so there’s about a three-year payback on that alone.”

Adams said the home’s performance in the objective division of the contest proved how well all the systems worked. The competition includes tests in 10 categories. Five are objective (hot water, appliances, comfort zone, home entertainment and net metering) and five are subjective (architecture, market viability, engineering, lighting design and communications).

U of I dominated the objective division, taking first place in three of the categories (hot water, appliances and home entertainment) and second place in two of the categories (comfort zone and net metering).

“All our systems worked well,” said Adams. “They were very reliable and they proved our design intent.”

U of I also took second place in one of the subjective categories, lighting design.

The U of I team was in first place at one point in the competition, but Germany moved ahead when it received a perfect score (150 points) in the biggest category, net metering. Net metering measures a home’s energy use. The U of I Gable House used a 9-kilowatt solar energy system and produced four times the energy it needed, earning 137 points. But Germany’s house was covered in black solar panels. Using an 18-kilowatt system, it generated a surplus of power even during three days of rain.

Mark Taylor, architecture professor and project manager, said Illinois “just couldn’t beat a house wrapped in solar panels,” but team members pointed out on the team blog site that taking “second place in net metering with a PV array HALF the size of the winning team is truly impressive.”

Other features of the Gable House included 10 inches of high-performance insulation in the walls, roof and floor, laminated bamboo (a strong, renewable wood) used for structural elements, and high-efficiency lights and appliances.

Adams said many people who came through the house were impressed with its comfort. “It’s a little deceiving from the outside. It looks small. But once people came inside they thought it was large and very spacious. They could see themselves living in the house. That’s always a good thing to hear.”

Overall, the Gable House was the second most affordable structure in the competition. When the house returns to Champaign, it will be installed by a pond near I Hotel, with prairie landscaping around it.

“It will be interesting to see the final use of the house,” Adams concluded. “I’m just glad it’s coming back to campus to stay.”

News Writer: Leanne Lucas

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