UrbanEden Built by UNC
The University of North Carolina at Charlotte built a beautiful concrete and glass, high-performing home for this year’s Solar Decathlon. The home was the overall winner of the coveted People’s Choice Award.
UrbanEden also won 1st place in Energy Balance, generating more solar energy than the house needed or used, 3rd place in Engineering and 4th place in Hot Water. The overall cost of the house with all the appliances included was estimated to be $350,686.
The exterior of the home was made from a concrete and fly-ash mixture. Because concrete is such a dense material, it acts as a thermal break between the sounds of the city and creates a serene, indoor living space. Within the precast concrete panels were a circulatory system of small diameter plastic tubes. Depending on the season, cooled or heated water can be sent through the tubes to help moderate the temperature of the home. During the warmer summer evenings, the ambient heat is expelled through copper fin heat exchangers located on the roof.
The Solar Decathlon truly tests a home’s performance. In order to receive a score in the Entertainment event, each team must host two dinner parties and screen an accompanying film. This tests the home’s general electrical systems and the combined efficiency of the appliances. They aren’t sitting around saving electricity and using candles. They’re watching films on large screen TVs, moving the solar panel arrays to create the ideal evening deck shading space, baking apple-brie tarts, making multi-course meals and leaving the lights on. It was all powered by the sun. Here are the Dinner Menus and Recipes from the University of North Carolina at Charlotte (21 page pdf).
Even with the house filled to the brim with visiting students, the house exuded a sense of calm.
- The pre-cast geopolymer cement concrete structure reinvents a historic building material to provide a sound barrier to city noise and a 90% reduction in carbon footprint over conventional concrete.
- A retractable solar photovoltaic panel rack, which remains over the roof in winter to allow the sun to stream in through the southern window wall, extends over the patio in summer to provide shade and cool the outside living space.
- Four rooms include both an indoor and outdoor component to maximize efficiency, comfort, and flexibility.
- Reconfigurable spaces and elements include a living room and home office. The living room features an entertainment center that transforms into a Murphy bed to accommodate overnight guests.
- An exterior living wall, or vertical garden, offers privacy while providing food, flowers, and the ambiance of a plant-filled room.
- A hybrid passive-active hydronic radiant cooling system uses only pump energy to control temperature, unlike conventional hydronic systems.
- A system of embedded “capillary” tubes circulates cool water through the high-mass, pre-cast concrete walls and up to a heat exchanger mounted on the roof, removing heat accumulated in the walls and resulting in cooling without the use of compressors or refrigerants.
- The use of geopolymers produces a unique concrete binder that contains no Portland cement and is one of the first-known uses of a geopolymer mix in a building envelope.
All of the teams had a great learning experience in the Solar Decathlon to design, build, finish, dismantle, transport, rebuild, compete in the competition and display the homes (with a smile, over and over and over again) to help educate the public. They all had amazing, sometimes arduous, yet highly educational and rewarding experiences. The final score is a summation of task completion, monitored performance of the homes and jury evaluations within 10 events.
Features and technologies sections from solardecathlon.gov.
Visit the team’s website: http://urbaneden.uncc.edu.