News & Updates

image of UrbanEden house taken from deck looking at south window wall

Research Highlight UNC Charlotte's U.S. Department of Energy 2013 Solar Decathlon House

Date Published: April 13, 2014

After much innovative design and hard work, UNC Charlotte was proud to compete in the U.S. Department of Energy’s international Solar Decathlon held last October in Irvine, California. Ingersoll Rand, a founding member of SIBS, was also a major sponsor and technical advisor of UNC Charlotte’s Solar Decathlon student team.

The Solar Decathlon challenges collegiate teams to design, build, and operate solar-powered houses that are cost-effective, energy-efficient, and attractive. The winner of the competition is the team that best blends affordability, consumer appeal, and design excellence with optimal energy production and maximum efficiency.

The team’s UrbanEden house won third place in the prestigious Engineering competition and first place in the People’s Choice competition (story).

Work began on the design in October 2011. The UNC Charlotte team began construction of its solar house in March 2013 and completed the house in September before transporting it to California.

UrbanEden is a net -zero energy solar powered home designed for the city of Charlotte, NC. Envisioned as an urban infill project for a couple ("DINKs" or "empty-nesters"), the house design is defined by a strong connection between indoor and outdoor living areas; even in an urban context, the outdoor living area allows one to privately enjoy the outdoors. The house incorporates truly revolutionary approaches to sustainable design and construction, including the choice of primary building material (geopolymer cement concrete), an innovative active/passive hybrid cooling system integrated into the walls of the house, PV panels on adjustable racks, and responsive technology that allows the house and its inhabitants to adapt to changing environmental conditions. Its design begins with an ancient urban material, expertly modified to become an eco-friendly, innovative building material: pre-cast geopolymer cement concrete. Aesthetically versatile with its many possible surfaces, but always appropriate to a city setting, the concrete provides an effective sound barrier to the noise of the city. Outdoor living defines UrbanEden's design. The home's southern facade is completely comprised of high-performance glass, which fills the home with light and connects the interior rooms to a set of private outdoor rooms enclosed by a vertical garden that provides a peaceful habitat for flora and fauna, as well as herbs and vegetables for sustenance.

The house has been designed to incorporate natural cross-ventilation when the humidity and temperature are in an acceptable range. But even with all doors and windows closed, a vital connection to the outside is maintained through fresh air supplied by the energy efficient Energy Recovery Ventilator.

Concrete is a key innovation in UrbanEden's energy-efficient concept and structure. In state-of-the-art, high-performance housing it is common to combine high-mass passive solar design with thermal-bridge free, airtight building envelopes. However, the mass component is usually limited to an insulated concrete floor slab. In UrbanEden, the mass has moved to the walls in the form of insulated precast panels. This seemingly simple choice is, in fact, a major innovation. By markedly increasing the surface area and related volume of our thermal mass in the passive solar context, we have been able to implement a hybrid passive/active hydronic cooling system that, unlike conventional hydronics, uses only pump energy to accomplish temperature changes.

Embedded in our precast panels are arrays of small diameter plastic "capillary" tubes. In the summer, the concrete slowly takes on ambient heat from the interior space during the day. At night, water is moved through the capillary tubes to copper fin heat exchangers above the roof. The combination of the large surface areas of the interior wythe of concrete and the embedded tubes creates a very efficient transfer medium for heat. Since the night sky, especially on a clear night, is a giant reservoir for radiant heat transfer, our system cools the concrete, and hence the space, even with a very low difference between interior and exterior air temperatures. The result is cooling without using compressors or refrigerants - essentially passive cooling.

A second major innovation is the use of geopolymers to produce a different class of concrete binder that contains no Portland cement. Portland cement, the conventional binding material in concrete, is responsible for 5-8% of our collective worldwide carbon footprint.  The geopolymer mix we are using completely replaces the Portland cement with a UNC Charlotte developed fly-ash mixture that results in a massive decrease in associated carbon emissions (theoretically up to a 90% reduction) and makes safe use of a waste product of coal production. Though there are some differences in the production cycle (the concrete has to be heated to cure for example), the precast panels for UrbanEden have been produced in partnership with a commercial pre-cast provider in a plant typically used for Portland cement mixes, suggesting that geopolymer mixes could offer essentially plug-and-play replacements for Portland cement.

UrbanEden will be reassembled on the campus of UNC Charlotte in conjunction with the opening in August 2014 of a new Charlotte-Mecklenburg Schools early college high school  which will focus on science, technology, engineering, and math (STEM). The house will be used as an educational and research facility serving both high school and college students. Stayed tuned to the website and the UrbanEden Facebook page for updates.

Image of daylit office building

Research Highlight: UNC Charlotte's Daylighting + Energy Performance Lab

Date Published: February 19, 2014

The Daylighting + Energy Performance Laboratory is an applied research unit of the School of Architecture at the University of North Carolina at Charlotte’s Integrated  Design  Research  Labs. Over the last twenty years, the D+EPL has partnered with architecture firms and building owners with a desire for in depth analysis of advanced daylighting design solutions for their buildings. In addition to supporting the design and performance goals of building professionals, the D+EPL’s research activities provide a valuable experience for student research assistants, who conduct the primary analysis work on projects.

The mission of the D+EPL is the advancement of applied knowledge through the specific study of architectural energy systems and lighting technology research. Through the dissemination of its research, the laboratory has taken an active role in shaping public policy on high-performance building standards, in addition to design assistance activities.

The D+EPL’s current research is focused on the refinement of climate-based computational analysis tools used to evaluate total building energy performance and the economic valuation of architectural systems and their design attributes. The D+EPL’s research investigates the performance attributes associated with architectural envelope systems that in turn impact choices of mechanical and electric lighting systems in new and retrofit construction. This research has focused primarily on public-sector building types (e.g., schools and libraries) to enable users, operators, and design professionals the means to effectively evaluate the impact of building decisions at the earliest stages of design.

The application of this knowledge to inform and improve the performance of our built environment has been the primary objective and the guiding force behind the cooperative outreach and professional design assistance activities of the D+EPL. The D+EPL continues to seek to understand the technical informational needs of designers, builders, and owners in order to continue the advancement of environmentally appropriate design methods, construction practices, and maintenance processes. Because of this, the laboratory actively pursues and engages in the establishment of applied research partnerships between academic, public, and private sector constituents.

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New Success Stories Page

Date Published: February 14, 2014

Follow SIBS success stories on our newly created success stories page.


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Spring 2014 IAB Meeting

Date Published: February 7, 2014

The Spring 2014 IAB meeting will be held in NYC on April 28th & 29th at Wells Fargo's facilities located at 150 East 42nd Street, New York, NY 10017.