Tuskegee Solar Home
Solar House on the Washington D.C. Mall
New Solar for the Old South
Take a drive through communities in the South, and you'll soon notice a favorite local pastime—settin' on the porch for a spell, sipping sweetened tea or an icy mint julep. According to student team member Trey Raines, "Traditional architecture in the South uses passive cooling strategies such as porches and breezeways. We based our design on a southern house type, the dog trot." Dating from at least the nineteenth century, the dog-trot house derived its name from the central shaded breezeway running through the house, where hunting dogs would sleep to escape the summer heat.
Intent on a successful marriage of new technologies to old traditions, the team set to designing their entry. Dr. Ben Oni, the team's faculty advisor says, "We wanted a design that was both a link to the past and the future—that makes it easier for people to accept." The students also wanted to design the most beautiful house they could, one that would settle gracefully into its permanent home on the university campus.
To get started, engineering students did research and calculations to determine what type and number of PV panels to use. They also considered the proper slope of the roof a key part of the design. Next, the engineering team supplied parameters based on energy efficiency and space requirements to the design team. Oni said that all the students were aiming for maximum efficiency coupled with compelling aesthetics.
Raines says that the team is quite pleased with the resulting two-story design with a southern-style screened porch. He added that the second story was no small feat given the 18-foot height limitation (to prevent one house from shading another) imposed by the competition. The house has an airy and inviting feel, with lots of interior open space, which, by design, is also easier to heat and cool. Most of the home's heating requirements will be met by passive solar from the south-facing windows, but there is a central heat pump unit for backup. Cooling needs will be met with ventilation to the extent possible, but the heat pump can serve as backup here as well.
For building materials, the decathletes are relying on wood, which is the most flexible in terms of building and transportation. The insulation is rigid foam for the roof and bat in the floor and the walls. The structure is wrapped in plywood siding, chosen for its insulating value and its tendency to release solar heat before it radiates in to the interior. All windows have double-pane insulating glass.
The home's solar electric system should provide enough power for about six sunless days. A 4-foot by 10-foot thermal panel with underlying pipes supplies the hot water. Standby electric hot water is also built in, but another faculty advisor Dr. Arunsi Chuku says, "We hope we don't use it."
To further reduce energy consumption, the team will use compact fluorescent lamps, which are cooler and more efficient than incandescent lamps. Lighting is controlled by a computer-automated system that adjusts lighting levels relative to available sunlight. Team members also incorporated light-colored interior paint as a daylighting feature to lessen the electric light requirements during the day. And when it came to zeroing in on the home's appliances, the team performed a Web search to identify only the models with the highest efficiency ratings.
To help get the word out, the decathletes landed a model of the house in the National Cultural Museum , a popular and well-known museum in the city of Tuskegee . The museum dedicated one entire room to exhibiting the project. In addition, the team designed its Web site to:
- Inform the Tuskegee University community of the university's participation in the project and its purpose.
- Communicate with the Tuskegee University Solar Decathlon team about upcoming meetings and events relevant to the Solar Decathlon Project.
- Educate Web site visitors with insightful information about solar energy and energy efficient technologies.
To complement the house on its permanent site on campus, Oni says that plans call for developing a Renewable Energy Center that will serve as an educational hub for students and visitors.
In summing up their experience, several decathletes mentioned the opportunity to learn things they "wouldn't have learned otherwise." And with the Tuskegee students finding out firsthand that these technologies work, it seems safe to say that energy efficiency and renewable energy are well on their way to bringing a new tradition to the old South.