Shown here is the solar house project
of the University of Puerto Rico, whose Solar Decathlon entry is one
of the best of the 2003 effort. A new Solar Decathlon will take place
in 2005, but a further exploration of these marvelous university-based
efforts is found at: <http://www.eere.energy.gov/solar_decathlon/
Design Approach
The University of Puerto Rico team's fundamental design is based on
the use of passive technologies. The students believe that it's also
important to achieve a very efficient spatial solution that feels comfortable
and looks attractive. They wanted to design a house that goes beyond
merely incorporating existing solar energy technologies—a house
that can actually influence lifestyles and make an impact on the way
we humans understand and relate to our space, our planet, and our sun.
The north end of the structure would have fewer windows than the south.
They designed the south glazing with a metal shading device that allows
the inhabitants to control solar gains. Even with the shading device,
the south glazing became a sticking point as the students worked to
resolve competing design issues—natural lighting versus heat gains.
Ultimately, they altered their design to reduce the glazing area on
the south.
The team was also interested in integrating solar technologies into
the overall architectural design. Many Puerto Rican residents use solar
hot water, but the team feels that the systems are very poorly integrated.
So they designed their roof with two main sections—one for the
solar electric system and one for the solar hot water system. Faculty
advisor Fernando Abruña says, "We wanted to address architectural
design discourse, to maintain a contemporary look. We wanted to integrate
the technologies with the building, not to end up with a pastiche of
stuff."
Although wood was considered as a material, moving components of the
house as wood structures would have been difficult because of torsion.
So the team chose a steel frame with an infill of a foam material with
masonite, called Dryvit. The decathletes are using Dryvit on the floor,
walls, and roof. Team member Destiny Young says, "The building
material leaves no room for air leakage; fiberglass, for example, has
more leakage. The panels we're using create a really good thermal resistance
for the house."
For the windows, the students chose lightly tinted double-paned windows,
with vacuum space in between and a silica perimeter on the indoor side,
which keeps the interior air quite dry all the time. The well-insulated
window frames are steel encased in plastic. The windows have a dual
operating capability—they can slope inward and permit some natural
cooling and ventilation. If a lot of ventilation is needed, about half
the windows on the southern exposure can be opened.
To arrive at the overall interior lighting design, the architects chose
light paint colors for the interior walls and fixtures, colors that
would complement the aesthetics of the space while supplying enough
lighting to satisfy the competition's requirements. Together, the engineers
and architects ran computer simulations to determine if the plan met
their energy efficiency goals. The result is a lighting strategy that
pleases both groups—a combination of natural daylighting, effective
task lighting, and compact fluorescent and other fluorescent fixtures.
The architects even ended up with some creative leeway—they designed
a signature system for the central vaulted ceiling of their house and
incorporated fixtures that reflect the overall geometry of their house
design without compromising on low-energy use. The vaulted ceiling and
the general lighting scheme work together to create a nice living space
with an airy feel. |
