Solar Decathlon 2002

University of Puerto Rico

Final Overall Points: 712.216
Final Overall Standing: 7

About the Home

The University of Puerto Rico team's fundamental design is based on the use of passive solar technologies. The students believed that it was 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 understand and relate to our space, our planet, and our sun.

The team designed the home to have an elongated rectangular shape with minimal east- and west-facing facades, fewer windows on the north side, and south glazing with a metal shading device to control solar heat gains.

Many Puerto Rican residents use solar hot water, but the team felt 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 said, "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."

The students are quite proud of their desiccant and vapor compressor cooling system, a hybrid system that uses less energy than a bigger compressor. The desiccant is incorporated to remove humidity. One student was awarded a National Science Foundation scholarship to continue work on the hybrid system. For heat, they used hot water passing through a heating coil in a nontraditional evacuated-tube system. The absorbing material in the heat pipes is a circular fin that goes around the perimeter of the evacuated tube. In addition, there's a reflector underneath the tubes, so any additional energy that goes between the tubes will be collected back in the tube because of the absorber material in the back of the tube.

About the Team

The University of Puerto Rico home ranked second in the Design and Livability Contest. Judges wrote:

Well crafted. Elegant in its simplicity. Quiet, the acoustics worked well. Calm, it felt good inside. Spatially well designed. Small gestures to their cultural heritage were evident. Venetian blind divider was superb. Nice lighting design.

The team was ecstatic over this result. This accomplishment was particularly sweet given the challenges the team faced. They had to ship the house by boat, which reduced the time they had to design and build the home. Students from two campuses collaborated on the project: architecture students from the Rio Piedras campus and engineering students from the Mayagüez campus. They had to design a house for the unfamiliar climate of Washington, D.C. Ultimately, the design embodied their teamwork, proving that people from different places with different ideas can pull together to build an energy-efficient house.

Key Home Features

Item	Specifics
PV kilowatts (standard test condition rating)	4.16
PV modules	26 BP Solar BP-160
Charge controllers	2 Trace C40
Inverters	2 Trace SW5548
Battery bank	1800 ampere-hour, 48 volt
Battery type	36 Clean Moura CM-200
Water heating	1 Solatron evacuated tube; 120-gal (454-L) storage tank
Construction	Steel framing 4-in. (10.2-cm) polystyrene, R19 (RSI 3) and R21 (RSI 4); synthetic word flooring
Space heating	4 evacuated tubes; 300-gal (1136-L) storage tank
Space cooling	Hybrid: liquid desiccant/1-ton carrier with Puron refrigerant

Manufacturers' Websites

• BP Solar
• Xantrex (formerly Trace; Trace charge controllers)
• Solatron
• Carrier Corporation (Puron refrigerant)

Source: These details have been adapted with permission from Home Power #94, April/May 2003