Case Study: Debs Park, California

Written on 11/21 at 10:11 PM by Andy Posner 1 comments

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Note: I wrote this paper for a class at Brown called Sustainability in the Built Environment The Audubon Society has plans to build "hundreds of urban nature centers. . .by the year 2020" with the aim of "bring[ing] nature to those inner-city children with few opportunities to leave the city. . ."1 Thus when it came time to build the first of these centers at Debs Park, located 10 minutes from downtown Los Angeles, the Society wanted something that would capture its ideals and values and create a model for future development. In order to do so, the design team started with the objective of creating a building "that complemented the landscape, blend[ed] into the environment" and focused the visitor's attention on the nature trails, courtyard and Children's Garden. Yet while sustainability was a high priority from the start, the decision to seek LEED Platinum status wasn't made until a donor made a contribution specifically for that purpose. Ironically, the donation freed the designers to pursue an entirely off the grid, or building, by forcing them to meet LEED's stringent criteria. The Center's unique geographical location enabled it to be in a natural setting while remaining close enough to urban centers to be relevant and accessible to large groups of people. This is because the 17 acre site, situated in the 282-acre Debs park, is only .25 miles from a freeway, half a mile from a light rail station, and within walking distance of 30,000 school children. At the same time, however, the center is sufficiently isolated from electricity, natural gas and sewer lines (1/4 mile) to justify generating all of its energy, as well as treating all of its wastewater, onsite, without adding significantly to the cost of the project. Indeed, the final cost was only 5-7% higher than that of a conventional project, despite the fact that the Center boasts, among other things, a 23 KW PV array, a 269 DC KwH battery bank, the first "completely solar-cooled [HVAC] system in Southern California," two solar water heaters, and extensive wastewater treatment systems.

Wastewater Treatment
Self-Sufficiency with respect to wastewater meant much more than saving money by obviating the need for a connection to the sewer line; it meant an opportunity to demonstrate new technology, conserve water and reduce the stress on Los Angeles’ wastewater treatments plants and beaches. The importance of this is highlighted by Los Angeles’ repeated violations of the Clean Water Act and the resultant beach closures and human health and economic impacts on the city.  By treating wastewater on site, the Center is able to recharge groundwater, avoid soil saturation, and remove solids and phosphorous that would otherwise be discharged into the Santa Monica bay during a storm.  Furthermore, the wastewater, which is tertiary-treated, is used to flush toilets and urinals, conserving water in a region with limited water supply and increasing demand.  The design team, however, had to overcome several bureaucratic hurdles.  The low-flow, dual-flush toilets, for instance, were only installed after negotiation with the city to make them code-compliant, and they were unable to gain permits for waterless urinals. 

These hurdles having been surmounted in some cases, and identified in others, future projects will find it easier to push for new levels of water efficiency. The decision to install these water conservation and recycling measures was made for several reasons.  The donation and subsequent effort to achieve LEED Platinum certification, along with the cost of extending existing sewer lines to the site, were certainly key.  But economics alone could not possibly have driven the decision, as the final cost of the system was still higher than had they simply connected to the sewer.  The Center’s role as a place for environmental education and protection made the final choice a clear and logical one.  The externalities avoided by on-site wastewater treatment are significant, and truly in line with the values and goals of the Audubon Society as a whole.

Energy
The Center takes “off-the-grid” to a whole new level by incorporating efficiency measures and time-tested solar electric and solar thermal panels alongside innovative technologies just hitting the market.  The end result is a building that generates all of its own energy, a fact made possible by the low overall energy consumption of just five kWh per ft.  The numbers speak for themselves: 75% reduction in energy for lighting, 96% for heating, 84% for cooling, 80% for water heating, and 15 of 17 possible LEED Energy and Atmosphere points earned.

Once again, the site’s isolation from existing power lines made the “self-sufficiency” decision that much easier and cost-effective (adding only a slight cost-premium), but it also forced the design team to look for greater efficiency and new technologies.  The most prominent of these new technologies is the solar HVAC system, which consists of 1,100 sq. feet of glass vacuum tube collectors on the south facing roofs.  The tubes heat water to between 160 and 180 F, which is then stored in a 1,200 gallon tank.  Cool air is created when the hot water passes through a 10-ton lithium bromide absorption chiller and is condensed and evaporated at low pressure; a small pump then moves the “coolth” through the building.  The $90,000 system was installed as part of the LEED Platinum goal, but a blackout in 2003 also highlighted the importance of demonstrating the technology in Los Angeles.  As a member of the installation team said, “The matter of peak-load power demand should be a top priority of every politician following the wake-up call” of the blackout.7 Solar AC lessens the strain on the power grid and alleviates the smog that descends on the LA Basin in the summer, while the photovoltaic and solar thermal systems are obvious choices in the sunny, warm Southern California climate.  Taken together, these systems represent self-sufficiency for homes, businesses and municipalities in the face of rising energy demand and declining supply.

The Audubon Center at Debs Park was able to achieve self-sufficiency thanks to a donation that forced an integrated design approach; the need to build an environmental science center that “walks the walk”; and a unique geographical location that lowered the cost-premium for creating a stand-alone site. Pressure from the 5,000 sq. foot facility on the city’s storm water systems and electrical grid was entirely eliminated.  Brand-new technologies were showcased, while age-old passive heating and cooling techniques were improved upon and coupled with highly water and energy efficient appliances.  The final product achieved the original goal of blending in with the surrounding landscape and “bringing nature to the city,” reached LEED PLatinum level, and still managed to accomplish the more subtle and challenging goal of self-sufficiency.  While cost comes to bear in any project, a unique combination of factors drove the Audubon Society to push beyond mere cost-effectiveness.  The center, visible from downtown Los Angeles, now stands as a bridge to the future; a symbol of ties to local energy and water flows, and freedom from insecure regional and global energy and water systems and markets.

Watch a video by T.H. and Sybille Culhane about the solar HVAC system at Debs park below!

Bibliography
1) http://www.ehdd.com/images/ehdd_pdf_154.pdf Pg. 1

2)http://www.buildinggreen.com/hpb/process.cfm?ProjectID=234 Accessed 11/19/07

3)http://www.bren.ucsb.edu/research/documents/LABasinGPP.pdf Pg. 1 Accessed 11/19/07

4)http://www.californiasolarcenter.org/solareclips/2004.02/20040210-10.html Accessed 11/19/07