The Environment and Oberlin: An Update

Page 4

In 1995, President Nancy Dye authorized planning to construct a 10,000-square-foot, $2.5 million environmental studies center that would be a model of ecological design for Oberlin College. The architectural firm of William McDonough and Partners (WM+P) was hired to oversee the programming stage, then subsequently to design the building and supervise construction.The 13,600-square- foot facility was completed in January 2000. Today, the design and construction budget sits at $6.5 million, and the College has had two full years to use the Lewis Center and evaluate its energy performance.

In the seven years since its initial approval, much has been written about the goals and intent of the Lewis Center, but little has been written about the building as it was actually constructed or its energy performance. As more details emerge about the facility’s design, I have grown concerned that the media and other publications have failed to capture important aspects of the building and its design history.

On the outside, the Lewis Center resembles the building that has been described all along. But a building’s energy consumption is not simply a function of architecture—it is equally dependent on engineering. The building’s engineering, or mechanical design, is hidden within. And it is here that the Lewis Center’s design deviated significantly from its original intent and public description.

Throughout 1997 the architect considered and simulated a range of mechanical design concepts. But these energy simulations, although useful for guiding the design process, were not constrained by building codes and other engineering realities that frustrate “real” building projects. In April of that year, WM+P settled on a concept described as a building that would be heated and cooled by geothermal heat pumps, with a backup connection to the College’s central steam plant—added, reluctantly, to satisfy concerns of the maintenance department.

But the first set of mechanical drawings does not support this description. They instead depict a building not with steam backup, but heated by steam and cooled by water circulated through ground wells. The design showed tempered-water heat pumps (similar to those used in motels for distributing heating from a central plant), not ground-source heat pumps appropriate for a geothermal building. In short, the heat pumps reduced the efficiency of an otherwise steam-heated system.

The discrepancy is but a historical footnote because this design proved too costly, and the heat pumps and ground wells were eliminated just days before College trustees met in September 1997 to approve the final building design and its $6.11 million budget. A mechanical redesign was authorized. What emerged that fall was a building, without heat pumps, heated with steam from the College’s coal-fired steam plant. Construction documents were developed for this design, and the project went out to bid in June 1998. Meanwhile, the College spent about $450,000 to extend the campus’ southern steam loop to the construction site. (These lines have never been used, nor has their expense been included in the Lewis Center budget.) Architect William McDonough, in a July 9, 1998, New York Times article, said the building was “…like a tree, that gives more than it takes, that makes oxygen and provides a habitat for hundreds of species…” The article appeared as bids were coming in for a building heated from coal-fired steam supplied by the College’s central heating plant.

Just weeks before the Lewis Center’s September 1998 groundbreaking, this second mechanical design was abandoned and another redesign initiated. As I understand it, Professor David Orr agreed to raise additional funds (as high as $250,000) to return to geothermal heat pumps and wells—this time without a connection to the campus steam plant. The building was to use only electric energy so that it might one day be powered by a rooftop photovoltaic array (which generates electricity from sunlight) or a fuel cell.

Groundbreaking went forward with neither a construction contract nor a mechanical design. Though the mechanical design would not be completed for another five weeks, the architect released a performance data sheet that summarized the building’s key features. Included was the projected annual energy consumption: 63,609 kilowatt-hours, which is roughly 20 percent of the site energy used by a conventional building and slightly more than the annual energy expected from a 3,700–square-foot photovoltaic array, thought then to be the largest array the roof could support. In the October 1998 issue of Atlantic Monthly, architect McDonough wrote that “[the Lewis Center] is designed to make more energy than it needs to operate and to purify its own wastewater.” Thus began an immense publicity campaign about this building that would be powered by sunlight and produce more energy than it used.

But the third mechanical design differed significantly from that described by the architect. In a September 1998 memo, WM+P’s engineers, Lev Zetlin Associates, wrote of their plans to go forward with a tempered-water heat pump system with the circulating water loop cooled by ground wells and heated with an electric boiler. This “redesign” essentially returned to the very first design of April 1997, replacing heat from steam with electric boilers. The “historical footnote” now becomes important. This redesign would have led to the least efficient heating system possible—a building heated entirely by electric, resistive heat!

The details are uncertain, but drawings dated September 18, 1998, showed pumps now taking heat from the ground to heat two-thirds of the building. A 112-kilowatt electric boiler would provide heat to the remaining third, including the atrium and Living Machine, spaces that account for 50 percent of the building’s heat load. Revised drawings issued a month later included a second electric boiler, as well as two electric air heaters, an electric hot water heater, and nine fans that exhausted air without energy recovery. The electric resistive heating power was nearly double the combined heating capacity of all the heat pumps! The potential electrical use was so large that in December 1998 engineers upsized the building transformer to 500 kilowatts—10 times larger than the photovoltaic array intended to power the building—and similar to the transformer that serves the local Ames department store, a building nearly six times larger! When the construction contract was finally signed in November 1998, it was for a mechanical design that differed significantly from the one described in documents released at the groundbreaking. Furthermore, it was incapable of achieving the design intent.

Construction of the Lewis Center was completed in January 2000 (the 4,700-square-foot photovoltaic array would be installed 11 months later). One month into occupancy, it was clear that the Lewis Center consumed far more energy than the architect had projected. In another month, it was clear that the assumptions used for the energy projections did not apply to the building that was actually constructed.

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