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By Nancy B. Solomon, AIA

Green technologies to the rescue

“One of the knocks about historic buildings,” explains Elefante, “is that they have crumby old radiators and boilers that can only be retrofitted with great difficulty.” There is some truth to this, but advances in environmental systems and strategies are offering new solutions to this preservation challenge.

One of the most striking examples of this can be found at Trinity Church in Boston. Designed by Henry Hobson Richardson in 1877, the landmark was recently renovated by Goody, Clancy & Associates of Boston. The work included a new undercroft, or meeting space, beneath the sanctuary. The architect wrestled with where to put a conventional mechanical system to condition this area. Steep roofs and high visibility made a roof-mounted cooling tower impossible. And a mechanical system inserted—only with much effort—into the unused tower-attic spaces would pose a risk to the priceless art below in terms of both vibrations and water damage.

 

Designed by H.H. Richardson in 1877, Trinity Church in Boston (this page) is now being restored and expanded by Goody, Clancy & Associates. Due to space limitations and rigorous aesthetic requirements at this national landmark, the engineering firm Cosentini Associates proposed subterranean geothermal energy (diagram, opposite) in lieu of a conventional mechanical system to heat and cool the renovated spaces. Although not the primary reason for the selection, reduced energy bills will benefit the Episcopal congregation. The geothermal wells were installed in 2002; the renovation will be competed in 2004.

Instead, the design team opted for a geothermal system. About 8 feet from the exterior walls, six holes were drilled 1,500 feet deep and filled with 4-inch-diameter hollow plastic tubes. Water in these tubes will hover between 50 and 55 degrees—the constant temperature of the earth at this depth—providing a moderate source for heating during the winter and cooling during the summer (see diagram, right). According to principal Jean Carroon, AIA, the first costs of the geothermal system was comparable to that of a conventional system in this sensitive renovation project, but over time it will provide an operational payback in terms of lower energy costs.

Preservationists are benefiting from new thinking about indoor environment. For example, Elefante explains that current research suggests that fresh air needs to be delivered to people to breath, but not necessarily to heat and cool them. Small amounts of air can be distributed via operable windows or underfloor ducts—providing oxygen to the occupant where needed—while room temperature can be modulated more efficiently with other systems. In addition, continues Elefante, studies indicate that radiant systems are much more effective than convective ones in terms of how the human body reacts to temperature change. “Why blow all this air around when I can more effectively change the temperature with water, which is also more efficient to move and takes up less space?” he asks.

In Dana, the existing operable windows were reconditioned to deliver fresh air, portions of the old steam-heating system were retained, and radiant panels were suspended from the ceiling for cooling. Cold water running through 11¼4-inch piping in these panels draws heat out of the rooms on hot days. Integrated with lighting, the thin-profile units eliminate the need for ductwork and suspended ceilings—the bane of historic buildings, which typically feature high and often decorative ceilings.

Goody, Clancy is looking into other innovative environmental technologies, as well, including photovoltaic panels, green roofs, steam backpressure turbines, condensate-heat-recovery and water-recovery systems, titanium-dioxide window coatings, and fuel cells—for possible application in GSA’s upcoming renovation of the John W. McCormack Federal Building, a 22-story Art Deco building in Boston originally designed by Cram and Ferguson in the 1930s.

The design team—which also includes Cosentini Associates for mechanical engineering and Steven Winters Associates as green-building consultant—hopes these and other green technologies will make this relatively unassuming building less expensive to operate and a great place to work, while maintaining its historic character. In this way, they hope to encourage owners of similar buildings to do the same, thereby helping to sustain the larger urban context. “Unless highly decorative,” explains Carroon, “older buildings are not very fashionable and are therefore most at risk for removal.”