Visitors center of Frank Lloyd Wright house showcases radiant heating and cooling.

The 7,775-sq.-ft. Eleanor and Wilson Greatbatch Pavilion serves as the visitors center to the Frank Lloyd Wright-designed Darwin D. Martin House complex. Photo credit: LPCiminelli

TheEleanor and Wilson Greatbatch Pavilion, the formal name of the visitors center at the Frank Lloyd Wright-designedDarwin D. Martin Housein Buffalo, N.Y., is a glass-walled building designed by New York City-basedToshiko Mori Architects. It sits adjacent to the main house and is named after the New York philanthropists. (Wilson Greatbatch invented the lithium-iodide battery cell used in cardiac pacemakers.)

The design includes a cantilevered roof, which is an inverted version of the Martin House’s hipped roof, where all sides slope downward to the walls. It also incorporates 21st century versions of Wright’s organic principles - stainless-steel columns and triple-glazed glass walls contrasted with the brick, wood and plaster of the Martin House. The building features flexible exhibition space, permanent galleries, interactive touch screen programs, and visitor amenities such as restrooms and a small kitchen for cultural and social events.

“Trying to emulate [Wright’s] style is a battle you can never win,” principal Toshiko Mori told Architect magazine in 2009. She was selected in 2002 to design the structure out of five up-and-coming architects who participated in an architectural competition. Mori, the chair of the department of architecture at the Graduate School of Design at Harvard University, was given the American Institute of Architects Buffalo/Western New York Honor Award for her design of the Greatbatch Pavilion.

LPCiminelli of Buffalo was hired as the construction management firm to build the visitors center, as well as do the reconstruction work on the main building and rebuild the carriage house and pergola.

“An apartment building existed at the current location of the visitors center, which was purchased and demolished as the carriage house and pergola were being reconstructed,” saysKevin Wagner, senior mechanical estimator/coordinator atLPCiminelli.

Three mechanical contracting firms worked in different areas of the complex, he adds:MLP Plumbing & Mechanicalof Cheektowaga, N.Y., worked on the main house;D.V. Brown & Associatesof Tonawanda, N.Y., rebuilt the carriage house and pergola; andMollenberg-Betzof Buffalo installed all the mechanical and plumbing systems in the steel-and-glass visitors center.

The triple-glazed glass walls in Toshiko Mori’s design give an undistorted view of the entire Martin House complex, but complicated the heat loads and the design of the center’s heating and cooling system.

Originally the center was to be a two-story building with a below-grade area, but it was redesigned to a single story because of funding issues. Construction on the $5 million, 7,775-sq.-ft. facility began in 2008 and was completed in 2009.

Mori’s design specified triple-glazed glass for the walls to give an undistorted view of the entire complex, but all that glass complicated the heat loads of the center’s heating and cooling system, saysPaul Kreitler, project engineer atLandmark Facilities Groupand designer of the building’s mechanical system.

“We wanted to build a thermal climb in the middle of the building above the occupant height,” he explains. “The whole building is based on displacement air cooling and heating, where we have a slow-entry volume of air coming in around the perimeter of the glass walls through a detailed network of supply grilles hidden in the architecture.”

That air comes from the Carrier air-handling unit, saysJoe Kilijanski, executive vice president at Mollenberg-Betz. The company has been installing in-ground heating tubing, called glycol heating, since 1920 - in ice rinks and refrigeration units. The Carrier air handler and controls system were purchased from V.J. Stanley in Rochester, N.Y., as well as the Armstrong circulating pumps.

“The air-handler’s ductwork runs the perimeter of the glass so it washes the walls with linear floor diffusers,” he notes.

Because of the large amount of glass in the building, and to keep the air-handling unit at a reasonable size, Kreitler designed a tempered water concrete slab for the radiant cooling and heating system, which absorbs the solar load coming in through the windows.

Mollenberg-Betz installed 8,991 ft. of 3/4 in. REHAU PEX-a tubing in the floor for space heating and cooling - 27 loops at 333 ft. each embedded in the concrete floor.

Exterior shades are installed on the east and south facades with automatic photovoltaic sensors. The sensors automatically close the shades at a certain temperature and help reduce some of the solar load in the building, Kreitler notes. The key, however, is the Carrier i-Vu Web-based controls system - a direct-digital-controlled building management system that runs the center’s cooling and heating system. An Andover system ties the three buildings together - main house, carriage house and visitors center - to monitor the heating and cooling loads.

“Cooling is a delicate thing,” he says. “If the floor surface temperature gets too cool compared to the dew point in the room, you can end up with sweating. So careful monitoring of the slab’s temperature is critical.”

In the winter, the concrete slab works like a standard radiant floor heating system, which provides about 90% of the visitors center’s heating requirements.

 The building is divided into two circuit headers, one north and one south, which are then subdivided into multiple circuits based on the floor slab sections, Kreitler says. A secondary pumping system was designed on the radiant side with three-way mixing valves to control the temperature, so the loop temperature in the radiant system is separate from the main loop temperature in the building.

One of the biggest challenges Kreitler faced in the mechanical system’s design was the occupant load.

“The building can accommodate as many as 200 people or as few as one,” he explains. “I had to design a quiet and hidden system that took care of a wide-ranging occupant load and also produce a museum-quality environment for traveling exhibits or archival materials. It was a fascinating system to design.”

Mechanical contractor Mollenberg-Betz installed 8,991 ft. of ¾ in. REHAU PEX-a tubing in the concrete floor of the Greatbatch Pavilion for space heating and cooling-27 loops at 333 ft. each. Photo credit: Mollenberg-Betz

Hidden geothermal

Because of the historical nature of the project, theMartin House Restoration Corp.- which oversees the restoration of the complex - did not want mechanical equipment such as air-conditioning units visible on the property, Wagner says. So a geothermal heating and cooling system was installed.

Caster Drilling Enterprisesof Asheville, N.Y., drilled the 350-ft. geothermal bore holes with 1 1/4 in. PE3408 SDR-11 looping tubing - 36 bore holes for the main house and the carriage house and 15 for the visitors center - in various locations on the complex, such as flower beds and near the greenhouse (which was not designed by Wright).

Two 28-ton geothermal water-to-water heat pumps provide chilled water to the air-handling unit and the PEX-a tubing for the radiant system, Kilijanski notes. The air-handling unit, which has chilled water and hot water coils, provides heating, ventilation and additional cooling for the building. The existing boilers in the carriage house, which is adjacent to the visitors center, provide hot water to the air-handling unit coil and miscellaneous vestibule heaters.

“We took the hot water supply and return off the boiler plant in the carriage house and ran it over to the visitors center,” he says. “That hot-water heat is a secondary system if the heat pumps can’t keep up with the heat load.”

A four-man Mollenberg crew installed the visitors center’s mechanical systems while a two-man crew installed the plumbing system for the two restrooms and the small kitchen.

Of course, where to house the mechanical equipment was a challenge. Mollenberg-Betz’ only choice was to use the center’s half basement, which is now full of mechanical equipment and ductwork.

“The heat load of the building is so high and the cooling load is so large, the mechanical space was very tight because of the large ductwork,” Kilijanksi says. “We squeezed a 10 lb. bag into a 2 lb. space down there.”

Frank Lloyd Wright designed this residential complex of interconnected buildings for wealthy Buffalo businessman Darwin D. Martin and his family in the early 1900s. Photo credit: LPCiminelli

The Martin House Complex

Between 1903 and 1905, Frank Lloyd Wright designed a residential complex of interconnected buildings for wealthy Buffalo businessman Darwin D. Martin and his family - the main house, a pergola that connects it to a conservatory, the carriage house with chauffeur’s quarters and stables, the smaller Barton House (built for Martin’s sister Delta and brother-in-law George F. Barton) and a gardener’s cottage (added in 1909).

Martin was instrumental in the selection of Wright as the architect of downtown Buffalo’s Larkin Administration Building, Wright’s first commercial project.

The Martin family lost most of its fortune after the 1929 Wall Street crash and the Great Depression. Martin died in 1935 and his family, after several failed attempts to donate the property, abandoned the complex in 1937.

Over the subsequent decades, the complex rapidly deteriorated and three of the five original buildings were destroyed. In 1992, the Martin House Restoration Corp. was formed to raise funds and oversee the complete restoration of the property. Reconstruction and restoration efforts began in 1997, with major work completed in five phases, for a total of $26 million.

The complex, which received National Historic Landmark status in 1986, is considered to be one of the finest achievements of Wright’s career. In addition to well-known Prairie-style elements such as horizontal lines, overhanging eaves, a central hearth and a prominent foundation, the house contains 394 examples of Wright-designed art glass, including the “Tree of Life” window.

Visitwww.darwinmartinhouse.orgfor additional information.