Unity Temple Update Article
Posted: Wed Mar 22, 2006 1:37 pm
Here is an article I found about Unity Temple and updating it..
Source: Architectural Record; Feb2006, Vol. 194 Issue 2, p139-140, 2p, 1c,
Frank Lloyd Wright's 1908 Unity Temple in Oak Park, Illinois, is considered an early Modernist masterpiece for its compact monumentality and the striking planar geometry of its cast-in-place concrete. Although its interior ranks among the great public spaces of the 20th century, it proved uncomfortable almost from the start. An advanced but poorly executed heating scheme meant noisy radiators in colder months, and the lack of air-conditioning and proper ventilation made the building a sauna in the summer.
Last year, the church's Unitarian Universalist congregation joined forces with the Unity Temple Restoration Foundation to kick off the building's first major restoration, which is slated for completion in 2009--the centennial of the building's dedication. A significant component of the $12 million to $15 million project addresses the building's HVAC problems by installing a new ground-source pump system for heating and cooling. The project will also involve repairs to the temple's reinforced-concrete structure, as well as improvements to interior woodwork, lighting, and art-glass windows; a new electrical system; and changes for ADA compliance, including the installation of an elevator.
The project team, consisting of architect Gunny Harboe of Chicago and engineers Architectural Consulting Engineers (ACE) of Oak Park, must balance the needs of the congregation with strict preservation requirements for the landmarked building, which comprises a temple, meeting hall, and entrance hall. "The original users are still occupying Unity," says Harboe, principal of Gunny Harboe Architects of Chicago. "So it must still function as a place of worship, despite the fact that it's also a major tourist attraction and one of the most significant Wright buildings in the world."
New HVAC efficiencies
In improving the building's thermal comfort, the congregation wanted to use a system that would reduce operating costs and have relatively few adverse effects on the environment. Ultimately, the design team developed a system of geothermal wells, drilled to a probable depth of 300 feet. The design calls for a closed-loop fluid circulation system that will carry an antifreeze formula of glycol, ethanol, or another environmentally benign substance. It also has provisions for an ice-storage system for producing ice overnight to reduce the required chiller capacity, according to Mark Nussbaum, principal of ACE.
Nussbaum and his team are still finessing the number of wells and their exact depth. But he says adding the water loop and ice-storage capability does not add significantly to the cost of the project, particularly given the reduced chiller capacity it affords.
The new HVAC system will also mostly fit within the existing utility trenches and ducts at Unity, lessening the impact on the original structure.
In a bit of function following historic form, the geothermal scheme will be augmented by radiant heat by converting Unity's existing radiator units. When the building opened in 1909, its radiators were connected to a forced-hot-air system--not common in its time--that was fed by a coal-fired steam boiler. But the system performed so poorly that Trinity's congregation converted the radiators to steam heat in 1910, according to Nussbaum. The boiler was later converted to oil in the early 20th century, and to natural gas by the 1970s. During the current renovation, a high-efficiency natural-gas boiler will replace the latter to provide backup heat and heat for cooking.
The new scheme's demand-controlled ventilation system, which is triggered by carbon dioxide levels (a proxy measurement for the number of occupants in the building), is tailored to the needs of both users and the historic building fabric. "The system brings in only enough fresh air to meet actual needs, and it allows for a porous building," Nussbaum says.
This last point is important because Unity's single-glazed leaded art glass is porous and difficult to control thermally. But measures like storm glazing would compromise the building's aesthetics and could also create moisture problems, according to the designers. Nussbaum says the overall HVAC design doesn't require an airtight building to work efficiently. "We don't have any delicate museum artifacts here," he says, "so we can improve indoor comfort without damaging the building's shell, which is pretty hardy."
ACE used software to model the structure's energy performance, even though its as-built conditions have never been fully documented. "It's difficult to do energy modeling for a building when we don't thoroughly know its construction," he says. "There are some voids in the masonry walls, for instance, but it's not clear exactly where they are."
The models, then, approximated the building's performance with its present equipment and consumption levels. Overall, the calculations show improved efficiency during the heating season, which should compensate for the new cooling load. "We expect to see a 40 to 50 percent reduction of utility bills over what a conventional HVAC system costs," Nussbaum says. Another benefit of the geothermal system is that it typically provides an 80 percent reduction of source emissions compared to systems powered by fossil fuels, he says.
Making the old new again
Aside from the HVAC improvements, the rest of the renovation ranges in complexity. Wright's cast-in-place concrete structure was innovative for its time, and structurally it is still in good shape overall, according to Harboe, despite some cracks and spalling. "We're not anticipating replacing rebar," he says. "The major work was the overhangs," he says. Unity's signature heavy eaves were rebuilt several years ago.
The temple skylight requires significant restoration. "It's our intent to go back to the original design. There is some of the original fabric, but there's a question of how much we can reuse," says Harboe.
Many layers of paint coat the interior oak woodwork, most of which is original. "Ultimately, we'd like to remove the paint and go back to Wright's original finish, which was a clear resin," Harboe says. Wright also applied color washes directly to the interior's plaster walls; the restoration team is making mock-ups to replicate the original washes.
The restoration team will also reevaluate Unity's previous, periodic maintenance program to see if changes are needed.
One concern for the interior is that the planned changes, such as the new mechanical systems, air handlers, and the like, might affect the original temple's excellent acoustics. The work is being reviewed by an oversight team of architects, engineers, and preservationist specialists, who pore over details to mitigate any physical and aesthetic intrusions, and ensure they are reversible, if necessary. "We want to make sure we do no harm," Harboe says. "I think it's doable without any major gymnastics."
Source: Architectural Record; Feb2006, Vol. 194 Issue 2, p139-140, 2p, 1c,
Frank Lloyd Wright's 1908 Unity Temple in Oak Park, Illinois, is considered an early Modernist masterpiece for its compact monumentality and the striking planar geometry of its cast-in-place concrete. Although its interior ranks among the great public spaces of the 20th century, it proved uncomfortable almost from the start. An advanced but poorly executed heating scheme meant noisy radiators in colder months, and the lack of air-conditioning and proper ventilation made the building a sauna in the summer.
Last year, the church's Unitarian Universalist congregation joined forces with the Unity Temple Restoration Foundation to kick off the building's first major restoration, which is slated for completion in 2009--the centennial of the building's dedication. A significant component of the $12 million to $15 million project addresses the building's HVAC problems by installing a new ground-source pump system for heating and cooling. The project will also involve repairs to the temple's reinforced-concrete structure, as well as improvements to interior woodwork, lighting, and art-glass windows; a new electrical system; and changes for ADA compliance, including the installation of an elevator.
The project team, consisting of architect Gunny Harboe of Chicago and engineers Architectural Consulting Engineers (ACE) of Oak Park, must balance the needs of the congregation with strict preservation requirements for the landmarked building, which comprises a temple, meeting hall, and entrance hall. "The original users are still occupying Unity," says Harboe, principal of Gunny Harboe Architects of Chicago. "So it must still function as a place of worship, despite the fact that it's also a major tourist attraction and one of the most significant Wright buildings in the world."
New HVAC efficiencies
In improving the building's thermal comfort, the congregation wanted to use a system that would reduce operating costs and have relatively few adverse effects on the environment. Ultimately, the design team developed a system of geothermal wells, drilled to a probable depth of 300 feet. The design calls for a closed-loop fluid circulation system that will carry an antifreeze formula of glycol, ethanol, or another environmentally benign substance. It also has provisions for an ice-storage system for producing ice overnight to reduce the required chiller capacity, according to Mark Nussbaum, principal of ACE.
Nussbaum and his team are still finessing the number of wells and their exact depth. But he says adding the water loop and ice-storage capability does not add significantly to the cost of the project, particularly given the reduced chiller capacity it affords.
The new HVAC system will also mostly fit within the existing utility trenches and ducts at Unity, lessening the impact on the original structure.
In a bit of function following historic form, the geothermal scheme will be augmented by radiant heat by converting Unity's existing radiator units. When the building opened in 1909, its radiators were connected to a forced-hot-air system--not common in its time--that was fed by a coal-fired steam boiler. But the system performed so poorly that Trinity's congregation converted the radiators to steam heat in 1910, according to Nussbaum. The boiler was later converted to oil in the early 20th century, and to natural gas by the 1970s. During the current renovation, a high-efficiency natural-gas boiler will replace the latter to provide backup heat and heat for cooking.
The new scheme's demand-controlled ventilation system, which is triggered by carbon dioxide levels (a proxy measurement for the number of occupants in the building), is tailored to the needs of both users and the historic building fabric. "The system brings in only enough fresh air to meet actual needs, and it allows for a porous building," Nussbaum says.
This last point is important because Unity's single-glazed leaded art glass is porous and difficult to control thermally. But measures like storm glazing would compromise the building's aesthetics and could also create moisture problems, according to the designers. Nussbaum says the overall HVAC design doesn't require an airtight building to work efficiently. "We don't have any delicate museum artifacts here," he says, "so we can improve indoor comfort without damaging the building's shell, which is pretty hardy."
ACE used software to model the structure's energy performance, even though its as-built conditions have never been fully documented. "It's difficult to do energy modeling for a building when we don't thoroughly know its construction," he says. "There are some voids in the masonry walls, for instance, but it's not clear exactly where they are."
The models, then, approximated the building's performance with its present equipment and consumption levels. Overall, the calculations show improved efficiency during the heating season, which should compensate for the new cooling load. "We expect to see a 40 to 50 percent reduction of utility bills over what a conventional HVAC system costs," Nussbaum says. Another benefit of the geothermal system is that it typically provides an 80 percent reduction of source emissions compared to systems powered by fossil fuels, he says.
Making the old new again
Aside from the HVAC improvements, the rest of the renovation ranges in complexity. Wright's cast-in-place concrete structure was innovative for its time, and structurally it is still in good shape overall, according to Harboe, despite some cracks and spalling. "We're not anticipating replacing rebar," he says. "The major work was the overhangs," he says. Unity's signature heavy eaves were rebuilt several years ago.
The temple skylight requires significant restoration. "It's our intent to go back to the original design. There is some of the original fabric, but there's a question of how much we can reuse," says Harboe.
Many layers of paint coat the interior oak woodwork, most of which is original. "Ultimately, we'd like to remove the paint and go back to Wright's original finish, which was a clear resin," Harboe says. Wright also applied color washes directly to the interior's plaster walls; the restoration team is making mock-ups to replicate the original washes.
The restoration team will also reevaluate Unity's previous, periodic maintenance program to see if changes are needed.
One concern for the interior is that the planned changes, such as the new mechanical systems, air handlers, and the like, might affect the original temple's excellent acoustics. The work is being reviewed by an oversight team of architects, engineers, and preservationist specialists, who pore over details to mitigate any physical and aesthetic intrusions, and ensure they are reversible, if necessary. "We want to make sure we do no harm," Harboe says. "I think it's doable without any major gymnastics."