One key result of the renovation project is often overlooked, perhaps because it will be invisible: revitalized, more precisely controlled air. That change will come from a major update to the heating, ventilation, and air conditioning systems—including a new one for the Elizabethan Theatre. All this fresh air goes beyond visitor comfort, though; it’s an essential part of preserving our landmark building and collection, too.
Given the renovation project’s ambitious and exciting goals, improving the Folger building’s heating, ventilation, and air conditioning systems could seem like a secondary issue. But “this is not just some side aspect,” says Folger Director Michael Witmore. “The mechanical questions are just as important as the programming questions. That’s because our first duty is to the material,” referring to the vast Folger collection of rare books, manuscripts, and other items. “The almost complete renovation of HVAC systems throughout the building is a major, vital investment in human safety and collection safety.”
In most historical renovation projects, similar improvements are needed to make a building more modern, comfortable, and usable, says architect Johann Mordhorst, a Principal at KieranTimberlake who is guiding the Folger renovation. “From a design standpoint,” he says, renovation projects offer a chance for a “dialogue with history.” But “from a sustainability standpoint, they give older buildings new life. Part of that is often to bring the performance of the buildings up to contemporary standards and better energy performance.”
In the case of the Folger, these changes continue a long-standing interest in air inside the building and new technology. In February 1930, Henry Folger wrote to the consulting architect, Alexander Trowbridge, with a question: “what is meant by the expression ‘Air-Conditioning'”? Air conditioning was still a fairly new concept at that time, however, so it was only installed for the Folger collection. In the 90 years since the building opened in 1932, that decision was revisited long ago, with the addition of numerous air handling units to air condition the entire building.
During the renovation project, Gilbane Building Company and its specialist trade contractors are updating some units and replacing others. The new plan was designed for KieranTimberlake by Altieri Sebor Wieber, an MEPF engineering design services firm. Equipped with high levels of filtration, the new units will also come with “demand control ventilation,” which provides more fresh air when there are more people present. In addition, “the new systems will control humidity in a much tighter fashion, which is extremely important for archival materials,” says Mordhorst. The changes also include a brand-new HVAC system in the Elizabethan Theatre, host to almost 200 annual events, from student festivals to performances, readings, and scholarly conferences.
A Theatrical Upgrade
Like many performance spaces, the Elizabethan Theatre has a high ceiling, making it difficult to adjust the temperature uniformly within such a large space. Before the renovation, the theater’s HVAC system was, in effect, “dumping in air from above in mass quantities and trying to force the entire theater to be at a comfortable temperature,” says Jeff Busch, the Gilbane senior general superintendent who is managing the renovation work. In the new scheme, he says, an underfloor displacement ventilation system on the first floor will “input comfortable air where the people are, underneath their seats. You’re trying to manage the air there, rather than the overall temperature.” In the other parts of the Elizabethan Theatre, the new system will use vents to distribute air to the stage, backstage, and the second and third floor balconies.
The system in the mechanical room below will gently disperse air up through diffusers below the seats, which will direct it along the floor. During performances, as the audience’s body heat warms the air, that air will rise and the air distributed below the seats will replace it. The system will not only be more comfortable, but it “is generally considered better from an indoor air quality standpoint,” says Mordhorst. “It creates movement of the air past the people and up and away from them, rather than constantly swirling the same air around and around.”
Today, such displacement ventilation systems are “very common in any kind of theater, for large auditoriums, and for newer movie theaters,” says Busch. As often occurs with renovation projects, however, “bringing it into a historical building is what really creates the challenge.” The diffusers will be mounted in holes drilled through the theater’s concrete floor to an air supply mounted underneath it, at the top of the room below. Adding to the complexity, the room under the theater is Mechanical Room 1, the main mechanical room. Effectively the heart of the building’s many systems, Mechanical Room 1 is a huge, two-story room where electrical power, water, and other services enter the building, and it will be packed with equipment when the Folger building reopens.
Soundproofing What Lies Beneath
The installation work inside Mechanical Room 1 is meant to make sure that no sound from below reaches the theater. The duct that supplies air to the plenum—a 12-inch-high space under the theater floor and above a newly built ceiling—will be lined with acoustic absorptive material on the inside and wrapped on the outside. The ceiling that forms the bottom of the plenum will be a thick acoustic ceiling made of three layers of drywall with added acoustical insulation. It will hang from the sloping theater floor overhead from more than 200 acoustically insulated suspension hangers, with an acoustical seal along the ceiling’s edges and wherever there is a penetration through it.
Under the acoustic ceiling, the rest of Mechanical Room 1 is also undergoing an extreme transformation as part of the renovation project. The team has made the entire room two stories high. In preparation for the changes, almost every piece of equipment and most of the big mechanical, electrical, and plumbing (MEP) lines were upgraded. “This is as empty as the room has been” since it was first built, says Kent Korgan, a Gilbane project engineer.
A Breath of Fresh Air
As Mechanical Room 1 is reassembled, the routing for the MEP lines—HVAC ducts, pipes, conduits, and more—has had to be completely reworked. Because of the plenum, the lines won’t be attached to the concrete deck overhead. Instead, a new grid of steel beams, anchored to the building’s steel structure, will be installed about 18 feet above the floor. A mass of MEP lines, including ductwork, will hang from the grid, occupying about 10 vertical feet of space. Still more MEP lines may be supported from below.
Figuring out where to place these lines in Mechanical Room 1—and in the rest of the building, where old and new lines mingle—requires expert knowledge and sophisticated software to solve. Each type of line is supplied and mapped out by a different subcontractor and has its own requirements. Pipes have to slope at a specified angle, electrical conduits cannot turn too sharply, and HVAC ductwork is the largest and least flexible element. In effect, each of the subcontractors’ maps are downloaded into a shared 3-D model, where “clash detections” reveal places where two or more lines cross through the same space.
Finding solutions is not always easy, but it can be “a really fun puzzle to work with,” says Korgan. To coordinate the MEP planning for the entire building, he says, “just over a year ago, I met about three times a week for months with a team in which there was one artist, as I would call them, from each subcontractor—electrical, plumbing, and so forth. There were five or six of us meeting to resolve these clashes throughout the entire building, one section at a time.” The artists, he says, are masters at working with AutoCAD or equivalent programs.
The complexity of fitting together and finding enough space for the HVAC, electrical, plumbing, and other lines sounds oddly familiar to Folger Director Witmore. “It reminds me of the challenge of integrating the different pieces of the Folger. You have a research library, a humanities institute, a museum, a stage for performing arts, a place for students and teachers, all of that in one building,” he says.
“I think the power of KieranTimberlake’s design,” he says, “is that it allows us to use our historic building in this much more powerful, integrated way, so that all those things can work harder within and underneath the original structure.” And, with the revived and improved contemporary HVAC systems, to enjoy it with a breath of fresh air.
Photography by Lloyd Wolf.