Can You Hear Me? Optimizing Learning through Sustainable Acoustic Design
What's next?
According to Brandon Tinianov, CTO of Serious Materials, "One important and overlooked category of acoustical materials is high-performance windows for classroom acoustics." New acoustical windows may be able to achieve sound transmission levels from 35 to 40 STC, STC ratings that are growing closer to wall acoustical performances. These windows will not look any different to the viewer, they will have the same visible transmission values, but they will be heavier and potentially have a thicker profile. Engineers will manipulate the air space in windows to achieve these greater performance levels.
PERFORATED WOOD VENEER AND METAL PANELS
| BIM-driven Manufacturing - Making Custom Designs Affordable |
BIM-driven manufacturing now allows competitively priced, mass customization of ceilings and interior walls panels. One progressive manufacturer, for example, creates three dimensional building information models (BIM) of ceiling or wall designs, then transfers the geometric data into automated punching machines that trim aluminum or wood-veneered sheets into any size and shape, with tolerances as close as 0.005-inch. After punching, panels are fed through automated machinery that curve panels and form the bends at panel edges. The newest generation of this computer aided manufacturing process allows designers to use curved surfaces, tessellated geometries, and other complex designs without paying the premium prices formerly associated with custom ceilings or walls. The same machines can make as many as 7,000 unique perforations per minute to give panels the desired appearance and acoustical properties. Designers can select the size, shape, and spacing of the perforations, and can even use the perforations like pixels to create patterns, logos, wayfinding cues, and other graphic images. Recent process improvements have made it possible to specify micro-perforations that are almost invisible when viewed at standard ceiling heights yet still afford high noise reduction properties. Larger perforations can be illuminated from above to create luminous ceilings. Ceilings increasingly require careful integration with light fixtures, fire sprinklers, HVAC louvers and grilles, and other building services. Required penetrations for these services are located in the BIM and then formed in the factory to simplify field installation, reduce job site waste, and assure that services are optimally located to maintain the overall good looks of the ceiling. |
New types of metal and wood ceiling and interior wall panel systems offer cost-effective alternatives with fresh aesthetic options, outstanding acoustical control, and impressive environmental benefits. Nancy Mercolino, President of Ceilings Plus, a ceiling producer, comments that "the 24 x 48-inch ceiling grid is no longer a given in contemporary architecture. Metal and wood panels now allow designers the freedom to use almost any panel size and shape, plus an increased range of finishes and acoustical options, without breaking the budget."
She explains that perforated metal has been used acoustically for about a hundred years. Yet the appearance and functionality of the products have changed dramatically in the past few years in response to evolving architectural needs and new fabricating technologies. For example, she points out, perforated panels can now be made with recycled aluminum sheets that weighs less than most other ceiling materials yet eliminates most of the oil-canning and visual distortions that used to limit the size of metal panels.
Another breakthrough has been the recent development of ways to laminate wood veneers to aluminum. In the past, Mercolino says, "wood panels were heavy, expensive, combustible, prone to warp with changes in humidity, and offered limited acoustical control. The new laminated products avoid all these problems, making wood ceilings and walls attractive from both the economic and aesthetic vantage." Wood, she suggests, adds a visual warmth and excitement that can soften the institutional feel of a school.
Perforated metal and wood panel systems can also contribute to the sustainability goals espoused by schools. In addition to controlling noise to create better learning environments, the panels have zero-VOC finishes and no added urea-formaldehyde, are durable, contain high recycled material content, do not support mold or mildew, have Class 1 surface burning characteristics, and provide outstanding life cycle value. They are available with finishes that have high light reflectance values to reduce energy consumption and optimize daylighting. And the panels are easily removable for access above a ceiling or inside a wall to commission and maintain HVAC, power and communication cables, and other building systems.
| Los Angeles Harbor College - Technology Instruction and Classroom Building |
This "smart classroom" is a high-end conference space/auditorium that supports the college TV studio. The room is used for lectures and presentations, as well as for sending and receiving classroom content and live television broadcasts to and from remote locations. Mark McVey, LEED AP, Design Principal at SmithGroup, explains that the acoustic considerations in this room were unique because the space is used for different purposes. "As a TV studio, the room should be dead, without any echo," he says. "But as a lecture space, it should be live enough to bounce the speaker's voice off the surfaces without too much amplification." The designers were able to achieve satisfactory results for both uses by installing perforated acoustic panels with fiberglass backing yielding an NRC (noise reduction coefficient) of 0.85. Because of the need for the raised projectors and projection screen, there is a one-story portion and a two-story portion of the room. Since the designer knew there would be some echoing or problematic acoustics up in the higher portion, he decided to use acoustic ceiling panels. Then, when he discovered that metal panels could be made with a radius, McVey and his team decided to continue the rounded shape down throughout the lower area as well. "It was a design opportunity that came out of the properties of the material," he says. The panel perforations are oblong. This was chosen for both acoustic and aesthetic reasons. "We needed a lot of porosity in the panel to get the acoustic benefits that were required," says McVey, "We thought that using standard circular perforation patterns would result in so many holes, and we wanted to be able to see as much of the material as possible." The aluminum was pre-finished before fabrication with a copper-toned paint that was chosen to give a warm look. Another ceiling achievement in this project was the designers' ability to incorporate a series of components in the room as flush elements, including mechanical registers, speakers, sprinklers, lighting, and projectors concealed behind perforated surfaces or in slots within the ceiling system. |
 |
This smart classroom in the new Technology Instruction and Classroom Building achieves both acoustic control and dramatic visual impact with the help of custom curved, perforated aluminum ceiling and wall panels that yield an NRC of .85. Photo courtesy of Ceilings Plus |
Notice
