Just how low the VOC level needs to be for a given product to qualify for inclusion in GreenSpec depends on the product category. For most products, we require certification to California’s health-based emissions standard, CDPH Std Method v1.1 standard (also referred to as California Section 01350), which tests a product’s resultant VOC concentrations in the space after a given period of time. For wet-applied products like paints, caulks, and adhesives, we still also look for VOC content instead of, or in addition to, verified low emissions; this is because emissions testing doesn’t adequately test initial offgassing, and VOC content is currently the only widely available proxy.
Background noise, whether from indoor or outdoor sources, adds to stress and discomfort, and poor acoustical design inside can exacerbate problems from background noise and reverberation of sounds. Products that absorb sound and prevent sound transmission can be considered green, although there are so many such products available that we also look for especially innovative products, as well as products with additional green attributes such as recycled content and strong energy performance. We also look for sound-masking systems with exceptional performance characteristics.
Tectum panels are high-impact, wood-fiber, acoustical wall and ceiling products available in a wide range of sizes. Panels are available with an NRC of up to 1.0 and light reflection of up to 70%. Tectum panels are made from strands of aspen wood fibers blended with an inorganic, hydraulic, cementitious mix of magnesium oxide, sodium silicate, and magnesium sulfate. They are noncombustible, lightweight, paintable, and formaldehyde-free.
Acoustical ceiling materials vary depending on the specific performance criteria desired—including durability, light reflectance, sound absorption, cleanability, design flexibility, and flame resistance.
Sound absorption is most commonly expressed as a Noise Reduction Coefficient (NRC), the percentage of sound waves absorbed by the material rather than reflected back into the room. Products listed by GreenSpec have an NRC of at least 0.80 (80%). Other measures of acoustic performance include Ceiling Attenuation Class (CAC), which rates a ceiling’s efficiency as a sound barrier between two rooms whose dividing wall doesn’t connect to the structural ceiling, and Sound Transmission Class (STC), which expresses how well a partition attenuates sound. For high acoustic performance, the CAC should exceed 35 or the STC 55.
Most common in commercial suspended ceilings are wet-pressed mineral-fiber tiles and panels, typically made from a mixture of waste paper, mineral fiber (which may include slag, a waste product from steel-making), cornstarch, and various other mineral-based components. A number of these products have high recycled content; some, however, may contain low levels of formaldehyde.
Fiberglass ceiling panels are also available with recycled content, although the percentage is typically lower than with mineral-fiber products. Most fiberglass ceiling panel products use a phenol-formaldehyde binder.
Though far more common in Europe, wood-fiber-based ceiling panel products are also available in the U.S.—these are free of mineral fibers and formaldehyde and may have some recycled content, but are typically more expensive.
Metal ceiling products may or may not include a backing of fiberglass.
Products for use in food service facilities, hospitals, or other areas with high sanitary standards have a PVC covering or scrubbable paint finish.
Residential acoustical ceiling panels are not available in as many materials or styles as commercial products.
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