Sustainable Design Doesn’t Have to Be Noisy
New products and techniques help to quell the noise

by Neil Moiseev

Summary: Good acoustics can be difficult to achieve in LEED® buildings. Neil Moiseev, an associate principal at Shen Milsom & Wilke, in New York City, has more than 30 years of acoustics experience, is a member of ASHRAE’s Sound and Vibration Control Technical Committee, and contributes to the ASHRAE Green Guide. He shares his tips and insights to help ensure that sustainable design achieves speech privacy and noise reduction for building occupants.

LEED-rated buildings generally perform better than non-LEED buildings when it comes to indoor environmental quality (IEQ), occupant satisfaction, and building performance. But surveys of occupants show that LEED buildings fall short in two key areas: lack of speech privacy and noise.

Good acoustics are difficult to achieve in LEED buildings. There are more windows, which facilitate natural lighting but add expanses of sound-reflecting glass. Loft-like ceilings, praised for providing increased airflow and deeper light penetration, are seldom covered with appropriate acoustical materials. Walls that contain noise are often absent. Natural ventilation invites outdoor noise.

The consequences vary according to building type. In schools, the ability for children to learn is compromised by poor acoustics. In health-care facilities, studies show that patients recover more slowly when there is noise. The Health Insurance Portability and Accountability Act requires speech privacy in many areas.

In the workplace, sound distractions have a direct correlation to worker productivity. Perhaps more importantly, a lack of speech privacy makes it impossible for workers to have quiet or confidential conversations.

Improving acoustics with sound-absorbing interior finishes; design that minimizes noise; HVAC systems, appliances, and electronics that are quiet; and other techniques, make LEED buildings better.

Incorporating materials that are renewable, incorporate recycled content, are locally manufactured, and don’t require a lot of smelly adhesives or chemicals to install is an exploratory process. Some of these products are not attractive and require creativity and proper detailing to make them usable. Involve an acoustical consultant early in the design process.

As green architecture becomes more predominant, however, the number of environmentally favorable acoustic products is growing. Some examples of these include cotton acoustical batts with recycled content; fiber-free duct lining (which doesn’t shed, so it improves air quality); sound-control gypsum drywall with recycled content; wood-fiber, formaldehyde-free acoustical wall and ceiling panels; and recycled-glass wall panels that are washable and inert. There are many high-quality green floor coverings and office systems as well.

Here are some other steps that can help quiet LEED buildings.

• Work with the team to specify products that don’t create noise in the first place. In a manufacturing facility, specify quieter equipment whenever possible. In the workplace, move printers, copiers, and other noisy components to a sealed space. Here’s a simple step: urge occupants to turn the ringers down on their phones.
• Good HVAC design is crucial. A balance must be struck among energy savings, minimizing materials used, and sound. Proper sizing helps minimize vibration and noise from fans. Lower air velocities, appropriate spacing between fittings, and using duct lining in lieu of duct silencers also saves energy and reduces noise.
• Conversely, the steady hum often provided by HVAC equipment may cover other distracting sounds and add to privacy. Underfloor air, for example, is so quiet, building occupants may long for the whoosh of a standard HVAC system. Carefully calibrated sound-masking systems are the solution here.
• Manage adjacencies so that noisy areas are not next to quiet ones. In a naturally ventilated building, orient “quiet areas” away from noisy building exposures—those that face roads or airports, for example.
• Seal sound leaks at the junctions between wall, ceiling, ducts, floor, and windows. Select a sealant that is low in volatile organic compounds (VOCs) and odors.

Green design minimizes the negative human impacts on the natural surroundings, materials, resources, and processes that prevail in nature. Preserving quiet, or creating it in the face of noisy HVAC equipment, heavy traffic, or just the day-to-day sounds of living and working, contributes to green design and makes the world a more comfortable place.