Vibration can be a determining factor in the success of many projects. While you might anticipate the need to handle noise levels, the room acoustics, noise isolation, and mechanical noise, are you considering the effects of vibration on the people who will live, work, learn, and heal in the building?
Effects of Vibration
The effects of noise and vibration in healing environments are well documented, but you probably know how difficult it can be to deal with annoying vibrations at work or at home. Basically, if you’ve ever tried to work, or sleep (hopefully not in the same place), while trying to put up with nearby vibration, you know how distracting it can be. Rest, stress-levels, and productivity can all suffer due to un-mitigated vibration. Vibrating sources can be bad enough that a space simply cannot be used the way it was intended.
Sources of Vibration
Vibrating sources can appear in the most unexpected or obvious places. Roads and highways, heating and cooling systems, elevators, parking structures, and rail lines are all pretty common. In medical facilities, MRI and other equipment can be a significant source of noise and vibration. Performance venues, weight rooms and gyms, and even heavy pedestrian traffic can be troublesome. It’s important to consider these seen and unseen sources, and potential future sources, whenever you begin a project.
Planning Ahead for Vibration
Before you begin, whether it’s renovation or new construction, it’s important to know how the spaces will be used, and establish specific vibration criteria. Healthcare has the FGI Guidelines to help guide medical facility design and construction, while educational, corporate, and residential properties can rely on criteria from ASHRAE (American Society of Heating, Refrigerating, and Air-Conditioning Engineers) and ISO (International Standards Organization). Additionally, if there are any sensitivities to noise and vibration, it’s important to take those into account. Sensitive equipment will have specific criteria to follow, while other spaces and uses may require more intuition to anticipate their needs.
Placing a gym adjacent to a spa or medical office may seem like a no-brainer for convenience, and like-minded purpose, but the rambunctious activity in the gym easily conflicts with the quiet and calm of the other. Planning ahead for vibration means more than following the specifics of standards and ordinances. Talking with the people who will use the spaces can go a long way to help you identify your noise and vibration criteria before you build. Placing vibrating sources on isolated slabs, and on grade, whenever possible can help prevent vibration trouble before it starts. Solving a vibration problem in an existing space can be complicated and costly.
Solving an Existing Problem
The paper (Reduction of structural vibration through slab cutting in an above-grade location – Justin Meyer) we presented, at the Inter-Noise 2015 Conference, described a case-study of an existing vibration problem in a healthcare environment. Shortly after relocating a biomedical optics laboratory, it was discovered that floor vibration was causing their vibration-sensitive equipment to operate improperly. The lab had been moved to an existing building, in a room next to a transformer, on an above-grade floor. The design and construction process did not include consideration of the vibration needs of the lab, nor had the site been evaluated for vibration. Once the vibration-sensitive equipment was installed, the amount of ambient vibration within the floor slab became obvious. In fact, vibration could be felt in the room before our testing.
We performed diagnostic vibration measurements, with the vibrating sources (electrical and mechanical systems) on and off, and confirmed the noise and vibration was structure-born, rather than air-born. When the vibration criteria was established, based on the needs of the lab equipment, and it was determined that the vibration criteria was not being met, we helped them evaluate a variety of alternative locations for the lab, along with options to reduce the vibration in the new space. Re-evaluation after the facility implemented some of our recommendations encouraged additional efforts to locate a more suitable laboratory location. Vibration was eventually reduced by over 90%.
As you might imagine, each of the construction steps were extensive, involving cutting the concrete, reinforcing the slab, and other measures. While it is naturally preferable to avoid the need to make such significant changes after the fact, it is possible to achieve reasonable vibration isolation in an existing space, and reduce existing vibration.
Choosing to work with an independent acoustical consultant, with the necessary experience and tools to measure and provide recommendations for vibration mitigation is the first step. Acoustics By Design is available to help you work through the site qualifications for new projects like MRI locations, fitness centers, and entertainment venues, along with spaces that need quiet and calm. Day spas, chiropractic offices, and therapy spaces typically want more peace and freedom from noise and vibration than are typical in a strip-mall. Restaurants are often overlooked due to the short time patrons spend in the space, but the negative effects of vibration can put off your customers, and make your staff uncomfortable. If you’re trying to solve an annoying vibration problem, we’re here to help.