Commissioning for Better Acoustical Performance
Although a typical commissioning process focuses on thermal comfort and indoor air quality, one factor related to space comfort that is often overlooked is acoustics. The identification of acoustic issues and their sources helps to identify if undesirable noises are the result of malfunctioning equipment, changes in the design intent of operating equipment or are inherent (and thus “normal”) to equipment operation.
Numerous factors can contribute to acoustic issues throughout a facility. From a commissioning perspective, abnormal space noises are often an indicator of improper operating equipment. These acoustic issues can be vetted by equipment testing and are often found to be a result of worn belts, improper belt adjustment, improper vibration isolation, improper bearing alignment and/or bearing failure. Acoustic issues are not only a nuisance to the space occupants, but a pre-cursor to larger equipment issues needing to be identified and addressed.
Commissioning can identify and prevent acoustic issues in both the design review and construction phases of a project. In design, potential sources of acoustic issues can be identified during design reviews and mitigated via modifications to the original design (prior to any equipment even being bought or installed). Examples of common design issues are excessive air velocity in supply or return systems and improper sizing of registers, grilles or diffusers removing or supplying air in the space itself.
During the construction phase, commissioning can help identify potential acoustic issues through review of equipment submittals. Submittals are reviewed to determine if the proposed equipment meets the acoustic requirements of the project. Additionally, the review of the equipment manufacturer’s sound rating data helps identify potential acoustic problems prior to installation of equipment. In projects re-utilizing existing equipment, functional testing can determine if acoustic issues are a result of failing equipment, non-calibrated equipment or if the equipment is operating in a way not intended in the original design. Review of the testing adjusting and balancing (TAB) reports can also identify acoustic issues caused by too much airflow being supplied to the space.
Your commissioning agent should always consider acoustic performance when testing equipment. Although ventilation and thermal comfort are extremely important factors in indoor air quality, acoustic performance should not be overlooked.