• Aesthetics. Whether the design intent is for a louver to be a major design element or simply disappear into the facade of the building, there are numerous aesthetic options to choose from. Louver systems are available that provide designers with a full palette of textures, the option of a wood grain appearance, and an almost unlimited range of finish color options.
• Testing. Knowing how a louver will perform is critical to ensuring that it will stand up to real-life conditions in the finished project. Manufacturers should be able to verify how their products perform based on independent testing to the louver standards provided by the Air Movement and Control Association (AMCA). These standardized tests address air performance, acoustic sound attenuation, still air water penetration and wind-driven rain. Some manufacturers can also provide custom air/water testing using their own on-site test chamber to address specific concerns related to custom applications which are not testable by AMCA. This can often be a concern when curtain wall construction is employed, and water penetration needs to be fully controlled.
• Airflow Calculations. In order to predict the airflow performance of architectural louvers, manufacturers may offer an online tool allowing design professionals to enter design parameters and determine the performance of selected louver products at a given size. The input information includes the designed width and height of a louver, the design wind load, and the selected louver. If applicable, HVAC fan information can also be entered in the form of cubic feet per minute (CFM) intake or exhaust. The program will then calculate and provide the results related to free area square feet and percentage, the free area air velocity, and tested pressure drop. There is also the opportunity to connect with manufacturer’s technical teams to review any or all of these aspects of acoustical louver design to confirm the total performance in a building project.

ACOUSTICAL CURTAINS

There are some situations where a solid wall is not appropriate, but acoustical control is still needed. A good example is in healthcare settings where a group of patients need to be in close proximity of each other to receive appropriate care, but still need their privacy protected. Surgical pre-op spaces need to protect patient confidentiality, outpatient surgery centers need acoustically private doctor consult areas before surgery, and patients need quiet areas for recovery post-op. That privacy is not only to help with their sense of comfort in the space but also to comply with the federal HIPAA requirements which all healthcare facilities must meet.

In such cases, long curtains are commonly hung on ceiling tracks to provide privacy but also so they can be opened to roll beds with patients in or out of the enclosed space or simply to tend readily to their care when needed. When those curtains are designed and manufactured with acoustical properties, then they can achieve the seemingly paradoxical goals of access plus privacy. Beyond healthcare, such acoustical curtains can be used in any building where a privacy setting is required such as hair salons, mother rooms in office buildings, or spaces that need to adapt fast to provide separated rooms or areas. Overhead tracks with privacy sound absorption curtains can easily be installed to provide those spaces with the acoustical privacy that may be needed.

Photo courtesy of Construction Specialties, Inc.

Acoustical curtains provide a design solution for needed access to an enclosable space while offering much improved acoustical privacy.

Image courtesy of Construction Specialties, Inc.

Field test reflects over a 70 percent improvement in reverberation comparing before the acoustical curtain was installed with after the installation.

Field test reflects over a 70 percent improvement in reverberation comparing before the acoustical curtain was installed with after the installation.

The means for acoustical privacy curtains to achieve their sound attenuation performance is a direct result of the way they are made. The curtains are essentially panels of fabrics that allow for absorptive inserts to be incorporated into them. This produces a noise reduction coefficient (NRC) of 0.95 and an STC of 11. Essentially these results are achieved by the panels blocking and absorbing sound by slowing the reflective velocity of the sound.

One of the benefits of these acoustic curtains is that they require virtually no extra space. Further, since they are double sided, more acoustical materials can be installed to suit different acoustical privacy needs. Their simplicity makes them appropriate for new construction or for retrofit/ renovation projects with no significant disruption in the use of the space. Their acoustic performance has been tested and some carry documentation that they are capable of aiding in patient privacy and HIPAA compliance. The panels are available in a wide range of fabrics with many different colors and patterns, which can also provide a visual setting that helps elevate patient spirits.

Jason Ellis, senior business manager of interior product solutions at Construction Specialties has reviewed some of the documentation and testing of these acoustical curtains. He observes, “Tested by third-party scientists, the acoustical curtain, when installed, showed a seventy percent improvement in reverberation time. It provides privacy by incorporating acoustical panels that help absorb sound that softens and muffles noise by slowing the reflective velocity within a space.”

Conclusion

Architects and designers are well served when they take time in the design process to consider the acoustical needs of the building occupants. Addressing the entire spectrum of sound control within individual rooms and spaces in a holistic or comprehensive manner will assure the best performance. By addressing the sound absorption, reflection, and transmission in a given room, the appropriate sound qualities can become part of a successful acoustic design. Overall, this holistic, coordinated approach will yield a design that creates a very positive contribution to the total indoor environmental experience of the building.

ACOUSTICAL CURTAINS CASE STUDY

Photos courtesy of Construction Specialties, Inc.

Project: St. Joseph Medical Center
Location: Tacoma, Wash.

The Goal: To provide a quiet, healing environment for patients, family, and staff in the neo-natal intensive care unit (NICU).

The Solution: Acoustical cubicle curtains were installed which significantly reduce reflected noise, quickly reduce the sound reflections from the neonates crying, and helps control other incidental noises.

Sound Absorption: The acoustical curtains contribute to a reduction in sound reflectivity to 165 percent less than the Facilities Guideline Institute (FGI) standards for healthcare facilities. The reduction in sound transmission makes the nursery pods quieter even when there is a significant amount of activity from nurses, patients, phones, and families. An increase in sound absorption makes a space quieter and more intimate, and makes sound very directional, which means nurses can clearly locate the source of crying as well as alarms.

Reactions: Some of the reactions of those using the renovated facility are captured in the following quotes: “The noise level in the NICU has changed 100 percent since the renovations. There is no longer any more echoing, families can have private conversations and the whole unit does not overhear them. We no longer hear the sound of high heels, babies crying, and the business of the daily activities. The staff complained initially because they had to really be aware of what alarms are ringing off. It's been wonderful to provide the level of care we do and have the soothing environment necessary for optimal healing and growing.” “Before the acoustical curtain installation, the level of speech privacy was marginal to no privacy. After completion of the renovation and installation of the curtains, the level of speech privacy increased to ‘normal non-intrusive.” “With the acoustical curtains the room absorption and speech privacy are improved to give families and nurses a ‘normal’ level of speech privacy. This means that when the curtain is closed for an alcove or pod, words will only be perceived when someone is trying to attentively listen but will not be intrusive. The sounds from alarms and crying will not be attenuated to a level that will put any patients at risk but will be reduced by 25 to 35 percent and be clearly audible. This should provide a more comforting acoustic environment for the families during this stressful experience.” “The RNs have commented numerous times on the difference the NICU sounds from the hectic activities of daily living to the soothing, calm environment today. The infants seem to be more relaxed and feeding and growing appropriately.”