ACOUSTICS AND INTERIOR GLASS PARTITIONS

When incorporating interior glass partitions into a building, sound privacy is always important, especially in applications such as government buildings, law firms, HR departments, and conference rooms. Accordingly, there is a trend for using dual-glazed interior glass partitions with improved STC ratings. Such systems typically feature insulating glass sealed completely into a frame that effectively mitigates incoming and outgoing sound transmission.

The level of STC rating needed is commonly debated with many architects often believing that a very high STC rating of 40 or more is needed for a partition system. However, there is often some background noise in most commercial environments such that effective sound privacy can be achieved with a system that achieves ratings on the order of STC-37 to STC-40. At this level, normal speech might be heard but is unintelligible.

Acoustical Details

In order to achieve this level of acoustic performance, framed interior partitions are likely the best choice. Some have been specifically developed to meet the acoustic needs of buildings and balance their physical appearance with acoustic performance to create an appealing solution. Frameless partitions can also provide some acoustic separation, but typically not as much as a framed system, particularly if gaps in the glazing are part of the design. Free-standing systems, by their nature, are not attached to the adjacent ceiling or walls, so sound is free to travel around the partitions. In all of those cases, other sound mitigating measures may be employed on the floors, ceilings, and walls near or around the glass partitions to absorb sound and reduce its transmission in other ways.

Photo courtesy of CRL

The acoustical privacy of a space can be important with interior glass partitions even as visual transparency is valued.

In framed partitions, there are several items to pay attention to when it comes to sound control. The first is the type of glass that is used. Insulating, double-layer glass is the best choice since it acts to insulate sound energy in the same way that it insulates heat energy in exterior situations. Other types of glass, such as single panes of laminated glass or thicker solid glass will likely conduct more sound than the insulating glass in most situations. Paying attention to the types of gaskets or seals that are used to hold the glass in place against the framing elements is important too. If good-quality seals are used, then sound is controlled, whereas if there are gaps or low-quality material, then the sound is less controlled. Taking all of the above options into account, it is quite realistic to expect that framed interior glass partitions with fixed glazing can achieve sound ratings of up to STC-42.

The next detail to consider is the use of doors being incorporated within the partitions. Many can accommodate either a glass or a wood door within normal size restrictions for the selected framing system. In either case, a drop-down seal is recommended for the best acoustical performance. That way, when the door is closed, it can be better sealed against sound transfer. The door type itself will influence the sound transmission since wood doors will typically have better acoustical performance than glass doors. Hence, for the partition panel that contains a door, it would be reasonable to expect a sound rating of STC-40 with a wood door, or about STC-37 for a glass door. Both are reasonable, depending on the sound transmission goals for a particular project.

Mark Suehiro is the technical director at CRL, a national manufacturer of glass partition systems, among other products. He points out that "Glass partition systems play an important role in interior design. They offer striking glass spans that seamlessly define spaces while maintaining transparency and promoting daylighting. Many design options are available to complement the project scope, as well as performance features such as sound attenuation.” Reviewing the technical specifications of such systems, as well as the visual aspects, can yield the best results in a building project.

FUNCTIONALITY IN THE DETAILS

There are a few places in an interior that deserve a little more attention including the following:

• Window Shades: Many interior design projects include the use of commercial window shades. Most of them are made of durable materials, but they have different aspects or traits that can be selected and specified. Specifically, there are three aspects of the makeup of the fabric that affect building interiors. First, is the Openness Factor which refers to the weave density of a shade fabric. For example, a shade fabric with a 5 percent Openness Factor is 95 percent material and 5 percent “holes”─the space between the weaves. A different openness factor may be needed for different uses such as a corporate office compared to a hospital patient room. Second, the Visual Light Transmission (VLT) is a measure of glare represented by the ratio of the amount of total visible solar energy (light) that passes through glass and shade combined. As a general rule, darker-colored fabrics offer better glare reduction than lighter colors and also offer better view-through. Third, the shading coefficient (SC) is a percentage that measures the solar heat gain (heat) through a combination of glass and shades. As a general rule, lighter-colored fabrics provide a lower heat gain and better thermal performance than darker colors. Recognizing the differences in window shade fabric for these three measures, designers can select the ones that best suit the needs of a project and fine-tune the overall appearance and functionality of the space.
• Elevator Interiors: There is a misperception among some building owners that the elevator interior doesn’t matter or is unimportant, but the reality is that any place that is used repeatedly by visitors, occupants, or guests in a facility makes an impact on the perception people walk away with of that building. Therefore, paying attention to the interior cab design of elevators can pay off in real ways.

A well-designed elevator interior that incorporates artwork or imagery helps to provide memorable experiences for guests or users. This is true when quality, durable materials are used but also when vibrant or dramatic artwork and imagery are incorporated. Artwork and imagery can provide a new personality to any building, particularly hospitality, retail, corporate, and educational facilities. Strategically placed art in an elevator that is being used by the same people multiple times a day can provide a sense of comfort, class, and happiness, particularly for first-time visitors. Imagery in elevators can also be used to reinforce the themes in company or facility branding, or even as a way to display large-scale photos of local landmarks and attractions. This helps guests and visitors connect to the location of their travel destination in unique and memorable ways.

Modernizing the elevators and incorporating artwork can impact the property’s overall market value too. When incorporating unique artwork and imagery inside elevators, the building is differentiated from the competition, enticing more guests and visitors to come to the building. It also can prove to be a positive return on investment when combined with new wall panels, grab bars, cabs, and lights. This can all contribute to increasing the financial value of a building not only on paper but also to the people using it.

Of course, a critical aspect of elevator renovation that often goes undetected is accessibility. Certain features must be present inside the elevator to ensure compliance with building codes and the Americans with Disabilities Act (ADA) so that people with mobility, vision, or hearing issues can safely use the elevator system. Artwork and imagery can help assist with wayfinding and defining a sense of place for all people to use equitably.

Photo courtesy of Inpro

Artwork, imagery, and logos used in interiors can create positive experiences as long as they are installed in a manner that protects the artwork.