Sound Engineering, Engineering And Conference Rooms
August 25, 2019
The technologies of building layout and of the seminar systems we install in them have both changed greatly since the phrase form follows function is introduced to the world. Regrettably, we frequently see that the lowly conference room having minimal infrastructure inspection during the design and construction process, more often than not taking a second seat in the design of the contemporary office.
At various trade shows and industry gatherings, I often hear people expressing regrets of not catching up to the latest industry trends and information. Interestingly enough, this is usually not about the technology from the seminar room but is rather a reference into the base building design and its effect on the standard of video and audio conferencing.
The shape and the dimensions of a room, the acoustical treatment, and HVAC (heating, ventilation, air conditioning) are all important factors in the successful implementation of sound conference systems. Ideally, when designing a conference room, you would enlist the services of allied professionals, especially an MEP Engineer (Mechanical, Electrical, and Plumbing) together with Acoustic and Audiovisual Consultants. But frequently people go to us for an engineering consultation for the commissioning of seminar systems where key professionals weren’t consulted. For all those spaces where the architect or owner are left to design the space on their own, we provide these guidelines and product ideas to help conquer such deficits.
Among the most difficult challenges we encounter is coping with too much ambient noise, typically caused by ill-designed HVAC systems. Noise curves are a common means to quantify and define background noise in unoccupied buildings and spaces. Their objective is to create a single value representative of a complete sound spectrum.
There are assorted noise rating methods for determining the ambient noise level of a room, such as Noise Criteria (NC), Noise Criteria Balanced (NCB), Room Criteria (RC), Preferred Noise Criteria (PNC), along with Noise Rating (NR) curves. For the purposes of the discussion, we will be focusing on NC (Noise Criteria) rating.
Typically, two sound problems can be produced by the HVAC system: mechanical noise in the equipment itself, and sound created by the air speeding throughout the ductwork. Mechanical equipment noise by fans, chillers, pumps, and dampers could be mediated by getting them out of the way from the conference room as far as possible — something often not addressable in a completed building.
The consequences of noise created by high air rate can, however, be reduced. Oversized ductwork (rather lined) should be employed, permitting the system to maintain the desired room temperature whilst retaining the airspeed to minimal. Ideally, an NC target of 30 or less would be desired for a conference space audio/video system in which microphones will be deployed. Both supply and return ducts have to be reviewed related to size and length in noise evaluation.
The size and shape of this space under layout should be assessed with an eye on occupancy and function. Where wall space permits, acoustical materials need to be used. Today, a multitude of effective interior acoustical treatments are available, making it feasible to create a much more acoustically inert conference space having an acceptable aesthetic appearance.
The current trend toward acoustically reflective glass partitions in seminar rooms makes the space more reverberant while reducing the wall surface area available. Therefore, any available wall surface should be considered for therapy with absorptive materials. Acoustical tile ceilings and carpets are also beneficial in this respect. For conference rooms that follow the latest trends, have a look at the Melbourne city conference centre and take your inspiration from them.
Conference room wall construction another major factor, and is frequently affected with the functions of surrounding spaces. In the event the conference space is situated adjacent to some mechanical equipment room, it is going to require a higher Sound Transmission Class (STC) partition than if it is alongside a storage cupboard. Doors and windows must also be carefully considered with regard to the essential acoustical isolation. It is important to match the STC rating of your walls in order to maintain the Noise Criteria (NC) rating of the room.
Sometimes the offending noise source is out the building in the kind of mechanical equipment, sirens, traffic sound etc.. These offending noise sources (outside walls/windows) should be taken into consideration when determining where to put a noise-critical space such as a conference room on your floor plan. Of course, one of the more obvious solutions is to use noise-cancelling walls, just like the ones used in some of the best conference venues in Melbourne, but oftentimes, it could not solve 100% of the problem. This is why location is still key.
Fortunately, even when one or more of these considerations are not accounted for during design/construction, improvements in conferencing engineering, networking, and low voltage infrastructure to have improved tremendously, supplying tools which may help alleviate the effects of less-than-optimal conference room layout.
Once the foundation building features are set up, it’s almost impossible (financially and/or logistically) to make the adjustments required to achieve suitable functionality. It’s always best to enlist the assistance of MEP, acoustical, and AV professionals to help with a few of the details of conference space layout, but the advice above should go a long way in helping to avoid some of the pitfalls in the design of your next conference room.