More and more office furniture is being designed to accommodate the burgeoning presence of IT (information technology) and A/V (audio/video) technology in the workplace. Furniture manufacturers have recognized the need for modern office workstations to manage cabling for telephones, monitors, and personal computers, and for conference tables to provide built-in access for multimedia communications. The result has been the development during the past decade of desks and tables known as “smart” furniture — though no active or “smart” components are actually involved.
Architects and interior designers have the option of transforming ordinary furniture into “smart” furniture. Rather than select available stock furniture equipped with connectivity devices, they may choose to purchase infrastructure hardware components, either standard or custom, as stand-alone units ready to install in furniture. There are, however, various connectivity issues to be addressed when equipping furniture with electronic devices, especially if furniture is to be stacked, folded, or stored.
While designers have been eager to adopt “smart” furniture solutions, it is often without full recognition of the special considerations they require. Today’s “smart” furniture includes the use of both proprietary connection systems and commercially available (non-proprietory) devices for IT and power connectors, as well as customizable A/V spaces. Some of these devices are part of larger families of components that may include connections to partition walls or raised floor systems.
Furniture IT/AV infrastructure components comprise three basic types: flush mounts, table pockets, and table boxes. The least expensive are flush-mount plates with exposed connectors. “Table pocket” components embed these plates into the furniture, with one or two pocket, “bomb bay,” or other access doors. Brushes, “mouse holes,” or indentations in the covers prevent cable abrasion and pinching. More complex devices include boxes that “pop up” from the table, either manually or electrically, boxes that “flip” up on one hinged side, and boxes that rotate, with a finished surface opposite that of the connectorized side.
A key aspect of table connectivity is whether the components allow integrators to customize them or whether they must be configured and assembled at the factory. A second factor is whether the device is modular, that is, whether it is configured so that the trades involved in installing it can work on their own specific area without disturbing other trades’ work. This is important in the construction process, where trades perform a variety of sub-installation procedures in sequence on the job site.
A third factor affecting connectivity is whether the connectors and their mounting hardware are standard and readily available (or project-specific), or whether they are unique to the device manufacturer. Finally, modularity and physical separation within each service category (electrical, IT, telephony, and A/V) are also desirable.
Equally important as the devices themselves is the management of cabling from the device to the floor, wall, or another furniture component. Some furniture interface products are equipped with standard or simple connection points, enabling each trade to install cabling as necessary for the project. Others products are supplied with fixed- or custom-length cables, often with connectorized ends. The termination points of these cables may vary from room to room, however, or may change during the course of the project.
Cabling situations differ widely. One cable may need to be pulled in its entirety from an equipment cabinet or patch panel, for example, and terminated in a fixed-furniture situation at the furniture interface. Other cables may require connectors for presentation to a floor or wall box. Still others may need to be extra long because they are expected to be frequently connected and disconnected to floor or wall boxes in different locations.
Cables must be managed beneath and within the furniture to which the device is affixed. They must be secure and free from excess slack, which can be a hazard and catch accidentally on one’s shoes, knees, or hands. Attaching cables to hidden portions of the furniture, such as the underside of large conference tables, is often best handled with hooks or standard cable raceway products. Any holes between millwork architectural components should be treated with “grommets” or other escutcheons designed to prevent cable abrasion. Pathways and raceways should be separated with respect to signal types of the furniture interface configuration.
Besides cable management, how the cabling is handled on and around the visible work surface is very important. These surfaces often contain unsightly elements such as excess cable, power supplies, transient suppressors, and signal converters — in addition to the usual workday clutter of laptop computers, audioconference equipment, coffee pots, paperwork, etc. The use of furniture interfaces, grommets, slots with brushes, or other on-table raceways is desirable to both connect and hide cabling.
Wall and Floor Boxes
A related task is locating wall boxes and floor boxes. Unfortunately, these infrastructure devices are often installed prior to the detailed design of furniture locations. Later furniture layouts can cause complete misalignments, such as when A/V credenzas or desks are located on a different wall! Designing connectorization within the floor and wall boxes of rooms with reconfigurable furniture is particularly problematic, as this cabling will be more frequently plugged and unplugged.
Common practice in these rooms is to plot the floor box locations beneath as many anticipated furniture layouts as possible by layering the furniture plans and looking for intersections. More robust cables and connectors (e.g., military-style, multi-pin) are often specified, and connectors even may be modified (e.g., removing the latches on audio XLR connectors) to permit easy unplugging where cables present tripping hazards. Another technique is to use right-angle, swivel, or other special connectors to orient the cable with respect to the connection point.
Procedurally, designers should select furniture with an integral connection system only after the technology team has discerned the project parameters, as the furniture may be very difficult to adapt later. Although well-meaning designers may select furniture because of its technology features, the particular furniture infrastructure may be inappropriate or inadequate for the client’s requirements.
Once a system is selected, its rationale must be communicated to the construction team. Questions are bound to arise, ranging from the physical locations in the furniture to how cabling is managed from the furniture to the room. All these issues should be discussed in both technology and architectural meetings — and tracked on both project minutes and project schedules — because of the several trades involved, chiefly IT, A/V, millwork, and electrical.
IT Issues. The design of IT infrastructure in a building follows very specific standards while being flexible enough to accommodate the space’s users and their technology needs. Although a variety of components and cables may be selected, designers do attempt to standardize particular aspects of the hardware implementation. This may include using certain jacks on each wallplate, a particular number of patch points in a data closet cabinet, color-coded cables for different signal purposes, a combination of copper and fiber, etc.
Moreover, one manufacturer’s components may be specified throughout the entire project in the interest, for example, of “certifying” the bandwidth of each of the point-to-point cable runs. Most of these features aimed at standardizing the installation are largely invisible to the casual observer, yet they are extremely important to the performance of the networks. And they apply, of course, to all the infrastructure components including the furniture connectivity components.
One frequent objection to furniture components from IT professionals is that they represent an “extension cord” to the building infrastructure, adding extra length to the network cabling. The total cable distance between active network components is fixed by industry standard. But to prevent the furniture cabling from exceeding these limits, the installation’s bandwidth and distance certification should be tested at the furniture endpoint, not just at the building endpoint. High-quality components and workmanship must be demanded in the assembly of furniture components, as the furniture endpoint also represents a potential point of failure in the system.
Furniture infrastructure components are not always specified by IT professionals. It is advisable, however, that specifiers utilize infrastructure components capable of being configured with exactly the devices desired by the IT designers. This way, at least, consistency of design is achieved from user endpoint to IDF (Intermediate Data Frame) through MDF (Main Data Frame), with patch point and sequencing standards maintained. Ideally, system certification may be guaranteed.
A/V Issues. Audio/video connection schemes pose a major challenge for successful furniture installations due to the rapid pace of industry development. A/V connectors come in many varieties and new ones are being developed all the time. Because of the expense in changing all the furniture hardware when new requirements arise, it is impractical (and irresponsible) to utilize fixed-configuration connection points for this purpose. Rather, planning for future system changes should be done at the time of the original installation.
Other considerations arise from the nature of A/V technology. For example, some A/V signals are more sensitive than others in terms of interference from adjacent cables (microphone signals are perhaps the most sensitive). This interference or crosstalk could include leakage from improperly terminated connectors or from proximity to other cables in parallel with them. Also, many connectors are sizable (deep when installed) yet require additional space behind the plate for the bend radius of the cable. (This is particularly true for high-bandwidth coaxial cabling, commonly used for computer video connectivity.)
Each connection point represents a potential point of failure. Hums, buzzes, and crackling often are caused by faulty connections points. Designers intentionally design systems with a minimum of connection points, yet they are also aware that to add new features to systems unprepared for them means pulling new cable and often the complete disassembly of connector plates. Value engineering that removes this flexibility should be decided very carefully.
Millwork Issues. When adapting furniture for infrastructure devices, the millworker faces any number of challenges: The location of the device could interfere with structural or decorative elements of the furniture; the cable management components beneath the surface may require channeling and cutting to install raceways; the legs or bases of the furniture may require cutting access holes and hatches for connecting to floor boxes below. Very likely the furniture must accommodate a variety of power supplies, interfaces, and cable excess.
The responsibility for cutting holes, routing edges, installing trim, etc., should be left to professional craftsmen, who have the proper tools and expertise. Outcomes such as damaged finishes, compromised structural integrity, and mismatched hardware have both functional and aesthetic ramifications that are unacceptable on a “high fit and finish” project. When furniture is modified in the field, workers are prone to mistakes, and millworkers will always prefer that any furniture modifications be made in their shops. This can only be accomplished with good project coordination.
Electrical Issues. Furniture infrastructure raises issues about how low-voltage cabling coexists with other types of cabling. In some jurisdictions, for example, power cabling must be completely enclosed in rigid or flexible conduit. Rubber cord that can be construed as an extension cord is often not allowed. The furniture infrastructure device usually must be UL approved in order to pass fire codes (which may mean installing a UL-approved standard electrical junction box).
The high-voltage and low-voltage cabling must be physically separated. This may be as simple as installing a steel or rated plastic barrier between the cables and any terminations, but these barriers must pass inspection. The cabling in some projects will pass through a plenum air space, and both the high- and low-voltage cabling must be plenum-rated, with a jacket made of Teflon or a similar material. In some locales, electrical codes mandate that the low-voltage cabling in any devices that mix high and low voltages be rated for high voltage, typically 600V. But most A/V cabling is not so rated.
Installation of furniture infrastructure devices should be coordinated with the general contractor, who must plan for these device locations relative to construction elements such as floor ducts, beams, rebar, etc. It may not be possible, for example, to install these devices in buildings constructed with prestressed concrete, as the structural integrity of the slabs cannot be compromised. Thus, relocating the floor or wall interfaces becomes necessary, which may trigger a redesign of the furniture locations. This, in turn, could affect the design of the A/V system!
Proper installation of furniture IT/AV devices requires a collaborative effort that includes both the design and construction teams. Poor planning can result in excessive construction delays and could affect many other trades such as carpet installers, painters, and furniture movers. Good planning can result in a highly functional project that both looks good and works well.