You’re reading an outdated article. Please go to the recent issues to find up-to-date content.
The need for modern mechanical and communication systems is breathing new life into aging buildings through technologies many decades newer than their bricks and mortar;
when building renovation includes integration, advanced wired and wireless infrastructures are allowing upgrades and networking of outdated control systems even when running new wiring might be impossible, impractical or cost prohibitive.
With the latest introductions to the integration market, business buildings, learning institutions, hospitals, museums, manufacturing plants and various historical facilities are benefiting from the integration of energy-efficient and sophisticated technologies including fire and life safety systems, security programs and lighting.
Integration also is incorporating data networking capabilities and the installation of standard communication protocols for more effective inclusion of future devices and technologies.
Rebuilding the power and data infrastructures in older buildings, however, can pose a number of structural challenges to electrical contractors starting with outdated, incompatible and unreliable wiring incapable of interfacing with advanced building automation devices.
From an architectural standpoint, ceilings and walls made of materials such as brick, stone, cinder block, plaster, asbestos and steel beams enclosed in columns are difficult to open and restore. Many retrofitting projects require minimal disruption to daily operations and occupants. Others mandate low physical impact to the structure, especially with vintage and historical facilities.
According to Jeff Raimo, product manager, Siemens Building Technologies Inc., specific vertical markets and facilities have their own unique challenges. For example, it is critical for healthcare facilities to minimize the amount of airborne contaminants for infection control, while modifications in industrial plants should not interfere with production or create safety hazards.
“Frequently the best strategy is to utilize a mix of hard-wired and wireless solutions. Many devices can be easily wired and this is often the most efficient way to connect them. However, other devices may have challenging wire runs to them, and wireless makes more sense,” Raimo said.
When wiring inside walls and ceilings is outdated, inaccessible or too time-consuming to modify, surface-mounted raceway presents high-capacity integration solutions. Generally, raceway provides flexibility for future moves, adds or changes and has increased capacity compared to conduit. Recent developments provide dual-channel raceway with the ability to carry both line and low-voltage in the same raceway, said Ray Szekretar, product marketing manager of metallic raceway for Wiremold.
“Dual covers allow contractors both [power and data] to access their respective channel whenever they need to without having to access the other channel or have everything open when working with a single cover product,” Szekretar said.
Northside Independent School District (NISD) in San Antonio is committed to incorporating technology into all facets of instruction and staying ahead of the technology curve during an ambitious construction and renovation program. The district is growing by approximately 3,000 students a year with a forecast of more than 100,000 students within the next eight years.
“We have to be prepared for change, and raceway systems allow that to happen. If a school needs more computers in one area, for example, we need to be able to easily expand without major renovations,” said Paul Megerle, NISD electrical/telecommunications project manager. “This is just as true in new schools as older ones that are being upgraded because they have the same changing needs.”
Even newer buildings, those from 10 to 20 years old, require extensive work. NISD has consistently invested in upgrade services with clean power, installing raceways in all classrooms for teacher and student computers as well as floor boxes or poles to support technology.
Bringing older buildings into the new millennium for data communications requires a large volume of low and line voltage and high-speed cabling. The Wiremold nonmetallic dual channel series has 10-gigabit-ready fittings to accommodate emerging Ethernet over copper applications. An integrated divider is built into the modular design and adjusts to fit couplings as well as obstacle-avoidance fittings for box-enclosed columns and vertically run conduit or raceway.
Updating contracts often have stringent time constraints due to current occupancy. Prewired raceway cuts down on field fabrication. “It can get contractors off the job in one-third the time. This is obviously a huge money saver, especially in light of the fact that raceway is usually one of the last things installed. It can potentially put a job back on time or finish a job early, which might result in a bonus,” Szekretar said.
A prewired option allowed 19 older schools in the Columbia County, Ga., school district to be wired with voice and data connections in a tight timeframe leading up to the first day of school. Prewired 4000 series raceway was installed to spec with mounted finished units, connected leads and communications cabling—a total of 753 drops in 33 days.
Wireless infrastructures also are gaining popularity in retrofit situations where spaces may be frequently reconfigured. Many times a power source is already present, so a new wireless controller can be retrofitted to an existing VAV box, eliminating the need to pull new wiring to each box if a hard-wired network infrastructure was degraded, incompatible or not present. Wireless sensors can then easily be added to existing interior spaces without regard to what wiring might be present or where it is located.
A recent development in the wireless arena has been the emergence of mesh communications, which is bridging some of the shortfalls of earlier point-to-point wireless systems. Siemens recently introduced Apogee Wireless, the industry’s first wireless building automation system. This mesh network uses a grid-like topology to provide multiple redundant communication paths with each node functioning as a sender, receiver and router. Engineered to route signals around obstructions, each node is required to communicate with only two or three neighboring nodes.
The mesh technology is appealing to building managers because of its reliability across a wide array of building types. “The technology is proving itself to be very adaptable, regardless of whether it is being used in a small commercial office building or a large, cavernous manufacturing plant,” Raimo said.
The advanced wireless automation system allows for a staged migration of legacy systems to meet budgets and existing occupant schedules. Typically, the wiring being used by legacy systems cannot be reused by new systems. Consequently, new wiring has to be installed, and the entire network has to be taken down and data transferred to the new network at the same time.
“With a staged approach, controls can be replaced and connected to the new system via wireless links—one by one—without affecting the remaining legacy control devices. This makes scheduling easier and allows a seamless migration with no disruption in service that can be staged over time if needed to better fit tight budgets,” Raimo said.
The impact on energy efficiency is measurable, Raimo said. Wireless automation systems allow previous stand-alone systems to be networked, controlled and operated from a central control location. Combined with wireless sensing, it allows the most efficient use of equipment.
“Heating and air-conditioning units, lighting systems, fans and other pieces of equipment are only operated when needed or scheduled, cutting down on wasted energy,” Raimo said.
Although wireless systems are poised for significant growth, current building codes and standards lack technology. IEEE has continued to drive the adoption of new wireless standards in section 802.11 of the protocol standards. For low-power, low-data rate wireless, Raimo said the ZigBee Alliance—an association of companies working together to enable reliable, cost-effective, low-power, wirelessly networked monitoring and control products based on an open global standard—has been active in developing a new wireless standard.
As the cost of wireless technology continues to decrease, a wireless connection will make sense for more devices, with some experts projecting it to be a low-cost infrastructure in the future.
Raimo speculates power requirements will continue to decrease, and the use of power-harvesting strategies will increase, allowing more battery-powered wireless devices to run longer without maintenance or eliminating batteries altogether. Radio frequency electronics will be embedded into more devices. Sensors will continue to shrink and be implanted into a larger number of devices to monitor for predictive maintenance, comfort, life safety and security, etc. Building automation system devices could use the larger ubiquitous wireless infrastructure.
“Each building contains a warehouse of information that can be mined and monitored via the Internet or automatically for optimal control, energy efficiency and occupant comfort. Technical advances in areas like wireless and sensors will make it practical to access all of this information,” Raimo said. EC
MCCLUNG, owner of Woodland Communications, is a construction writer from Iowa. She can be reached via e-mail at [email protected].
About The Author
Debbie McClung, owner of Woodland Communications, is a construction writer from Iowa.