R&D demands quality electrical, wireless systems By Tod O. Moore, RCDD, CSI, and Troy W. Thrun, PE, LEED AP The research conducted in laboratory facilities is constantly in flux, but one thing is certain: problems with power translate into many dollars in lost research. Eliminating the risk of electrical outages, surges, and sags will always be primary considerations in design of lab facilities. In addition, electrical systems must be flexible to limit down time during renovation of lab space as research teams are switched out. Another relatively new consideration for labs is wireless design. Many modern lab facilities include breakout spaces where researchers can meet and informally collaborate. Having technology in place to travel wirelessly in these spaces is becoming more desirable. While the specialized power requirements of most labs ensure that wireless will never completely replace wired technology, research facilities are increasingly being outfitted with conduit and data connections, at a minimum, to provide coverage for wireless local area networks (WLAN), either now or in the future. Electrical considerations Electrical interference, reliability, and redundancy all come into play in providing power to world-class laboratory facilities. Specialized power needs of modern laboratories range from reducing electrical noise in animal areas to providing dense power for computational server rooms. Providing the appropriate amount of electrical power and managing electrical interruptions are critical in lab design. This process has been facilitated over the past few years as research companies are increasingly relocating from retrofitted warehouses and office buildings to facilities that are more tailored to their specific needs. In this scenario, engineers have the opportunity to provide clean and flexible power right where it is needed. Capacity The average research laboratory draws from 16W to 20W of electrical power per ft2, which is significantly more than the amount for the average computer-filled office building (approximately 6 W/ ft2). As the square footage in labs increases, the electrical requirements in W/ft2 decrease. Larger labs generally have added support functions, which require less electrical load. Computational server rooms located in many modern research labs have high-density server racks that can accommodate up to 130 servers each. To support this level of computing power and the associated individual cooling requirements, electrical loads may be up to 150 W/ft2. Graphs of data assembled from existing labs can be used to calculate power requirements for new lab space. In this way, engineers can determine the appropriate amount of power with acceptable spare capacity for each lab. It’s also smart to provide access to a nearby panelboard in lab spaces. Due to frequent turnover of lab space and the evolution of power needs, 25 to 40% spare capacity should be available in panelboards so adjacent labs aren’t interrupted. IRS and WLAN systems provide power to different types of wireless devices, making system redundancy within a single building a must for most science clients. Diagram: Sparling. Click to enlarge. Reliability While most lab owners would like their electrical system to be 100% reliable, accommodating this request is neither realistic nor possible. It is possible to achieve 99.9 to 99.999% reliability, though the difference between an annual 9-hr outage and a 3-min outage is a large and potentially expensive jump. Backup systems can be especially costly for labs that are located in areas where local power is commonly interrupted. Facilities can build a strong initial base of reliability into the electrical distribution system by using a three-transformer spot network, which can provide up to 99.995% reliability within the normal power system. A 1.5 MW back-up generator for certain critical loads and equipment brings the reliability to 99.999%. Many electric utility companies in large cities use a spot network to serve the downtown core, but labs located in suburbs and outlying areas will experience longer, more numerous outages. Adding additional medium-voltage feeders from separate substations or installing multiple on-site generators is recommended to achieve maximum reliability. Interstitial space Interstitial spaces are “floors between floors,” complete with poured concrete flooring and access to the lab area or floor below. These storage spaces provide a level of storage beyond what an accessible ceiling can offer, and can save a facility thousands of dollars in labor and remodeling costs when they are installed above labs. The interstitial space method of laboratory construction has several benefits, from an electrical design standpoint: • Workers and contractors aren’t required to use ladders because most electrical equipment and systems can be accessed and maintained from the interstitial space. • Construction schedules can be compressed, resulting in cost savings. This is mainly due to the fact that lab spaces can be fitted up at the same time building systems are being installed. Ongoing operation and maintenance of equipment and infrastructure systems is simplified. The result is direct operational cost savings and reduced life-cycle costs for the building. • Maintenance of equipment and systems can be completed without disrupting laboratory services. • Panelboards, transformers, bus ducts, and disconnects can all be located in the interstitial space, maximizing space on the lab floor for equipment and bench space. • In many cases, electrical and mechanical alternations can occur in interstitial spaces while research continues below. To prevent disruption, final connections to any new equipment can be performed during off hours. Interstitial space is more expensive to construct at the outset. Thus, many publicly funded lab buildings opt for a more traditional design that utilizes pathways within accessible ceilings. Some facilities plan for interstitial space above the most crucial or sensitive lab areas, such as animal holding areas. Controlling building systems workers’ access to animal spaces dramatically reduces the potential for human contamination. Lighting systems While often overlooked, laboratory lighting systems are a critical component in the design of research facilities. The Illuminating Engineering Society of North America (IESNA) recommends 50 footcandles in the horizontal plane and 30 footcandles in the vertical plane in research areas. To support fine instrument bench work, researchers typically prefer to have more than 50 footcandles in the horizontal plane. A common way to illuminate research areas is to provide rows of recessed fluorescent fixtures over benches. This configuration easily meets IESNA guidelines at ~70 to 100 footcandles, but introduces shadows in work areas. The desired light level can be achieved without accompanying shadows by using three-lamp T-5 HO fixtures. To obtain the vertical requirement, a single row of “drop-basket” fixtures recessed in the ceiling and located between benches at 10.5 ft apart is an example of an indirect configuration that can provide up to 60 footcandles in the vertical plane. The lab lighting market is evolving rapidly, giving the designer a broad choice of fixture configurations. For instance, pendant direct/ indirect fixtures are gaining popularity. Make sure to discuss your needs thoroughly with your project team, not only in terms of illumination but also cleanability. As energy requirements for technology in laboratories increase at a steady rate, reducing the energy used by lighting becomes more critical. Energy-saving controls and daylight dimming can contribute significant value to a laboratory building’s overall sustainable design. Lighting of animal areas is another important consideration. Dimming and override fixture control are critical to prevent animals from being disturbed during research. Wireless system considerations Research staff are increasingly using wireless devices in labs, including local area network systems, PDAs (Blackberries and Treos), maintenance radios, cellular and cordless phones, Bluetooth devices, and cordless headsets. It is critical that users understand the differences between these devices in terms of infrastructure costs during planning and design of a new lab. A common misconception is that “wireless is wireless,” when in fact different wireless devices typically require different infrastructure, so two or more separate wireless systems might be needed. The subtle difference between a WLAN, a cellular phone, and a fire department handheld radio is the frequency band on which these signals are carried. Each frequency band requires a different infrastructure to properly support the devices that operate in that band. Users may ask “Why can’t we run our WLAN over the same cables and antennas as our cellular phones and fire department radios, thereby saving money by installing only one ‘super’ wireless infrastructure system?” The reason this is tougher than it sounds is fundamental to wireless communications design: Signals of different frequencies require specific handling of antenna configurations. The required characteristics vary enough between “radio” and “WLAN” to make a combined antenna system unworkable in most cases. Due to the potential mayhem surrounding this issue, the Federal Communications Commission has defined certain devices to reside within certain frequency bands. This ensures the required separation, which helps to avoid interference problems. Poor antenna design, reconfigured office space, and other devices at the same frequency are the most common causes of interruptions. Wireless local area networks and internal reradiating systems (IRS) are examples of two different antenna systems that capture various wireless signals needed in today’s labs. Common building device frequency bands The subtle difference between a WLAN, a cellular phone, and a fire department handheld radio is the frequency band on which these signals are carried. Six different frequency bands and the devices they power are as follows:   1. 2400 MHz (2.4 GHz): PDAs, WLANs, cordless phones, cordless headsets, Bluetooth devices.   2. 1900 MHz (1.9 GHz): PCS (personal communication system) and paging systems.   3. 900 MHz: Private repeater and paging systems.   4. 800 MHz: Cellular phones, private repeater systems and specialized mobile radios (SMR).   6. 450 MHz (UHF): Business two-way radio and paging.   7. 160 MHz (VHF): Business two-way radio and paging. Wireless local area networks Laboratories have slightly different requirements than typical office space, so full-building wireless coverage is generally not needed. Unplanned interruptions of signal, limited bandwidth, slow data transfer, and security of information are major concerns for lab clients. The need to have a reliable, secure line far outweighs the need to be mobile inside the individual lab and support spaces. Therefore, data outlets located in the benches are still the choice of most research firms. With today’s emphasis on collaboration, however, most new buildings contain a plethora of “interactive” spaces where wireless access is desirable. In response, engineers are now designing antennae called wireless access points (WAPs) into public spaces such as corridors, small meeting rooms, cafeterias, and lounges to allow researchers to travel wirelessly in these spaces. The WAPs operate in the 2.4 GHz and 5 GHz range and receive signals from laptops with wireless network cards. The antennae are powered to accommodate approximately 25 individual “data sessions” at one time. Adjacent WAPs are tuned to different frequency channels. As users move from one coverage zone to another, they unknowingly change frequency channels but maintain connection. Internal reradiating systems The “wireless” technology of IRS, more aptly termed “radio technology,” has been around for decades but is becoming more prevalent in many research facilities. How do IRS systems differ from a WLAN in labs? While WLAN coverage is typically only desired in public spaces, the equipment used by the IRS is required buildingwide. Also, the type of devices that use the IRS are different, one example being the common non-PCS type cellular phone. Distributed antenna systems (DAS) are one component of IRS that receives the signals within the space before re-routing to a roof-mounted antenna. “Leaky coax” is another way to gain extra signal bars to cellular phones in a building. As the name suggests, the coaxial cable itself is the antenna, and it “leaks” a signal along the entire length. A number of buildingwide IRS systems will include a combination of both media to cost-effectively cover the building. The IRS system, whether DAS or leaky coax, is entirely different than the WLAN. The antennae are different, the components are different, and in most cases, WLANs are not required buildingwide. An example of how the need for wireless access is changing building requirements is occurring in Bellevue, Wash., where Ordinance 5529 now mandates the installation of internal reradiating systems in high rises and low-rise metal buildings. This ordinance not only mandates the use of IRS but also specifically indicates how the system will be tested to ensure such coverage. The testing requires radio coverage in 95% of the building. Users might ask why labs are changing to require the increased need for IRS components. First, more devices now require IRS systems. Second, some construction methods can block those signals. For example, low-E (low-emissivity) glass is gaining popularity in projects where LEED (Leadership in Energy and Environmental Design) certification is desired. This high-efficiency glass creates energy savings for the HVAC systems, but the metallic coating blocks radio waves from entering or leaving the building. The U.S. Green Building Council is in the process of creating a new LEED application guide specifically for lab buildings, which will continue to fuel the increased usage of low-E glass. IRS systems are almost certain to be installed at an increased rate because of these issues. Looking to the future With laboratories becoming more collaborative and sustainable, an increasing number of wireless systems are filling the airwaves and fueling scientific breakthroughs. As the use of technology in laboratory buildings continues to grow, it is more important than ever to effectively manage electrical interruptions. A thorough examination of researchers’ needs will permit easy and quick lab renovations, ensure capacity for future equipment and technologies, and allow scientists to focus their attention on research, not the health of building systems. Tod Moore, RCDD, CSI, and Troy Thrun, PE, LEED AP, are principals at Sparling, an electrical engineering and technology consulting firm with offices in Seattle and Portland, Ore. (www.sparling.com). Article reprinted from the 2006 Laboratory Design Handbook.