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    Integration: electrical and HVAC systems

    Learning objectives:

    • Understand how building systems can be integrated, such as electrical and mechanical systems.
    • Learn about building management systems and building automation systems.
    • Assess ways to integrate engineered systems to achieve greater energy efficiency in buildings.

    Technology has changed the way modern buildings are designed and operated. It has improved the reliability and efficiencies of the modern electrical and mechanical systems. Equipment is more efficient due to advanced component design and the incorporation of onboard computer controls and logic.

    Building management systems (BMS) are more advanced than ever and can operate the systems to much tighter tolerances. The improvements have changed the way today’s engineers can design and operate buildings to maximize energy consumption and minimize their impact on the environment.

    To achieve these goals, the various building systems must operate together instead of working as stand-alone systems. Integration has compelled electrical and mechanical engineers to work more closely together during the various design phases so they can incorporate the required tools and logic to seamlessly operate the modern smart building.

    The integrated design team

    For many years, projects were designed by teams comprised of architects and engineers (civil, structural, fire/life safety, mechanical, plumbing, and electrical). This team approach worked well for most projects because the design expertise was contained within the group. The design team was a stand-alone component that had limited exposure with the construction team and the owner once the building was in operation. This relationship is illustrated in Figure 2.

    Although each team was coordinating internally, the coordination efforts between the design team, contractor, and owner were disjointed and disconnected. This resulted in buildings that were designed with specific efficiency measures but constructed with systems that were more cost-effective than base design, which resulted in them not operating according to the original design intent. This dynamic needed to change as buildings became more complex due to advancements in technology, building materials, and construction methods. It was necessary for the traditional design team to expand and seek advice from specialized consultants who work for the architect (acoustics, vertical transportation, building envelope, audio/video, security and surveillance, information technologies, etc.) and nontraditional resources that work for the owner.

    As building systems become more advanced and energy consumption becomes a prime driver in system design, it is imperative that the systems operate according to the design intent. Building owners have been turning to commissioning agents (CxA; often called commissioning providers, or CxP), energy engineers, and in some cases, various specialized trade contractors to certify the actual system operation meets the design specifications. In the past, these consultants and contractors were typically hired by the owner and operated independently of the design team.

    In recent years, however, the various experts have become involved early in the design process and are integral members of any successful design team. This model has become so successful that many engineering firms have hired these consultants and contractors to provide an expanded service offering to their clients. Allowing these specialists to participate in the early phases of design is key to delivering a successful smart building to the owner.

    These specialized disciplines can assist the engineers by providing operational feedback during design that can greatly influence how systems are sized, configured, and operated. This feedback can include but is not limited to:

    • Review of sequence of operations to incorporate practical experience
    • Preliminary electrical, heating, and cooling load profiles based on region and building type
    • Estimated energy consumption for proposed systems to identify the most efficient system option
    • Financial models to assist the owner in making informed decisions
    • Review of equipment submittals to assist the engineers in identifying variances
    • Review and analysis of potential value-engineering (VE) solutions proposed by trade partners.

    The feedback loop between operations and design allows the integrated team to operate under a different model that includes more communication and coordination throughout the entire lifecycle of the building (see Figure 2). The operation-driven design model facilitates sharing of information between the design team, contractor, and owner. The model produces a building with integrated systems that are operated as they were designed and to peak efficiency. As the building ages, the operational feedback is used to tweak the systems to improve efficiency or identify areas of the building that may require maintenance or upgrades.

    Coordination during the design phases

    The design effort required to successfully integrate the building electrical and mechanical systems cannot be viewed as a single checkbox in the designer’s to-do list. Integration must be a conscious effort among the various design professionals involved in the project. As each member of the team begins their respective designs, information needs to pass freely from one discipline to the other. Coordination between the engineers must be intentional to deliver the appropriate information at the right time so as to minimize mistakes and prevent wasted effort.

    For example, as the electrical engineer begins to conceptualize the electrical distribution system, that engineer will need to understand the impact that the mechanical systems will have on the electrical infrastructure serving the building. What are the estimated equipment loads? Where are the loads located? How does the equipment operate? The electrical engineer can make assumptions based on experience, but will need the input of the mechanical engineer to finalize the design.

    As buildings systems become more advanced, collaboration during each phase of design is crucial to the successful delivery of a high-performing building. It is even more critical when design services are provided by multiple firms or the design is dependent on the input from architects and other specialized consultants. To make the collaboration effort meaningful, each member of the design team needs to understand what information is important to the other designers and when it is required.

    Schematic design phase

    The schematic design (SD) phase of the project is the starting point for every design and is the time where the electrical and mechanical engineers begin to conceptualize the building systems to meet the project needs. The intent of this phase is to investigate various system options and arrive at a clearly defined concept that meets the owner’s objectives. The SD phase defines the parameters that will influence how the building systems are sized and configured.

    The concept design is typically conveyed through a basis-of-design (BOD) narrative and large-scale drawings that can demonstrate basic spaces, scale, and relationship of components. Once approved, this concept will guide the engineers through the design evolution of the various building systems.

    During the SD phase, the electrical and mechanical engineers begin to investigate different system options that meet the needs of the project. Each discipline starts to perform calculations and develop technical schematics to define the various options.

    Expected engineering tasks that require coordination and input from others at this stage are:

    • Review applicable building codes, building certifications (LEED, Green Globes, Energy Star, etc.), and design standards to identify impacts on the proposed building systems.
    • Determine the level of energy performance based on building-use type and define key metrics, such as energy use intensity or power usage effectiveness.
    • Estimate electrical loads for the project and begin coordination with the civil engineer and electrical utility.
    • Estimate mechanical loads (heating, cooling, water, sewer, and gas) and begin coordination with the civil engineer and utility companies.
    • Preliminary sizing of electrical and mechanical equipment.
    • Preliminary sizing of required plant rooms.
    • Preliminary electrical single-line distribution.

    Coordination efforts between the various disciplines should begin to ensure that the proposed systems can integrate. At this point, much of the coordination is kept within the mechanical, electrical, and plumbing (MEP) design team. Critical information required to preliminarily size the electrical and mechanical systems include:

    • Estimated electric loads for the major mechanical equipment (chillers, cooling towers, pumps, air handling units, large fan systems)
    • Estimated heat-rejection rates of major electrical equipment (substations, transformers, uninterruptible power supplies, also known as UPS)
    • Preliminary locations of major electrical and mechanical equipment
    • Available power and voltage
    • Estimated UPS and generator loads (if applicable).

    Design development phase

    The design development (DD) phase of the project expands upon the concepts developed in the SD phase. The design-team members begin to focus more time on developing the technical aspects of the building systems and material specifications. At the same time, open issues identified at the completion of the SD phase can now be addressed and resolved.

    The refinement of the system concepts and increased coordination help to minimize the possibility of major system revisions during the next phase of design. During this process, the relationship between each system and its spatial impact on the design is defined. The owner is now able to start envisioning what the project will look like when complete and how it will function. While most design issues should be resolved by the end of the DD phase, some will continue to be refined, resolved, or modified during the subsequent phases of the project.

    The DD phase also is the point in the design where coordination efforts expand beyond the electrical and mechanical engineers to include the CxA and the energy engineers. The entire design team reviews the various system concepts, preliminary control diagrams, and sequences of operation. Preliminary load profiles are defined for the building to assist with preparing electrical, heating, and cooling loads. Based on this information, system modifications are made that will enhance the performance of the equipment and maximize energy savings.

    The anticipated deliverables at this stage will include an updated BOD document, drawings of appropriate scale to convey the more detailed level of coordination and outline specifications that begin to define the quality level of the materials and system components. It also is important to note that many of today’s projects use these deliverables to produce preliminary construction-cost budgets or lock contractors into a guaranteed maximum price. At this point, it is imperative that each discipline is coordinating and disseminating the correct information to the entire design team.

    During the DD phase, the electrical and mechanical engineers select the systems that best fit the function of the building and start to incorporate more detail into the technical design. Each discipline refines load estimates, calculations, and equipment sizing and develops plant-room layouts and system layouts. Expected engineering tasks that require coordination and input from others at this stage are:

    • Review proposed system design is in accordance with applicable building codes, building certifications (LEED, Green Globes, Energy Star, etc.), and design standards.
    • Define energy efficiency measures and incorporate them into system design.
    • Refine electrical-load estimates for the project based on the chosen design, and continue coordination with the civil engineer and electrical utility.
    • Refine mechanical-load estimates (heating, cooling, water, sewer, and gas) for the project based on the chosen design, and continue coordination with the civil engineer and utility companies.
    • Refine electrical and mechanical equipment sizing based upon selected system design.
    • Finalize plant-room sizing and layouts.
    • Develop system layouts detailing major horizontal and vertical infrastructure (ductwork, piping, conduits, bus ducts, etc.) pathways.
    • Refine electrical single-line distribution.
    • Develop BMS and metering control sequences and control diagrams.

    Coordination efforts between the various disciplines intensify as more detail is incorporated into the design of the systems. The DD phase is also the start of coordination with the specialized consultants. Their input at this stage helps the design team to identify system modifications required to incorporate the technology that makes today’s high-performance buildings efficient and environmentally friendly. Information critical to continue coordination and integration of the electrical and mechanical systems include:

    • Revised electric loads for the major mechanical equipment (chillers, cooling towers, pumps, air handling units, large fan systems) and preliminary loads for secondary mechanical equipment (fans, fan coils, terminal boxes, heat pumps, split systems, dampers, etc.)
    • Revised heat-rejection rates of major electrical equipment (substations, transformers, UPS) and preliminary heat-rejection rates for low-voltage and information technology (IT) equipment
    • Revised locations of major electrical and mechanical equipment and preliminary locations of secondary electrical and mechanical equipment
    • Revised UPS and generator loads (if applicable)
    • Identify life safety equipment locations and power requirements.
    • Preliminary electrical-, heating-, and cooling-load profiles based on project-specific criteria
    • Preliminary BMS and metering control sequences and control diagrams
    • Preliminary electrical loads and locations for direct digital control (DDC) panels and devices
    • Preliminary energy modeling (if applicable).

    Construction document phase

    The construction document (CD) phase of the project is the culmination of the design effort. It is the point in the process where the engineers address the remaining outstanding issues and evaluate the proposed VE options presented by the contractors. If value-engineering options are proposed, the design team can evaluate the options and coordinate with the other disciplines to make sure a mechanical VE option does not adversely affect the electrical design or cost. This information, along with all the concepts and comments from the previous phases, is compiled into the final system design.

    The engineers will provide detailed information about the technical aspects of the overall systems and the specified equipment that set forth the requirements for the construction of the project. During this process, the relationship between each system and its spatial impact on the project is finalized. The design team is tasked with coordinating the final design information between disciplines to ensure that all project requirements are satisfied. Coordination becomes even more important within the last few weeks of the design schedule to identify last-minute changes and the impact these changes may have on the designs of the other disciplines.

    As the CD phase progresses, the role of the CxA and the energy engineers becomes more critical. This is the last opportunity for the design team to incorporate comments and suggestions based on a review of system concepts, control diagrams, and the sequences of operation. This feedback, usually based on operation experience, allows the designers to modify the systems with the appropriate technology and components required to achieve the proposed building performance. The system enhancements will make it possible for the building owner to control the building systems and collect analytical data to provide real-time feedback to the BMS. Without this operational feedback, the BMS cannot adjust system performance to achieve the anticipated performance and predicted energy savings.

    The anticipated deliverables at this stage would include a final BOD document—drawings of appropriate scale that set forth the detailed requirements necessary for construction, and final specifications that define the requirements of the building materials, equipment, and systems. When the construction drawings are complete, the client will have sufficient information to secure contractor bids, obtain the required permits, and ensure that the contractor is building the project as the design team intended.

    During the CD phase, the electrical and mechanical engineers complete the system design and incorporate final technical details. Each discipline finalizes load estimates, calculations, equipment sizing, plant-room layouts, and system layouts. Expected engineering tasks that require continued coordination and input from others at this stage are:

    • Perform a final review to ensure the system design is in accordance with applicable building codes, building certifications (LEED, Green Globes, Energy Star, etc.), and design standards.
    • Evaluate final energy efficiency measures and verify all components and modifications are incorporated into the final system design.
    • Calculate final electrical loads associated with the system design and verify that the system is fully coordinated with the civil engineer and electrical utility.
    • Calculate final mechanical loads (heating, cooling, water, sewer, and gas) associated with the system design and verify systems are fully coordinated with the civil engineer and utility companies.
    • Finalize the electrical and mechanical equipment sizing based upon final load calculations.
    • Finalize plant-room sizing and layouts.
    • Finalize system layouts detailing major horizontal and vertical infrastructure (ductwork, piping, conduits, bus ducts, etc.) pathways as well as all secondary and branch pathways.
    • Finalize electrical single-line distribution.
    • Finalize BMS and metering control sequences and control diagrams.

    Coordination efforts between the various disciplines and specialized consultants continue as the design of the systems are finalized. At this stage, most of the systems are fairly defined and only require minimal modifications. The design should be nearing completion, and it is important that the communication between the disciplines and specialized consultants does not stop. Information critical to continue coordination and integration of the electrical and mechanical systems include:

    • Final electric loads for the major mechanical equipment (chillers, cooling towers, pumps, air handling units, large fan systems) and secondary mechanical equipment (fans, fan coils, terminal boxes, heat pumps, split systems, dampers, etc.)
    • Final heat-rejection rates of major electrical equipment (substations, transformers, UPS), low-voltage equipment, and IT equipment
    • Final locations of major and secondary electrical and mechanical equipment
    • Final UPS and generator loads (if applicable)
    • Final electrical loads and locations of the life safety equipment
    • Final electrical-, heating-, and cooling-load profiles based on project-specific criteria
    • Final BMS control sequences and control diagrams
    • Final electrical loads and locations for DDC panels and devices.

    Bid and construction administration phases

    The importance of the bid and construction administration (CA) phases is sometimes overlooked by the design team. In most cases, the design teams have limited exposure during the construction phase. The design-team involvement is usually limited to review of contractor shop drawings, response to contractor requests for information, perform a limited quantity of onsite observation visits, and address issues related to design as the systems are installed.

    However, there is a unique opportunity for engineers to provide value to the owner during construction through continued coordination of the design. The engineers become guardians of the design during the bid and CA phases. The design team can work with the owners to de-scope the contractor bids and make sure that the integrity of the design is maintained. The design team can work with the CxA to implement the coordinated design that was agreed upon during the DD and CD phases.

    Modern owners and developers are pushing the limits of building design and challenging today’s engineering professionals to become more creative with system design. The demand to bring projects to market quicker and more cost-effectively is reducing the margin of error during the design phase. Engineers must place more emphasis on effective communication and increased coordination between the disciplines to deliver a fully integrated building. Thorough coordination of the design has never been more critical.


    Hans Grabau is executive director of mechanical at NV5. His expertise is in multiple market sectors including large mixed-use gaming and hospitality projects, mixed-use commercial developments, mission critical facilities, and central plant design both domestically and internationally.

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    The benefits and challenges of wireless fire alarm systems

    Learning objectives:

    • Explore the fundamentals of wireless fire alarm technology. 
    • Understand how to use wireless fire alarm technology and its advantages for nonresidential applications. 
    • Realize the benefits of fire alarm technology and its current developments. 

    When provisions for wireless alarms were in their infancy, most authorities would not permit their installation due to reliability concerns and the fact that manufacturers had not actively sought development. Architects and interior designers complained that if they, or the owner, did not like the location of a fire alarm device or appliance, it would require multiple trades to relocate the device or appliance, even if it was just a foot or two away from the original location. An electrician would have to come out to relocate the conduit, backbox, and wiring, and the fire alarm technician would have to reinstall the device or appliance. In many cases, other trades would also have to get involved, like drywall, framing, etc. 

    While the advent of 3-D modeling allows design teams to coordinate equipment locations more accurately, owners and designers still may not get the “feel” for a space until it is built. Mock-ups are often used, but it is not cost-effective to mock-up an entire building. Fortunately, for those designers dealing with last-minute locations for fire alarm devices, wireless technology has come a long way in the past 20 years, and the future looks bright.  

    Defining wireless fire alarm technology 

    In its present state, wireless technology is not the be-all and end-all that allows designers to put devices and appliances wherever they want. The spacing criteria of NFPA 72: National Fire Alarm and Signaling Code still applies. Designers must meet the minimum standards set by NFPA 72 for locating equipment on walls and ceilings. The locations of devices and appliances must meet the performance objectives for either detecting fires or notifying occupants, as applicable. Most important, wireless does not mean that there will not be any wires. Just like your Wi-Fi connection at home, there will be transmitters and receivers that must be wired and powered.  

    Residential detection and notification are specifically known in NFPA 72 as single- or multiple-station smoke alarms. Smoke alarms that are installed in new homes are generally required to be connected to 120 V ac power along with a battery backup. New installations also require the alarms to actuate in multiple rooms if smoke is detected in only one room. That technology is wired or wireless depending on the type of system installed.  

    Ultimately, though, what designers and owners have been yearning for is wireless fire alarm systems for commercial applications.  

    Wireless fire alarm technology is referred to in NFPA 72 as low-powered radio (wireless) systems. That specifically refers to the use of wireless signal transmission via radio wave signals. The frequencies and modulation types are all regulated by the Federal Communications Commission (FCC), but the low-power frequencies for fire alarm systems are typically outside of thresholds requiring licenses. 

    The term low-powered radio also indicates that signals are not able to be transmitted over appreciable distances. Manufacturers of wireless fire alarm systems will clearly indicate the maximum distance between transmitting and receiving devices. Some manufacturers have developed technology that uses fire alarm devices as both a transmitter and a receiver to create a mesh that allows the network to communicate in multiple directions rather than just bi-directionally. However, the distance limitations still apply, and often the groups of transmitter/receivers must still be within range of a repeater or a primary network panel.  

    Historically, authorities have been wary of wireless fire alarm systems, primarily because of their reliability. These days, however, even in-building firefighter two-way communication systems are being prescribed by building and fire codes requiring two-way radio communication systems and eliminating the traditional firefighter phone jacks in buildings. Two-way radio communication systems are being enhanced within buildings with the similar type of repeater technology used in wireless fire alarm systems. Both technologies also follow similar principals for distributed antennae systems (DAS) that are provided in buildings to enhance mobile telephone signals.  

    Implementing wireless fire alarm technology 

    Similar to what is required by the International Fire Code for two-way radio communications, designers and installers of the available wireless fire alarm systems must determine if the site and building are suited for wireless technology by conducting a radio frequency (RF) survey. For emergency two-way radios, heat maps often can be used by identifying the emergency broadcast frequency-signal strength at various locations and identifying when the signal falls below acceptable levels. In-building repeaters or DAS would be used to boost the primary signal. For wireless fire alarm systems, the approach may vary but generally requires that actual wireless fire alarm transmitters and receivers be onsite with equipment to evaluate their signal strength throughout areas of the building or property where they will be installed.  

    There are instances where the use of wireless fire alarm systems may not be effective. As with most radio frequency transmission, building materials or other environmental aspects may impact the ability to install wireless fire alarms. In some cases, concrete construction may limit signal strength and even metal buildings may interfere with signals. Cores of taller buildings, like concrete/masonry elevator cores or stair cores, may reduce signals due to their construction. Prior to installing, the designer and installer should conduct a thorough RF survey with their equipment. If the building is new construction, designers should evaluate construction materials with the design team and still conduct an RF survey after construction. For new buildings, there should be mitigation measures in place in the event that the RF survey determines wireless fire alarm system communication may be questionable.  

    Where are the best places for wireless fire alarm systems? While most manufacturers would like to answer with “everywhere,” they are also honest enough to state in their literature that not all facilities may be appropriate for wireless fire alarms. If you paired one of the greatest advantages of wireless fire alarms with one of their strongest detractors, existing construction or retrofits would be where wireless fire alarms are most advantageous. Since there are significantly fewer wired pathways, and RF surveys can be conducted at any time, existing buildings are key markets for wireless fire alarm systems.  

    Casa de Shenandoah: Renovating a private residence into a museum 

    While Las Vegas is known for its bright lights and pizzazz, there are actually sites that locals and tourists agree are historical. Mr. Las Vegas himself, Wayne Newton, formerly owned Casa de Shenandoah, a 52-acre property with eight homes. The property now serves as an attraction with the main house, a 9,000-sq-ft mansion, serving as a museum showcasing his lavish lifestyle.  

    Unfortunately, changing a private residence to a museum does not happen overnight. To make the private residence accessible to the public, negotiations with authorities required that fire alarm detection devices be installed throughout the mansion with notification appliances along the publicly accessible path of the museum tour. The most effective means to make this happen was to provide a wireless fire alarm system.  

    The benefits of a wireless fire alarm system were immediately apparent. Wireless smoke detectors could be installed throughout the building without impacting historical finishes. While the fire alarm panels and repeaters required wiring for power, they could be strategically located to limit the impact to aesthetic finishes. Since not all parts of the mansion were open to the public, the fire alarm panel and repeaters could be placed such that they could easily transmit and receive yet were not in plain sight of the public.  

    However, one aspect became clear: A wireless fire alarm is not truly wireless. The notification appliances required wiring both for monitoring and power. Fortunately, the installation of notification appliances was limited to areas that were directly accessible to the public. In this case, it was possible to group appliances in strategic locations near repeaters and panels to limit the impacts to the building.  

    Today, thousands of visitors visit Casa de Shenandoah each year to marvel at the lifestyle Mr. Las Vegas was able to accrue. For the owners and authorities, they know the public is afforded more safety than the previously private residence allowed. 

    The case study demonstrates that wireless fire alarms are not truly wireless because of the panels and notification appliances. However, with savvy designers and installers, those obstacles become simple workarounds. During the RF survey, and working with the owner and architect, the designers and installers of the Casa de Shenandoah project were able to identify locations for panels and repeaters while simultaneously identifying how they could install the notification appliances with minimal intrusion.  

    As noted previously, even a home Wi-Fi system is going to require some wires for power and a connection to the internet; so it is with wireless fire alarms. The additional challenge is that most required notification appliances are not wireless. At least one manufacturer has developed a low-frequency sounder for audible notification, but speakers and visual notification appliances (strobes) may require years more of development. To the developers of the low-frequency sounder’s credit, they tapped one of the most popular markets for wireless fire alarms: residential hotels, motels, and dormitories, since NFPA 72 requires low-frequency audible alarms in sleeping areas.  

    The biggest issue associated with wireless notification appliances is the power consumption they require. Fire alarm system designers know from battery and voltage-drop calculations that the power-hungry notification appliance is the primary driver of battery size. In their quiescent state, notification appliances consume very little power. When the alarms sound and the strobes flash, the alarm appliances can and will drain batteries quickly.  

    Technology in both sound and light is continually improving such that wireless notification appliances should be developed long before automated flying cars. Improvements in consumer-use wireless home speaker technology may assist with further development of audible fire alarm notification appliances. Developments in LED technology and its low-power consumption will inevitably improve visual fire alarm notification appliances. Even battery technology has advanced in leaps and bounds over the past decade. However, further development of these products and technologies as applied to wireless fire alarm notification appliances will not happen quickly without consumer demand, authority approvals, and appropriate standards development.  

    One potential benefit of wireless fire alarm notification appliances is making them “smart.” Fire alarm notification appliances are not addressable on fire alarm systems. That is, depending on how the notification appliance circuits are installed, it may be difficult to determine which in a series of appliances is dysfunctional since they do not have independent addresses like detection devices. A wireless notification appliance would be required to be monitored through the same means as a detection device. It would have a physical address on a network so that if something were wrong with the appliance, a trouble signal would be annunciated at the fire alarm control panel. With an independent address, it would be easily identifiable within the building.  

    Even though wireless notification appliances are not fully developed, the devices associated with initiating technology are mostly covered. Smoke detectors, carbon monoxide detectors, and manual fire alarm pull stations have been fully developed. Water flow switch monitoring, valve tamper monitoring, and similar technology will require a box wired for power near the devices to be monitored. Similarly, relay boxes for elevator recall, HVAC shutdown, and other equipment interfaces will have a box requiring power and monitoring. However, if your sprinkler riser room is remote from your fire alarm control panel or you need to retroactively implement elevator recall and do not want to or cannot wire, wireless could be the way to go. 

    For now, there are many projects that can take advantage of the existing wireless fire alarm technology that is available. One of the early users of wireless fire alarm systems were low-rise hotels and motels. While most existing hotels and motels have the minimum required single-station smoke alarms, many are upgrading to addressable systems so they know almost immediately if they have problems with guests tampering or disabling smoke detectors. Wireless smoke detectors, combined with wireless low-frequency sounders, become an easy choice for hotel and motel operators that want to upgrade their systems with minimal downtime. With minimal wiring for power to panels and repeaters and the requisite Americans with Disabilities Act guest rooms, the installation is quicker and allows operators to turn over guest rooms with very little interruption to business.  

    Wireless fire alarm systems are particularly effective for campus-style hotels or garden-style apartments. If each of the buildings is sprinklered and requires fire alarm systems, wireless fire alarm system panels and repeaters are much easier to install than trenching wiring underground to each building. Similarly, industrial facilities with multiple buildings separated from one another can benefit from the wireless technology. Wireless fire alarm technology can be equally effective for common, but not often thought-about applications like carnival funhouses, zoos, or mobile exhibits. 

    In cities like Las Vegas, where conventioneers descend upon the scene frequently and in masses, authorities often regulate well to protect the public. Two-story convention booths, 5,000-sq-ft mobile exhibits, and 60,000-sq-ft “tents” are not uncommon places where fire departments have required fire detection and alarms due to the unique hazard to the public. A wireless fire alarm system is also portable and more easily relocated from one event to another.  

    With their portability, ease of installation, and flexibility, wireless fire alarm systems can be an easy sell for some. Cost is also a factor. A wireless fire alarm system is going to be more expensive part-for-part than a traditional wired fire alarm system. Smaller systems are likely to cost more than larger systems. There are cost savings in larger systems as a result of the associated wiring, terminations, and troubleshooting associated with wiring.  

    What generally is not on the sell sheets is the long-term costs associated with wireless fire alarms. If you think changing your batteries in your home smoke alarms is a hassle every time you move the clocks forward or back, consider changing all the batteries in a 300-room hotel/motel once a year, both for the smoke detectors and the low-frequency sounder. Some might argue that they should be doing that anyway if the properties have single-station alarms, and they would be right. However, upgrading to a wired, addressable smoke-detection system with low-frequency sounder bases wouldn’t require the same battery replacement, since the batteries are at the panel and not the detector.  

    The required types of batteries and what they cost should also be considered. Will the building maintenance personnel be able to obtain the required battery types off the shelf or are they a custom order? How long will it take personnel to change the batteries? Most forward-thinking manufacturers have developed their products based on commercially available batteries that are readily available either off the shelf or through bulk purchase and are as simple as changing batteries in home smoke alarms. However, caution should be taken to confirm that this is the case; otherwise, the building maintenance personnel and management will forever question who made the decision to go to wireless.  

    Though it may be obvious to consulting-specifying engineers, designers should thoroughly evaluate the properties of any fire alarm system and the local installer prior to final engagements. Commercial wireless fire alarm systems must have the appropriate listings with a nationally recognized testing laboratory. UL 864: Standard for Control Units and Accessories for Fire Alarm Systems applies to both wireless and wired fire alarm systems and has specific provisions for low-powered radio (wireless) systems. Wireless fire alarm system manufacturers may have their systems listed through Factory Mutual (FM) or UL, and their listings may contain useful information concerning applicability and/or installation criteria. Some states, larger cities, and other jurisdictions may have specific listing criteria or approval organizations. The California State Fire Marshal and City of New York Fire Department are two examples of public agencies that may evaluate fire alarm systems for specific installations.  

    Since wireless fire alarm systems are subject to the requirements of NFPA 72, their data sheets should indicate the approved pathway-class designations that the system can achieve. Wired-systems pathway classes include A, B, C, D, E, or X designations. Wireless systems might include Class A, C, E, and X. Another benefit of wireless fire alarms is they are not subject to ground faults and open circuits.  

    The technology, flexibility, and portability of wireless fire alarm systems are appealing for many reasons. To successfully incorporate the newest low-frequency radio (wireless) fire alarm systems into a specific project, the first step would be to evaluate the technology that manufacturers have to offer and consult with them. Local fire alarm companies may have some experience and knowledge, but designers should definitely consult with the manufacturers’ technical representatives as they should know their technology best.  

    The development of wireless fire alarm systems is continually improving. Advancements in wireless speaker and strobe technology must continue so that both detection devices and notification appliances may be considered truly wireless. Perhaps in the not-to-distant future, architects and interior designers will be able to have even more flexibility with field-placing devices and appliances—within the guidelines of NFPA 72, of course. 


    Gregory K. Shino is technical director of fire protection engineering at NV5, with more than 15 years of experience in design and commissioning of fire suppression, fire alarm and detection, and smoke-control systems. He is a member of the Society of Fire Protection Engineers, NFPA, and the International Code Council

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    Electrical codes and standards within healthcare

    When working with a facility’s equipment system, it is crucial to understand how it supports the major electrical equipment necessary for basic facility operation and patient care. Essential systems include emergency systems and equipment systems-the emergency system is limited to circuits that are essential to life safety and crucial patient care. These are named the life safety branch and the critical branch.

    • The life safety branch of the emergency system supplies power to lighting, receptacles and equipment—such as illumination of means of egress and alarm and alerting systems—to provide adequate power needs to ensure patient and personnel safety. Additionally, HVAC controls are on the life safety branch as HVAC operations can impact smoke control and life safety.
    • The critical branch of the emergency power supplies power for task illumination, fixed equipment, selected receptacles, and special power circuits serving certain functions and areas—such as nurse call systems and blood, bone and tissue banks—related to patient care. This branch is intended to serve a limited number of locations to reduce the load and minimize the chances of a fault condition.

    Here are a few National Fire Protection Association (NFPA) documents that address primary issues related to emergency power for hospitals include:

    1. NFPA 99, Healthcare Facilities – establishes criteria for levels of healthcare services or systems based on risk to the patients, staff, or visitors in health care facilities to minimize the hazards of fire, explosion, and electricity.
    2. NFPA 110, Emergency and Standby Power Systems – addresses installation, maintenance, operation, and testing requirements for emergency and standby power systems that provide an alternative source of electrical power in facilities if the normal electrical power source fails.
    3. NFPA 101, Life Safety Code – establishes strategies on how to protect people based on building construction, protection and occupancy features that minimize the effects of fire or other related hazards.

    The location of each project determines which codes to follow. Healthcare facilities also need to adhere to State Department of Health requirements, which can vary from state to state.

    – This article originally appeared on RTM Engineering blog. RTM Engineering is a CFE Media content partner.

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    Integrating teams for success

    Globalization of markets, social media, the Internet of Things, sustainability, and global politics all have a profound impact on an engineer’s daily life. The rate of change of every aspect of life also results in unprecedented volatility in an engineer’s work. Social media has created a new level of transparency to the internal workings of corporate entities. This transparency, combined with the pressure from the “instant gratification” generation to respond to any stimulus immediately and resolutely, pushes clients to move more quickly than before.   

    Sustainability, once commonly used as a buzzword for those seeking marketing material, is now considered good practice.  ASHRAE has continued to press for more energy efficiency through increasingly stringent requirements in ASHRAE 90.1: Energy Standard for Buildings Except Low-Rise Residential Buildings.  Subsequently, ASHRAE published Standard 189.1: Standard for the Design of High-Performance Green Buildings to up the ante even more.  In April 2017, the International Code Council (ICC) and ASHRAE announced that the 2018 iteration of the International Green Building Code will align ASHRAE’s 189.1 and the ICC’s International Green Construction Code into a single unified green building code. These codes and standards place increasingly stringent demands on all aspects of building design and construction as facilities become increasingly treated as homogeneous entities with multiple components and systems, rather than with a series of discreet and unrelated silos of equipment. 

    With virtual reality, networking, BIM coordination, and other available tools, the ability to present questions and obtain feedback from clients has reached a new high. These tools allow engineers to not only convey questions more clearly, but also to review options and determine paths forward more quickly. These tools help address the increased pace at which projects are now executed. 

    There is, however, one link that traditionally eludes a large percentage of projects. While code officials and clients push toward more integrated solutions and faster delivery, all too often, the architectural and engineering (AE) industry continues to operate under the same process. The architect meets with the clients, determines their goals (with a heavy emphasis on architecture), creates space plans, obtains client buy-in, and then engages the engineers to do their part. This results in either multiple revisions to an “approved” floor plan (or worse, increase in building footprint) or the popular “make it work” scenario. In today’s market of high-speed design and integrated buildings, engineers continue to design in silos.   

    Architectural/engineering team integration 

    Recently, an increasing number of projects are executed with a fully integrated AE team from programming through to completion. This should not be confused with an AE firm, as sitting under the same roof does not mean integral operation, nor should it be assumed that separate architects and mechanical, electrical, and plumbing (MEP) cannot operate as an integrated team. This is about project approach and team chemistry. This is about making team members integral to the discussions and decisions, not resources to which tasks are assigned. 

    One of the most critical decision points early in a project is choosing the type of HVAC system. If involved during programming, engineering can inform architecture on optimum equipment room sizes and locations. Increasing efficiency requirements have rendered many rules for space allocation obsolete. Variable refrigerant flow systems don’t have the same space requirements as centralized air handling unit systems, which affects the program dramatically. Improvements in acoustics have made centrally located equipment rooms less objectionable, giving architects more flexibility in space layouts. Finally, as there are far fewer exceptions for economizers, understanding the options for economizer type, available exceptions, and architectural implications if an economizer is used can play a key role in building configuration.  

    Electrically, changing requirements in NFPA 70E: Standard for Electrical Safety in the Workplace has introduced options such as arc-resistant switchgear. The required accessories significantly impact mechanical and architectural design with blast panels and louvers. Transformers have increased in physical size, again, to improve efficiency. Code requirements relating to lighting design, lighting controls, and daylight require unprecedented coordination between the architect and electrical engineer, not only to clearly explain options to clients, but also to document the design for permitting. 

    While some may view changing MEP requirements a headache, if an integrated design approach is used, it makes the process run more smoothly. Through programming, architects and engineers can work out a space program and floor plan that is viable from the day it is approved. By using BIM tools, engineers can locate equipment while checking site lines to ensure it is not visible from certain locations within a facility. But most importantly, by working as an integrated AE team from start to finish, architects and engineers can provide the owner with a facility where the infrastructure melds into the design, becoming as integrated into the final product as the people and data it contains.   


    John Gross is the principal /mechanical engineering director at Page in Houston. With 13 years of experience in data center, green building, and large chiller plant design and commissioning, Gross is Page’s lead direct digital controls and forensic analysis engineer. 

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