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Vol. 62 • No 4
Contents JULY/AUGUST 2025
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NEWS&BUSINESS 5 | How to align integrated building systems with expectations
Engineers and product manufacturers should collaborate with building owners to design and implement integrated building systems.
BUILDING SOLUTIONS 6 | AHU design from an owner and operator's perspective
Developing an understanding of and a collaborative approach with owner expectations for how AHUs should be designed, installed and maintained is a best practice that facilitates project success and the long-term reliability of this infrastructure.
12 | Five disinfection strategies and technology options for AHUs This article focuses on the different disinfection strategies and technologies available for air handling systems, their effectiveness and their proper application.
ON THE COVER: Return and outdoor air mixing can be complicated during freezing temperatures. Courtesy: Smith Seckman Reid, Inc.
18 | Decarbonization: How we got here and where we’re going
Climate change poses significant financial and infrastructural risks, prompting debates over whether proactive decarbonization and resilience efforts are more cost-effective.
p.18
28 | What you need to know about the types of standby power systems
Ensuring adequate backup power is crucial for safeguarding personnel safety and enhancing the resilience of facility operations during interruptions.
p.28
36 | Coordinate IECC, ASHRAE 90.1 and ASHRAE 90.4 for data centers By understanding the differences in code or standard editions, data center designers can know which version to use.
ENGINEERING INSIGHTS 38 | What should engineers know about industrial facility design?
p.38
Three engineers discuss current trends, common challenges and important codes when designing industrial facilities.
CONSULTING-SPECIFYING ENGINEER ( Vol. 62, No. 4, ISSN 0892-5046, USPS PUBLICATION #901000 ) is published bimonthly by: WTWH Media, LLC; 1111 Superior Ave., Suite 1120, Cleveland, OH 44114. Periodicals postage paid at Cleveland, OH & additional mailing offices. POSTMASTER: Send address changes to CONSULTING-SPECIFYING ENGINEER, 1111 Superior Ave., Suite 1120, Cleveland, OH 44114. CONSULTING-SPECIFYING ENGINEER copyright 2025 by WTWH Media, LLC. All rights reserved. CONSULTING-SPECIFYING ENGINEER is a registered trademark of WTWH Media, LLC, used under license. Circulation records are maintained at WTWH Media, LLC, 1111 Superior Ave., Suite 1120, Cleveland, OH 44114. Telephone: 630-571-4070. Publications Mail Agreement No. 40685520. Return undeliverable Canadian addresses to: 1111 Superior Ave., Suite 1120, Cleveland, OH 44114. Rates for nonqualified subscriptions, including all issues: USA, $120/yr; Canada/Mexico, $150/yr (includes 7% GST, GST#123397457); International air delivery $260/yr. Except for special issues where price changes are indicated, single copies are available for $30 US and $35 foreign. Please address all subscription mail to CONSULTING-SPECIFYING ENGINEER, 1111 Superior Ave., Suite 1120, Cleveland, OH 44114. Printed in the USA. WTWH Media, LLC, does not assume and hereby disclaims any liability to any person for any loss or damage caused by errors or omissions in the material contained herein, regardless of whether such errors result from negligence, accident or any other cause whatsoever.
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July/August 2025
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CONTENT
NEWS&BUSINESS
CONTENT SPECIALISTS/EDITORIAL
VIEWPOINT
AMARA ROZGUS, Editor-in-Chief ARozgus@WTWHMedia.com
ANNA STEINGRUBER, Associate Editor ASteingruber@WTWHMedia.com AMANDA PELLICCIONE, Marketing Research Manager APelliccione@WTWHMedia.com MICHAEL SMITH, Art Director MSmith@WTWHMedia.com
EDITORIAL ADVISORY BOARD DARREN BRUCE, PE, LEED AP BD+C, Director of Strategic Planning, Mid-Atlantic Region, NV5, Arlington, Va. MICHAEL CHOW, PE, CEM, CXA, LEED AP BD+C, Principal, Metro CD Engineering LLC, Columbus, Ohio CINDY COGIL, PE, FASHRAE, Vice President, SmithGroup, Chicago TOM DIVINE, PE, Senior Electrical Engineer, Johnston, LLC, Houston CORY DUGGIN, PE, LEED AP BD+C, BEMP, Energy Modeling Wizard, TLC Engineering Solutions, Brentwood, Tenn. PAUL ERICKSON, LEED AP BD+C Principal, Affiliated Engineers Inc., Madison, Wis. ROBERT J. GARRA JR., PE, CDT, Vice President, Electrical Engineer, CannonDesign, Grand Island, N.Y. JASON GERKE, PE, LEED AP BD+C, CXA, Senior Design Phase Manager, JP Cullen, Milwaukee JOSHUA D. GREENE, PE, Associate Principal, Simpson Gumpertz & Heger, Waltham, Mass. RAYMOND GRILL, PE, FSFPE, LEED AP, Principal, Ray Grill Consulting, PLLC, Clifton, Va. DANNA JENSEN, PE, LEED AP BD+C, Principal, Certus, Carrollton, Texas WILLIAM KOFFEL, PE, FSFPE, President, Koffel Associates Inc., Columbia, Md. WILLIAM KOSIK, PE, CEM, LEGACY LEED AP BD+C, Associate Principal, Sector Leader, HED, Chicago KENNETH KUTSMEDA, PE, LEED AP, Engineering Manager, Jacobs, Philadelphia DAVID LOWREY, Chief Fire Marshal, Boulder (Colo.) Fire Rescue JASON MAJERUS, PE, CEM, LEED AP, Principal, DLR Group, Cleveland JUSTIN MILNE, PE, PMP, Senior Engineer, Southcentral Region, Jensen Hughes, Allen, Texas CRAIG ROBERTS, CEM, Account Executive, National Technical Services, McKinstry, Powell, Tenn. SUNONDO ROY, PE, LEED AP, Director, Design Group, Romeoville, Ill. JONATHAN SAJDAK, PE, Senior Associate/Fire Protection Engineer, Page, Houston RANDY SCHRECENGOST, PE, CEM, Austin Operations Group Manager/Senior Mechanical Engineer, Stanley Consultants, Austin, Texas MATT SHORT, PE, Project Manager/Mechanical Engineer, Smith Seckman Reid, Houston MARIO VECCHIARELLO, PE, CEM, GBE, Senior Vice President, CDM Smith Inc., Boston RICHARD VEDVIK, PE, Senior Electrical Engineer and Acoustics Engineer, IMEG Corp., Rock Island, Ill. TOBY WHITE, PE, LEED AP, Associate, Boston Fire & Life Safety Leader, Arup, Boston APRIL WOODS, PE, LEED AP BD+C, Vice President, WSP USA, Orlando, Fla. JOHN YOON, PE, LEED AP ID+C, Lead Electrical Engineer, McGuire Engineers Inc., Chicago
consulting-Specifying engineer — www.csemag.com
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How to align integrated building systems with expectations Engineers and product manufacturers should collaborate with building owners to design and implement integrated building systems.
C
highlighting this as a major hurdle. onsulting engineers are at This often puts MEP designers in the a key point in the integratposition of advocating for long-term ed building systems landsolutions, only to face resistance from scape. Like many other industries, building owners who are focused on architecture, engineering and concapital costs or who underestimate the struction are looking at a significant total cost of ownership and transformation, driven by a complexities of integrated need for greater operationsystems. It’s a constant battle al efficiency, sustainability to justify the return on investand enhanced collaboration ment when clients expect across all stakeholders. smart systems to function The 2025 State of Integratautonomously or misintered Building Systems report pret the balance between iniunderscores the critical role Amara Rozgus, tial outlay and future savings. in designing and integratEditor-in-Chief So, how do we deal with ing these complex systems, this? Collaboration emerges as a critand it also shines a spotlight on the ical success factor. The report emphapersistent challenges mechanical, sizes that suppliers need to step up as electrical, plumbing (MEP) and fire strategic partners. Engineers clearly protection engineers face. indicate that supplier collaboration The data reveals that energy effiis “critical” (71%), meaning suppliers ciency remains a cornerstone of the should provide comprehensive trainpriorities. Engineers are actively ing and technical support tailored to incorporating strategies like variable project needs. frequency drives (73%) and highOvercoming these barriers requires efficiency HVAC systems (70%) into a multifaceted approach centered specifications. Building automaon stronger financial justifications, tion systems are the most frequently enhanced client education, improved used tool for integration (69%), with cross-system interoperability and sigbuilding information modeling folnificant investments in workforce lowing at 57%. development. By enhancing collabHowever, efforts are often met by oration, there are new opportunities familiar obstacles. Budget constraints, for efficiency, sustainability and innocited by 58% of respondents, remain vation, paving the way for truly intethe most significant barrier to achievgrated and intelligent buildings that ing energy efficiency and integration deliver on their promise. cse goals. High upfront costs are a dominant factor preventing full implementation, with 68% of respondents July/August 2025
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BUILDING SOLUTIONS AIR HANDLING
Mike Gable, PE, CEM, Senior Director of Facilities Management, Vanderbilt University Medical Center, Nashville, Tenn. and Gavin Green, PE, Senior Mechanical Engineer, Smith Seckman Reid Inc., Germantown, Md.
AHU design from an owner and operator's perspective Developing an understanding of and a collaborative approach with owner expectations for how AHUs should be designed, installed and maintained is a best practice that facilitates project success and the long-term reliability of this infrastructure.
FIGURE 1: An example of a supply fan array with backdraft dampers. Courtesy: Smith Seckman Reid, Inc.
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hen a new air handling unit (AHU) is installed, whether as a replacement in an existing facility or as part of new construction, building owners have specific expectations for this new component of their building's infrastructure. Understanding these expectations is key to forging a positive partnership with owners and achieving project success. Typically, owner expectations for air handling units revolve around two primary questions. First, was the AHU designed properly to meet owner needs? Secondly, was the AHU installed properly to meet the design intent? At a minimum, all owners expect AHU fan and coil capacities to meet building load demands and anticipate AHUs to fulfill their specified service lives with routine preventative maintenance. However, needs beyond this baseline can vary from owner to owner and project to project. Because of this diversity, this article is not going to focus on outlining details of AHU construction, fan/coil sizing and configuration options. Instead, what better way to understand an owner’s expectations than understanding an owner’s perspective? Examining one owner’s processes, standards and expectations will serve as a useful reference when collaborating with other owners. So, let’s meet our owner representative.
An owner’s perspective Vanderbilt University Medical Center (VUMC), located in Nashville, Tennessee, is a multi-building healthcare facility with nearly 200 large AHUs. VUMC works with AHUs ranging in airflow capacity from a few thousand cubic feet per minute (CFM) to hundreds of thousands CFM. These AHUs also vary in age from brand new to more than 50 years old. consulting-Specifying engineer — www.csemag.com
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As with any healthcare facility, properly operating equipment is critical to the well-being of VUMC’s patients, visitors and staff. The building systems management group and the heating, air and refrigeration shop for the Department of Facilities Management at VUMC are responsible for the day-to-day operation of all the AHUs on the medical center's campus. Over the years, VUMC has developed and published standards to provide design engineers with an understanding of the general expectations for AHUs being provided for the medical center. Below are examples of day-to-day operation, routine maintenance and AHU essentials recommended and, in many instances, required by the VUMC Facilities Management department. With hundreds of central station AHUs being maintained daily across the campus, these examples and expectations are born from the facilities management department’s experience with a variety of conditions that help and hinder the operation and maintenance of AHUs.
AHU day-to-day operation essentials Fan arrays The VUMC Facilities Management department mandates that individual fans in an arrayed system be equipped with backdraft dampers to automatically prevent reverse spin. This precaution is crucial because de-energized fan motors that spin in reverse can generate voltage back to the motor's variable speed drive, potentially causing it to fail. To maintain optimal performance, all fans, especially supply fans, in an arrayed system should operate without any individual fans in standby mode. If any supply fans in an array are de-energized, it can create an uneven velocity profile across the cooling coil, leading to moisture carryover. VUMC also requires N-1 configuration fan redundancy for arrayed systems. This redundancy provides 100% capacity even with one fan offline, as all fans, including the standby fan, operate at a reduced speed during normal operation. For arrayed systems with redundancy, it is recommended that the design engineer schedule the quantity of fans and their design, minimum and maximum operating conditions (such as airflow and brake horsepower) to ensure that the AHU manufacturer fully understands the fans' requirements when making their selections. consulting-Specifying engineer— www.csemag.com
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Return/outdoor air mixing A common issue with AHUs in regions where winter outdoor air temperatures fall below freezing is insufficient mixing of the return air and outdoor air. This problem can lead to the tripping of freeze stats and frozen coils. Insufficient mixing is not limited to the heating season. During the cooling season, stratification can cause uneven temperatures across a cooling coil, potentially resulting in an undesired coil leaving air temperature. The VUMC Facilities Management department has found that, regardless of how the return air and outdoor air are arranged in an AHU's mixing section, complete de-stratification typically does not occur without the use of a dedicated mixer. Humidifiers The VUMC Facilities Management department prefers to position a humidifier within an AHU downstream of the pre-heat coil (if present) and upstream of the cooling coil. A cooling coil located downstream of a humidifier acts as an eliminator for any moisture not fully absorbed into the airstream. Conversely, placing humidifiers downstream of cooling coils can inadvertently trip smoke detectors, often leading maintenance personnel to limit humidifier output or shut them off altogether.
FIGURE 2: Return and outdoor air mixing can be complicated during freezing temperatures. Courtesy: Smith Seckman Reid, Inc.
Learning
Objectives
u
• Understand various air handling unit features considered to be essential by owners/operators for day-to-day operation. • Identify what is required by owners/operators to properly maintain an air handling unit. • Recognize that each owner/ operator has their own unique requirements for operating and maintaining air handling units.
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BUILDING SOLUTIONS AIR HANDLING
‘
Maintaining clean hydronic coils is essential for both the air and water
sides of the system. Sediment can easily become trapped in a coil’s piping system, significantly affecting its
’
flow and ability to transfer heat.
FIGURE 3: Maintaining clean hydronic coils is necessary for both the air and water side of an AHU. Courtesy: Smith Seckman Reid, Inc.
UV lights at cooling coils To extend the life of ultraviolet (UV) light bulbs located at cooling coils, the VUMC Facilities Management department requires a control strategy that activates UV lights only when mechanical cooling with dehumidification is possible. A straightforward control strategy involves energizing the UV light when the outdoor air dry-bulb temperature is equal to or greater than the design cooling coil leaving air temperature, which guarantees that the coil will be irradiated when moisture is present. Alternatively, in systems where chillers that do not operate year-round provide the source of mechanical cooling, UV lights could be activated at the same outdoor air dry-bulb temperature at which the chillers are enabled. Hydronic coils (airside) Regardless of how frequently the upstream air filters are changed, a coil will accumulate dirt over time. According to the ASHRAE handbook, "chilled-water coils with more than four rows and close fin spacing are virtually impossible to clean even using extraordinary methods." It is common for AHUs with a high percentage of hot and humid outdoor air to require cooling coils with more than four rows. Eight rows with a fin density of ten fins per inch are typical high limits preferred by design engineers and building owners/operators. When cooling coils require more than four rows, a potential solution to the cleaning issue is to provide two coils in series with no more than four rows each. When calculating an AHU’s static pressure requirement, design engineers commonly account for filter loading, but they may overlook the increased pressure drop associated with ‘coil loading’. Failure to consider ’coil loading’ impacts not only the available motor power but also the proper operation of the cooling coil trap.
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The VUMC Facilities Management department recommends that cooling coil trap depths be oversized to accommodate an increase in a coil’s airside pressure drop over time. When selecting and ultimately approving an air handling unit, the design engineer must consider the location of the cooling coil drain, as some manufacturers discharge through the unit’s base rail, which reduces the available trap height. Under such conditions, typical solutions are either providing a concrete pad of sufficient height or providing cut-outs in the floor near the trap. Hydronic coils (waterside) Maintaining clean hydronic coils is essential for both the air and water sides of the system. Sediment can easily become trapped in a coil’s piping system, significantly affecting its flow and ability to transfer heat. As indicated in most engineers' hydronic coil connection details, the VUMC Facilities Management department requires strainers in the supply piping to the coil. The department prefers tapping branch piping feeding hydronic coils from the top, although side taps are also permitted. However, bottom taps are not allowed at the facility. Controls AHU controls should be kept as simple as possible. When controls become overly complicated or have too many variables, the maintenance group may resort to locking the unit into a manual override mode. This manual override would likely compromise the energy savings intended by the design engineer and, in many instances, required by code.
AHU maintenance essentials Service clearances The original fans and coils provided with a new AHU seldom, if ever, endure throughout the life of the unit, necessitating their replacement. As recommended by ASHRAE, "the room must have space for removing the fan(s), shaft(s), coils and filters. Installation, replacement and maintenance of this equipment should be considered when locating and arranging the room." Unless the width of a coil bank is split into multiple sections, which requires staggering the coils and consequently adding length to the AHU, coils will typically have a width nearly equal to that of the unit. Providing adequate space to remove and replace coils is a mandatory requireconsulting-Specifying engineer — www.csemag.com
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CASE STUDY: Air handling solutions for the Jim Ayers Tower THE JIM AYERS TOWER, currently under construction at the Vanderbilt University Medical Center (VUMC), is a product of advanced engineering and meticulous planning. Spanning levels three through 16, the tower features a total connected supply air capacity of 420,000 cubic feet per minute (CFM), distributed among four custom Nortek Air Solutions Temtrol units, each with a capacity of 105,000 CFM.
Design and redundancy The four air handling units (AHUs) are organized into two pairs of “twinned” units—with each pair sharing a common discharge plenum. This configuration allows each twinned pair to provide 50% of the total capacity, accommodating planned and unplanned shutdowns of an entire single AHU. For additional redundancy, each pair of twinned units is cross-connected to the other pair, enhancing reliability and operational flexibility.
Space Constraints and Configuration Given the limited footprint of the building, the space available in the penthouse to house the four 105,000 CFM AHUs necessitated innovative configuration solutions. The units feature a return fan array and economizer section stacked on the mixing plenum, as well as split and staggered cooling coils. These design choices optimize the use of available space while maintaining high performance and efficiency.
Meeting VUMC design standards To align with VUMC’s design standards, the below key features were incorporated into the AHUs:
ment for the design engineer when laying out and sizing an AHU equipment room. More often than not, the "coil pull" space is contained within the equipment room itself. However, when limited space is available, coils are sometimes required to be pulled through doorways into adjacent spaces. Interior access With the fans and coils of AHUs located inside cabinets, access to the interior of the unit is essential. While side access filter housings, which eliminate the need to enter the unit to change filters, may be acceptable for smaller AHUs, there comes a point when it becomes necessary to "front load" the filter bank, requiring entry into the unit. When it is necessary to enter an AHU to service fans, clean coils or change filters, providing access sections and doors of sufficient size for a person to physically pass through is crucial. Although an AHU manufacturer may offer a 10-inch-wide access door, the consulting-Specifying engineer— www.csemag.com
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• Return and supply fan arrays with N-1 redundancy: Both return and supply fan arrays are equipped with N-1 redundancy and individual fan backdraft dampers, supporting continuous operation even if one fan fails. • Air blenders for mixing: Return air and outdoor air mixing is facilitated by air blenders from Blender Products, which promote efficient and uniform air distribution. • Strategic humidifier placement: Humidifiers are positioned between the pre-heat and cooling coils to optimize humidity control. • UV lights for air quality: UV lights are installed downstream of the cooling coils to enhance air quality by reducing microbial growth.
Maintenance considerations VUMC’s maintenance requirements were also a critical factor in the design of AHUs. Features to facilitate maintenance include: • Service access doors: Minimum 24-inch-wide service access doors were provided, allowing maintenance personnel easy access to the interior of the units. • Fan and motor replacement rails: Internal rails for fan and motor replacement streamline the maintenance process. • Service platforms with jib cranes: Return fan array service platforms are equipped with jib cranes and electric chain hoists, simplifying the handling of heavy components. The Jim Ayers Tower showcases an AHU design process driven by an understanding of the owner’s needs, expectations, and requirements, resulting in air handling solutions that will be durable, maintainable and reliable.
average adult would have difficulty maneuvering through it. Access doors with a minimum width of 18 inches are recommended, with the VUMC Facilities Management department preferring 24-inchwide access doors. As previously mentioned, coils with more than u csemag.com four rows are difficult to clean, and attempting to do so from only one side of the coil virtually AHU insights guarantees an insufficiently cleaned coil. VUMC u The Vanderbilt requires access to both the upstream and downUniversity Medical Center’s Facilities stream sides of any coil bank, but understands that Management department unit length restrictions sometimes prohibit this.
Insights
Fan and fan motor replacement While it is uncommon to replace fan wheels in an AHU, motors fail far more often than building owners and maintenance staff would prefer. Even though fan arrays have smaller motors than their single fan counterparts, replacing a fan motor is still often a challenging task.
standards serve as a case study for how engineers and building owners can work together for AHU best practices.
u AHUs must be designed
and installed correctly to meet specific owner needs that are unique to each project.
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BUILDING SOLUTIONS AIR HANDLING
Field observations AHUs are typically equipped with a multitude of sensors that report to a building automation system (BAS), which then makes operational decisions based on the design control sequences. However, maintenance staff often need to make field observations of the AHU’s current conditions. Measurement devices intended for direct visual readings, such as pressure (both direct and differential) and temperature gauges, provide invaluable instantaneous information, including filter status, unit leaving temperature and coil entering and leaving conditions. For example, while differential pressure across a filter bank is typically reported to the BAS, the VUMC Facilities Management department also requires magnehelic gauges to be provided across each filter bank. This allows maintenance staff to determine if the filters need changing without having to access the BAS.
FIGURE 4: An example of a split and staggered cooling coil. Courtesy: Smith Seckman Reid, Inc.
Motor removal rails for fan array systems are required by the VUMC Facilities Management department. Additionally, the VUMC Facilities Management department does not permit non-standard or fractional-size motors, as replacement by maintenance personnel would likely involve using a readily available off-the-shelf motor not intended for the original service, leading to premature motor failure and higher maintenance costs. Drain pans Design engineers are fully aware that drain pans are necessary where wet conditions occur, such as during humidification and dehumidification. Although drain pans are typically not provided for heating coils, these coils still require cleaning, albeit not as intensely as cooling coils, since they usually have fewer than four rows. Spray washing a heating coil without a drain pan in place necessitates that maintenance staff vacuum the ponding water throughout the cleaning process. Therefore, drain pans are recommended at all coil locations.
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A unified approach The operation and maintenance of AHUs play a crucial role in ensuring the reliable functioning of facilities such as the Vanderbilt VUMC. Examining the VUMC Facilities Management department's standards and expectations reinforces that a proactive, unified approach to AHU design, installation and maintenance not only meets the immediate cooling and heating needs of a building but also enhances the long-term health and safety of its occupants. By prioritizing the integration of robust operational strategies and a thorough understanding of owner expectations, we can foster successful collaborations between facility managers, designers and owners. Ultimately, the design and installation measures taken today contribute to the longevity and efficiency of AHUs, paving the way for a more efficient, reliable future in facilities. cse Mike Gable, PE, CEM, is a Professional Engineer and Certified Energy Manager with more than 30 years’ experience in the design, construction and maintenance of HVAC systems at Vanderbilt University Medical Center (VUMC) in Nashville, Tenn. He is a Senior Director of Facilities Management. Gavin Green, PE, is a Senior Mechanical Engineer at Smith Seckman Reid Inc. with more than 37 years of experience in HVAC system design for healthcare, institutional and commercial facilities. consulting-Specifying engineer — www.csemag.com
6/17/25 11:10 AM
The ROI on IAQP: clean air, big energy savings
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BUILDING SOLUTIONS HVAC
Bryan Bucchianeri, PE, CDM Smith, Boston and Madeline Doyle, EIT, CDM Smith.
Five disinfection strategies and technology options for AHUs This article focuses on the different disinfection strategies and technologies available for air handling systems, their effectiveness and their proper application.
FIGURE 1: Multiple rows of UV light bars, supported by Unistrut, installed downstream of a cooling coil in a large capacity air handling unit. Courtesy: CDM Smith
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A
ir handling units (AHUs) are an essential and significant part of the ventilation and conditioning systems developed to better the spaces we live and work in every day. The variability of an AHU’s function, form and location is chosen to best serve the people and products that rely on expected temperatures and air quality. Multiple components comprise AHUs, including filters, mixing boxes, dampers, heating/cooling coils, energy recovery devices and fans. The ventilation and conditioning requirements of a building must be calculated and reviewed to provide the proper selection and combination of components that will satisfy the needs of the building occupants. These components are used in combination to efficiently and effectively condition the outdoor and return air streams of a building’s heating, ventilation and air conditioning (HVAC) system. However, beyond the common contaminants of a workspace or home, there are additional health considerations regarding the passage of air particles and reducing their spread. AHUs can vary in capacity and size based on the area, volume and interior design conditions of a space. For example, in a wastewater treatment plant, an AHU can be used to provide continuous airflow at a specific rate defined by NFPA 820: Standard for Fire Protection in Wastewater Treatment and Collection Facilities. In this application, an AHU may only be composed of two parts: a filter section, to remove contaminants from the outdoor air stream, and a heating coil, to condition the outdoor air to keep the space above freezing conditions. To provide ventilation in commercial applications, such as office buildings or schools, several of the components described above may comprise an AHU, as required by the applicable mechanical codes. To provide conditioned air for occupant comfort, an AHU must comply with the consulting-Specifying engineer — www.csemag.com
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required applicable building and energy codes and standards developed by ASHRAE. In recent years, building owners and HVAC designers have been presented with a more difficult challenge: including the ventilation system of a building in their approach to minimize the spread of airborne diseases. ASHRAE Standard 62.1: Ventilation for Acceptable Indoor Air Quality (IAQ) and ASHRAE 62.2 outline the minimum ventilation rates and measures to help provide acceptable IAQ for occupants and minimize adverse health effects. Building owners and occupants now have an increased responsibility to ascertain how additional measures can be taken to provide a healthier indoor environment that helps reduce the spread of viruses.
Disinfection strategies With the heightened focus in recent years on HVAC technologies that can disinfect the air supply in any given space, it is equally important to be aware of these technologies’ limitations. These products must be installed correctly to optimize their effect, and the technologies require adequate time to capture the particles and reduce concentrations to mitigate the chance of infection. No existing disinfection system completely eliminates the pathogens in the air. However, it is possible to implement a system that addresses the concerns and realities of a world focused on public health and decreasing the spread of diseases through air ventilation. As with any HVAC design, this goes beyond required code, and there are likely additional costs and installation constraints. Understanding the disinfection options and limitations for an AHU provides realistic expectations for installation and disinfection levels. A thorough site review and investigation is required to determine the feasibility of implementing these strategies on existing equipment and retrofits, which is largely dependent on the existing conditions of the equipment. It is more feasible to apply the strategies outlined below to new build projects. Strategy one The first strategy for providing disinfection includes increasing ventilation rates and providing room differential pressurization. As stated in ASHRAE’s “Position Document on Infectious Aerosols”, published in April 2020, the majority of larger emitted droplets greater than 100-micron size are drawn by gravity to land on surfaces within a radius consulting-Specifying engineer— www.csemag.com
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of three to seven feet. Some larger droplets evaporate to 10-micron size as they travel and land much farther away. Aerosols less than a 10-micron size can remain airborne for hours and travel longer distances to infect secondary hosts who had no contact with the primary host. ASHRAE determined that increased ventilation rates and room differential pressurization did not reduce the short-range transmission of larger particles but did help to dilute the transmission of aerosols less than 10-micron size. This means that increasing airflow to a space can limit the spread of airborne particles of a certain size. ASHRAE also noted that the effective directional airflow created clean-to-dirty airflow patterns to move aerosols toward exhaust locations. Though airflow designs likely incorporate these patterns of supply to exhaust already, the design is reinforced through this strategy. Furthermore, many space types are not currently designed to meet the six to 12 air changes recommended for airborne infection reduction. This may again be a factor in updating an existing system or a reason for limits in the expected capabilities of an AHU. Being mindful of the air changes that lessen the spread of infection is an important basic component of disinfection that can be used in conjunction with further technology to achieve the best results. The operating and maintenance costs of increasing ventilation rates, however, will likely be higher than with other strategies, and increasing the ventilation of an existing unit could involve installing a new motor or a new supply air blower, depending on the increased airflow.
FIGURE 2: Multiple rows of bipolar ionization bars, supported on the upstream face of a cooling coil, in a large capacity air handling unit. Courtesy: CDM Smith
Learning
Strategy two The second strategy is to improve the air filtra- u tion efficiency ratings. ASHRAE determined that • Understand the different high-efficiency filters, filters with a minimum efficomponents of an air ciency reporting value (MERV) of 13 or greater, handling unit. installed in central AHUs reduce the airborne load • Learn the different disinfection strategies of recirculated infectious particles. However, the and technologies that can filters will not eliminate all risk of transmission of be implemented in an air airborne particles due to other factors that conhandling system. tribute to disease transmission, such as infectious • Identify the pros and cons to consider when selecting aerosol concentration. Researchers at the Illinois the strategy or technology Institute of Technology found, “HVAC filtration for to implement in a specific controlling infectious airborne disease transmission application.
Objectives
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BUILDING SOLUTIONS HVAC
in indoor environments: Predicting risk reductions and operational costs,” that, “recirculating HVAC filtration was predicted to achieve risk reductions at lower costs of operation than equivalent levels of outdoor air ventilation, particularly for MERV 13–16 filters.” The recommended high-efficiency filters have significantly higher pressure drops that require an increase in fan horsepower, energy and, occasionally, more installation space inside the AHU. Thus, existing systems may not have adequate motor sizes or cabinet space to accommodate these filters.
FIGURE 3: A cooling coil installed in the air handling units mentioned in the case study. Courtesy: CDM Smith
Strategy three The third strategy includes ultraviolet lights with nanometer wavelengths within the C band (UV-C). UV-C lights inactivate microorganisms by damaging the structure of nucleic acids and proteins within the microorganism, depending on the UV dose and susceptibility of the microorganism. The UV dose is intensified by decreasing the distance between the UV source and the microorganism and by increasing the exposure duration. Historically, UV-C applications treated specific
surfaces within HVAC systems, such as cooling coils and condensate drain pans. UV-C lamps were mounted inside AHUs perpendicular to the airstream, downstream of the cooling coil, to project their light back onto the coil and drain pans, preventing microbial growth on surface areas. UV-C is applied inside distribution ductwork to destroy airborne microorganisms in the air stream as they travel down the length of the UV-C device. By traveling the length of the device rather than perpendicularly, the light provides more exposure time to damage the cellular structure of the pathogens. Tests indicate killing vegetative bacteria is successful, but smaller-sized bacterial spores are more difficult to kill, yielding an approximate 90% success rate. Retrofitting existing AHUs is nearly impossible because the lamps are typically 48 to 60 inches in length, and commercial air handling compartment sizes are typically designed to provide about 30 inches in width. Designers often misapply UV-C lights in AHUs because they do not recognize the correct positioning needed for lamp orientation to kill airborne microorganisms, versus those on a surface. Again, paying special attention to ensure that the UV lights are installed either perpendicularly to the airstream or, ideally, the length of the unit will make a difference in how well this
CASE STUDY: Air quality and humidity control for college auditorium IN EARLY 2020, CDM Smith performed a site evaluation of the the equipment was past its useful life. The major concern, howevmechanical systems serving an auditorium on a college camer, was the subsequent mold growth from the excessive humidity. pus in the northeastern United States. The goal of the evaluHumidity control became the priority for the college and was ation was to provide the college with bid-ready drawings and the focal point for CDM Smith’s final recommendation and soluspecifications that addressed multiple tion. During this time, however, the world mechanical issues, including upgrades was dealing with a major virus outbreak, The major concern, however, to the existing building management and clients began asking which additional was the subsequent mold growth. system, repairs to the existing chilled strategies or technologies could be impleHumidity control became the water system and a solution to address mented to help reduce the spread of this the auditorium’s humidity issues. virus and future viruses. Some governing priority for the college and was the The auditorium is used for musibodies even mandated that preventative focal point for CDM Smith’s final cal theater and performing arts multidisinfection technologies be implementrecommendation and solution. ple times a year. At full capacity, it can ed on their active projects - such was the seat approximately 2,000 people. At the case with this project. time of the evaluation, the facility staff and personnel noted Meanwhile, manufacturers of the five most common remedithat the auditorium was uncomfortable to be in during hot and ation strategies were marketing their products by claiming that humid summer days. It was determined that the existing AHUs theirs were the best choice to remediate the virus. Many of these did not have enough capacity to handle the cooling loads and claims were substantiated by single “in-house” test results that
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consulting-Specifying engineer — www.csemag.com
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method works to meet designer and owner benchmarks for disinfection. While it has been argued that upper room germicidal UV air disinfection is the most effective approach toward stopping the spread of airborne diseases, measuring a relative economic efficiency more than nine times higher than rate with ventilation alone, the proper installation of such technology can have a significant impact on effectively limiting the spread of airborne pathogens within an indoor environment.
Strategy four The fourth strategy is the generation and distribution of ozone particles to attach and remove microorganisms from air streams and airborne microorganisms within building spaces. Ozone is the product of separating oxygen molecules (O2) that then collide to form ozone (O3). In April 2020, the University Institute of Cardiology and Pneumology of Quebec published an article titled, “Ozone efficacy for the control of airborne viruses: Bacteriophage and norovirus models.” The article detailed how low concentrations of ozone reduce virus infection when applied with high relative humidity. Ozone eliminates viruses by damaging the ribonucleic acid of the virus.
Although it is effective for air disinfection, ozone in concentrations exceeding five parts per billion is harmful to human health. The low concentrations of ozone employed in the study were at least 0.23 parts per million. Exposure to ozone creates risk for a variety of symptoms and diseases associated with the respiratory tract. Many products of ozone homogeneous and heterogenous reaction processes also increase risks to human health, including formaldehyde, unsaturated aldehydes (produced during the reaction of ozone with ketones and alcohols) and ultrafine particles less than 10-micron size. Remediation strategies involving ozone are best used in low-occupancy spaces during unoccupied times, such as at night, when the ventilation system has had an adequate period to remove the microorganisms and remaining ozone particles from the space. It is often used in medical or hospital settings where a certain level of disinfection is necessary. Caution should be applied with this technique when looking to implement it elsewhere.
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downstream of the cooling coil installed in the air handling units mentioned in the case study. Courtesy: CDM Smith
Strategy five The fifth strategy involves the generation and distribution of positive and negative oxygen ions to attach and remove microorganisms from air streams
had not been validated by independent testing agencies, labs or ASHRAE. Some manufacturers claimed that the virus could be instantly killed using their products, when in fact, there are no available technologies that kill 100% of airborne particles. These technologies require time to attack the particles and reduce concentrations, which mitigates the risk. In addition to finding a solution to the humidity issue within the auditorium, CDM Smith was now tasked with including, at minimum, MERV 16 filters and UV light technology. One of the major design challenges of this project was the space constraints. The new AHUs would be installed, similar to the existing AHUs, in a narrow mezzanine that wrapped around the back perimeter of the auditorium. After the heating and cooling load calculations were finalized and the initial equipment selections were coordinated with the manufacturer, the layout consisted of a combination of horizontal and vertical AHUs with hot water and chilled water coils and MERV 8 filters. Because of the college’s mandate to include MERV 16 filters, however, we
consulting-Specifying engineer— www.csemag.com
FIGURE 4: The UV light bars
had to reselect the AHUs; and, owing to the additional static pressure requirements, the AHUs had to be upsized. These new selections would not fit in the mezzanine space. After review and consideration, the college approved a final configuration of MERV 8 pre-filters and MERV 13 post-filters, which then allowed the AHUs to maintain their initial smaller footprint. UV lights were installed on the upstream side of the cooling coils, and additional bipolar ionization bars were installed downstream of the cooling coils. The final design consisted of eight AHUs with MERV 8 pre-filters, MERV 13 post-filters, hot water heater coil, chilled water-cooling coil, UV lights, bipolar ionization bars and supply fan. As of the end of 2024, the AHUs were installed, tested and operational. The final design provided the college with a solution to their initial concern of humidity and mold growth affecting the health of their patrons, while also providing a solution that would help reduce the spread of viruses and address the concern into the future.
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BUILDING SOLUTIONS HVAC
FIGURE 5: A detail showing the installation of the UV light bars and bipolar ionization bars, with control modules, on a vertically configured air handling unit. Courtesy: CDM Smith
FIGURE 6: A detail showing the installation of the UV light bars and bipolar ionization bars, with control modules, on a horizontally configured air handling unit. Courtesy: CDM Smith
Insights
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csemag.com
Air handling insights u Covid-19 put disinfection
strategies for HVAC systems top of mind for many building owners and engineers.
u Understanding the pros and
cons of different disinfection strategies allows engineers to pick the best option for specific projects.
and airborne microorganisms within building spaces. The positive ions are missing an electron, while the negative ions contain an extra electron, thereby resulting in an unstable condition. To restabilize, the bipolar ions search for and trade electrons by seeking out the airborne particulates, bacteria, aerosols, volatile organic compounds and odors in the space or distribution pathways. This process increases the size of the harmful pathogens into larger clusters as ions are added. Those particles then return to the central AHU, where they are more easily captured by the filters. As the captured pathogen clusters divide to reproduce, they bond with oxygen ions, thus destroying the microorganisms. It is important to note that the concentration level of the ions begins to reduce after 100 seconds, which ultimately limits their total count available to attach to the contaminated molecules after that time frame
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Bipolar ionization bars are small, lightweight and easy to retrofit on the leaving face of cooling coils to prevent air flow obstruction. Special attention should be paid to the veracity of manufacturers’ claims for these technologies because there are inconclusive viewpoints regarding the safety of introducing ions as a disinfecting method. A 2022 study by the Toho University Department of Infection Control and Prevention, titled, “Evaluation of a bipolar ionization device in inactivation of antimicrobial-resistant bacteria, yeast, Aspergillus spp. and human coronavirus,” reported that bipolar ionization, specifically for healthcare spaces, is largely understudied and requires more information before its efficacy is entirely understood. This method would be the easiest to retrofit to an existing unit; however, without combining it with another method, such as increasing the ventilation or the filter efficiency, it would not be as effective or useful. Therefore, bipolar ionization should not be the sole solution towards air disinfection, but it has the potential to reduce the spread of airborne diseases. Like any technology, these techniques continue to be studied and will develop in relation to our understanding of infection and what can be done to mitigate the spread of diseases. Cognizance of how impactful a certain device or system is toward disinfection means going beyond marketing language and designing around an AHU that is a part of a greater whole. Creating a holistic HVAC design that considers disinfection strategies presents a broader understanding of what an AHU can provide in terms of overall building design, and ultimately contributes to a better use of the power and maintenance put toward operating the unit. While the applications of these strategies are often in medical settings, HVAC engineers and building owners may look at how they can better serve the health of the occupants of any building with a number of these disinfection approaches. cse Bryan Bucchianeri, PE, CDM Smith, Boston, Massachusetts. Bryan is a mechanical engineer with CDM Smith and has more than 10 years of industry experience in HVAC and plumbing systems. Madeline Doyle, EIT, CDM Smith, Boston, Massachusetts. Madeline holds a mechanical engineering degree from Syracuse University and is a mechanical engineer, EIT with CDM Smith. consulting-Specifying engineer — www.csemag.com
6/17/25 11:12 AM
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BUILDING SOLUTIONS
ENERGY EFFICIENCY AND DECARBONIZATION John Yoon, PE, LEED AP, McGuire Engineers Inc., Chicago
Decarbonization: How we got here and where we’re going Climate change poses significant financial and infrastructural risks to the U.S. economy, prompting debates over whether proactive decarbonization and resilience efforts are more cost-effective than maintaining the status quo.
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Learning
Objectives
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• Examine the financial risks of climate change and review of the role of decarbonization in addressing climate change. •R eview the current state of decarbonization legislation as it relates to the building construction industry. Review how building energy efficiency aligns with decarbonization efforts. •C reate a playbook framework for building decarbonization.
uch of the U.S. economy depends on the stability and predictability of the environment. For example, changing weather patterns can disrupt agricultural production, increase the quantity and severity of storms that can damage property, cause strain on aging utility infrastructure that wasn’t designed for extreme weather, etc. Given the potential for these types of adverse outcomes, there’s a cost associated with a “business as usual” approach toward climate change. The question is how do you quantify that cost to decide if it is acceptable and by extension, if a proactive or reactive approach should be taken? Is proactive climate risk mitigation through decarbonization or resiliency efforts to adapt more effectively? For fiscal year 2025, the Office of Management and Budget published a white paper titled, “The federal government’s budget exposure to financial risk due to climate change.” This paper provides macroeconomic assessments of the impact that climate change has on federal spending and revenue. The expectation is that any increase in discretionary governmental spending to address physical risks (disaster relief, agriculture/flood insurance programs, infrastructure damage, etc.) must be offset by an associated increase in revenue (taxes) and/or decreases in funding for other discretionary federal budget line items (defense, transportation, veterans’ benefits, education, etc.).
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Economic projections from the federal government comparing Biden-era federal decarbonization policy to “do nothing” scenarios have estimated a potential yearly impact of just under 3% of U.S. gross domestic product (GDP) by 2048 — over a trillion dollars per year. While climate change affects the entire U.S. economy, the socioeconomic groups that are most likely to be affected are typically the least able to afford the costs associated with adaptation to climate change. Due to the current political climate, many individuals question the validity of government data. However, the insurance industry can offer additional independent insight. The expectation is that the insurance industry has a vested business interest in quantifying the risks associated with increased frequency and severity of weather events. In 2022, there were approximately $275 billion in global economic losses from natural disaster events. Over the past 40 years, medium value ($1 billion to $5 billion) and high value (>$5 billion) loss events make up an ever-increasing percentage of overall losses. In the U.S. alone, there were 27 separate billion-dollar weather and climate related disasters. Continuing urbanization and development in regions susceptible to severe weather (coastal regions, in flood plains, areas prone to drought and wildfire, etc.) make this worse. Insurance losses associated with natural catastrophes are predicted to grow 5% to 7% annually. Because of this, many insurers will opt to mitigate risk by raising premiums, reducing coverage or withdrawing altogether from markets that are highly susceptible to weather related disturbances. Currently, an estimated one in 13 homeowners is uninsured. As insurance coverage becomes unaffordable or unavailable, this number will increase and put additional strain on governmental resources. consulting-Specifying engineer — www.csemag.com
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Energy models are not just for buildings For a system to remain stable, inputs must equal outputs. Systems will try to self-stabilize by internally transferring energy from place to place. Engineers are keenly aware of this every time they perform a load calculation to determine equipment sizing. Anything that changes the amount of energy within a system and how quickly it can be dissipated from or transferred within that system has the potential to destabilize the system. This concept also applies to much larger systems, like Earth. The planet has the capability to absorb and release carbon dioxide (CO2). This ability is known as the “carbon cycle.” The amount that is absorbed and released in this cycle every year is roughly 350 gigatons. The Energy Information Administration estimated that for energy related emissions in 2019, the United States emitted 5.13 gigatons compared to approximately 33 gigatons of overall global energy related emissions. These types manmade emissions can skew the carbon cycle and lead to an increased concentration of CO2 in the atmosphere. CO2 is a greenhouse gas and can change how much thermal energy is dissipated from the planet. Although the global warming potential of CO2 on a per unit basis is significantly less than other gases, the sheer overall volume of CO2 emissions make it the single most impactful greenhouse gas. In general, a 10 parts per million (ppm) increase in atmospheric CO2 concentration equates to a mean global temperature increase of 0.1°C. Based on NOAA data, the concentration of CO2 in the atmosphere has steadily increased from roughly 316 ppm in 1958 to 424 ppm in 2024. Returning to the energy model analogy, greenhouse gas emissions (GHGe) have increased the heating potential of the atmosphere by 1.11 watts per square meter since 1990. CO2 is responsible for about 78% of that increase. That additional energy is absorbed and dissipated through various mechanisms (weather patterns, melting of polar ice, etc.). Because of the potential impact of these trends, most climate change treaties and legislation now target CO2 emissions. The process to decarbonization started long ago, you just haven’t noticed Decarbonization has slowly progressed on the global, federal, state and local levels, but those efforts haven’t always been coordinated. The nexus of most federal decarbonization polconsulting-Specifying engineer— www.csemag.com
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FIGURE 1: Climate changes potential impact on U.S. gross domestic product, and excerpt from Analytical Perspectives, Budget of the U.S. Government, FY24, pg. 22. Courtesy: Budget of the U.S. Government
icy was the 1997 Kyoto Protocol. The Kyoto Protocol was an international treaty where member countries committed to reducing global GHGe from 1990 baseline values. This treaty originally had 192 signatory countries. However, it incorporated certain prescriptive requirements that resulted in significant backlash in many of those signatory countries. The primary contention was that an unequal top-down burden was placed on already industrialized countries, while exempting developing countries. Among the excluded developing countries were India and China, both of which had rapidly growing economies and dramatically increasing GHGe. As such,
FIGURE 2: Global atmospheric carbon dioxide compared to annual emissions (1751-2024). Courtesy: Climate.gov
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BUILDING SOLUTIONS
ENERGY EFFICIENCY AND DECARBONIZATION
FIGURE 3: Earth’s surface temperature and atmospheric carbon dioxide (1850-2023). Courtesy: Climate.gov
the governments of numerous signatories, including the United States, did not ratify the treaty. While the U.S. did not ratify Kyoto, the Environmental Protection Agency did issue a determination in 2009 that reclassified CO2 and other GHGs as air pollutants that endangered public health and welfare by causing climate change and ocean acidification. As such are subject to regulation under the Clean Air Act. This reclassification power was afforded to the EPA under the concept of Chevron Deference. The 2015 Paris Agreement superseded the Kyoto Protocol as the primary regulatory treaty for controlling climate change. The Paris Agreement’s stated goal was to limit global temperature rise to 1.5°C above pre-industrial levels compared to Kyoto’s target of a 2.0°C risk. The agreement addressed some of the concerns about Kyoto by expanded responsibilities to all signatory countries and allowing countries to have more self-determination in setting emission reduction targets. Initial efforts by the U.S. federal government to meet the Paris targets were limited. The most prominent was provisions of the Inflation Reduction Act (IRA) of 2022, which provided funding and tax incentives for clean energy production, carbon capture and industrial decarbonization among others. Of significance to the building construction industry were tax incentives for increasing energy efficiency in various building systems by at least 25% beyond the ASHRAE Standard 90.1: Energy Standard for Buildings Except Low-Rise Residential Buildings baseline. Those incentives ranged from $0.54/square foot to $5.81/square foot. Ultimately, these incentives
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FIGURE 4: Electrification is an integral part of decarbonization efforts. Robust electrical distribution equipment such as this low-voltage switchgear helps ensure that those systems are resilient. Courtesy: McGuire Engineers
help promote adoption of energy-efficient technologies by making them more affordable and accessible.
Uncertainty will delay efforts to achieve any decarbonization goal The executive branch’s stance on decarbonization has changed dramatically from between past and current administrations. Trump’s presidential administration withdrew from the Paris Agreement on two separate occasions (the Biden administration had rejoined after the first withdrawal). In March 2025, the EPA in accordance with executive orders from the Trump administration has also announced the intent to rollback several established environmental policies related to carbon emissions. These policy changes could adversely impact discretionary programs that are subject to executive authority. A key example is EPA’s Energy Star program, which is integral component of many jurisdictions’ building performance standards (BPS) and benchmarking requirements. consulting-Specifying engineer — www.csemag.com
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BUILDING SOLUTIONS
ENERGY EFFICIENCY AND DECARBONIZATION
FIGURE 5: Electrical utility meters are evolving to become smarter. Traditional meters such as this one will eventually give way to meters with distributed intelligence that will allow real-time monitoring and control. Courtesy: McGuire Engineers
However, certain statutory requirements, such as IRA tax incentives, are technically not subject to executive order. Consequently, the exact impact of these rollbacks is unclear. Absent consistent guidance from the federal government, multiple states and local organizations have taken the initiative to further decarbonization efforts. For example, the U.S. Climate Alliance (USCA) represent a coalition of 24 governors committed to the 2015 Paris Climate Accords after the Trump administrations 2017 withdrawal. Ultimately, the USCA’s goal is to reduce GHGe 50% to 52% below 2005 levels by 2030 and achieve net-zero emissions no later than 2050. At this time, 24 different states and 257 local municipalities have adopted climate action plans. Climate action plans are roadmaps that are intended define objectives for addressing climate change and typically include targets for reducing GHGe relative to emissions in a baseline year. However, the methods by which those goals are achieved or measured can vary significantly from jurisdiction to jurisdiction. As they relate to building construction, the first step in implementation is developing benchmarking requirements to quantify current energy usage in building and establish baseline values. The step following benchmarking requirements is usually implementation of a BPS. BPSs are local laws that require building to achieve reductions in carbon emissions by improving its electrical, gas and water efficiency. Typically, BPS requirements become stricter over time with a glidepath toward a 2040 or 2050 goal. With reduced guidance from the current federal administration, nongovernmental organizations such as the Institute for Market Transformation have developed BPS policy design, implementation and adoption frameworks. However, requirements still vary dramatically between the jurisdictions that have already adopted a BPS.
Disruption in the electrical utility business Historically, energy usage and economic growth in the United States had shown a clear trend of decoupling from each other. In other words, increases in GDP have not resulted in a proportional increase in energy usage. This trend is typical of post-industrial economies where GDP is dom-
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inated by tertiary market sectors that are focused primarily on services (health care, finance, information technology, etc.) as opposed to energy intensive primary and secondary market sectors (mining, construction, manufacturing, etc.). However, after 20 years of stagnation, electrical usage is once again on the rise in the United States. Federal Energy Regulatory Commission forecasted in 2023 filings a 4.7% electrical five-year demand increase compared to a previous estimate in 2022 of 2.6%. Peak demand is expected to grow in the U.S. by at least 38 gigawatts (GW) over the next five years. This growth has been driven primarily by data centers and the construction of new industrial facilities. The reality is that because of deferred investment, the U.S. electrical grid is not prepared for this load growth. While the rate of connecting new loads to the grid is increasing, bringing new generation online can take significantly longer. Even if sufficient generation may exist in a particular geographic area, the transmission capacity to transfer power from one region to another may also be insufficient. The inability to obtain electrical power has delayed many projects. It is expected that investment in the grid will eventually grow to meet demand. However, as expected in any market driven economy, electrical costs will increase in the meantime. For example, PJM Interconnection, the electrical regional transmission organization responsible for all or parts of 13 different states, has a capacity auction to ensure that enough electrical generation is available to meet future demand. For the 2025/26 delivery year, the cost to consumers increased to $14.7 billion from the previous auction’s $2.2 billion. Compared to the previous auction year, there was approximately 6.6 GW less generation compared to an estimated 3 GW higher peak demand. Decarbonization’s focus on electrification of buildings and transportation will further increase demand and make this situation worse. It is expected that any efforts to electrify buildings will not be easy. Wholesale replacement of gas fired equipment with electric will be unusually expensive. In many cases, this work will trigger other seemingly unrelated items such as electrical service upgrades, physical modifications to accommodate equipment that wasn’t originally present in the building, code updates to previously grandfathered installations, etc. consulting-Specifying engineer — www.csemag.com
6/20/25 10:47 AM
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BUILDING SOLUTIONS
ENERGY EFFICIENCY AND DECARBONIZATION
FIGURE 6: Building HVAC controls are nothing new, as demonstrated by this 75-year-old temperature control system Improving monitoring and control of building systems is critical in reducing energy usage. Courtesy: McGuire Engineers
However, with increasing energy costs, energy conservation effort will become increasingly important in controlling a building’s operational costs. Depending on how much energy costs increase, certain fringe energy conservation measures may become economically viable based on an improved return on investment. In that scenario, it is expected that utilities will offer larger rebates to reduce grid demand which will further help offset those costs.
Decarbonization playbook for engineers The expectation is that given the current political environment, guidance/support for decarbonization efforts from the federal government will be inconsistent for the immediate future. Even with this uncertainty, local governments may still forge ahead — albeit on indeterminate timelines. While efforts may be uncoordinated between various jurisdictions, it is expected that all will follow the same basic framework. The following are some basic steps to point you in the right direction. Lay ground rules to determine if outcomes are successful Engineers need to know what they are trying to achieve. Simply saying “decarbonization” is meaningless if you don’t know what you need to measure to determine if you’re successful. As such, understanding what metrics to use (energy use intensity, source/site greenhouse gas intensity) for that end goal is important. If the local government has a climate action plan, reviewing its stated goals will be important. Following a nationally recognized standard with
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defined metrics like Energy Star is recommended if local government has not implemented benchmarking or BPS requirements. There are 18 broad categories within Energy Star that cover most, but not all building types. Warning: While multiple jurisdictions across the country intend to adopt decarb legislation and/ or a BPS, there appears to be little standardization. As such, what is required from place to place will vary. Every jurisdiction that has already passed decarbonization laws has had legal challenges from special interest groups which may change future requirements. The basis of the challenge is typically a preemption argument — a local government cannot void or re-regulate existing federal requirements. The 1975 Energy Policy and Conservation Act is the federal legislation that is most referenced in preemption challenges. Although there may be nationally recognized decarb programs (Energy Star Nextgen) at some point in the future, those emerging programs are still in flux and there is no guarantee that they will be fully implemented or universally adopted. In general, it appears that the most stringent end goal for most BPS’ will be “net zero” COe/carbon emissions by 2050. However, that is not guaranteed to be universal. For example, the Chicago Climate Action Plan’s stated goal is 62% overall GHGe reductions from 2017 baselines by 2040. As part of this first step, you should discuss the goals and overall process described in the following steps with the client or building owner. You can’t improve what you can’t measure: Develop a baseline To measure your progress toward that eventual goal, you need to know where you’re starting from. Generally, this means knowing: • Building usage, occupancy, size/floors, location. This information should harmonize with the Commercial Buildings Energy Consumption Survey (CBECS). Energy Star uses CBECS criteria, so it is a good starting point. • Quantify past whole building energy usage. Determine if there is any documentation regarding past energy usage. Most common starting point for this information is Energy Star. For example, in Chicago or New York City, if the building is larger consulting-Specifying engineer — www.csemag.com
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than 50,000 square feet, it was most likely required to comply with local benchmarking ordinances. If so, that ordinance required uploading utility info to Energy Star and the associated data should already be online on the city’s web portal. If the building does not have this documentation: – Assemble utility bills (gas, electricity, water) for at least five years. – Apply to Energy Star to consistently track this info going forward. • What major systems in the building use natural gas or electricity? • Although not needed as part of this step, it is also recommended that an energy model based on existing conditions be created. This will become important in the next step. Determine how good or bad things are Again, it appears that there will be little standardization regarding initial decarbonization and/ or BPS requirements. However, it is likely that either initial benchmarking data for that building or performance compared to peer buildings will play a prominent role in measuring any type of progress. It is also likely that building systems that depend on fossil fuels (i.e., natural gas fire equipment) are the most likely things to be phased out as part of any decarbonization requirement. While energy usage data was assembled in the earlier step, this step is focused on determining how far you are away from the end goal identified in step No. 1 compared to peer buildings. As part of this step, you should: • Compare peer buildings using the metrics you selected as part of measurements. Again, Energy Star will do this for you based on CBECS data. While there are other valid sources of building energy performance data, such as DOE’s Building Performance Database, their usability varies and they can’t always provide a statistically representative sample of peer buildings. • Determine rough order of magnitude energy usage associated with major systems in the building. The building’s fuel mix (kilowatts British thermal unit or kBtu electrical versus kBtu gas) will be important. consulting-Specifying engineer— www.csemag.com
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• If you completed an energy model, compare that model against the actual energy usage for the facility. There are multiple variable that can impact energy consumption in building — building population, occupancy patterns, weather, maintenance, etc. If there are significant deviations between actual and the model’s predicted energy consumption, it’s better to normalize those variables in the model early in the process. Having an accurate baseline model will be extremely useful in evaluating any proposed energy efficiency measures. • Perform a property condition assessment to characterize the age, condition and configuration of the base building systems. This is especially important for any system that uses fossil fuels. Decarbonization will be a multi-year process and understanding the relative complexity and replacement costs of major buildings systems in comparison to their useful service life will be important for the owner in developing a long-term capital plan. The basic goal of this step is to help the client accurately assess the relative energy performance of their building and how many of its systems are in play in any decarb effort.
FIGURE 7: Technologies that improve energy efficiency, such as these variable frequency drives, often have other benefits such as improved controllability. Courtesy: McGuire Engineers
Prioritize which systems should be first From the earlier step, it should be apparent what systems are prime candidates for retrofit or replacement. As such, you should also be able to give the client a basic idea of relative costs versus its percentage of the building’s overall carbon dioxide equivalent (CO2e) emissions. However, there are other considerations that may factor in deciding what upgrades/replacements should be performed first. For example, some systems such as old steam boilers may be problematic from an operations standpoint and take a disproportionate amount of labor to run properly. July/August 2025
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BUILDING SOLUTIONS
ENERGY EFFICIENCY AND DECARBONIZATION
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It is likely that
Conversions from pneumatic to direct digital controls may also provide benefits beyond energy either initial bench- usage in that the building engineers would be able to respond faster to tenant hot/cold calls. There marking data should be an interview with the building operating engineers to discuss these types of considerations for that building that aren’t necessarily reflected in the retrofit/ or performance replacement costs. Even in modern all-electric buildings, there will compared to peer still be decarbonization requirements. Most decarbonization legislation is also tied to utility electribuildings will play cal generation. Utility companies still have thermal a prominent role in generation assets (natural gas and coal-fired power plants), which won’t be retired for several years. As measuring any type such, electrical usage has a carbon emissions component as well. Energy Star does estimate source of progress. CO2e emissions associated with the production of electrical power. Inefficient systems that use electricity should be targeted as well. As a reference point for utility decarbonization efforts by state governments, Illinois’s CEJA legislation mandates decarbonization of the elec-
’
trical generation industry by 2045. Because of the planned retirement of those thermal generation assets, PJM is forecasting an electrical capacity shortfall before 2030. This will most likely result in higher electricity prices and other ways to curb electrical demand as we get closer to that deadline. While a reduction in a building’s electrical usage will have to happen at some point, it may be advisable to delay more costly retrofit/replacement projects that address electrical consumption until the increased cost of electricity/availability of incentives make it more advantageous from a business case. The expectation is that your client’s financial resources need to be managed carefully and that investing in affordable projects that have more immediate impact should be prioritized. Note: When preparing an energy model as part of the earlier step, thermal envelope deficiencies (windows, insulation, etc.) may have been identified. Passive solutions that reduce energy usage are typically preferred because they offer more persistent savings. Many engineering firms do not have
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in-house capabilities to perform these building envelope evaluations. Partnering with a firm that has technical expertise in this field is advisable. Optimize what you must buy time before making major changes Decarbonization will not happen overnight. For older buildings, the costs associated with the replacement of major building systems will be prohibitive. While engineers may advise clients to be proactive and replace major pieces of equipment at the end of their useful service life, the reality is that equipment often remains in operation well beyond that timeframe simply because a funding source isn’t available to support the work. Given that reality, energy efficiency considerations are relatively low on a client’s equipment replacement priorities unless incentives are available. It is unclear if/when government funds or a financing mechanism like PACE loans will be available to incentivize those energy efficiency/ decarbonization efforts. Until there is clarity
about where the money will come from, the recommended course of action for the near term is to at least optimize the performance of existing sysu tems. Retro-commissioning is often encouraged csemag.com by local utility companies with rebates that can Decarbonization significantly offset implementation costs. insights Ignoring all of these and taking a “wait and see” u Improving approach is unlikely to be viable. If the decarbondecarbonization in ization legislation passed by New York City (local buildings is a key strategy law 97) is any indication, any local decarbonizafor meeting climate action goals, with federal tion legislation has the potential to take the form incentives and local of a carbon tax. Local law 97, for example, imposbuilding performance standards driving es a penalty of $268 per ton of CO2e for anything reductions in carbon beyond a set annual emissions limit. That annuemissions. al emissions limit will become progressively more u As climate change stringent year over year until the final 2040/2050 increases financial risk and strains end date is reached. cse
Insights
John Yoon, PE, LEED AP, is the lead electrical engineer at McGuire Engineers Inc. He is a member of the Consulting-Specifying Engineer editorial advisory board.
infrastructure, investing in decarbonization efforts offers a proactive approach to stabilize systems and reduce long-term economic and environmental costs.
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BUILDING SOLUTIONS POWER
Taha Mohammed, PE, Electrical engineer, CDM Smith, Fairfax, VA and Ian Smith, PE, Electrical engineer, CDM Smith, Fairfax, VA.
What you need to know about the types of standby power systems Ensuring adequate backup power is crucial for safeguarding personnel safety and enhancing the resilience of facility operations during interruptions.
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ackup power ensures a supply of electricity is provided during a utility failure. While backup power comes in many forms and with various terms and definitions, there are particular types of backup power defined by NFPA 70: National Electrical Code (NEC). The key question is: what do I need the backup power for? Is it for life safety, is it legally required by code or the authority having jurisdiction (AHJ) or is it a standby to prevent loss of productivity in the absence of normal or utility power?
FIGURE 1. Example generator installed without maintenance platform, requiring maintenance staff to use a ladder for access. Courtesy: CDM Smith
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Backup power sources can be a reciprocal engine, or engine-driven generator, which can use diesel or gaseous vapor fuels. Other sources include stored-energy systems, which come in different types and technologies. This article will discuss different types of backup power systems and their applications, appropriate power sources and design considerations/best practices.
Codes and standards for backup power systems Important codes and standards for backup power include: • NFPA 70: National Electrical Code • NFPA 70E: Standard for Electrical Safety in the Workplace • NFPA 101: Life Safety Code • NFPA 110: Standard for Emergency and Standby Power Systems • International Building Code (IBC) • International Mechanical Code • International Fire Code (IFC) • National Electrical Manufacturers Association The NEC defines three types of backup power systems: emergency systems (Article 700), legally required standby systems (Article 701) and optional standby systems (Article 702). Additionally, NFPA 110 discusses emergency and standby power systems, but does not discuss optional standby systems.
Emergency/life safety systems “Emergency” or “life safety” systems are the most critical type of system that can be installed within a facility. These systems are specifically designed to protect the life and safety of personnel. consulting-Specifying engineer — www.csemag.com
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The NEC defines emergency systems as “systems legally required and classed as emergency by municipal, state, federal or other codes, or by any governmental agency having jurisdiction. These systems are intended to automatically supply illumination, power, or both, to designated areas and equipment in the event of failure of the normal supply or in the event of accident to elements of a system intended to supply, distribute and control power and illumination essential for safety to human life.” NFPA 110 classifies emergency systems according to the system’s level of criticality. Emergency/ life safety systems generally correspond to Level 1 systems in NFPA 110. This is defined as systems where “failure of the equipment to perform could result in loss of human life or serious injuries.” In addition to level, NFPA 110 also defines the system’s type (the maximum time that the emergency system is permitted to transfer power from the normal to the emergency source when the normal source fails) and the system’s class (the minimum number of hours that the emergency system is designed to operate without requiring refueling or recharging). For example, a Type 10/Class 48 system is required to begin supplying emergency power within 10 seconds of the failure of the normal power source and have a minimum of 48 hours of fuel storage.
Legally required standby systems The second type of backup power system is a legally required standby system. The NEC defines legally required standby systems as, “systems required and so classed as legally required standby by municipal, state, federal or other codes or by any governmental agency having jurisdiction. These systems are intended to automatically supply power to selected loads (other than those classed as emergency systems) in the event of failure of the normal source.” These systems do not include loads that are considered emergency and essential to the safety of human life. Legally required standby systems also often correspond to “Level 2” systems, defined by NFPA 110 as systems “where failure of the emergency power standby system (EPSS) to perform is less critical to human life and safety.” Not all legally required standby system will be covered by NFPA 110. If the system does not play a role in the safety of human life, then NFPA 110 does not apply. consulting-Specifying engineer— www.csemag.com
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Optional standby systems The last type of backup power system is the optional standby system. The NEC defines optional standby systems as “systems intended to supply power to public or private facilities or property where life safety does not depend on the performance of the system.” Because optional standby systems do not supply life-safety loads, NFPA 110 does not apply to optional standby systems.
FIGURE 2. Simplified one-line diagram from a lab expansion project showing separate breakers for emergency and optional loads. Courtesy: CDM Smith
Application of emergency, legally required and optional standby systems Often, the requirement for a backup power system is defined by standards other than the NEC or NFPA 110. One of the most common drivers for an u emergency system is emergency lighting. Both the • Differentiate between IBC and NFPA 101 have requirements for emeremergency, legally required gency lighting. IBC requires “an emergency electriand optional standby cal system (to) be provided to illuminate” certain systems. areas (IBC 1008.3), while NFPA 101 mandates • Recognize the available sources for backup power emergency lighting for means of egress be provided systems. in a variety of types of buildings and requires “new • Understand the basic emergency power systems for emergency lighting installation requirements for shall be at least Type 10, Class 1.5, Level 1, in accoreach type of power system.
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BUILDING SOLUTIONS POWER
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The most common type of power source for emergency and standby power systems is an engine-driven
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dance with NFPA 110,” (NFPA 110 7.9.2.2),” and corresponding to a system that can supply emergency power within 10 seconds for a minimum of 90 minutes. Other drivers for the installation of backup power systems include requirements based on the facility type. For example, Virginia Sewage Collection and Treatment regulations require that, if a certain sewage pump station cannot be fed from two redundant transmission lines, then an auxiliary power source must be provided. This is a good example of a legally required standby system that is not an emergency system. Other requirements for backup power systems may be driven by conditions such as the storage of hazardous materials. The IFC requires that where mechanical ventilation is required for hazardous materials, storage mechanical ventilation must be fed via an emergency or standby power system. Additional requirements for backup power systems may be located in facility specific codes, such as NFPA 99: Health Care Facilities Code or other locally adopted codes.
Power Supply Sources Backup power systems can use a variety of sources.
FIGURE 3. Lab expansion emergency automatic transfer switch and optional/ emergency manual transfer switches from left to right. Courtesy: CDM Smith
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The NEC lists the following power sources for emergency systems: •G enerator sets: Engine-driven generator sets (i.e., diesel or natural gas generators). • Stored-energy systems: Systems that store the required backup energy. Types of stored-energy systems are uninterruptible power systems, fuel cell systems, energy storage systems and storage batteries. The most common type of power source for emergency and standby power systems is an engine-driven generator. Most generators are fueled by either diesel or gaseous vapor (natural gas, propane or liquified petroleum gas). The NEC requires that emergency and legally required standby systems have an on-site fuel supply of at least two hours and generally prohibits the use of municipal gas systems as the sole fuel source unless specifically approved by the AHJ. The basic design requirements for emergency and standby systems are outlined in the NEC and NFPA 110. The engineer must do a complete code analysis to determine all applicable codes and standards for the design and select the appropriate backup power system type and requirements. This may include coordination with the owner, architect, mechanical engineer and process engineer.
Requirements for emergency systems Emergency systems typically have the most stringent requirements. For instance, because of the critical nature of the loads, the wiring for the emergency system must be entirely separate from the wiring for the normal power system. One of the major requirements for emergency systems is the separation of the emergency power supply (EPS) and EPSS equipment from other equipment and the rest of the building. For Level 1 systems, NFPA 110 requires that the EPS (i.e., the generator) must be located either in a dedicated room protected by a two-hour, fire-rated wall or located outside. Furthermore, in Level 1 systems, the EPSS (which includes the electrical system from the EPS up to and including the transfer equipment) cannot be installed in the same room as the normal electric service equipment when the consulting-Specifying engineer — www.csemag.com
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FIGURE 4. The main electrical room from a lab expansion with uninterruptable power supply, main switchboard and optional loads automatic transfer switch. Courtesy: CDM Smith
normal service equipment is rated over 150 volts to ground and is greater than or equal to 1,000 amperes. These requirements apply to a large number of commercial buildings and are often met in one of two ways. Either the design includes a separate emergency power room or the generator and transfer equipment (i.e., the automatic transfer switch) are located outside the building. Power sources and generators for emergency systems can also feed legally required and optional standby systems, but the system must be designed with dedicated and separate circuit breakers from the EPS to feed the emergency and the legally required/optional. This is often implemented by installing multiple circuit breakers directly inside the generator enclosure. However, it is also permissible to have a switchboard or switchgear (including a main circuit breaker, if selectively coordinated)
CASE STUDY: Applying backup power systems in a laboratory facility WASHINGTON Suburban Sanitary Commission’s (WSSC) Consolidated Laboratory Facility, located in Silver Spring, Maryland, was originally constructed in 2001. The laboratory performs approximately 500,000 tests annually to support WSSC’s water and wastewater services. In partnership with WSSC, CDM Smith provided design and engineering services during the construction to expand the existing laboratory, including incorporating new office and laboratory spaces. The project is currently in the final stages of construction. The project included the installation of new electrical service and backup power systems to feed the lab expansion. To determine the appropriate type and capacity of the backup power system, CDM Smith personnel coordinated with WSSC’s operational staff to assess the specific requirements and equipment that would be located in the new laboratory. They also collaborated with architectural and mechanical engineers to properly size the backup power system. A comprehensive code analysis, including national and local codes, indicated that an emergency power system was necessary for life safety applications, such as emergency and egress lighting. It was also determined that an optional standby system was needed to feed laboratory equipment to ensure the facility remains operational during utility power outages. A diesel generator was selected to provide both emergency power for life safety equipment and the optional standby power for essential loads. The generator was equipped with two cir-
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cuit breakers directly connected to the alternator. One circuit breaker designated for emergency power and another circuit breaker for optional standby power loads. This configuration ensures that any overload or fault within the optional standby system does not trip off the emergency circuit breaker housed within the generator enclosure. Emergency and optional standby power is distributed through dedicated automatic transfer switches and power panels located through the new laboratory expansion. In compliance with Chapter 7 of NFPA 110, the automatic transfer switch for the emergency system was installed outdoors in a location separate from the normal service equipment. The selection of the generator fuel type and storage size was determined in collaboration with WSSC. Additionally, a facility-size uninterruptible power supply with batteries was included for critical laboratory loads to ensure continuous power during utility failures, as requested by WSSC operations staff. Considerations for safety and maintainability of equipment, such as the generator, were addressed during the design phase. An access platform was provided to facilitate ease and safety during routine maintenance. After construction was completed, the expansion included acceptance testing of all the electrical equipment, in accordance with InterNational Electrical Testing Association and manufacturer standards. An arc flash analysis was also completed by CDM Smith and labels were installed within the new expansion in accordance with NFPA 70E.
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BUILDING SOLUTIONS POWER
However, some requirements still apply. For example, legally required systems are still required to use listed and marked transfer equipment. Legally required systems must also still receive AHJ approval to use natural gas as the fuel source.
FIGURE 5. Diesel generator installed with access platform at a lab expansion. Courtesy: CDM Smith
Insights
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csemag.com
Backup power insights u Emergency power
systems have the most stringent requirements compared to legally required or optional standby systems.
u Identifying which local
and national codes apply to each system will allow engineers to design the best power source for each project.
to distribute the power to the separate system circuit breakers (provided that each circuit breaker is in a separate vertical section). If the system supplies both emergency and legally required/optional systems, then the system must either be capable of carrying all loads or be provided with load management to ensure that optional legally required loads are shed and that power is available for the emergency loads. As of 2024, an additional requirement in NFPA 110 for emergency/Level 1 systems is that generators used for Level 1 applications cannot be equipped with U.S. Environmental Protection Agency (EPA) mandated inducement engine shutdowns related to emissions systems. This essentially means that EPA stationary non-emergency/Tier 4 certified diesel generators can no longer be used for these systems. Additionally, based on this code change, the major diesel generator manufacturers have stopped producing Tier 4 certified diesel generators.
Requirements for legally required and optional systems Generally, the requirements for legally required and optional systems are less stringent than those for emergency systems. For example, the wiring for legally required and optional systems is permitted to be installed along with the normal wiring system. Because legally required and optional systems are not Level 1 systems, the requirement for a separate room or to locate the EPS/EPSS outdoors does not apply.
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Other design considerations In addition to conducting code analyses, determining the appropriate backup power size for the required loads and selecting the correct application, designers should consider the following: • Maintenance and accessibility: Consider how staff will maintain the generator. If the generator does not sit directly on the ground (i.e., if a subbase fuel tank is provided), consider providing an access platform for ease of maintenance. The height of the generator from the ground/floor with a subbase fuel tank could pose a safety hazard for maintenance personnel. For emergency lighting using batteries, a centralized battery system with a testing mechanism is generally easier to maintain and periodically test compared to individual battery packs installed in high or hard-to-reach locations, such as on walls or ceilings. • Environmental conditions: Ensure the generator is suitable for the environment in which it will be installed. This includes accounting for the mounting structure and protection from harsh weather conditions and storms. If heavy winds or storms are expected, consider installing the generator indoors with a plenum to protect the generator and generator room. • Fuel type and storage size: For non emergency generators, consult the owner about the preferred fuel type and storage quantity (generator run time). Determine how fuel will be delivered. • Generator capacity: In general, it is recommended to design generators to not exceed 80% of their rated capacity. However, generators should also not be significantly oversized, particularly to prevent diesel generators from wet stacking. Additionally, consider whether any future expansion or new loads are expected. • Noise mitigation: Consider the generator location and what the impact of the generator noise will be. Zoning requirements for noise may apply, but some zoning ordinances exclude emergency operations from the noise requirement. If noise is a concern, consider installing a sound-attenuated consulting-Specifying engineer — www.csemag.com
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generator enclosure and/or implementing sound-mitigation techniques if the generator is located inside a building. • Ventilation: If the backup power is located indoors, consider how the room will be ventilated. It is critical to ensure that air flows over the entire generator set (genset) and does not short-circuit past the alternator. For interior generators, a carbon monoxide detector is recommended and may be required by code. • Sequence of operation: Consider how the generator will integrate with the electrical system. Loads may need to be “staged” to not exceed the generator starting capacity when loads are reconnected. Multiple automatic transfer switches may be required, or load-shedding switchgear can be used. • Remote monitoring and testing: For some applications, remote monitoring of the generator is required by code. Consult the owner about remote monitoring methods and permissible locations. Remote monitoring will also aid periodic maintenance. • Emergency shutdown: Generators greater than 15 kilowatts are required to have an emergency shutdown. Coordinate with the owner and/or the AHJ/fire department regarding the best and most logical location for the emergency shutdown switch. • Periodic maintenance: Periodic testing and maintenance is critical for all generator applications, but only some generator applications require it. Consult the owner about the recommended maintenance schedule and consider including an automatic exercise timer to routinely run the generator to ensure generator readiness. NFPA 110 Chapter 8 contains requirements and recommendations for routine maintenance and operational testing. cse Taha Mohammed, PE, CDM Smith, Fairfax, Va. is an electrical engineer with more than 20 years of experience designing mediJuly/August 2025
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um- and low-voltage power systems, as well as performing analysis and engineering services during construction for municipal, industrial, and federal facilities. Ian Smith, PE, CDM Smith, Fairfax,
Va. Is an electrical engineer at CDM Smith focused on power system design and protection, including medium- and low-voltage systems as well as communications and SCADA systems.
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BUILDING SOLUTIONS CODES AND STANDARDS
Bill Kosik, PE, CEM, LEED AP, kW Mission Critical Engineering, Member of WSP, Chicago
How to coordinate IECC, ASHRAE 90.1 and ASHRAE 90.4 for data centers By understanding the differences in code or standard editions, data center designers can know which version to use.
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•U nderstand how IECC and ASHRAE 90.1 work together regarding energy-efficient building design.
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•R eview the different editions of the standards to determine which compliance path should be used. •K now that data center codes and standards are frequently shifting due to the vast changes in the industry.
ike the ASHRAE standards, the International Energy Conservation Code (IECC) has regular review periods and updates. Throughout the updated editions, ASHRAE Standard 90.1: Energy Standard for Buildings Except Low-Rise Residential Buildings continues to be the backbone of the IECC. For example, the first requirement listed by the IECC in Chapter 4, Commercial Energy Efficiency, is to follow Standard 90.1. When investigating how the IECC is written visà-vis ASHRAE Standard 90.4: Energy Standard for Data Centers, it is necessary to remember that ASHRAE 90.4 is not stand-alone but rather a compliance path for data centers extending from ASHRAE 90.1 (a normative reference for Standard 90.4).
Demarcation of data center spaces for MLC/ELC calculation
Also, energy efficiency conformance requirements for data centers differ between the 2018, 2021 and 2024 editions of the IECC. These differences manifest in significantly divergent technical approaches for demonstrating conformity to the respective edition of IECC and are worth exploring.
Updates to IECC 2018 The 2018 edition of IECC does not include language on the use of ASHRAE 90.4. Also, unlike subsequent editions, data centers are not acknowledged or defined. IECC Chapter 4 requirements indicate three methods for attaining energy efficiency conformance, the first being ASHRAE 90.1.
FIGURE 1: A data center has many types of spaces, including those directly supporting the information technology equipment. These spaces are defined in ANSI/TIA Standard 942A and NFPA 70: National
Mechanical rooms Data center operations and offices
Energy consumption included in calculation
Data center Electrical rooms
General offices and admin support spaces (not directly related to data center)
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Electrical Code, Article 645. Courtesy: Bill Kosik, WSP
Energy consumption not included in calculation
Because the requirements for data center minimum energy efficiency come from Standard 90.1, this compliance path will differ depending on the edition of Standard 90.1 enforced by the authority having jurisdiction. As discussed in “ASHRAE 90.4 created to boost data center energy efficiency,” it wasn’t until the release of ASHRAE 90.1-2019 that ASHRAE provided an alternate compliance path.
IECC 2021 edition Regarding Standard 90.4, the 2021 edition of consulting-Specifying engineer — www.csemag.com
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IECC 2024 for data centers If the 2021 edition of IECC is the bridge, the 2024 edition is the destination. The 2024 edition is the first IECC to fully address data center energy efficiency using ASHRAE 90.4-2022 as a compliance path and referenced standard. Section C403.1.2 consists of a single sentence, “Data center systems shall comply with Sections 6 and 8 of ASHRAE 2024.” This change eliminates the need for standalone tables or additional guidance in the code. There are also electrical requirements for data centers in the 2024 IECC. A completely new section, C405.9, data centers and computer rooms, indicates that “electrical equipment in data centers and computer rooms shall comply with this section.” There are two new subsections, C405.9.1 “Data centers” and C405.9.2 “Computer rooms.” Subsection C405.9.1 is the same as Section 405.1 in consulting-Specifying engineer— www.csemag.com
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THE HOME RULE DESIGNATION allows jurisdictions to use a model building code with modifications.
Code reviewer comments REFERENCES
Model building codes are written Form CEC-NRCC-PRC-E so a municipality can modify them to (certificate of compliance) account for local conditions such as REFERENCES climate, local construction force capability/capacity, established building CEC Sections 120.6 and 140.9 practices, permit review process, etc. (mandatory and prescriptive These factors can result in model code requirements for data centers) adaptations ranging from wording changes to major modifications. CEC GUIDANCE “Home rule” is a specific situation in which a municipality is designated a CEC document: “Compliance manual, home rule jurisdiction. Typically grantsection 10.4 - computer rooms ed through state legislation, this designation enables the jurisdiction to pass FIGURE 2: Data center projects local building code ordinances and located in California include addioperate independently. An example is tional compliance processes. the City of Chicago’s Energy TransforCourtesy: Bill Kosik, WSP mation Code (CETC), developed under the city’s home rule designation. The CETC illustrates how a municipality can adopt the International Energy Conservation Code (IECC) by incorporating changes and adaptations. The CETC is based on the 2021 edition of IECC and includes amendments that address issues critical to the City of Chicago’s short- and long-term energy goals. These include energy efficiency, transparent self-reporting of energy use of commercial buildings and climate goals. Chicago's changes to the IECC are integral to revised/new flexible compliance methods, including prescriptive and performance methods, paths related to green certification and passive building design. Another example is projects in California. The California Energy Commission has additional requirements for demonstrating compliance with its energy code (see Figure 2).
DOCUMENT COMPLIANCE
IECC bridges the gap between the 2018 and 2024 IECC editions. This is accomplished by providing Section C403.1 (building mechanical systems), which indicates that data centers are exempt from the requirements of sections C403.4 (heating and cooling system controls) and C403.5 (economizers). Section C403.1.2 covers the requirements for mechanical system efficiency. Although this section indicates that data center systems shall comply with ASHRAE 90.4 Section 6, the mechanical load component (MLC) values are included in tables in the IECC. These tables replace the ones in Standard 90.4 Design MLC, Tables 6.2.1.1 and 6.2.1.2. Although Standard 90.4 is not listed in the IECC Chapter 6, Referenced Standards, Standard 90.42016 must be the basis for the data center energy conservation requirements, as it is the only edition that uses design MLC. Design MLC was eliminated in the 2019 and 2022 editions of Standard 90.4, relying wholly on the annualized MLC metric. The design and annualized MLC values are lower than those shown in Standard 90.4-2016, meaning the IECC requires higher efficiencies for the mechanical systems. By increasing efficiency requirements, the IECC-2021 significantly raised the bar on the ASHRAE requirements. In addition to the mechanical requirements, the IECC also includes electrical system compliance. Section C405.1 indicates “transformers, uninterruptable power supplies, motors and electrical power processing equipment shall comply with section 8 of ASHRAE 90.4, in addition to IECC.”
When can municipalities use codes to make their own rules?
the 2021 edition; it indicates compliance with Section 8 of ASHRAE 90.4. With the advent of artificial intelligence and u csemag.com other technology, data center power and cooling systems must be flexible, expandable and cost-efIECC insights fective, while using the least energy possible. Havu The variations between ing codes and standards developed specifically for different versions of codes data center facilities creates a foundation for judgand standards should be carefully reviewed to ing data center energy efficiency with a consistent, ensure the proper edition is clear-cut and technically accurate approach. cse being followed.
Insights
Bill Kosik, PE, CEM, LEED AP, is an Assistant Vice President, Mechanical Engineering at WSP. He is a member of the Consulting-Specifying Engineer editorial advisory board.
u Because these codes
differ, engineers should know which is being used to design a data center to meet energy efficiency needs.
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E NGINEERING INSIGHTS MEP ROUNDTABLE: OTHER BUILDING TYPES
What should engineers know about industrial facility design? Three engineers discuss current trends, common challenges and important codes when designing industrial facilities. CSE: What are current trends in industrial and manufacturing facilities that engineers should be aware of?
Jarron Gass: Overall, I see a lot of effort being expended to increase efficiency, not only in the process being performed or the item being manufactured, but also in the energy efficiency of the struc-ture. This can manifest in various ways, but increased automation is the primary method that tends to have the greatest impact on fire protection specifically. Often, automated processes introduce addi-tional challenges for fire protection due to obstructions caused by conveyance systems or other plat-forms. Additionally, these facilities are growing in size beyond what the prescriptive solutions current codes offer. Matt Merli: Certainly, the biggest trend we're seeing right now is the advancement in robotics and au-tomation within industrial and manufacturing facilities. For example, a client of ours that does ad-vanced technical manufacturing has recently created a completely automated line for its process. We completed a similar line for them six or seven years ago with stations for people, whereas now it's
Learning
Objectives
u
• I dentify current trends driving industrial and manufacturing facility design. •U nderstand how new technology like AI is changing manufacturing processes.
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fully robotics with a single person monitoring at a front-end computer. For the architecture/engineering industry, this means much more electrical, compressed air and piping engineering for robotics and automation as opposed to workbench (or person-based stations). CSE: What future trends should engineers and designers expect for such projects?
Jarron Gass: I am continuing to see new challenges in safely protecting the manufacturing and storage of lithium-ion batteries. The protection of electric vehicles, personal vehicles and battery-electric buses has introduced heightened fire safety concerns, particularly within structures. At the same time, industrial chemical facilities are navigating the complexities of addressing environmental concerns related to perfluoroalkyl and polyfluoroalkyl substances. Specifically, their presence in traditional fire-fighting foam and the implications of modifying fire protection systems to accommodate alternative suppression solutions are large concerns. Matt Merli: The growth of robotics, AI and automation is here to stay and only going to grow. This will also cause considerable growth in the server room and data center infrastructure. The amount of power and energy needed to support the data center growth will be immense (at the local building and grid level), which will take a lot of creative thinking and coordination with the utility.
CSE: How is the growth of immediate-delivery services impacting industrial and manufacturing facili-ty projects?
Jarron Gass: Supply chain logistics is continually pushing the envelope to balance the cost and envi-ronmental impact of manufacturing, aiming to minimize the time and distance between each link in the chain until the product reaches the end user. This is frequently driving infrastructure to its current limits, or requiring increased capacity or the development of private infrastructure. This “last mile” fo-cus is stretching existing systems and contributing to the creation of more mixed-use zones. CSE: What are professionals doing to ensure such projects (both new and existing structures) meet challenges associated with emerging technologies?
Jarron Gass: While this has likely always been true, it’s especially important now to stay current with emerging technologies. One of the best ways to do this is through trade associations, engineering societies and other professional industry groups that provide opportunities to collaborate with peers. Understanding the challenges others are facing and how they’re addressed is essential for driving positive outcomes. The learning never stops, and competent engineers will continue their education through CEUs or other available means. consulting Specifying engineer
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Participants Jason R. Gerke, PE, LEED AP BD+C, BCxP Senior Design Phase Manager JP Cullen Milwaukee
Jarron Gass, PE, CFPS Fire Protection Discipline Leader CDM Smith Pittsburgh
Matt Merli, PE, Principal / Client Services Director Fitzemeyer & Tocci Associates, Inc. Woburn, Mass.
FIGURE 1: Increased automation in industrial facilities changes the piping and cooling considerations for design engineers. Courtesy: JP Cullen
Matt Merli: It’s crucial to design for growth and flexibility. These companies may start with a single manufacturing line or stage, but they're always looking to grow fast. From an infrastructure perspec-tive, it's important to understand the one-year, five-year and 10-year plans for the client and weigh those against upfront infrastructure cost to support that growth. Designing things like a building's electrical service entrance, chilled water capacity and other major infrastructure for future expansion is important to these clients. CSE: In what ways are you working with information technology experts to meet the needs and goals of an industrial or manufacturing facility?
Jarron Gass: In some of the sectors I’ve had the opportunity to work in, older plants that are upgrad-ing and expanding their capacities are increasingly looking to integrate and network systems across multiple buildings onto a single operating platform. The goal is to unify building management systems, fire consulting Specifying engineer
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alarm, HVAC, SCADA and other automation processes. When these systems can communicate and automate functions between each other, where permitted by code, end users can in-crease efficiency by reducing redundancy. These types of upgrades also enable more remote control capabilities, allowing for a reduced footprint at each facility or at various stages of a given process. CSE: In what ways have supply chain issues impacted the industrial and manufacturing sector and how do you work with building owners to address any issues?
Jarron Gass: Supply chain issues have made planning more critical than ever, and they have driven an increased emphasis on the early identification of procurement items for projects. It’s essential to identify long-lead items that need to be designed, selected, specified or otherwise flagged as early as possible in the design process to facilitate timely procurement. On the manufacturing side, striking a balance between maintaining adequate resources or stock with-
out running out or overstocking, which increases storage needs and costs, relies heavily on data analytics. The rise of AI is also con-tributing to this process, providing real-time input and forecasting. Understanding the impact these items can have on a project schedule forces earlier decisions, and often commits engineers and cli-ents to specific choices sooner than was historically required. Jason R. Gerke: On the construction side, we work with owners to establish allowances and contin-gencies for every project, whether there is a concern about tariffs or not. The primary tariff risks we are addressing on projects include steel, electrical wiring/devices and specialized equipment. We see the greatest risk for cost escalation or tariffs on any products that are manufactured outside the United States. Matt Merli: The biggest challenge from an architecture, engineering and construction perspective is that these buildings require large infrastructure (switchgear, generators, air handling units, etc.) that are all affected by supply chain concerns. It’s important to consider this equipment as part of early procurement design packages. July/August 2025
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in the design phase of the project. This involvement will not only allow for input on constructability, coordination and local preferences, but also on the materials and products specified. The trade contractors can give immediate information on design attributes that may increase project costs and offer suggestions on ways to reduce or control the cost to more closely align with the project budget. CSE: What are plant owners and managers requesting from consulting engineers to make the facility more prepared for the future?
FIGURE 2: Coordinating with owners early on in the design process ensures that systems work with new technology. Courtesy: JP Cullen
CSE: Tell us about a recent project you’ve worked on that’s innovative, large-scale or otherwise noteworthy. Please tell us about the location, systems your team engineered, key players, in-teresting challenges or solutions and other significant details. If one is available, please link to or attach a case study or portfolio description of the project.
Matt Merli: A recent project example is a client in the advanced tech market located in New England. They have manufacturing 'lines' on their campus that historically had more 'people-based' assembly, so we'd design flexible work and cooling stations for employee comfort. The design essentially ena-bled people to be part of the process. They've now moved to robotic assembly with one person at the front-end computer monitoring the process, changing the focus of the design. CSE: How are engineers designing these kinds of projects to keep costs down while offering appeal-ing features, complying with relevant codes and meeting client needs?
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Jarron Gass: Incorporating a value engineering process into the overall design can help analyze building features, systems and material selections to achieve greater efficiency, increase cost sav-ings, reduce life-cycle costs or meet other predefined objectives. This approach can lead to more managed and predictable costs and processes, while still maintaining key design goals. Additionally, these efforts can guide builders to enhance efficiency and cost-effectiveness further down the line. For example, in fire suppression, a value engineering item might involve using alternative fire protec-tion methods that eliminate the need for in-rack sprinklers or proposing alternative suppression sys-tems in challenging environments. These alternatives can be evaluated by weighing effectiveness, component intrusion and cost, while still delivering a high-quality solution that meets or exceeds ex-pected safety standards. Jason R. Gerke: Our work focuses on design-build projects. It is important that design teams allow for options on materials and products. It is also important to ensure each of the trade contractors is involved
Jarron Gass: With rapidly developing and advancing technologies becoming available nearly every day, the front-end due diligence process is expanding significantly. This requires more thought, dis-cussion and preparation for future expansions and the potential implementation of emerging technologies. Coordination and input from the design team, owners, operators and other key stakehold-ers are essential to developing a strategic and comprehensive plan. This plan should address the current process, potential future expansions or upgrades, optimization initiatives and sustainability goals in order to determine the full extent of impacts. For instance, should you build the entire build-ing now and only develop a portion of the manufacturing process, adding more equipment later into the existing space, or should you build only what is currently needed and expand both the building and the process in the future? Jason R. Gerke: It is very difficult to look into the future and make an accurate prediction of building or process needs. It is important that the design team works together with the owner team and process engineers to establish the requirements for utilities early in the design phase. Estimates, assumptions and guesses must be well documented to ensure everyone is aligned with the require-ments and Continued on pg. 42
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ENGINEERING INSIGHTS
MEP ROUNDTABLE: OTHER BUILDING TYPES
can defend design decisions as construction progresses and process systems are started. Focused conversation around process expansions, redundancy, reliability and cost will create a future-proof facility. CSE: Does your firm anticipate more industrial or manufacturing building projects, considering the supply chain issues with non-U.S. facilities? Describe the business development process for these clients and the re-shoring of industrial and manufacturing buildings.
Jarron Gass: Yes, there seems to be a growing push to bring manufacturing back to the U.S., par-ticularly in the tech sector and renewable industries. The U.S. government is supporting this effort through favorable financing, expanded access to capital and increased investment in research and development. Providing greater access to funding, especially for small businesses, is crucial
to developing and building the necessary infrastructure to support these new or expanded industrial and manufacturing facilities. It also enables the modernization of older facilities to meet the demands of a technology-driven economy. Domestic production can have a domino effect on the supply chain, increasing demand in various sectors, which further stimulates activity downstream. Communities with the foresight to prepare for this influx will be well-positioned to accommodate these needs and capi-talize on the benefits that industry brings to the local tax base.
Automation, Controls and Technology CSE: From your experience, what systems within industrial and manufacturing facilities are benefit-ing from automation that previously might not have?
FIGURE 6: Owner needs vary from project to project. Understanding specific processes and needs, like in this ice cream processing facility, from the early stages of the design process ensures smooth implementation. Courtesy: JP Cullen
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Jason R. Gerke: There are many industrial facilities constructed that are not highly sophisticated buildings. These buildings may be big spaces to perform a set of tasks that have limited impact on air quality and minimal dehumidification needs. Designing buildings that may be a more straightforward configuration still allows for a level of HVAC controls to monitor spaces and equipment performance. Adding an HVAC control system that is a fairly packaged solution to a set of heating and cooling equipment in a building can greatly expand the capabilities of the facilities operators and allow for remote monitoring when staffing may be low, such as overnight shifts. CSE: Have smart technologies (defined as a system with controls that self-monitor, analyze and re-port using technology) come up in discussion or been implemented on such projects? Has this integration impacted the project? If so, please give an example.
Jarron Gass: Yes, the topic of new or smart technology seems to come up in most industrial projects now. I believe this is because it helps drive innovation with an eye toward the future, as well as to-ward effectiveness, sustainability and efficiency. Taking advantage of technology will continue to help bring manufacturing back to the U.S. Technology has shifted workforce demands from unskilled to increasingly skilled labor, so enhanced worker and workplace safety continues to drive innovation through ongoing advancements. The availability of real-time analytics across manufacturing process-es supports greater efficiency, reduced downtime and improved safety. Jason R. Gerke: Smart controls, including systems that monitor, report and identify potential issues, are becoming more mainstream. These systems are either an add-on or a separate control sysContinued on pg. 44 consulting Specifying engineer
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tem with the HVAC building automation system. While not popular yet due to cost and capability, the more data these systems receive, the more accurate their alerts and recommendations will be for operators. CSE: Cybersecurity and hacking are increasing concerns — are you seeing such concerns impact-ing your work on industrial and manufacturing facilities?
Jarron Gass: Fire alarm systems face the ongoing challenge of maintaining communication integrity across multiple components. Whether it’s wireless devices or the connection between the fire alarm control panel and the monitoring service, these systems are vulnerable. Safeguards must be in place to ensure that facility safety is never compromised. CSE: Please explain some of the codes, standards and guidelines you commonly use during the project’s design process. Which codes/standards should engineers be most aware of?
FIGURE 3: Many industrial facilities are replacing human workstations with automated processes. Courtesy: Fitzemeyer & Tocci Associates, Inc.
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Jarron Gass: For fire protection, we start with the various codes adopted by jurisdictions to provide prescriptive protection solutions. The most common fire codes are the International Fire Code and NFPA 1: Fire Code. These codes, and others like them, specify requirements based on the different occupancies you are constructing or maintaining, dictating the need for various fire systems, from suppression and alarm to handheld fire extinguishers. The codes often reference other standards that explain compliance, such as NFPA 13: Standard for the Installation of Sprinkler Systems and NFPA 72: National Fire Alarm and Signaling Code. Additionally, nationally recognized groups or agencies, such as Underwriters Laboratories or Factory Mutual, publish guidance documents for various occupancies and protection systems. Matt Merli: The most common are certainly still the International Building Code, the International Mechanical Code and NFPA 70: National Electrical Code (NEC). With energy and sustainability being such a focus, we also spend a significant amount of time reviewing the International Energy Conservation Code, ASHRAE and local 'stretch' codes from a mechanical, electrical and plumbing (MEP) perspective. When it comes to specific industrial applications in the MEP world, the Industrial Ventilation Handbook is still a common resource for our firm. CSE: What are some best practices to ensure that such buildings meet and exceed codes and standards?
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Jarron Gass: I’m a strong advocate for front-end due diligence, recognizing the significant value of early code research, pre-planning and collaboration with stakeholders, end-users and authorities having jurisdiction to support effective project design and development. When this is done early, it can help minimize unknowns, stabilize costs and allow for smooth-
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er progression through the design and eventual construction phases of large and complex facilities. Early and frequent communication between all relevant stakeholders fosters collaborative relationships that allow for progress, even when significant challenges arise during the design process. Matt Merli: These facilities can sometimes have a lot of HVAC requirements, resulting in enormous energy use. Along with increased energy code and local stretch codes, this typically results in energy recovery in most (if not all) of our designs. We're now not just identifying 'if ' we use energy re-covery, but rather the discussion is now what 'type' of energy recovery is best for this client and/or application. CSE: How are codes, standards or guidelines for energy efficiency impacting the design of industrial and manufacturing facilities?
Jarron Gass: In line with due diligence, I find it imperative to weigh each project against its own particular merits and to navigate potential unintended consequences that can arise in the pursuit of energy efficiency, particularly in existing facilities. Efficiency improvements in one area may ne-cessitate upgrades in others, such as adding structural elements to support new photovoltaics or replacing an entire fire alarm system that cannot be expanded to accommodate a renovation. Typically, it is more straightforward in new projects to incorporate various levels of efficiency and pur-sue LEED certification or other accrediting statuses. Certainly, the ROI tends to be shorter for new builds than renovations, but typically, there is still an ROI regardless. Jason R. Gerke: ASHRAE provides a number of resources that should be referenced to establish the standard of care when designing an industrial building. There are guidelines and standards applica-ble to multiple industrial facility design needs. These guidelines and standards are used across mul-tiple building types and include documents such as ASHRAE Standard 62.1: Ventilation for Ac-ceptable Indoor Air Quality, Standard 90.1: Energy Standard for Buildings Except Low-Rise Residen-tial Buildings and other commissioning standards when it comes to the startup of facilities. There are also active ASHRAE technical committees working to establish best practices for specific building types, ventilation needs or control strategies that can help guide the design process. These committees include TC9.2 for example that focuses on the building environmental conditions that can be controlled through ventilation and filtration. CSE: What new or updated code, standard, guideline, organization or association do you feel will change the way such projects are designed, bid out or built?
Jarron Gass: With the current code update cycle occurring every three years for most major codes and standards, these codes and standards are unable to keep pace with industry consulting Specifying engineer
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36 is a good document to track to ensure the latest recommendations for HVAC equipment control sequences are used. ASHRAE 90.1 remains a strong reference document for best practices and recommendations for both new and existing building systems. CSE: What are some of the biggest challenges when considering code compliance and designing or working with existing buildings?
FIGURE 4: This rendering of an industrial facility demonstrates the unique mechanical, electrical and plumbing considerations in this kind of design. Courtesy: Fitzemeyer & Tocci Associates, Inc.
innovation. I be-lieve the landscape is ripe for alternative organizations or groups to publish standards either in the interim or more frequently. These could better keep up with the pace of change and provide sustained guidance on efficiency-related items as well as other pertinent topics.
Jason R. Gerke: ASHRAE continuously provides updates to their standards and guidelines. These standards are developed in code-enforceable language, so at some point, the documents issued by ASHRAE, which should be considered the standard of care, will become codes in some areas. Guide-line
Matt Merli: This isn't new, but we're certainly in a cycle where older refrigerants are again being phased out (i.e., R-410A) and replaced with newer ones (i.e, R-454B) that have lower global warming potential. There are new challenges arising with that, as they have higher flammability concerns; thus, things like ventilating shafts and refrigerant detection are important design discussions to have. cse
Insights
u
csemag.com
Industrial facility insights u Increased automation is driving the efficiency
of manufacturing processes, changing the focus of the building’s design.
u Concerns with supply chain, tariffs and
emerging technologies are speeding up the design process.
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6/23/25 11:07 AM
DRIVE PERFORMANCE TA K E T H E L E A D W I T H H V 6 0 0
Is your drive performance on track with your building automation program? Trust the Yaskawa HV600 variable frequency drive in the clutch to maximize energy savings and occupant comfort. • Support for PC and mobile device programming • Safe programming without main power
s HV600drive
• Hand Off Auto LCD keypad with tactile buttons and LED status ring • Built-in building automation protocols • Emergency Override for occupant safety • Built-in impendance for harmonic reduction • Advanced application presets for fans and pumps • Unmatched Yaskawa reliability What performance issues do you need in your variable frequency drives? Call Yaskawa at 1-800-927-5292.
HV600 Family of Drives
FOR MORE INFORMATION: https://www.yaskawa.com/hv600
Yaskawa America, Inc. 1-800-YASKAWA Email: info@yaskawa.com | yaskawa.com
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6/12/25 10:54 AM
CENTUM™ SERIES
WELCOME TO THE NEXT GEN
INTRODUCING C2750D6E & C3000D6EB GENERATOR SETS The latest addition to our award-winning Centum™ Series. Powered by the robust QSK78 engine and designed to meet the needs for right-sized power and reduced emissions in the most critical applications. Stay powered with Centum.
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6/12/25 10:47 AM