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See pages | 7, 9
20 | Converged networks for controls and operational technology
By better understanding building controls and converged networks, engineers can make smarter IT and OT choices
28 | Important things to know when designing and applying AWHPs
5 | Is it engineering competition or camaraderie? Know your enemy
Think about the educational, financial and professional reasons why every MEP/FP engineer should keep a close eye on their competitors
7 | The 2024 MEP Giants get a big paycheck this year
The 2024 MEP Giants firms increased revenue substantially
9 | One-quarter of MEP Giants finalized a deal last year
Although cooling from record highs, M&A activity by the 2024 MEP Giants remained robust
14 | Is a battery energy storage system right for your project?
When and where to consider BESS for energy storage in an electrical distribution system
Air-to-water heat pumps offer a straightforward solution for heating, electrification and facility decarbonization; however, their selection and application require expertise to specific and unique criteria
36 | How to mitigate risk with arc flash study project safety plans
Arc flash studies have inherent risks due to live electrical equipment. Creating a safety plan before studies can help protect employees and contractors
40 | Explore ways to go beyond requirements for electrical safety
Design engineers have many opportunities to go above minimum code requirements to decrease risk to facility personnel and electricians working on electrical systems
46 | What trends to specifying engineers see on college campuses?
Five engineers discuss current and future trends for college and university building design
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
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
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.
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, Lead Senior Mechanical Engineer, kW Mission Critical Engineering, Milwaukee
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
GREGORY QUINN, PE, NCEES, LEED AP, Principal, Health Care Market Leader, Affiliated Engineers Inc., Madison, Wis.
BRIAN A. RENER, PE, LEED AP, Principal, Electrical Discipline Leader, SmithGroup, Chicago
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
Think about the educational, financial and professional reasons why every MEP/FP engineer should keep a close eye on their competitors
Understanding the competitive landscape is vital for any professional, especially for mechanical, electrical, plumbing and fire protection (MEP/FP) engineers. In an industry driven by innovation, efficiency and safety, knowing your competition is not just about staying ahead, it's about sustaining your career, growing your business and continuing to learn.
Understanding your competition allows you to benchmark your own capabilities. If a rival firm consistently secures contracts in a niche market, it’s worth analyzing what they’re doing differently. Is it a specific certification their engineers hold? Is it a unique approach to problem-solving? This analysis can inform your own educational path and those of your junior engineers. From a financial perspective, knowing your competition is crucial for setting your business strategy. Understanding their pricing models, service offerings and market positioning helps you establish competitive rates without undervaluing your services. If you’re unaware of what competitors are charging or the scope of services they provide, you risk either overpricing yourself out of potential contracts or underpricing and damaging your profit margins.
Amara Rozgus, Editor-in-Chief
who are aware of the strengths and weaknesses of their peers are better equipped to differentiate themselves. This differentiation is not just about offering lower prices but also about highlighting unique value propositions, whether that’s a specialization in fire protection systems for highrise buildings or a reputation for innovative, sustainable design solutions. Networking is another critical aspect. By understanding who your competitors are, you can identify potential collaborators for projects that require diverse expertise. The MEP/ FP industry often involves complex projects where collaboration is essential. Recognizing where your competitors excel can help you form strategic partnerships that benefit all parties involved, leading to better project outcomes and stronger professional relationships.
Professionally, understanding your competition strengthens your position within the industry. Engineers
In the MEP/FP engineering field, knowing your competition is far more than just a business strategy — it’s a professional necessity. It drives your educational growth, informs your financial decisions and shapes your professional trajectory. In an industry as competitive and dynamic as ours, the engineers who succeed are those who are always one step ahead, not just of the latest technology, but also of their peers. cse
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The 2024 MEP Giants generated $14.64 billion in mechanical, electrical, plumbing (MEP) and fire protection engineering design revenue, an increase over last year’s MEP Giants’ revenue of $11.96 billion. This year, the 2024 MEP Giants earned approximately $75.5 billion in gross annual revenue during the previous fiscal year, a jump of 12%.
MEP design revenue rose a whopping 22% over last year’s numbers. Figure 1 shows the various building specialties in which the 100 firms that make up the MEP Giants earned revenue.
Once again absent from the top 10 was AECOM, which has been on this list pre-
viously. There were also some newcomers to the total of 100 companies. Several companies either joined the list for the first time or returned after time away from reporting data (in alphabetical order): Barton Associates Inc., DLB Associates Consulting Engineers PC, Ewing Kessler, HPE Sustainable Data Center Modernization, Introba Inc., Kohrs Lonnemann Heil Engineers Inc., LEAF Engineers, LiRo-Hill, Page, Ramboll, Re:Build Optimation Technology LLC, Robert Derector Associates and SSOE Group.
The list this year comprises 59% private companies (up from 54% in 2023), 23% employee-owned companies, 8% public companies and 10% limited-
liability companies. The 2024 MEP Giants are made up of consulting engineering firms (60%, down from 63% last year) and architectural engineering firms (31%, up slightly from last year).
Several mergers and acquisitions occurred in the past year; 25% of the firms reporting acquired another company, a slight dip from last year’s 26% acquisition rate (see page 9 for the article “One-quarter of MEP Giants finalized a deal last year”).
Table 1 shows the top firms based on MEP design revenue, which is how the MEP Giants are ranked. cse
Amara Rozgus and Amanda Pelliccione, Consulting-Specifying Engineer, Chicago
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Although cooling from record highs, M&A activity by the 2024 MEP Giants remained robust
Booming backlogs, flush balance sheets and robust valuations have sparked a post-pandemic acquisition spree by Consulting-Specifying Engineer’s MEP Giants that continued into 2023. As a group, the largest mechanical, electrical, plumbing (MEP) and fire protection engineering firms completed 54 transactions in 2023 with one-quarter (25%) of the 2024 MEP Giants finalizing at least one deal. Although merger and acquisition (M&A) activity remained at historically high levels last year, the pace of dealmaking by the MEP Giants cooled from the record-setting 70 transactions in 2021 and a still-high 65 deals in 2022.
According to Morrissey Goodale’s propriety database of architecture, engineering (AE) and environmental industry deals, MEP firms in 2023 garnered very strong prices relative to historical norms, which could have deterred MEP Giants pursuing sellers in competitive processes, particularly those that are employee-owned firms.
by
The slight dip in M&A activity among the 2024 MEP Giants reflected the AE and environmental industry. With 658 industry deals worldwide, 2023 was another historically high year for global transactions. While down 9% from the record-high 724
deals in 2022 and slightly behind the 2021 total of 661 transactions, last year’s global M&A deal volume remained a step function above pre-pandemic levels.
As with the broader AE and environmental industry, Sun Belt firms continue to be the most attractive M&A targets for MEP Giants. With six deals each, California and Florida were the top states where MEP Giants completed acquisitions in 2023.
Publicly traded firms were the most prevalent buyers among the 2024 MEP Giants, far outpacing their role in the wider
AE and environmental industry. Although publicly traded buyers accounted for just 8% of U.S. domestic AE and environmental industry deals in 2023, these buyers executed 43% of the transactions made by the MEP Giants.
Somewhat surprisingly given recent trends, private equity-backed buyers were responsible for 20% of deals consummated by the MEP Giants in 2023, down slightly from 26% in 2022 but far lower than the 39% of acquisitions attributed to them across the entire industry last year. While employee-owned buyers closed more than half (53%) of AE and environmental industry transactions in 2023, they represented 30% of deals completed by the MEP Giants last year, up from 25% in 2022.
There are several reasons that publicly traded firms have executed the most transactions involving MEP Giants. First, publicly traded firms generally have even easier access to capital than private equity firms, particularly in a higher interest rate
environment such as occurred in 2023. The increased cost of debt restricted the available flow of capital from private equitybacked buyers to sellers.
Second, public buyers typically selffinance transactions without the need to borrow money or solicit third-party lenders or other stakeholders beyond the board of directors. Third, data collected by Morrissey Goodale indicate that publicly traded firms, all else being equal, pay more than even private equity-backed firms to complete deals, thus making more attractive offers to sellers.
Since its initial public offering in 2021, MEP Giant Bowman (Reston, Virginia) has pursued acquisitions as a key part of its growth strategy, and last year proved no exception. The publicly traded firm, which earlier this year won Morrissey Goodale’s Most Prolific and Proficient Acquirer Award, completed a dozen deals in 2023
that added more than 400 employees in 11 states. That’s on top of the eight transactions it concluded in 2022.
Additional MEP Giants that continued recent buying sprees included IMEG (Rock Island, Illinois), Salas O’Brien (Santa Ana, California) and NV5 (Hollywood, Florida), each of which consummated six transactions. Other MEP Giants that made multiple deals in 2023 were Page (Washington, D.C.), Stantec (Edmonton, Canada), Jensen Hughes (Baltimore), WSP (Montreal, Quebec) and RTM Engineering Consultants (Schaumburg, Illinois).
Since the start of 2021, the domestic AE and environmental industry has experienced a dramatic acceleration in deal-making — with more than a merger a day. Despite geopolitical conflicts abroad and political uncertainty at home, Morrissey Goodale expects the volume of M&A activity to remain elevated in 2024 and beyond. cse
Nick Belitz, CVA, is a Principal with Morrissey Goodale LLC, a management consulting and research firm that exclusively serves the architecture, engineering and environmental consulting industry.
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Tyler Roschen, PE and John Drawbaugh, PE, CDM Smith, Raleigh, North Carolina
and where to
energy storage in an electrical distribution system
Battery energy storage systems (BESS) are current candidates for cleaner energy in providing power for electrical distribution systems. During design for projects, electrical engineers need to have a basic understanding of the components, applicable applications and benefits that BESS may have on new and existing electrical systems.
• International Building Code.
• International Electrical Testing Association.
• International Fire Code (IFC) Section 1207.
• NFPA 70: National Electrical Code Articles 705 and 706.
• NFPA 72: National Fire Alarm and Signaling Code.
• NFPA 855: Standard for the Installation of Stationary Energy Storage Systems.
• National Electrical Safety Code.
• Institute of Electrical and Electronics Engineers (IEEE).
• IEEE 1547: Standard for Interconnection and Interoperability of Distributed Energy Resources with Associated Electric Power Systems Interfaces.
• Understand what a battery energy storage system (BESS) is.
• Learn how a BESS is applied to an electrical system.
• Comprehend why a BESS is uniquely suited to renewable energy applications.
BESS can be incorporated into several different types of applications and in conjunction with renewable and distributed generation technologies and the utility grid. Solar photovoltaic (PV) (see Figure 1) and wind energy sources are inherently intermittent when applied in nonutility scales as the energy they harness from the world around them waxes and wanes. BESS can smooth these intermittent sources into more reliable, steady sources of power, helping to maximize the benefits of solar PV and other renewable energy technologies by reducing power fluctuations on the system.
BESS can be used strategically for cost-saving and backup power applications. BESS will also be an important part of future grid plans for distributed energy resources as localized generation increases.
The following codes and standards should be considered when designing a BESS.
• IEEE 2800: Standard for Interconnection and Interoperability of Inverter-Based Resources (IBRs) Interconnecting with Associated Transmission Electric Power Systems.
• UL: 1741 Inverters, Converters, Controllers and Interconnection System Equipment for Use With Distributed Energy Resources.
• UL 9540: Energy Storage System Requirements.
It should be noted that the above codes are still catching up to the state of the market. The primary concern of the codes is fire safety. IFC (2021) Section 1207 and NFPA 855 are some of the more recent codes written specifically for energy storage systems.
A BESS comprises several main components. Each component within the BESS could be its own
discussion, but for this article, they will be briefly discussed with a general overview. There are two main configurations of BESS, container and cabinet, both of which incorporate the major components of a BESS as discussed within this article.
Container configurations are preconfigured with all components integrated into a single container (see Figure 2). Shipping containers, similar to those on cargo ships, are typically used as enclosures for container configurations with the same standard sizes. In general, the nominal output power for these types of units can range from 250 kilowatts (kW) up to 2 megawatts (MW), depending on the manufacturer and are more common for large-scale facilities or for electric utilities.
The components within these containers are all provided and tested by a single manufacturer to ensure conformance with equipment and project requirements. These containers can also be paralleled together to increase the overall capacity required by the system being served. These types of containers are better used for large-scale applications.
Cabinet configurations are commonly built at the project site and components can be provided from several manufacturers. Because of this, these types of configurations require more coordination of system components to ensure the entire system is properly functioning. As with the container type configuration, all the components are housed in these individual cabinets. The enclosure of this type would be like an outdoor enclosure for a motor control center or other comparable types of equipment.
Battery system: The battery is the most critical component of the BESS because this is the piece of equipment that will store the energy to provide
‘ BESS will also be an important part of future grid plans for distributed energy resources as localized generation increases. ’
power. When thinking about batteries, the immediate thought may be to jump to household AA batteries that many small electronics use.
However, while the batteries for the BESS are fundamentally similar (storing chemical energy that is converted to electrical energy for power consumption), they are constructed and packaged differently. The main components that comprise the overall battery are battery cells, which are connected in series to form modules. The modules are then combined in parallel to form racks (see Figure 3), with several racks being connected in series or parallel to create the energy storage system with the required capacity, voltage and current of the system.
Lithium-ion batteries are most prevalent for these types of systems. Other battery technologies are being developed for better use in BESS, so this discussion of batteries may differ in the coming years. Following are the two main types of battery chemistries.
Lithium nickel manganese cobalt oxide (NMC) is the battery chemistry typically used in the automotive industry. It is used in stationary applications as well because of its high energy density. This high energy density allows the battery to have a smaller footprint without losing the ability to store high amounts of energy. Compared to other lithiumion chemistry discussed below, NMC has a lower thermal runway temperature and is considered
less thermally stable. The cost for NMC can also be more expensive because it requires rare earth materials.
Lithium iron phosphate (LFP) is the battery chemistry more commonly used in stationary applications because it has a lower energy density than NMC. LFP has a higher thermal runaway temperature and is more thermally stable, which makes it a better option for applications where fire safety may be a concern. LFP also has a lower cost as compared to NMC because LFP does not require rare earth materials for construction and is able to have higher maintained charge.
The battery management system (BMS) provides controls and monitoring for the battery packs, typically within each module. This system serves several important functions, including:
• Monitoring individual battery cells in each module in real time.
• Maintaining battery operation in normal and safe states.
• Provides battery protection and optimizes battery performance.
Within electrical systems, there are two different types of power: alternating current (ac) and direct current (dc). ac power is typically used in power distribution systems to provide power for a wide
range of equipment, from homes to industrial-type applications.
However, dc power is typically used in power electronics (e.g., laptops, batteries, renewable energy systems) and only used for highly specific distribution/transmission applications. The batteries for the BESS operate and store energy as dc power. To allow facilities such as homes, office buildings, industrial applications to use the BESS, an inverter or power conversion system is required to convert the dc to ac power. These inverters are bidirectional and allow the ac power to be converted to dc power as well to allow charging of the batteries.
The energy management system (EMS) acts as the overall controller for the BESS, not to be confused with the controller for the BMS that is solely for batteries. This is typically used in microgrid-type applications, but it is not required for all types of BESS, such as a BESS operating independently from other power sources on an electrical system.
Operation of the EMS is achieved by having the EMS communicate with the entire system — including the battery system, inverter and power system — to determine when to charge and discharge power. This is primarily determined by the type of application as discussed in the following paragraphs.
Although components such as heating, ventilation and air conditioning , fire suppression, transformers and cabling are essential to the success of a fully functional BESS and for providing additional protection of the system, they are not discussed in detail within this article.
THIS BUILDING combined solar photovoltaics and energy storage to reduce its electric utility costs
The battery energy storage systems (BESS) can be a valuable system used in electrical designs in a wide range of applications. There are several benefits, including allowing energy independence of electrical systems for facilities and reducing greenhouse gas emissions.
The high-level one-line diagram (see Figure 5) illustrates a utility service feeding a service entrance switchgear. The new BESS and solar photovoltaic (PV) arrays are also connected to the switchgear and they have the capability of providing power to the site loads during a utility outage or during peak demand times. Switching to the BESS would be automatic in the event of an incident. However, without an energy management system (EMS) in place, the batteries may not be used efficiently.
This example is an existing water treatment facility that was provided with a new BESS and PV arrays. The facility averages about 40 million gallons per day of treatment. The PV arrays were sized based on the land available for installation and the BESS was sized to fully support the facility in the event of an outage for a short period of time. The facility experiences large peaks of demand for a couple of hours a day, which leads to large energy bills that are disproportionate to the total energy metered because of demand costs.
The PV arrays allow the batteries to charge in conjunction with the utility for redundancy. Energy waste is minimized with this
setup. Even when the facility is experiencing low electrical load usage, the PV arrays can charge the batteries in lieu of directly providing power to the facility loads. Without the BESS in this scenario, the energy buildup with the PV arrays would be wasted because this system normally cannot store usable energy. The facility also benefits by allowing the BESS to provide peak-shaving capabilities during peak demand periods. In turn, this reduces the overall utility costs and greenhouse gas emissions.
This facility was a good candidate for a BESS because of the unfavorable sell-back policy with the utility. With the growing popularity of solar, utilities have more competition in the power producing industry. In most jurisdictions, they are not required to allow a renewable energy site to connect to their power grid. In these cases, excess energy is 100% wasted without a BESS.
At the case study facility, the utility allowed interconnection but only offered to buy back excess energy at a fraction of the cost that the facility pays for it. Without a BESS, the financials of installing solar made sense only up until a certain size. With the BESS, the facility took full advantage of the land they had available for solar PV.
For the BESS, a prepackaged containerized type of battery storage was selected because of the required capacity of the site. Lithium iron phosphate battery chemistry was also selected because this was a stationary application. The containerized selection allows the flexibility for future expansions if ever necessary.
FIGURE 5: A one-line diagram depicting the components of the electrical distribution system incorporating photovoltaic arrays and battery energy storage systems.
Courtesy: CDM Smith
BESS may offer a level of independence from the utility grid and can be used with renewable generation systems and traditional fossil fuel-based generation systems in residential/commercial/industrial distribution systems, microgrids or electric utility systems. The following applications are written with a renewable integration focus in mind.
• Renewable smoothing: If a large cloud passes over a solar field, a PV array can lose significant power output. If the wind ceases to blow, a wind turbine will lose significant power output. The electrical system (e.g., building or industrial plant) being powered from these sources will immediately need power from the utility. This type of on-and-off surge can negatively affect an electrical grid and, depending on the utility, may not be allowed for interconnection. A BESS can smooth these fluctuations by acting as an in-between source, automatically injecting electrical energy when a renewable source temporarily loses power.
• Peak shaving. Peak demand can significantly affect many electrical utility bill costs. It is typical to see this peak used as the billing rate for an entire month of usage, even if the peak was only attained for a few minutes. BESS can be designed to target these peaks and reduce them by taking on chunks of the demand load that would otherwise be billed by the utility. Similar techniques include scheduled power or commanded power, where the energy market is monitored to determine when it would be most cost-effective to use on-site-distributed generation to power facility loads in lieu of the utility source. This means that BESS can be used to reduce energy costs even without an on-site generation source (e.g., solar, wind or fossil fuel-based generator). The batteries
charge when energy costs are low and supplement facility power (discharge) when utility demand costs are high.
• Emergency/standby backup. BESS can also be used as a backup power source upon loss of utility power. This practice is referred to as “islanding.” To accomplish this, the system complexity is enhanced. Using some additional components, the system would need to take measurements, perform automatic switching and trip/reclose circuit breakers. Islanding using BESS is more practical for smaller energy consumption facilities and some BESS require another source (such as a diesel generator) to provide a voltage synchronization source. A properly sized backup battery system can provide complete independence from utility grid interruptions. However, unexpected islanding can cause major issues to an electrical system that is not prepared for it. Utility workers and maintenance staff should always be made aware of a system that can be islanded during utility power outages. Utilities may require extra interconnection stipulations to enable safe isolation.
BESS are commonly sorted into three categories based on size. All three sizes are applicable to renewable energy systems. Front-of-the-meter or utility-side BESS can range upward from 10 megawatt-hours (MWh) into the hundreds of MWh. Behind-the-meter or customer-side commercial and industrial BESS can range from 50 kilowatthours (kWh) to 10 MWh. Behind-the-meter residential are generally less than 50 kWh. Power system study requirements from utilities are often a significant barrier to interconnection. The complexity and cost of these interconnection requirements increases with the size of the BESS.
A graphic example of how renewable energy is captured in excess against facility demand is shown in Figure 4.
Along with the applications discussed above, BESS provide some not-so-obvious benefits. In addition to cost savings and the potential for energy independence, BESS helps reduce greenhouse gas emissions when used in conjunction with renewable energy power sources. This has a real impact on the social cost of carbon, a concept of the real dollar cost of damage done to society by fossil fuels. Unused energy from a renewable source will otherwise be wasted if a battery system is not
present and the demand is not high. Overall energy efficiency is improved with this practice and, thus, a reduction in power provided by nonrenewable sources may be achieved.
One trend coined by the uniquely name “duck curve” could be corrected with the widespread use of BESS. The curve resembles a sitting duck and portrays the timing imbalance between peak demand and drop-off of solar production per day. Peak demand generally happens around sunset each day, which is when solar power starts to wane.
Batteries are also sources of immediate backup power. Unlike a gas-engine generator that needs time to get up to speed, a charged battery can provide rated power as soon as it is switched to, allowing for more seamless transfers.
The BMS is the main hub for operations and maintenance information. However, some maintenance items are unique to battery systems. The BMS can automate these items if configured properly.
• Occasional power cycling: Both main types of lithium-ion batteries will degrade faster if kept at 100% charge all the time. If a BESS system at a facility is only used for backup and rarely gets discharged, it could lose maximum capacity faster than the average expected life of 5 to10 years.
• Temperature performance: A cold battery does not perform as well as a warm battery. Most manufacturers will specify their batteries at an ideal operating temperature of 60° to 80°F. At this temperature, the battery can fully charge and discharge
at rated specifications. However, most BESS will live at temperatures higher or lower than this. Both extremes can shorten the life of the battery, but cold temperatures specifically will also hurt performance. BESS perform best in temperature-controlled environments that can be set by an operator or a BMS.
A battery’s function and operating life can significantly impact its expected life. A 10-year life is possible in ideal conditions while a five-year life is more likely in adverse environments (i.e., extreme ambient temperatures, frequent full discharges).
The end of life does not necessarily mean that the battery completely fails; it simply does not achieve its rated amp-hour capacity. A cause of complete failure in lithium-ion batteries would be thermal runaway. Thermal runaway is a condition that begins when heat dissipating from a battery is less than the heat being generated by the battery. The increase in heat can increase the reaction rate and vice versa causing the runaway condition. High ambient temperatures and age of the battery are likely culprits in these scenarios. cse
Tyler Roschen, PE, is an electrical engineer at CDM Smith with a focus in design of electrical power systems. John Drawbaugh, PE, is an electrical engineer at CDM Smith working in the construction engineering industry and specializing in renewable systems and substation design.
csemag.com
BESS insights
u Battery energy storage systems (BESS) are rechargeable batteries that can store energy from various sources and distribute it on demand for energy management purposes.
u BESS can be useful without renewable sources, but they are uniquely suited for the incorporation of renewable sources into electrical systems.
Will Maxwell, SmartScore AP, Smith Seckman Reid Inc., Nashville, Tennessee
Building controls can have life cycles that exceed 30 years, so it takes a long time for advancements in controls to gain widespread adoption. Traditionally, the networks connecting controllers to the operator’s station have been in silos with segregated networks for each system. Because it has been easier for the vendors to coordinate than the engineer, they were only addressed with performance specs and maybe a generic wiring diagram.
Many communication protocols have been used to run these networks over the years, but internet protocol (IP) has rapidly increased in usage. As technology has evolved, we are now at the point where most new control systems have at least some IP components, with many going native IP for all core infrastructure.
• Define converged a network and understand the difference between information technology (IT) and operational technology (OT).
• Understand how to plan for and document an OT network during design.
• Know the benefits and risks of a converged network.
At the same time, there is a push to integrate the different building systems — like the building automation system, lighting control system or energy management system — onto a common (or converged) network. Using a converged network can reduce the amount of cabling and headend needed while setting the foundation for interoperability between the different systems.
While these converged networks have greater functionality, they are also more complex and require more coordination to get the most out of them and to keep them secure. In the past the information technology (IT) group may have provided a couple of data drops to facilitate remote access, but new management strategies and tight coordination between IT and facilities are needed to implement converged operational technology (OT) networks.
Since all of this starts in the engineering design process with the engineers, it is important to understand the difference between IT and OT, what a converged network is, how to design one and the benefits and risks to the building owner and operator so that owner project requirements can be met in efficient and effective ways.
The definition of OT from the National Institute of Standards and Technology (NIST) is “programmable systems or devices that interact with the physical environment (or manage devices that interact with the physical environment)” and can include building controls, internet of things (IoT) devices, access control and anything else that is used to make the building function
This differs from IT, devices such as personal computers (PCs) and printers that allow work inside the building to happen. While they both use networks to allow devices to communicate, there are major differences between how they operate.
IT networks became much more complex as the internet became integral to daily work. It is now standard to employ large teams to manage these networks and all the devices that live on them. Technology designers and consultants are regularly brought onto projects in addition to mechanical, electrical and plumbing engineers to design this infrastructure and coordinate with the owner’s IT group.
OT networks exist in many buildings as a collection of siloed systems that each serve only one building system and connect to the owner’s IT networks for remote access, although these connections are often not accounted for until construction. With proper planning in design and coordination with IT and facilities, we can get OT networks that use appropriate hardware while still being cost effective and secure, and eliminate system silos. This results in a unified architecture that is scalable, central-
ly managed and secured and less dependent on the vendors that installed it.
Converged OT networks eliminate the duplicated components that come with silos like separate backbone cabling and switches or panels for each system by sharing common network infrastructure like copper and fiber cabling, switches and routers. There are two approaches for creating this converged network: expanding the IT network to incorporate all OT systems or creating a standalone OT network.
The best approach will depend on the complexity of the OT systems and the sophistication of the facilities and IT teams, but most of this article’s content is applicable for both approaches. Opinions may vary, but in general, simple commercial, residential and K-12 buildings can make sense to integrate OT with the IT network. Health care, higher education and other complex buildings or campuses can benefit from a dedicated OT network. Federal and critical infrastructure projects have increasingly strict standards around OT networks for cybersecurity so extra caution must be taken.
Bringing the control network together
Whichever method is chosen, the overall architecture and components are similar. Figure 1 shows an example riser diagram of a converged OT network. Starting at the edge and moving in, we can see
‘ Using a converged network can reduce the amount of cabling and headend needed while setting the foundation for interoperability between the different systems. ’
the physical equipment (air handlers, lights, meters, etc.), field controllers and gateways, network switches, servers and computers, core switch, a router and firewall.
Field controllers connect to the equipment, delivering commands and collecting data. There are many options for manufacturers, input/output types and quantities and compute power. They communicate with open protocols like BACnet, LonWorks and Dali or proprietary protocols specific to their vendor, although an increasing number are adding IP as well.
Gateways can come from the same manufacturer as the controllers or third parties and are used to convert other protocols to IP, which is necessary to connect to the network switch if IP capability is not built in, allowing communication between all connected devices. The characteristics to consider with these switches include the layer type, number of ports, power over Ethernet (PoE) capacity
and speed; specific requirements will depend on the controls being used and owner’s requirements.
The servers and computers run the software programs controlling everything; they are defined by their electronic components and operating system and may be cloud-based instead of in the building. Dedicated workstations that both run the software and serve as the user interface are not common any more as most applications are web-based so that any PC on the network with the right credentials can access any application. Virtual machines can also be used to remotely access programs on servers that are not web-based.
The switches connect via fiber to a core switch that helps route all traffic on the network. The router, which controls communication between networks, is used to connect to either an internet service provider or to the IT network for remote access.
Firewalls can be placed at any point between components where there is a desire to control the data that can pass between for cybersecurity. They are often used near routers to control information going between networks and their requirements are defined by the owner.
Other miscellaneous pieces of equipment can include uninterruptible power supplies, a network controller that gives more management options and other gateways or firewalls as needed.
The main benefits of a well-implemented converged network are flexibility, control and data
accessibility. By using a common infrastructure for all building systems, it becomes simpler to add new systems or change components not performing to expectations. When controllers are on the network, the owner has increased visibility of them from their computer, making it easier to manage firmware updates and reprogramming remotely.
With the increased bandwidth of Ethernet cabling, devices at the edge like field controllers can do more computing of trends and alarms locally while still transmitting everything back to the server and eliminating the need for physical supervisory controllers, which act to pull information from other controllers before sending back to the headend. By owning and managing the physical infrastructure, the owner is set up well to make the most out of the data coming from building systems because it can all be accessed through a single network.
As we move into the artificial intelligence era, there are countless potential uses for robust building data but the main ones today are building optimization and tracking and reporting things like energy or carbon use and indoor environmental quality (IEQ). The next step of integration is consolidating data into an integrated data layer (IDL) or single pane of glass (SPoG) user interfaces.
The IDL acts a single point of integration for all building systems to share information, a cleaner alternative to many individual direct connects between systems. The SPoG provides a single platform for facility operators to quickly access information on all building systems. While some owners may not be willing to make that investment on Day One, having a converged network layer makes it much easier to implement the IDL or SPoG in the future because all the communication needed can happen on this single network instead of having to cross over multiple or be limited to the cloud. These benefits are all in addition to the elimination of redundant infrastructure and devices inherent to the traditional building system silos.
A wiring topology is one of the first things you can add to your specifications to design better OT networks. The topology is the typical way in which devices are physically connected; more than one can be used on the same project.
The list below describes the common topologies along with the benefits and limitations of each (see Figure 2). Reference ANSI/TIA-568-D for more information in general on cabling standards and topologies.
• Star topology: Every device is connected directly to a switch with one cable. This is the most robust approach, but also the costliest. The main limitation is the maximum length of the cable being used, 300 feet in the case of category 5/6 copper cabling. This is best used for critical equipment that requires high uptime and is constantly sending data.
• Daisy chain: Every device connects to the one before and after it in the chain, with only one device connecting directly to the switch. Each Ethernet cable in the chain is still limited to 300 feet, but the controllers can repeat the signal allowing devices more than 300 feet to be connected to the network. This is a cost-effective option and does not require as much planning, but a device or cable failure in the line means every device downstream loses connection. This topology should generally be avoided when using IP controllers due to the cascading effect of device failures, but can be useful for reaching distant devices.
• Ring topology: Similar to daisy chain, but with the devices on both ends of the chain having a connection to a switch. This simple modification to the daisy chain requires little additional infrastructure but provides increased resiliency as any single failure will not impact other devices. More planning is required as the devices used in a ring, including the switch, must be set up to use rapid spanning tree protocol to communicate and ring sizes should be kept in check to limit risk, but the ring topology will be the preferred option most of the time.
The second part of planning the cabling for building controls is assigning responsibilities. RS-485 wiring has been run directly by controls vendors, but there are several reasons that those vendors may not be the best option for pulling the Ethernet cabling between controllers and switches. For one, controls vendors may not have the BICSI certification, skill set or tools needed to terminate onto RJ45 connectors and test the cable.
Second, you will be much more likely to have neat and organized cable trays or J-hooks when only one trade is running the cabling. Cost savings can also be expected from having all cabling provid-
ed by one trade rather than splitting it up. The biggest potential pitfall of having the structured cabling contractor run all Ethernet cabling for controls is that they are used to only accounting for a few data drops to be coordinated with controls.
Therefore, providing enough information in the construction documents for them to properly estimate those costs and communicating with them early is the best way to avoid change orders stemming from using a converged network. Considering the OT network, simple projects can pull the scope under the structured cabling vendor by using ARCAT CSI Division 27 specifications for cabling requirements with the general contractor overseeing coordination between them and the other trades.
As projects get more complex, there is more potential value in assigning the scope to a master systems integrator (MSI). A relatively new role on construction teams, MSIs are responsible for connecting all the building systems on the converged network, implementing any interoperability use cases and coordinating between all the trades; they often respond to Division 25 specifications.
For example, their scope could include working with the mechanical, electrical and security contractors, facilitating their connection to the OT network by coordinating IP addresses and cabling, implementing software integrations between the systems and ensuring cybersecurity standards are met.
In addition to the wired infrastructure, there can be many wireless devices in the OT category. If multiple vendors are brought in to provide different IoT solutions such as IEQ monitoring and occupancy sensing, it is likely that each system will want to use its own proprietary gateway(s) to connect their wireless devices.
There are different reasons they claim to operate in this way, but locking owners into their ecosystems is almost always an ulterior motive. Each additional gateway is another device on the network that must be managed, kept secure and potentially comes with a yearly license. They could also be using a different wireless protocol, each with its own strengths and weaknesses that impact how well they fit with a particular project.
Below are some of the more common protocols with short descriptions of how they work. Covering
‘ Reference ANSI/ TIA-568-D for more information in general on cabling standards and topologies. ’
‘ With all the benefits of a converged network, the cybersecurity risks cannot be overlooked.’
all the differences and technical aspects could be an entire article on its own and the landscape of devices compatible with each is always changing, so this is not an exhaustive list.
• Wi-Fi: This system exists in almost every building and most people interact with it daily. The physical infrastructure includes access points scattered throughout the building connected back to switches with Ethernet and are typically PoE. Devices connect directly to the network that is being broadcast and receive IP addresses. It can be tempting to use, but it is not the most reliable connection and traffic from OT devices can reduce speeds for IT devices trying to use the Wi-Fi. This protocol is also more energy intensive and so battery-powered devices will die quicker. In addition, the frequencies Wi-Fi operates at (2.4 and 5 GHz) is crowded so transmissions are more likely to suffer from interference.
• LoRaWAN: This is an open standard that has gained a large market share for connecting environmental sensors outside the U.S. It has very low data speeds (<50 kbps), which limits the amount of information that can be sent, but single access points can cover large areas and penetrate walls well, reducing the amount of physical infrastructure needed. Transmission also has lower energy consumption than Wi-Fi. In most cases, a LoRaWAN access point will be compatible with any LoRaWAN devices, even if they come from different manufacturers.
• Zigbee: This protocol involves connected devices creating a mesh network in which they both receive and send data. Because every device extends the reach of the mesh network, you can often use just one gateway to physically connect to the rest of the OT network. Speeds are low, but still higher than LoRaWAN, coming in around 250 kbps. Reliability is also strong in a mesh network because transmissions can take multiple routes back to the gateway. However, systems using Zigbee made by different manufacturers are unlikely to be able to communicate with one another.
• Cellular: This is primarily used at the head end for vendors to connect to the internet without going through the IT or OT network, but many solution providers are developing devices that can connect directly with it using SIM cards. Cellular is a highly reliable wireless system with huge bandwidth and very high speeds available through 5G, so potential
use cases include everything from field controllers to security cameras. However, there is a high cost to implementing a private cellular network using citizens band radio service, so very few owners are investing in this currently and we are unlikely to see a large movement toward it outside of niche cases in the next 5 or more years.
With a little bit of planning and coordination, you can often select a single protocol to be the standard for the building and specify an infrastructure solution for all wireless systems to communicate on, putting the control back in the owner’s hands. To do this, you will need to consider what the use cases for wireless technology within the building are (IEQ sensing, leak detection, people counting, etc.) and see how the applicable solutions overlap in connectivity options. Always start with the use cases and end with the technology, so limiting to a single solution may not always work out, but considering all wireless systems together will result in a more efficient design.
With all the benefits of a converged network, the cybersecurity risks cannot be overlooked. When all building systems exist on the same network, vulnerabilities in one system can lead to all of them being impacted. When connected with the IT systems as well, an entire company can be hacked through one compromised device without proper protections in place.
Cybersecurity for OT devices is also different from IT devices in many ways, so owner’s IT departments are often ill-equipped to manage the OT network. It is important to note that engineers are not cybersecurity experts, nor are they expected to be. At the same time, cybersecurity cannot be entirely ignored in specifications.
The role of the specifying engineer in this process is to communicate with the owner and understand what standards, if any, they have for cybersecurity to which the building controls will need to adhere. Ideally, the owner will provide a standards document that can be incorporated into or referenced by the specifications. If they need guidance, there are OT cybersecurity specialists available to create standards for them and/or manage their OT network directly. Public guidelines like NIST CSF, UL 2900, ISA/IEC 62443 and the Real Estate Cyber Consortium are also available.
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FIGURE 3: Diagrammatic comparison of traditional building system silos and integrated operational technology (OT) network. Source: Smith Seckman Reid Inc.
While the design and setup of the systems and networks can mitigate risk and set a secure foundation, operational standards and practices will play the biggest role in maintaining cybersecurity.
Because of this, the expectation must be set that the owner understands and drives the standards, even if they must bring in a specialty consultant to accomplish this. No matter your level of knowl-
edge around cybersecurity, the conversation must be had on every project.
A second risk that directly impacts the construction process is timing. IT networks are typically not fully activated until late in the construction process, but vendors need access to a network for their systems to program them. If the OT network is not put on an accelerated schedule to be available for each systems’ vendor, temporary networks will be required which comes with a cost.
There is also additional effort needed to move from the temporary to permanent network. If not properly coordinated, the OT network schedule can cause delays and cost increase to a project. “Pull planning” exercises in which all parties coordinate the time and resources they need to deliver their systems are essential for establishing when a network must be available. Network availability is dependent on more than just the equipment and cabling, as things like network switches can be damaged by dust in the air, power surges,
water leaks and are often targets for theft so preparing spaces to house them requires coordination between multiple disciplines. It is certainly possible to create a clean environment in IT rooms or other designated spaces before the surrounding areas reach that point, but only if the need is identified and clearly communicated from the start.
As the controls industry moves in the direction of IP, converged networks are the logical next step for best-practice design. With the long life span of building controls, every project needs to consider ways to future-proof its buildings and prepare for the new technologies that will drive efficiency, resilience and exceptional occupant experiences. Engineers looking to take on the role of trusted adviser to their clients should be leading the charge in this area of innovation. cse
Will Maxwell, SmartScore AP, is a Smart Building Consultant at Smith Seckman Reid Inc. and handles the development, design and execution of smart building projects along with guiding SSR’s standards and strategies for smart building design.
uEngineers must design converged networks that integrate IP components across building systems, reducing cabling and enhancing interoperability. uThis requires careful coordination with IT to ensure security and efficiency, understanding different topologies and planning for futureproof infrastructure that can adapt to evolving technologies.
Mark Ridenour PE, HDR Inc., Arlington, Virginia; and Andrew Peck, Metropolitan Equipment Group, Beltsville, Maryland
Air-to-water heat pumps offer a straightforward solution for heating, electrification and facility decarbonization; however, their selection and application require expertise to specific and unique criteria
Various technologies are available to provide heating in facilities without using on-site fossil fuels, which can help meet the decarbonization agenda. Air-to-water heat pumps (AWHPs) are an approach growing in popularity and this technology does not have the limitations associated with other nonfossil fuel burning technologies such as solar, geothermal or electric heating.
• Understand project requirements necessary to select an air-to-water heat pump (AWHP).
• Become familiar with how to select and evaluate airto-water heat pumps.
• Understand the hydronic application of air-to-water heat pumps.
Coefficient of performance (COP) for AWHPs exceed the 1.0 COP associated with electric heating. AWHPs do not have the associated cost and land area needed for geothermal bore fields and unlike solar heating, AWHPs may not need backup heating equipment.
However, owners of facilities with AWHPs commonly experience startup and operational issues due to misapplication of equipment. While AWHPs have been increasingly used in Europe over the past decade, the technology being applied in North America is a new practice leading to misinformation and limited application knowledge.
Proper application of AWHPs starts with the expected building load. Figure 1 shows a typical building load profile where the blue line represents
the cooling load over the course of a year and the red line represents the heating load over the same period. Once the load profile has been determined, equipment can be selected that meets the peak heating and cooling load. Oversizing the equipment is not recommended.
The next step in the design process is when AWHP operating modes should be considered. In addition to providing heat for a building, AWHPs can also provide cooling. There are two distinctly different technologies available to achieve this. Sometimes referred to as a simultaneous or multipurpose unit, these AWHPs can provide cooling, heating or both cooling and heating simultaneously. Alternatively, a more simplistic unit is available that can produce either heating or cooling, but not both at the same time. It is important to evaluate the building load profiles to determine how many units should be simultaneous versus a more traditional AWHP for the equipment to operate effectively and efficiently while also being cost conscious at the time of installation.
AWHPs are available as a packaged type and a modular type. From an output perspective, packaged and modular type AWHPs can be used interchangeably (i.e., a packaged type could be installed in place of a modular type and vice versa), however building constraints will have an impact on which type of AWHP is best suited for the application.
If the AWHP will be installed in an existing building, a review of the building’s structural capacity is necessary. A structural engineer should identify the load-bearing capacity of the build-
FIGURE 1: In this sample building load profile, the blue line represents cooling load, and the red line represents heating load. Courtesy: Metropolitan Equipment Group
ing’s structural system. This load bearing knowledge may limit the equipment selection to a specific AWHP type or indicate that reinforcement of the existing structure is required if either AWHP types are to be considered.
Physical space availability also impacts AWHP selection. AWHPs resemble air-cooled chillers in their basic configuration, however, an AWHP has a larger footprint for a given capacity than a comparably sized air-cooled chiller.
Airflow restrictions are another similarity between AWHPs and air-cooled chillers. Each AWHP manufacturer has minimum distance requirements between the perimeter of their AWHP and surrounding building elements as well as minimum distance requirements between the perimeters of adjacent AWHPs. Installing an AWHP in a “pit” where it is surrounded on all four sides by building elements brings additional minimum distance requirements into consideration. If an AWHP is installed in a pit setting, most AWHP manufacturers will recommend installing the top of the equipment at the same elevation as the top of the surrounding building elements. During equipment evaluation and selection, clearances should be requested from the manufacturers.
Although AWHPs can be installed within a building, for the purposes of this article, we are
‘ It is important to evaluate the building load profiles to determine how many units should be simultaneous versus a more traditional AWHP for the equipment to operate effectively and efficiently.’
focusing on AWHPs being provided as standalone, outside of the building envelope. It should be noted that within the UK and Europe, AWHP are typically located and installed within central utility plants..
A packaged AWHP provides a single large machine capable of a greater heating and cooling output when compared to the modular machine. Packaged machines typically have smaller footprints than modular types providing the same capacity, providing a benefit for overall space consumption and weight distribution. Packaged types also come with fewer components which impacts reliability and regular maintenance.
For example, a typical packaged AWHP might only have a maximum of four compressors where an equivalent modular type could have as many as 16 compressors.
FIGURE 2: This shows sample ambient temperature versus leaving heating water temperature. The blue line represents a standard scroll compressor’s operating envelope and the green line represents a vapor injection scroll compressor’s operating envelope. Courtesy: Metropolitan Equipment Group
Projects with tight space constraints such as retrofit or a project with limited rooftop or surface areas are good candidates for modular type AWHPs due to their flexibility for design. Modular AWHPs are provided in incremental sizes as low as 25 tons and up to 80 tons. The ability to take a 150ton building load and split it up among six AWHPs provides the flexibility to space out the modules across multiple locations, versus having to be stacked together on the roof and occupying a large single footprint.
If a split approach is applied to modular machines, additional connections will be required. Each of the individual module typically has two compressors, so in this example, there would be 12 compressors to maintain for the 150-ton machine versus the single large, packaged machine requiring only four compressors. End users and designers must consider the positive and negative aspects of a packaged approach versus a modular approach when preparing to design an AWHP project.
Upon selection of an AWHP approach for a building’s heating and cooling demand the next critical step is identifying the building load profile (see Figure 1). If the load profile indicates a
simultaneous heating and cooling load all year, it is typically beneficial to use a simultaneous heating and cooling AWHP that allows for production of chilled and heating water and doesn’t require switch over from heating mode to cooling mode. In this approach, the simultaneous heating and cooling AWHP would be paired with supplemental reversing AWHPs that can handle the additional heating load in winter and the additional cooling load in the summer. If the building load profile indicates minimal simultaneous heating and cooling throughout the year, an AWHP that can reverse from cooling mode to heating mode depending on the time of year and the demand should be selected.
A simultaneous heating and cooling AWHP should be selected so that the machine is always running close to 100% of its maximum capacity for both heating and cooling. The optimal operating point of the simultaneous heating and cooling AWHP is a balanced load at maximum capacity. However, a balanced load is typically not achievable year-round and therefore the simultaneous AWHP should be selected close to the simultaneous heating and cooling demand that the building has throughout the year. Avoid using simultaneous heating and cooling AWHPs for heating only or cooling only applications Instead,
use a reversing AWHP that either provides heating only or cooling only.
Simultaneous AWHPs typically need to be supplemented with reversing AWHPs to efficiently meet the building load. Select the simultaneous AWHP(s) to accommodate the shoulder season heating and cooling simultaneous demand. The heating and cooling differential between shoulder season and peak heating and cooling loads will be covered by the reversing supplemental AWHPs. Simultaneous heating and cooling AWHPs are capable of handling unbalanced heating and cooling loads unlike heat recovery chillers (HRCs).
For example, if a building’s load demand is only 80% of heating maximum and 40% of cooling maximum, a simultaneous AWHP will be able to provide the building with the high demand for heating and still be able to provide the decreased cooling demand. HRCs only provide their maximum heating capacity while the machine is providing the maximum cooling capacity. As the cooling demand drops so does the heating capacity of an HRC.
Jurisdictions throughout the United States are adopting regulatory requirements that may dictate the application of AWHPs. For example, since 2022, the Washington State Energy Code requires a percentage of water be heated using heat pumps. An early step in the design of AWHPs is researching the codes in the jurisdiction of the project.
Once the relevant equipment has been selected for a project, the next step is to examine the operating limitations and design capabilities of the AWHPs along with the intended project design conditions. Consultation with AWHP manufacturers typically starts at this point in the design process.
One of the most critical items when designing an AWHP system is the ambient air temperature due to its importance when the AWHPs are in heating mode. The ambient air temperature will dictate the leaving heating water temperature the AWHP will generate. As the ambient air temperature decreased, there is an operating point where the leaving heating water temperature starts to decrease (see Figure 2).
‘ The optimal operating point of the simultaneous heating and cooling AWHP is a balanced load at maximum capacity. ’
If the ambient air temperature drops below the AWHPs minimum operating point, the AWHP will no longer operate reliably requiring backup heating.
Heating water system temperatures associated with AWHPs differ from typical design practice. In the past many projects used boilers capable of generating heating water from 160° to 180°F. Heating water temperatures of 160° to 180°F will not be possible with the AWHPs currently on the market. A leaving heating water temperature for AWHPs is recommended from 90° to 120°F as good practice.
Another important consideration is the difference between the supply and return water temperatures known as the temperature differential (delta T). Boilers can use a 20° to 30°F delta T. AWHPs either have difficulty or are not capable of handling a 20° to 30°F delta T. A good practice is to design for AWHPs is to have a primary pumping loop delta T of between 10° to 15°F paired with a secondary building side pumping loop that operates at a higher delta T.
The points presented above are for AWHPs using standard scroll compressors. However, there are AWHPs available that use vapor injection scroll compressors. Vapor injection compressor machines can provide additional lift to either provide a warmer heating water leaving temperature up to 160°F or provide the standard AWHP leaving water temperature at much lower ambient temperatures down to as low as -0°F ambient. It’s important to consult the AWHP manufacturer on the ambient operating limits. Scroll compressor machines and vapor injection compressor machines are not interchangeable as the system design required is different for each technology.
After the project criteria and design conditions have been identified the AWHP selection begins. There are a few critical items that must be understood and evaluated before finalizing the equip-
ment selection. AWHPs require a minimum and a maximum system water volume to operate properly, particularly the primary pumping loop system volume.
A good pumping arrangement for AWHPs is to incorporate a constant volume primary loop paired with a variable secondary loop. There are exceptions to a primary/secondary pumping layout where AWHP manufacturers are recommending variable pumping primary loops. This should be reviewed and understood before selection of the machines and consultation with the AWHP manufacturer it is recommended.
‘ Providing the AWHP manufacturer with the required glycol percentage is critical to being able to account for the glycol performance penalty. ’
System water volume is the most important requirement that an AWHP system needs to operate properly. Failure to meet the active system water volume requirements will result in the AWHP machine being unable to provide the proper design leaving water temperatures and could result in premature failure of the machine’s components. Depending on the manufacturer and the type of AWHP used, the gallons per ton (gal/ton) will vary.
However, a basic rule of thumb is to provide a minimum of 6 gal/ton for reversing AWHPs and 10 gal/ton for simultaneous heating and cooling AWHPs. The recommended gallons per ton, which represents the total system volume, should not be confused with the system flow, which is represented in gallons per minute, or gpm.
The system volume given in gallons per ton that is required for the AWHP machine is for “active” system volume only. Active system volume is the water that is always readily available to the AWHP system regardless of the load condition on the building. Consult with the AWHP manufacturer to ensure that the active system water volume is sufficient for the application.
AWHPs located outside in colder climate zones can potentially require a glycol solution to offer freeze protection. As with other system types, adding glycol to the system causes less heat transfer to occur in the system and, therefore, there is a sacrifice in overall system performance referred to as “glycol performance penalty.” Providing the AWHP manufacturer with the required glycol percentage is critical to being able to account for the glycol performance penalty.
When using glycol in an AWHP system it is good practice to make the primary pumping loop the glycol side and use a heat exchanger to separate the primary side from the secondary side, keeping the glycol from circulating through the entire building. Using the heat exchanger prevents derating any indoor equipment’s capacity. AWHP manufacturers may also offer an option for heat tracing and an electric heater for freeze protection. This is an option that should only be considered if the project is in a milder climate and or the project cannot use glycol.
When an AWHP is in heating mode, the coils can begin to ice up. To remove this ice buildup, it is necessary to reverse the machine into defrost mode. When using AWHPs for heating, it is very important to look at the defrost cycle along with the defrost penalty for capacity that all AWHPs have between 25° and 40°F ambient air temperature.
In defrost mode, hot refrigerant will pass through the coils to heat them and melt the ice. Reversing the AWHP introduces neutral to cool water into the heating loop, which diminishes the leaving heating water temperature. The active system volume becomes critical because having the proper amount of system volume will lessen the impact of this cooling effect on the overall system.
Without enough active system volume, having an AWHP go into defrost mode could result in a runaway heating water loop. A runaway heating water loop occurs when the leaving water temperature is decreased and as a result the returning water temperature is much lower than design. This cycle continues until the machine leaves defrost mode at which point the return water temperature is too low and the AWHP cannot provide enough
‘ The AWHP manufacturer should provide the heating performance with the defrost penalty included otherwise there is a risk of having a machine short on heating capacity and undersized by up to 33%.’
lift or heat to get back to the required leaving water temperature.
It should also be understood that in North America, it is not required for AWHP manufacturers to provide their machine’s heating performance with a defrost penalty. There will be derated heating performance of an AWHP while it is heating in defrost mode. The AWHP manufacturer should provide the heating performance with the defrost penalty included otherwise there is a risk of having a machine short on heating capacity and undersized by up to 33%.
European manufacturers are required to include the defrost penalty in their reported performance. It is best practice to request defrost penalty information from AWHP manufacturers during the design process.
AWHP systems should include the ability to monitor return water temperatures to verify that the system is functioning properly. The return water temperature sensor is a remote device that is not manufacturer provided. When finalizing AWHP selections, it is a good practice to explore the additional accessories that can be provided by the manufacturer.
• Request that the AWHP manufacturer provide its machines with integral constant volume primary pumps. Most manufacturers can provide integral pumps including a redundant pump for N+1 redundancy.
• Explore the option for an integral buffer tank. Otherwise, the designer will either need to provide an external buffer tank or enlarge system piping to provide the minimum system volume.
• Designers should consider the AWHP manufacturers’ integral control panel when using multiple AWHPs. These multimachine control panels can operate all the AWHPs evenly and at their most efficient operating point when compared to controlling the AWHPs with a building automation system.
As an alternative to the manufacturer-provided accessories listed above, some of the components can be provided by the installing contractor and field installed in the hydronic distribution system. For example, a four-port buffer tank can be used to mechanically separate the primary and secondary pipe systems. With this approach, the four-port buffer tank can be provided with the ability to install the return water temperature sensor in a factory provided opening rather than in a field installed opening located in the return piping.
When retrofitting AWHPs in existing systems, the original operating parameters need to be considered. If the system was originally designed with coils using 180°F supply heating water and 50°F return heating water, the coils in the entire heating water system may require replacement. Alternatively, measures to raise the supply heating water temperature may be implemented.
In conclusion, AWHPs are an easy solution to provide heating, which helps decarbonize a facility if the above measures are observed and incorporated into the design of system. However, application of AWHPs requires a rethink of previous system parameters. When using AWHPs, they system can heat with lower heating water temperatures and cool with higher chilled water temperatures than the industry has used in the past. cse
Mark Ridenour, PE, is Mechanical Engineering Principal at HDR Inc.
Andrew Peck is Senior Sales Engineer and the Vice President of Engineering at Metropolitan Equipment Group.
AWHP insights
u Although air-to-water heat pumps (AWHPs) resemble an air-cooled chiller, an AWHP differs significantly.
u Successful application requires attention to details that distinguish this technology from traditional heating solutions.
Edward Chinnis, PE, RCDD, LEED AP, HDR, Charlotte, N.C. and;
Jesus Gonzalez, HDR, Charlotte, N.C.
Arc flash studies have inherent risks due to live electrical equipment. Creating a safety plan beforehand protects employees and contractors
An arc flash is a sudden release of electrical energy through the air that occurs when a high-voltage gap exists and a path to ground or lower voltage is introduced. This can result in an explosive discharge of light and heat, potentially causing damage to equipment and posing serious injury risks to personnel. According to industry statistics and research studies, there are an estimated five to 10 arc flash incidents daily in the United States that result in over 2,000 people receiving treatment each year for various levels of arc flash burns. In addition, they typically cause significant equipment failure, which leads to further system shut-
down costs. Understanding arc flash risk can help mitigate these incidents and associated costs.
In the design and delivery of electrical engineering consulting services, it is common for clients to request an arc flash study for their facilities. This study helps to identify existing arc flash risks in different components of the electrical system and provides solutions to mitigate these risks for employees.
One component of an arc flash study requires gathering existing electrical equipment information. Because the person gathering information may encounter live electrical equipment, there is an increased risk of an arc flash incident during this task. Both human error and equipment failure can cause an arc flash. Common human errors include accidental contact with live equipment, not following adequate safety procedures to operate live equipment, improper use of tools and wearing inadequate personal protective equipment (PPE) for the risk.
Engineering companies that conduct arc flash studies often hire an electrical contractor to undertake the electrical survey. The Occupational Safety and Health Administration Safety Act of 1970 establishes that “Each employer shall furnish to each of his employees employment and a place of employment which are free from recognized hazards that are causing or are likely to cause death or serious physical harm to his employees.” This does not absolve a company hiring an electrical contractor to perform electrical work on their behalf from complying with safe work practices. Therefore, the hiring company still bears some responsibility for the safety of the contractor at the site. This
• Understand the risk of undertaking an arc flash study.
• Identify the safety requirements surrounding arc flash.
• Learn what responsibilities employers have in keeping employees and contractors safe from arc flash risks.
‘ The first step in any safety plan is to understand the intrinsic risks associated with gathering information for an arc flash study and identifying ways to minimize these risks.’
must be communicated as a known hazard covered by NFPA 70E: Standard for Electrical Safety in the Workplace.
The first step in any safety plan is to understand the intrinsic risks associated with gathering information for an arc flash study and identifying ways to minimize these risks. Once the risks are understood, there should be a discussion on a safety plan and mitigation steps.
An effective arc flash safety plan should discuss the hierarchy of risk controls proposed in NFPA 70E, article 110.1 (H), ranked as follows:
1. Elimination: Physically remove the hazard.
2. Substitution: Replace the hazard.
3. Engineering controls: Isolate people from the hazard
4. Awareness: Increase visibility of the hazard
5. Administrative controls: Change the way people work.
6. PPE: Protect the worker.
In many arc flash study surveys, the first levels of the hierarchy cannot be effectively achieved without impacting the business operation. This sit-
uation is most noticeable on continuous operations businesses in industries like health care, utilities or manufacturing. Therefore, training must concentrate on the last three levels.
When addressing “awareness” of existing risks, the safety plan should use the facility’s existing oneline diagram to discuss each piece of equipment involved in the study. This helps identify any equipment that, by design, has the potential for a high arc flash incident and may elevate the risk to the contractor. For example, a low voltage substation in
inherent risks for contractors and employees conducting arc flash studies. Courtesy: HDR
the main breaker section of the switchgear that is connected to the secondary side of the transformer may pose significant risks, unless additional protection schemes are in place.
csemag.com
Arc flash safety insights
uConducting arc flash studies involves risks with live electrical equipment, necessitating comprehensive safety plans and strict adherence to NFPA 70E standards.
uEnsuring contractor safety during arc flash surveys requires the implementation of the hierarchy of risk controls
uPre-survey safety training is crucial for mitigating risks associated with arc flash incidents.
The concept of establishing appropriate administrative controls within safety training involves discussing how to conduct the electrical survey safely. The topics include the tools to be used, appropriate clothing and methods for approaching each piece of equipment.
During general electrical work and, most importantly, while opening electrical equipment that could expose live parts, all tools used should have insulation and be rated for the work undertaken. Before commencing the survey, the contractor should inspect all tools to ensure they are in good working condition and that the insulation has not been compromised.
Regarding clothing and methods for approaching equipment, PPE provides a layer of protection for the contractor. PPE is listed as the last resource in the hierarchy of risk control since this does not eliminate or minimize the risk., but only provides limited protection for the arc flash incident ener-
‘
Employers are required by law to provide a safe environment to employees and contractors. Implementing pre-survey safety training is the most effective way to protect contractors, assess potential risks and minimize the possibility of accidents.’
gy. If it’s available, learning how to read the arc flash labels on electrical gear is the first step. Using methods from IEEE 1584-2018: Guide for Performing Arc-Flash Hazard Calculations or tables from NFPA 70E, contractors can determine the level of PPE required for the available incident energy listed on the label.
The label will also list the typical working distance and the arc flash boundary. The working distance is the space from a person’s face and chest to the prospective arc source, while the arc flash boundary is the distance at which the incident energy is limited to 1.2 cal/cm2. This level of incident energy is considered an acceptable risk, as it likely will only create curable burns on exposed skin that are curable. Safety training should discuss ways for contractors to remain beyond the arc flash boundary when not conducting direct work with the electrical gear.
If arc flash labels are not available, the safety training should explore ways to eliminate or minimize the arc flash risk, per levels one to three of the hierarchy. This will require coordination with the facility to limit the impact of electrical system shutdowns.
Employers are required by law to provide a safe environment to employees and contractors. Implementing pre-survey safety training is the most effective way to protect contractors, assess potential risks and minimize the possibility of accidents. cse
Jesus Gonzalez is the electrical engineering section manager at HDR in Charlotte, N.C. Edward Chinnis, PE, RCDD, LEED, AP is the senior electrical engineer and North Carolina / South Carolina building engineering services lead at HDR in Charlotte, N.C.
Henry Baker, PE, Kohler Ronan Consulting Engineers LLC, Danbury CT
Design engineers have many opportunities to go above minimum code requirements to decrease risk to facility personnel and electricians working on electrical systems
To meet baseline safety criteria and design requirements for electrical power systems, engineers review a wide range of codes, standards and product literature throughout the design process. The consulting engineer must understand that codes present minimum safety requirements, and that there are many opportunities to enhance system safety for facility personnel and third-party electricians by going above and beyond code requirements. When selecting equipment, the consulting engi-
neer should seek opportunities to leverage product features and improve end-user safety. They must prioritize limiting operational hazards that electricians face when working directly on energized equipment or maintaining machinery and fuel-burning equipment.
Facilities may have policies in place regarding live or energized work that can influence design decisions related to phasing, data collection, temporary conditions and points of interconnection. While, from a safety standpoint, it’s desirable to work on de-energized equipment, sometimes live work is advantageous to avoid an electrical service shutdown and preserve operations. Additionally, equipment surveys or metering performed pre-construction may require live equipment cabinets to be opened, exposing personnel to energized buses.
For buildings where a lengthy shutdown could be especially disruptive, like hospitals, it is important to discuss shutdown protocols with the project stakeholders to understand if energized or de-energized work should be assumed for construction. If the client requests live work to be done by the contractor, it should be clearly noted in the construction documents so associated costs are captured in the bid, and so contractors who are unable to perform live work are filtered out of the awarding process. If included in their scope of services, the engineer should monitor bid forms and bid qualifications to confirm bidders have priced live work.
During design, the engineer may be required by code to specify products that reduce the arc flash incident energy levels at the equipment to make live work safer for electricians. Arc flash incident energy can be defined as how much energy is released
‘
By producing a comprehensive short circuit, coordination and arc flash study, the design engineer can specify the appropriate overcurrent protection devices that can limit short circuit current and clear faults quickly to limit arc flash hazards.’
during an electric arc per unit area at a certain location. An arc flash occurs when an electrical current jumps between two conductors (busbars, feeders, etc.) through the air, effectively creating a short circuit. In commercial power systems, the energy released can be significant and extremely dangerous. NFPA 70: National Electrical Code (NEC), Article 240.67: Arc Energy Reduction and Article 240.87: Arc Energy Reduction for Switchboards and Panelboards require fuses and circuit breakers rated 1,200A or higher to be equipped with means to reduce arc flash incident energy levels by reducing the time it takes for the overcurrent protection device to clear a fault. The lengthier the fault, the more energy can be released during the fault.
Examples of technologies that satisfy NEC requirements include zone-selective interlocking, differential relaying, energy-reduction maintenance switching and instantaneous trip settings. Certain technologies are more sophisticated than others and can be more effective in reducing hazards to equipment and personnel. Intelligent differential relaying and arc quenching relays are more advanced than simple, fast-acting fuses that have fixed trip characteristics determined by their physical properties. Furthermore, the robustness of equipment construction can influence arc flash hazard potential. Products such as arc-quenching or metal-insulated switchgear reduce the risk of arc-related hazards compared to basic switchboard construction.
The design engineer can use short circuit, coordination and arc flash analysis software to determine key parameters. Parameters include maximum available fault currents and arc flash incident energy levels at equipment throughout their project’s power system. By producing a comprehensive short circuit, coordination and arc flash
FIGURE 2: The partial arc flash study single-line diagram shows arc flash boundaries and incident energy levels at equipment. Courtesy: Kohler Ronan Consulting Engineers, LLC
study, the design engineer can specify the appropriate overcurrent protection devices that can limit short circuit current and clear faults quickly to limit arc flash hazards.
It should be specified in the construction documents for the contractor to engage a third-party engineer to produce their version of a short circuit, coordination and arc flash study. This study accounts for the exact field routing of feeders along with the characteristics of submitted equipment and devices to verify that the design intent is met. The facility should keep an up-to-date record copy of the study on-site for easy reference when planning equipment maintenance and energized work.
The contract specifications should require the contractor to provide system-specific arc flash hazard labeling for each piece of equipment that informs those operating the equipment of safety parameters, such as arc flash incident energy levels, arc flash boundary and the required level of personal protective equipment (PPE) required for
FIGURE 3: This arc flash warning label includes information per NFPA 70E, including arc flash boundary, incident energy levels and certain personal protective equipment requirements.
Courtesy: Kohler Ronan Consulting Engineers, LLC
• Understand select code requirements pertaining to safety in power systems design, and how those code requirements can be built upon to provide added safety for electricians.
• Learn about product features and services that may be specified in the construction documents to improve electrical power systems safety
110.16, which requires FIGURE 4: This arc flash warning label is generic. It meets the requirements of NFPA 70, but lacks information per NFPA 70E. Courtesy: Kohler Ronan Consulting Engineers, LLC
energized work. These are outlined in NFPA 70E: Standard for Electrical Safety in the Workplace. Note that the arc flash labeling standards indicated in NFPA 70E are referenced in NFPA 70, Article 110.16: Arc-Flash Hazard Warning via an informational note regarding labeling requirements for service equipment. Adding arc flash labeling with the detailed information noted above to distribution equipment throughout the facility is a recommended best practice that goes beyond the requirements of NFPA 70, Article 110.16, which requires more basic warning labels. This study will also enable the design engineer to specify equipment with adequate short-circuit current, interrupting and withstand ratings. It also allows them to specify fault current limiting overcurrent protection devices to reduce available equipment short-circuit currents to the lowest possible levels. Short-circuit and withstand ratings each define a piece of equipment’s ability to maintain its physical, electrical and functional integrity after a fault event. The interrupting rating of a device defines its ability to clear a fault up to a certain fault current level.
A fault may occur when operating a switch mechanism, and if a piece of equipment is under-rated, it may catastrophically fail during a fault event and cause harm to personnel. NFPA 70, Article 110.9: Interruption Rating and Article 110.10: Circuit Impedance, Short-Circuit Current Ratings and Other Characteristics require adequate short-circuit and interrupting ratings. Withstand ratings of equipment are parameters listed by the manufacturer. For switches upstream of transformers with potentially high inrush load currents, selecting switches with adequate close-on ratings is important. A switch’s close-on rating is its ability to close during an inrush up to a certain current, usually expressed as a multiple of the equipment’s nameplate current. Specifying high close-on rated switches can reduce the risk of a switch arcing between its contacts if closed during an inrush.
At other high-power switching equipment, such as switchgear, remote switching options should be considered in addition to standard manual switch-
ing. This allows personnel to operate large switch mechanisms with the push of a button, leaving them out of potential harm’s way. Whenever possible, it is also recommended to specify mechanically held switches as opposed to electrically held switches, which rely on power to hold their position. Infrared scanning of distribution level feeder terminations and splices should be specified to evaluate the integrity of the termination at the time of initial energization. A loose termination could leave the feeder vulnerable to electrical stresses that could ultimately result in an arc event.
Follow up scanning should happen months after the initial scan to ensure that there are no noticeable changes in heat mapping, which could signal a failing connection. Adding surge and switch operation counters to key distribution switches can help facility personnel track the condition of their infrastructure and schedule necessary maintenance before equipment becomes less safe to operate.
There may be a large range of short circuit currents and arc flash incident energy levels experienced in buildings’ electrical systems, so the design engineer should evaluate each piece of equipment and their application against the project’s budget and space constraints before specifying a product. For example, switchgear with electronic fault-clearing relays and low-voltage power circuit breakers takes up significantly more space and costs significantly more than a less substantial switchboard with molded case circuit breakers. However, the switchgear provides greater resilience to faults and improved arc mitigation.
The engineer should also familiarize themselves with the technical knowledge of the facility personnel and equipment operations protocols to specify a product appropriate to their level of involvement with the systems. In the construction documents, the engineer should include training sessions for the personnel on how to operate and maintain specified arc energy reduction and fault mitigation equipment.
Maintenance or isolation bypasses are other features that can limit hazards due to energized work and are available on a wide variety of products. Bypass switches, or sections in automatic transfer switches, variable frequency drives and uninterruptible power supplies can allow maintenance
PRIVATE HIGH SCHOOL in Connecticut included electrical safety measures beyond the minimum code requirements
Designing electrical systems for safe building operations impacts more than just electricians. Schools, for example, are equipped with numerous systems designed to keep students and staff safe by de-energizing potentially hazardous equipment they interact with every day. This private high school in Connecticut included a new performing arts wing and commercial kitchen.
The performing arts wing included a wood shop and dressing rooms to support the school’s theater program. In addition to emergency stop buttons provided by the manufacturer, all machinery and appliances in the shop were provided with local disconnect switches to provide an additional layer of safety. There also was an emergency power off (EPO) switch at the door that opened the shop panelboard’s main circuit breaker via a shunt trip mechanism to de-energize all circuits within the room in the event of an emergency.
At each dressing room, all receptacles and lighting at the makeup counters were circuited via local, above-ceiling and multi-pole contactors that were controlled by a switch at the door leaving the room. The contactors were wired so that pilot lights, located directly outside each room, were illuminated when the makeup counter lighting and receptacles were energized. The intent was to notify those passing by if power was inadvertently left on during a show and to alert them to a potential fire hazard. Wall switch control with a pilot light indication for makeup counters such as these are required by NFPA 70: National Electrical Code (NEC) and 520.74.
The new kitchen and serving spaces designed in this project significantly increased the food service capacity for the school to accommodate its growing footprint and enrollment. Cooking in the
personnel to work on energized critical equipment while reducing, or eliminating, their exposure to live parts. Bypasses are available in different configurations, with the safest being a separate section that is electrically isolated from the primary section by a vertical barrier within the equipment cabinet.
Even safer than an integral bypass is a separate, redundant piece of equipment. Bypasses and redundant equipment often add to project space needs and costs, so it is worth discussing with the client early in the project to understand their tolerances for shutdowns and energized work compared to the spatial and financial costs. Common applications
kitchen would be done predominantly with gas, which produced smoke and grease-laden vapors, thereby necessitating a Type 1 kitchen hood, equipped with an ANSUL fire suppression system. EPO buttons were provided at each door out of the kitchen to open the gas solenoid valve serving the cooking appliances below the hood. The EPO buttons and gas solenoid valve control panel were specified with key switch resets, requiring qualified persons to inspect conditions, and then manually reset the EPOs and control panels before resuming gas service to the cooking equipment.
‘ Schools are equipped with numerous
The ANSUL system was also circuited to control shunt trip circuit breakers serving appliances below the hood to cut power to potential sources of ignition. Circuiting and controls related to the kitchen hood and ANSUL system were coordinated closely with the mechanical engineer, the kitchen consultant and the fire alarm system to ensure the sequence of operations would work as intended to safely extinguish a fire and signal occupants to evacuate the building in the event of a manual pull of the ANSUL system pull station.
systems designed to keep students and staff safe by de-energizing potentially hazardous equipment they interact with every day.
’
In these spaces, supplementary emergency lighting was also provided, exceeding the minimum requirements from the building code for emergency egress. This lighting enabled students and staff to safely exit their work areas without risk of spills, slips or burns in the event of a power outage.
In all, the submitting engineering firm prioritized the safety of the end-user throughout this project, whether they be electricians, teachers, food service staff or students. The design provided stakeholders with the emergency systems necessary to help avert potential hazards that may present themselves.
for bypasses and redundant equipment include hospitals, data centers and other occupancies where shutdowns to work on de-energized equipment would be costly to business operations and occupant safety or would otherwise compromise the building’s internal environmental conditions.
During design, the engineer should meet with the owner’s electricians and facility personnel to review their procedures for maintenance and shutdowns and ensure specifications align with their
Courtesy: Kohler Ronan Consulting Engineers, LLC
operations. As a best practice, all distribution-level switches and switches feeding mechanical equipment should be lockable. Lockable switches allow electricians to enact their lock-out tag-out procedures during regular maintenance and shutdowns, reducing the risk of inadvertent energization of equipment. It is also recommended to provide disconnecting means within the line of sight of mechanical equipment and other equipment that requires regular maintenance for an additional layer of safety.
system configurations are easily identifiable by facilities personnel and first responders in the event they need to act quickly to remedy a situation.
Electrical rooms should always be clearly labeled and should have access control or keyed locks accessible only to qualified personnel. In terms of electrical room design, it is recommended that doors swing outward so that someone working on a panelboard within the room does not get inadvertently bumped by a door swing into harm’s way. Note that this is in excess of NFPA 70, Article 110.26: Spaces about electrical equipment, which only requires doors to swing outwards and be equipped with panic door hardware when equipment within the room is rated 800A or greater. It is recommended that all electrical rooms be provided with emergency lighting for safe egress in the event of an outage, but this is only required by certain building codes.
Electrical safety insights
u Engineers should prioritize exceeding minimum safety requirements by specifying advanced safety features.
u The design process should include comprehensive short circuit, coordination, and arc flash studies to specify appropriate overcurrent protection devices.
Note that it is not always required to have disconnecting means within the line of sight of equipment served. The NEC often permits it to be omitted, so long as the upstream disconnecting means is lockable in accordance with Article 110.25: Lockable Disconnecting Means. Emergency power off, emergency pull stations and shunt trip modules are useful products an engineer can employ in design to add means for the safe shutdown of remote equipment. Specific applications include emergency shutdowns of machinery and fuel supplies to mitigate hazards such as kitchen grease fires, entanglement in rotating shop machines and fires at classroom science labs or fuel-burning equipment.
Certain items pertaining to safety in power systems design may be of particular interest to architects for coordination, space-proofing and aesthetic purposes. Detailed signage, labeling requirements and record documentation should be included in the construction documents as diagrammatic placards at conspicuous locations. This ensures that
At key equipment, such as service and generator rooms, it is often required to provide emergency backup battery lighting packs, even if generator backup is present, to allow maintenance personnel to safely leave equipment working clearance during a power outage. If an electrical panel is recessed in a wall within a space that is required by energy code or building operations, then controls must be provided to bypass or override the automatic shut-off so that an electrician can safely work on the panelboard without lights potentially shutting off. Where electrical equipment is floor-mounted, concrete housekeeping pads are also recommended to keep equipment off the ground and away from potential pooling water, particularly if located in a room with piping. It is recommended to extend concrete housekeeping pads a few inches outside the electrical equipment’s footprint to protect it from physical impacts, such as accidental kicking or rolling equipment.
In conclusion, design engineers have many opportunities to go beyond the baseline requirements of construction codes and standards. Engineers should work with equipment manufacturers and clients to pursue such opportunities whenever possible. cse
Henry Baker is an associate, senior electrical engineer specializing in power systems, lighting controls and fire alarm systems design.
Peter Fung | Director of sales, Addison
This paper explains how DX-Dedicated Outdoor Air Systems (DX-DOAS) dehumidify 100% outdoor ventilation air to a low dew point. Utilizing free reheat, the system then increases the air temperature to achieve a state of neutral Conditioned Air (CA) and delivers the air to each occupied space. The DOAS unit is a de-coupled system and operates independently from the building space (zone) HVAC system. This de-coupled approach to handling ventilation air provides optimum space temperature and humidity control. By conditioning the outdoor air before it enters the building, the space (zone) HVAC equipment can be, solely, used to address the sensible and latent loads of the space.
AHRI Standard 920, Performance Rating of DX Dedicated Outdoor Air System Units, is used to rate the performance of DX equipment that is used to dehumidify 100% outdoor air to a low dewpoint. Prior to the introduction of AHRI Standard 920, our industry has been confused on what direction to take when selecting and specifying DX DOAS units. Common engineering practice in the past has been to apply AHRI Standard 340/360; however, this standard has shortcomings as it pertains to gauging the true performance of a DX DOAS unit.
industry professionals with the necessary understanding to effectively apply the appropriate standards for specifying and rating DX DOAS units.
Specifying engineers should familiarize themselves with Standard 920 and begin to specify equipment with the minimum required efficiencies per 90.1. With the implementation of this standard, manufacturers will be motivated to build DX DOAS equipment with features that more appropriately address high humidity while continuing to improve on efficiency.
As the industry marches towards more sustainable solutions, it is important for engineers, owners, and manufacturers to keep performance and quality in mind, while also utilizing/providing the most efficient equipment designs.
Download the paper: https://tinyurl.com/a8ucw2y8
This paper examines the objectives of each standard and outlining their differences. By doing so, we aim to equip HVAC
info@addison-hvac.com • 407-292-4400 www.addison-hvac.com SCAN CODE AT LEFT FOR SMARTPHONE ACCESS
CSE: What's the biggest trend in college and university buildings?
Matthew Goss: The biggest trends I'm seeing in college and university buildings are in support of carbon neutrality goals. Designs incorporate more efficient and sustainable design components. Whether we're talking new facilities or renovations, sustainability and efficiency are key to future campus and facility success.
Stephanie Lafontaine: Engineers should expect to see a continued trend toward more stringent energy efficiency requirements and electrification as colleges and universities strive to meet their decarbonization and energy reduction goals.
Jeff Wurmingler: One of the biggest trends we are experiencing is the re purposing of buildings, especially as the industry looks for opportunities to reduce a project's carbon impact. Existing buildings typically provide the least amount of embodied carbon generation during construction, and often offer the opportunity to improve operational carbon impacts with wholesale system improvements that increase energy efficiency. We highly recommend undertaking a study that cap-
• Understand what trends are driving design changes in college and university buildings.
• Identify key environmental considerations for these projects.
• Learn specific challenges that come with designing buildings for college campuses.
tures the existing conditions and evaluates the building for a new use prior to generating any design.
CSE: How do changes or new designs from COVID-19 still impact these buildings and projects?
Matthew Goss: Recent designs have incorporated COVID-related precautions, such as enhanced air filtration, UV, plasma ionization and the capability for systems to provide 100% outside air. I expect these technologies to remain, and I anticipate the development and refinement of additional solutions.
Abdullah Khaliqi: Changes or new designs stemming from COVID-19 continue to impact buildings and projects significantly. Ventilation has become a crucial aspect, as people are still very interested in meeting health guidelines. Enhanced air filtration systems, increased fresh air intake and the integration of advanced heating, ventilation and air conditioning (HVAC) technologies are now standard considerations to ensure healthier indoor air quality. Additionally, there is a growing emphasis on energy efficiency. Modern systems are designed to optimize air quality while minimizing energy consumption to balance health concerns with sustainability goals. This dual focus not only helps mitigate the spread of airborne pathogens but also improves overall indoor air quality and energy efficiency, contributing to occupant well-being and comfort.
John Mongelli: Post-COVID design
is minimal. MERV 13 filters represent the only remarkable standard still being implemented following the pandemic.
CSE: If enrollment continues to decrease, what changes do you anticipate seeing?
Abdullah Khaliqi: If enrollment continues to decrease, we anticipate seeing a shift toward renovation over new construction. Minimizing the carbon footprint is at the front of most people's minds, and embodied carbon is being discussed more. Fewer new buildings mean less embodied carbon, so renovation becomes a more attractive option. Renovation projects often focus on improving energy efficiency in existing structures, further aligning with sustainability goals and reducing overall environmental impact. Clear sustainability goals and reduced environmental impacts are anticipated to be significant enrollment considerations for new students in a competitive selection process.
John Mongelli: We have not witnessed a decline in enrollment. As a matter of fact, the opposite appears to be true among many of the higher education institutions we work with. In recent years, these institutions have built new housing to accommodate the growing number of students.
CSE: How are engineers designing these kinds of projects to keep costs down while offering appealing features, complying with relevant codes and meeting client needs?
Matthew Goss: I believe engineers are typically cost-conscious and consistently face the challenge of balancing budgets with needs, requirements and wants.
Abdullah Khaliqi: Engineers carefully consider energy costs and utility incentives when selecting new equipment to keep costs down and offer appealing features. By focusing on energy-efficient systems, engineers can reduce operational expenses and take advantage of available incentives. Incorporating energy-efficient technologies not only lowers costs but also ensures compliance with environmental standards and enhances the project's overall sustainability. This approach balances initial investment with long-term savings and performance.
Stephanie Lafontaine: College and university buildings are being designed to be more energy efficient by meeting requirements for LEED, Passive House, Living Building Challenge and other "green" standards. This includes high-performance envelopes, dedicated outdoor air systems with energy recovery, heat recovery chillers, LED lighting, low-flow fixtures and domestic hot water recirculation.
John Mongelli: Keeping costs down is a challenge. The installation costs for
mechanical, electrical, plumbing and fire protection systems have gone up significantly in recent years. At the same time, institutions wish to monitor more points (energy, water, etc.) than they have in the past. Minimizing ductwork and piping distribution along with centralizing major equipment has typically provided the optimal cost-cutting solution.
CSE: What is the biggest challenge you come across when designing such projects?
Jeff Wurmlinger: When working on historic campuses, we often face land constraints, leading to building renovations rather than greenfield construction. This creates financial challenges, as project budgets typically do not prioritize applying funds to improving the envelope.
Matthew Goss: Working within existing spaces, dealing with infrastructure with limited room and phasing projects in an overall campus master plan or active campus site always present challenges. Projects must be designed to minimize disruption to campus activities as much as possible during construction.
Abdullah Khaliqi: The biggest challenge we encounter when designing
Matthew Goss, PE, PMP, CEM, CEA, CDSM, LEED AP
MEP + Energy practice leader
CDM Smith
Latham, N.Y.
Abdullah Khaliqi, PE, CPQ
Academic market leader
Fitzmeyer & Tocci Associates, Inc
Woburn, Mass.
Stephanie Lafontaine, PE, LEED BD+C
Lead mechanical engineer
RMF Engineering
Boston
John Mongelli, PE
Associate
Kohler Ronan Consulting Engineers
Danbury, Conn.
such projects is the electrical service size, which is a common limiting factor for renovation projects. Reducing gas-fired equipment generally means the heat load needs to be produced via electric heat, which may not have been factored into the original electrical service size. This necessitates upgrading the electrical infrastructure, which can be costly and complex. Additionally, incorporating energy-efficient systems and technologies requires careful planning to ensure that the existing electrical capacity can support the new demands without compromising performance or compliance with energy efficiency standards. Balancing these
Improving IAQ has
For today’s schools, indoor air quality can go a long way in impacting student health and performance. That’s why Carrier offers a full portfolio of solutions to help schools optimize learning environments with students, staff and sustainability in mind.
• Rooftop Units
• Air Handlers
• Chillers
• Variable Refrigerant Flow (VRF) Systems
• Building Automation and Controls
• Air Purifiers and Filters
• Service and Replacement Parts
• Equipment Rentals
From design to ongoing maintenance, Carrier will work with you to customize a solution to fit your school’s unique needs. Connect with us today to create better spaces for learning – and a better future for your students, staff and planet.
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requirements while keeping costs manageable is a significant challenge in renovation projects.
John Mongelli: Cost and the availability of electrical equipment, such as switchgear and generators, pose the biggest challenge today. This equipment can have lead times over 52 weeks. To address availability issues, the design engineer may need to make certain assumptions during the schematic design phase, often
before the program is fully developed. Ordering equipment this early in the process is inherently challenging.
CSE:How are engineering systems in university buildings designed to accommodate future expansion and adaptability?
Matthew Goss: Systems are being designed with the future in mind. We typically design systems with additional capacity or the ability to be expanded. For example, systems are being created so that they can be incorporated into or adapted for next-generation energy distribution systems.
Jeff Wurmlinger: The more information that a college or university can provide about future changes (such as growth, increased capacity or flexibility),
the more the team can tailor the design. However, we cannot broadly apply this approach to all projects, due to potential capital cost impacts. We strive to deliver the requested expansion and flexibility while sharing the cost benefit ratios to support the clients’ decisions. Modular designs in distribution, which provide space allowances, can use the overall system diversity to support flexibility. Additionally, modular capacity in equipment can allow for future expansion, increased capacity and enhanced reliability. cse
University insights
u University buildings should be future-proofed to account for changes in the student body and updated environmental goals.
u Challenges in designing these projects often come from space and time limitations, especially when retrofitting buildings.
The data center industry is poised for continued growth as technology advances and our dependence on digital infrastructure increases. Innovations in areas such as quantum computing, AI and 5G will likely drive even greater demand for data center services.
Data centers are critical
As a result, data centers will remain a critical component in the global technology ecosystem. The growth of data centers has had a significant impact on the HVAC industry. As data centers expand, the demand for sophisticated HVAC systems also increases.
Addison and United CoolAir products excel in data centers for our unmatched reliability, efficiency and redundancy features. Engineered to maintain precise environmental conditions,
Addison and UCA products ensure the uninterrupted operation of sensitive equipment. Our customizable options make them the ideal choice for safeguarding critical infrastructure.
Register to watch the webinar on-demand
We are excited to offer a webinar focused on the latest trends and advancements in data center HVAC systems. Join us to explore how Addison and UCA solutions can help meet your client’s needs more effectively.
This is a valuable opportunity to expand your knowledge of data centers while refining your sales strategies with the cutting-edge products from Addison and UCA.
Register HERE to watch the webinar or scan the QR code at right. Once you complete the registration form, you’ll receive an email with a link to watch the webinar on-demand.
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www.addison-hvac.com
www.unitedcoolair.com
Belimo is the global leader in the development, production, and sale of actuators, valves, sensors, and meters.
Belimo University offers comprehensive online and onsite training on HVAC fundamentals, as well as ways to optimize building performance.
• Online Learning Resources: unlimited access to a library of high quality, current, and engaging HVAC content. Registration is free and easy, allowing for on-demand training at your convenience. Create an account at belimouniversity.myabsorb.com
• Professional Development Hour (PDH) courses: available online, they qualify for continuing education credits for Professional Engineers (PE). All PDH courses have been pre-approved by the appropriate governing bodies. Go to belimo.com/e-newsletter to join our mailing list and learn more about future courses.
• Webinars: learn about Belimo’s latest products and tools, as well as ways to maximize your building’s performance. All sessions are recorded for future viewing and can be found on our website or the Belimo YouTube channel.
Belimo University offers both onsite and online courses on a variety of topics, including sizing and selection, mounting and installation, as well as building optimization.
• Onsite classroom training: led by highly skilled instructors offering hands-on interactive training, either at your facility or at Belimo. Connect and share experiences while expanding your skillset and knowledge. For more information, contact Bellimo at training@us.belimo.com.
• Belimo recently opened a state-of-the-art Customer Experience Center at its Americas headquarters in Danbury, Connecticut. Displays include the Demo Building, a 10´ x 40´ functioning model of a commercial building powered by its own air handling unit and mechanical room. Live demos are conducted where customers can observe real-time feedback to the BMS. To schedule a visit, contact your local Belimo representative.
marketing@us.belimo.com
Tel: +1-800-543-9038
www.belimo.com/training
Prometha® by Cleaver-Brooks transcends traditional monitoring tools by integrating People, Process, and Technology to enhance boiler operations. Unlike basic systems offering superficial trending and notifications, Prometha delivers actionable intelligence, supported by experienced local representatives poised to resolve operational challenges effectively.
Central to Prometha’s functionality is the Boiler Score—a unique operational health index that consolidates safety, sustainability, efficiency, and reliability into a single measure. This innovative feature prioritizes areas needing attention, facilitating efficient resource allocation and ensuring swift response capabilities.
Key features of Prometha include:
• Real-Time Insights and Historical Trends: Offers 24/7 access to operational parameters and alarms, fostering immediate awareness and providing long-term operational insights.
• Actionable Intelligence: Advanced data analytics transform raw data into meaningful insights, empowering operators to make informed decisions that optimize efficiency and equipment longevity.
• Comprehensive Support: Supported by Cleaver-Brooks renowned expertise, Prometha ensures users receive professional assistance and support, maximizing boiler efficiency.
Prometha ® provides enhanced visibility via a mobile app and online dashboard for the timely delivery of crucial analytics.
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prometha.com
Prometha complements existing Building Management Systems (BMS) or Distributed Control Systems (DCS), offering additional insights through a secure, encrypted channel. BMS and DCS systems typically only focus on immediate data, while Prometha analyzes patterns to proactively identify potential downtime risks. It provides enhanced visibility via a mobile app and online dashboard, designed to deliver crucial information to the right people at the right time. This approach ensures that operational decisions are informed, timely, and effective.
Explore how Prometha can transform your boiler operations by visiting prometha.com or contacting us at info@prometha.com Embrace a sophisticated solution designed to optimize your systems and secure operational success.
In today’s digital era, engineers know that absolute dependability of their data centers is essential. Downtime can disrupt operations, resulting in significant financial and reputational damage. As the world demands power that’s always on, designers, operators, and engineers seek 24/7 solutions that exceed their needs.
That is why Cummins Inc., as a leading backup power provider, works closely with the people operating the world’s most crucial data centers, aiming to give them absolute confidence in every aspect of their operations.
Discover the Cummins Generators at the Heart of Engineering Solutions
The Centum™ Series generator sets offer engineers consistent and dependable power, built for sustainability, efficiency, and flexibility. From unexpected power outages to natural disasters, Cummins’ generators can help engineers handle any challenge of the modern world and keep Data Center customers’ critical systems operational.
The Centum evolution continues with:
• Power Density: Compact generators specifically designed to deliver more power.
• Sustainability: Engineered for the next 100 years with sustainability and low emissions in mind.
• Right-Sized: Delivers exactly the right amount of power without compromise.
• Reliability: Designed, built, installed, and serviced by Cummins for rock-solid dependability.
• Affordability: A smaller footprint reduces installation, fuel, and maintenance costs.
Our end-to-end solutions encompass design, installation, maintenance, and support. Engineers can expect tailored solutions from a trusted partner that combines traditional and renewable energy sources for optimal efficiency and sustainability.
If you would like more information on how Cummins can support your data center needs, visit Cummins Data Centers and explore their detailed case studies – or just reach out for a conversation.
ClIC k or scan the QR code at right to learn more.
It is crucial to maintain a relative humidity level between 40% and 60% RH for a facility to function at its highest level of productivity while minimizing costs and meeting the needs of its users. Keeping the RH consistently within this range helps protect the quality of products and materials, ensures optimal equipment functionality, and safeguards occupant health.
Boiler steam is a valuable resource that can be repurposed to achieve precise and efficient humidification, offering a sustainable and cost-effective solution for optimizing operational goals in facilities. DriSteem offers advanced humidification solutions that convert boiler steam into clean, chemical-free steam, transforming it into a powerful tool for maintaining optimal humidity levels throughout a facility.
DriSteem’s Ultra-sorb® XV steam dispersion panels fit into air handlers and ducts, offering the industry’s shortest absorption distances. Whether connected to a boiler or a steam generator, these panels can be installed
(800) 328-4447
sales@dristeem.com
www.dristeem.com
within inches of downstream devices, ensuring minimal non-wetting distances and highly effective steam distribution. In an industry first, these panels also vaporize the dispersion-generated condensate and return pressurized condensate to the boiler without additional pumps, valves, vents, or controls.
If clean steam is your top concern, pair dispersion panels with the DriSteem STS® humidifier for maximum efficiency. The STS humidifier channels boiler steam through high-efficiency heat exchangers to vaporize clean, fill water into pure, chemical-free humidification steam. This process guarantees no boiler steam or chemicals enter the humidified space, preserving the building’s air quality while returning the boiler steam to the system for reuse.
DriSteem representatives offer experience and expertise in specifying humidification, dehumidification, adiabatic, and water treatment systems.
Contact your local expert and discuss your project’s humidity control needs at www.dristeem.com/get-in-touch-with-ahumidity-control-expert.
Scan the QR code to watch a video of these units in action.
The Fan Energy Index (FEI) is a powerful new tool to help engineers compare energy consumption between similar fan systems. Unlike past metrics used to measure fan energy, FEI takes the whole fan system into account, including belts, pulleys, motors, and VFDs.
A fan with a higher FEI uses less energy at the same duty point as a comparable fan with a lower FEI. Higher-FEI fans tend to be quieter and have a more forgiving selection point against unforeseen static pressure impacts in the field. Less power consumption also means lower operating costs and carbon emissions.
Greenheck’s eCAPS® online selection suite for engineering products includes AMCA-certified FEI ratings for hundreds of fan models, so you can see how Greenheck’s fans stack up against each other and our competitors.
Based on the project requirements you enter, eCAPS® provides a ranked list of products by performance and cost. Compare operating costs, first costs, sound levels and more, all on one screen. From there, you can share or print your selections, create schedules, and download drawings in 3D and 2D from AutoCAD® and Revit®
A small difference in FEI ratings can point to a significant difference between fans. Isn’t it better to see that difference right away?
CLICK here or scan the QR code below to start exploring Greenheck’s eCAPS®
As the urgency of addressing climate change grows, specifying engineers face the challenge of selecting fire suppression systems that meet both performance and environmental standards.
Janus Fire Systems’ FK-5-1-12 offers an exceptional solution. This clean agent not only delivers reliable fire protection but also aligns with global sustainability goals, making it a superior choice for modern applications.
FK-5-1-12 is engineered with the environment in mind. It has an impressively low Global Warming Potential (GWP) of 1—equivalent to that of CO2— and zero Ozone Depletion Potential (ODP). This makes it an environmentally responsible alternative to predecessor agents like Halon, which are known for their high GWP and detrimental impact on the ozone layer.
By choosing FK-5-1-12, engineers can significantly reduce the environmental footprint of their projects while maintaining compliance with stringent international regulations, such as those set by the NFPA, particularly NFPA 2001, EPA’s SNAP program and the European Union’s F-gas regulations.
Beyond its environmental benefits, FK-5-1-12 is highly effective and safe. It quickly extinguishes fires without leaving residue and minimizing vital
equipment damage making it ideal for protecting sensitive electronics and valuable assets to ensure business continuity. Its non-toxic nature ensures safety for occupants, allowing it to be used in spaces where people may be present during discharge. Additionally, FK-5-1-12 supports green building initiatives, contributing to LEED certification and helping projects achieve sustainability targets.
By choosing FK-5-1-12, engineers are not only specifying a high-performance fire extinguishing system but also contributing to global efforts in combating climate change, ensuring a safer and more sustainable future.
janusfiresystems.com
Lennox is helping you prepare for HVAC projects in 2025 and beyond with everything your team needs to stay informed and competitive. Meet new requirements without skipping a beat. Lennox equipment is designed to meet updated codes and regulations. We’re introducing new products, including more heat pumps and dual fuel options, while adjusting our product nomenclature, allowing you to easily tell whether a piece of equipment contains Low GWP refrigerants. We’re meeting the needs of a changing industry so you can minimize disruption and convert with confidence.
Our new design maximizes safety and minimizes complexity while meeting updated building code requirements.
As part of the transition to Low GWP refrigerants, HVAC equipment must be updated to include additional safety features, like a refrigerant detection sensor. Lennox goes a step beyond to maximize safety minimizing complexity. Our proprietary leak mitigation system delivers peace of mind with the same service and efficiency you expect.
Our strategy is simple. We’ve added a sensor, a blower-proof switch, and advanced controls to ensure your equipment will operate safely. These components together allow us to mitigate the risks associated with A2L refrigerants.
Mitigation occurs in one of two states: when a sensor needs service or when a sensor detects a leak. When a leak is detected, the unit immediately disables, the blower activates and alerts the occupant. Once the refrigerant concentration reduces below lower flammability limit (LFL), the unit resumes regular operation. We provide blower-proving functionality to ensure blower operation when servicing demands. Our mitigation strategy fully complies with UL 60335.
Consider the alternative to “Rip and Replace” with “Retrofits and Retrofills” instead!
If your existing switchgear power lines and enclosures are in good condition, upgrading your breakers to modern ones can be a sensible choice!
Here’s why :
Retrofits: Typically associated with Air Circuit Breakers (ACBs), retrofits are pre-engineered solutions. A skilled service provider can remove the old ACB or Switch, lock the rack, and install a new rack and breaker in just a few hours. Retrofits are available for many brands and capacities of breakers from various suppliers.
Retrofills: Generally referring to Medium Voltage Vacuum Circuit Breakers, (MV VCBs), retrofills
require the bus structure to be engineered. This might necessitate two shutdowns: one for measurements and another for installation. However, companies like a March Equipment (based in the Cincinnati area), can accomplish this in a single shutdown by measuring and fabricating the bus on-site. Even with two shutdowns, the time required can faster than waiting on new switchgear.
The benefits of these approaches are numerous. You may only need one shutdown, and the entire
process is much quicker than removing the old gear and bringing in the new. Sometimes walls may need to be removed to get the new gear into an older facility.
Lastly, the overall cost is usually less than new gear. When you factor in the time savings, it becomes an attractive option. So, rethink your strategy and consider the benefits of retrofits and retrofills!
When it comes to speccing out steam needs for your clients, Miura is the engineer’s go-to solution.
Our modular steam boilers are designed to meet the demands of any project, offering unmatched reliability, safety, and energy efficiency. Whether you’re working on a large industrial facility or a smaller-scale operation, Miura’s compact design ensures that our boilers fit seamlessly into your plans.
Miura boilers are not only easy to install and maintain, but they’re also engineered to maximize uptime and minimize fuel consumption, making them the smart choice for any engineer focused on delivering top-notch results.
Plus, with their quick start-up capabilities and ability to run at peak efficiency, Miura boilers help you stay ahead of deadlines and within budget.
From energy savings to unparalleled performance, Miura’s steam boilers are built with engineers in mind, ensuring your clients receive the best in steam technology. When you spec Miura, you’re choosing a partner that prioritizes efficiency, innovation, and sustainability— qualities that make Miura the top choice for engineers across America.
Our sales engineers are experienced in building out complete steam systems and are ready to work with you.
We’ve got all the technical resources you need at www.miuraboiler.com
Integrating Noritz BIM files into your projects is crucial for achieving exceptional efficiency and reliability.
Our comprehensive BIM resources streamline your design process, ensuring that each tankless water heater system fits your project’s specific needs.
Whether for residential or commercial applications, these BIM files provide essential data to create effective and efficient heating solutions. Enhance your project efficiency and stay ahead by incorporating Noritz BIM files into your workflow.
Elevate your design process with Noritz’s detailed Building Information Modeling (BIM) files, available at www.noritz.com/bim
These files integrate smoothly with your design software, simplifying the creation of accurate and efficient tankless water
heater systems. The ease of access allows you to tailor designs precisely to your project requirements.
Complement your design expertise with our self-paced training resources at www.training.noritz.com. Our platform offers video modules suited to various experience levels, from beginners to advanced professionals. This training supports your continuous learning and ensures you can effectively integrate Noritz technology into your projects.
In the world of engineering, continuous learning is essential for career growth and stability. That’s why Pentair offers learning opportunities through Pentair Pump Room Online, our digital training platform, tailored specifically for our Pentair Aurora, Fairbanks Nijhuis, Hydromatic and Myers pump brands.
Designed to help engineers enhance their knowledge and skills, Pump Room Online offers on-demand training courses covering Pentair products and general water movement principles. Whether you want to revisit pump and hydraulic fundamentals or delve into more advanced pump system topics, Pentair Pump Room Online can be a helpful resource.
Create your free Pump Room Online account today by scanning the QR code below and using the exclusive promotional code Pent0004 when registering.
The platform is accessible from anywhere with an internet connection, making it convenient for
engineers worldwide to benefit from high-quality, flexible learning opportunities. We aim to provide a resource that supports continuous learning and contributes to your professional growth.
Not quite ready to jump into training just yet, but still intrigued by all the incredible things Pentair is achieving? Do not miss out—make sure to subscribe to our Pentair Pump Room YouTube channel! There you will find informative and educational videos showcasing our unique capabilities, brands, and exciting commercial, industrial, and infrastructure projects.
Scan the QR code at right to visit the Pentair Pump Room YouTube Channel.
Big regulatory changes are becoming the norm. Rheem takes a proactive and agile approach to preparing for the future and can help you stay on top of ongoing trends. Here are the three most important topics the HVAC industry needs to be aware of:
New Energy Efficiency Standards
• In 2025, M1 will cover three-phase systems under 65k btu/h and threephase VRF rated less than 65k btu/h
• In 2029, the minimum efficiency requirement for all large commercial baseline equipment will change from 28% to 35%
Low-GWP Refrigerant Transition –
EPA’s 700 GWP limit
• Compliance date is Jan. 1, 2025, for ACs and HPs
• Sell-through periods vary by system type (split vs. packaged)
Ongoing Decarbonization Efforts – the Shift to Carbon Neutrality
• Many countries are targeting 2050 as a neutrality deadline
• State and local trends show a shift toward all-electric policies
Positioning the Industry for the Future, Today
Rheem understands that engineers need clear and actionable information in this dynamic environment of regulatory changes at the local, state, and national level. we are committed to being a trusted partner that advocate for the needs of the industry while designing compliant solutions without compromising quality. As a leader in the industry with ambitious sustainability goals of our own, Rheem will continue to engineer innovative products that continue to deliver the ideal mix of comfort, profitability and dependability—all while helping protect the environment.
2025 AHR EXPO .4 .www .ahrexpo .com
ADDISON .25, 45 .www .addison-hvac .com/data-centers
AGF Manufacturing, Inc .27 .www .agfmfg .com
BELIMO .C-2 www .belimo .com
BERNER AIR CURTAINS .35 .www .Berner .com
Carrier .48 .www .carrier .com/k-12
CDM Smith .64 .www .cdmsmith .com/en
CHAMPION FIBERGLASS .26 .www .championfiberglass .com
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.C-3 www .cleaverbrooks .com
Cummins .C-4 www .cummins .tech/csejulyaug24
Eaton .6, 8 .www .Eaton .com/microgrid Greenheck .11 .www .greenheck .com
Hammond Power Solutions .33 .www .hammondpowersolutions .com
Industrial Cybersecutiy Pulse .63 .WWW .ICSPULSE .COM
LS Electric America, Inc .12, 13 .www .lselectricamerica .com
Navien, Inc .1 .www .Navien .com
Pentair Flow Technologies .39 .www .pentair .com
Pritchard Brown .63 .WWW .PRITCHARDBROWN .COM
Ruud Commercial Air .2 .www .RuudCommercial .com
Tjernlund Products .64 .www .tjernlund .com
ULINE . . . .34 .www .uline .com
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The CBEX-3W Firetube Steam Boiler has the high ef ciency needed to reduce fuel usage and minimize emissions. The integral head burner and integral economizer provide a smaller boiler footprint to save space and reduce installation costs.
The Prometha Optimize Plan provides real-time insights into boiler status and performance, helping quantify your investment, maintain ef ciency, and support sustainability goals all while optimizing your boiler room.
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Cleaver-Brooks recognizes the crucial role of having access to spare parts. With a vast inventory of ready-to-ship parts, we have a specialized Genuine Spare Parts Program available to help keep your boiler room up and running.
We understand the challenges that data center and mission critical operators face. Get industry-leading power technology built with sustainability in mind with the approved use of alternative fuels such as HVO. Get up to 90% reduction in GHG without compromising performance with the award-winning Centum™ Series, powered by the fail-safe QSK78 engine. For your most critical applications - switch on sustainability. And keep it on
