RSES Journal Winter 2025, RETA-RSES

Commercial & Residential Winter Maintenance 10 Understanding Airflow Tools 14 Primer on Electrical Schematics 18 Thermal Energy Management 26 Boiler Maintenance Essentials 36

WINTER 2025 • rsesjournal.com • $5.95

AHR GOES TO VEGAS

Odds are good that the 2026 AHR Expo is being held amidst more HVACR industry turmoil than ever seen before. Pg. 22

We’ve put it all in one place

FEB 2-4 2026

VEGAS

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10

FEATURES 08 “Safer” Refrigerants Revisited Leak detection and safe handling practices are as important with alternative refrigerants as with the refrigerants they are replacing.

10 Optimizing AHU Performance with Winter Maintenance Air handling units play a vital role in commercial building performance—from supporting energy efficiency to enhancing indoor air quality and maximizing occupant comfort. That is why it is critical to keep them running properly. 13 Next-level Maintenance Drives Winter Residential Heating Success Proactive maintenance is essential to avoid breakdowns in the coldest months. 14 Proper Use of Airflow & Air Velocity Measuring Instrumentation Use of airflow measuring instruments brings with it key protocols and best practices. 18 Charting a Service Path with Electrical Schematics Quite often, an HVACR equipment problem turns out to be an electrical problem. Electrical schematics serve as maps to assist HVACR technicians trying to solve any number of HVACR system failures. 22 2026 AHR Expo: HVACR at Many Crossroads The issues facing the HVACR industry are invariably connected, and they all intersect at the AHR Expo. 26 Thermal Energy Management: Smarter Cooling Strategies for Modern HVACR Systems Expanding needs for superior energy management strategies have increased the demand for thermal energy management systems, a technology that continues to offer energy efficiency solutions. 32 Small Diameter Copper Tubes Offer Design, Supply Chain and Performance Benefits Not only do they use less raw material, they use less raw materials and enhance heat transfer when produced with inner grooves. 36 How to Approach Preventive Boiler Maintenance The work a technician performs on a commercial boiler establishes that technician as the caretaker of record for that system. It is a large responsibility and one a technician should only accept if properly licensed and insured.

VOLUME 30 • NUMBER 3 • WINTER 2025 covering heating, ventilation, air conditioning and refrigeration

PERSPECTIVES 04 Leading Off 05 Heating Up 38 Shade Tree Mechanic 39 Last Word

WHAT’S NEW 06 Field News 28 RSES/RETA News 34 Products

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Leading Off

An Exciting Year Awaits

PERSPECTIVES

I want to begin my first President’s Message by saying that I am extremely humbled and honored to have been selected to lead our organization. Never in my wildest dreams did I think that I would be sitting here today writing this column. As I mull over what I would like this upcoming year to look like, I want to take a minute to honor several of the largest contributions that former Executive Director Jim Barron made to this organiza tion. First, he was the catalyst that made RETA the only ANAB accredited refrigeration organization in the world. Without him, RETA’s credentials would be just another piece of paper. Second, as Executive Director of the organization, he led us through the first years of self-management, establishing policies and building a strong financial foundation for our organization. The financial restraint that Jim demonstrated over the years enabled RETA to not only purchase a building for its headquarters, but to pay it off. Finally, he was instrumental in helping RSES adapt and survive such that our two organizations could begin the process of becoming one again. Thanks to Jim’s contributions, RETA is ready to break out of the mold of an industrial trade organization. With our training materials and ANAB accredited exams, we can lead the way in addressing the manpower shortages that the industrial refrigera tion and HVAC/R industries face. Before that can happen, we must finish what we started in integrating RETA and RSES. The goal for this year is to complete the financial integration of the two organizations. By this time next year, we will have one set of general ledger accounts showing one set of numbers for our entire organization. Another goal for this year is to identify all of the moving pieces that need to be addressed to integrate us organizationally, from membership benefits, to chapters, to logos and everything in between. With all these pieces, it is unlikely that organizational integration will be completed within the next year. That being said, HQ has been challenged to establish a timeline for completion before the end of May demonstrating when we will see our two great organizations as one. In April, the board, along with the HQ department heads, will spend three days focusing on strategic planning. Out of that will

come a 1-year, a 3-year, a 5-year, a 10-year and a 15-year plan for the organization. These plans

will become the roadmap for our organization moving forward. Each year, the board and HQ staff will be charged with reviewing and tweaking the routes to get us to our goals. As I mentioned during my address at conference, this will take a lot of outside the box thinking. I am excited to say that many of the committees are already demonstrating this. For instance, the Marketing Committee is pursuing the establishment of a RETA RSES podcast to reach a wider audience than just our membership. The Education Committee is evaluating a new structure for our educational materials that will streamline the process of establish ing them as an international resource. The Conference Commit tee is looking at the possibility of holding regional conferences to attract more people, many of whom do not have the support of their companies when they attend. The Membership Committee is working on establishing new member benefits. The Certifica tion Committee is hard at work in the process of developing an exam for the Book 1: Introduction to HVACR that was recently published. In addition, the CRES exam is due for a rewrite using the RETA Energy Efficiency book which did not exist when the exam was created. Also, the RAI exam is due for a refresh in order to pull in content from the CRST exam, which also did not exist when the RAI exam was first developed. All of this will require a lot of manpower. The easy answer is to hire more people. Our new Executive Director, Vern M. Sand erson, is already evaluating the staffing needs. However, one of RETA’s longtime strengths has been its volunteer base. Our orga nization cannot survive, much less thrive, without the contribu tions of our volunteers. So, we need your help. To paraphrase the late President John F. Kennedy, “Ask not what your association can do for you, ask what you can do for your association.”

Bill Lape, CARO, CIRO, CRST RETA-RSES International President

RETA HQ 844-801-3711 info@reta.org RSES HQ 800-297-5660 general@rses.org Vern M. Sanderson Executive Director, RETA/RSES vern@reta.com Lori Schiavo Senior Director of Operations, RETA/RSES lschiavo@rses.org Chantell Schaumburg HR Manager/Controller, RETA/RSES chantell@reta.org Larry Copeland Customer Service Rep., RSES lcopeland@rses.org

Stephanie Date Events Manager, RETA/RSES stephanie@reta.com Dan Denton Chapter Relations Liaison, RETA dan@reta.org Allie Dulabaum Assistant Editor, RETA/RSES adulabaum@rses.org Kali Grigorica Marketing and Communications, RETA/RSES kali@reta.org Halie Hugenberg Training/Testing Coordinator, RSES hhugenberg@rses.org Samantha Ibarra Certification Coordinator, RETA samantha@reta.com

Winter 2025, Volume 30, Number 3

© 2025 Refrigeration Service Engineers Society www.rsesjournal.com • general@rses.org

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Heating Up

PERSPECTIVES

A Big Year, with More in Store

A s the year draws to a close, this is the traditional time of reflection for the year ending and for planning of the year ahead. 2025 The RETA-RSES family has had a big year. We have just concluded our most successful Conference ever. Thanks to all who attended and took advantage of the Conference had to offer. After an extensive vetting process, our new compliance guide for implementers has been released. We believe it is the best we’ve ever published; and we are anxious to get your feedback. HQ has moved our publication resources to a centralized loca tion. Cutting some of the outside publication costs allows us to bring more information to Membership at the same price point. We also reflect on President Gulcynski’s year at the helm of our organization. Dave has led us through many changes over the past year. Few understand the work that is needed from our President up to, during and after their presidential year. I wish to thank Dave for his past and future service. 2025 saw the retirement of long-time Executive Director Jim Barron. Jim served our country as a member of the armed forces before becoming a refrigeration professional in private indus try. Jim dedicated himself to our industry, becoming one of the select few to wield the RETA President’s gavel. When RETA needed an Executive Director to lead the self-management transi tion, Jim, as always, answered RETA’s call. He led the business of the organization through that transition and beyond. He led through the initiation of the RETA-RSES merger, working tire lessly with both sides of the organization to bring alignment. His list of accomplishments in his various RETA-RSES roles is longer than my short article can convey. We thank him for his

service, wish him an enjoyable retirement, and send our prayers for a long and happy life. After the retirement of Executive Director Jim Barron, Don Tragathon returned to the Executive Director’s role on an interim basis. Don has served the organization for decades in various roles, including an earlier tenure as Executive Director and a term as President of the organization. To me, Don will always be remembered as a member of that special officer core that saved RETA from oblivion two decades ago. Planning for 2026 Our newly elected leadership has been sworn in, and they are ready to move the organization forward. President Lape has assumed the gavel and will lead our vision for 2026. At HQ West and HQ Central, we will continue to build constructive collaboration between our traditional RETA and RSES assets, always keeping our mission at the forefront of our thoughts and actions. We appreciate you, our dedicated members. Without you, nothing we do would have meaning. Thanks for being a member of the RETA-RSES familiy.

Honored to be your Executive Director!

Vern M. Sanderson Executive Director RETA-RSES

Cadie Johnson Admin./Conference Assistant, RETA cadance@reta.org Jason Kenny Production Specialist, RETA/RSES jkenny@rses.org Lupe Lopez Education Support Specialist, RETA/RSES lupe@reta.org Eileen Lundin AP/AR Specialist, RSES elundin@rses.org Brenden Lurie Member/Chapter Relations Rep., RSES blurie@rses.org Terry McIver

Scott Melton Education Coordinator, RETA/RSES scott@reta.com Mitzy Osgood Admin./Membership Assistant, RETA mitzy@reta.org Kim Turner AP/AR Specialist, RETA kim@reta.org

RSES Journal will soon be available again at an annual subscription rate of $54 for U.S. residents; $72 for Canadian addresses; and $78 for all other international locations. RSES Members receive RSES Journal automatically as part of their annual dues ($24 of total dues). Articles and materials published in RSES Journal reflect the views of their authors and do not necessarily represent official positions of RSES or its membership. RSES neither supports nor endorses particular products or services. RSES Journal (ISSN 1085-0538) is published by the Refrigeration Service Engineers Society. Please send all correspondence related to editorial/advertising/reprint requests or permission to photocopy to: PO Box 248, Arlington Heights, IL 60006-0248, general@rses.org. Periodical Postage paid at Arlington Heights, IL, and at additional offices. POSTMASTER: Send address changes to: RSES Journal , PO Box 248, Arlington Heights, IL 60006-0248.

Editor, RETA/RSES tmciver@rses.org

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In The Field

Compiled by Terry McIver

2025-26 BOARD OF DIRECTORS Chairman of the Board David Gulcynski, CRES, CIRO Dot Foods, Inc National President Bill Lape, CARO, CIRO, CRST SCS Engineers Executive Vice President Ray Urban Jr, CARO Lineage Logistics Treasurer Jeremy Murfin AC&R Specialists Second Vice President Melissa Cassell General Refrigeration Company Board of Directors Jeremiah Armstrong Brakebush Brothers Dale Clinton, CIRO, CRST Stellar Jason Daniel, CIRO APSM Mike Davis Republic Refrigeration, Inc John Farnham Meier Supply Ron Fetterley, CARO, CIRO, CRST APCCO Jayson Goff, CMS CoolSys C.I.S. Rich Hoke, CMS Retired Brandon Jones, CARO Tyson Foods, Inc. Eric Kaiser TruTech Tools, Ltd Casey McConnaughy Bosch Home Comfort Group Mike Missall, CARO Summit Refrigeration Group

Copeland Canada Welcomes 60 to Apprentice Day Event C opeland Canada held its seventh Annual Apprentice Day event

on September 27 at Cope land’s Integrated Learn ing Centre in Brantford, Ontario, Canada. Copeland Canada’s Apprentice Day was devel oped as a response to the

Nearly 60 apprentices, 20 industry sponsors and Copeland team members were in attendance at Copeland Canada’s Apprentice Day.

systems. Apprentices and students had the opportunity to network with indus try professionals and leaders, gain valuable insights and make connections to help advance their careers. “Apprentice Day is about more than just training; it’s about investing in the future of our industry. Attendees have chosen an industry with a bright future, which deserves our recognition,” said Ryan Garrah, Vice President for Cope land in Canada. “The fact that this event sold out so quickly shows just how committed apprentices are to building

HVACR industry’s ongoing shortage of new technician candidates. The objec tive is to help strengthen the future of the HVACR industry by fostering innovation and skills development. In a news release, Copeland sources cited data that estimates there to be about 42,500 HVACR job openings each year. Sources described the event as an immersive and interactive experience for HVACR apprentices, students and future industry leaders designed to enhance their understanding of the industry through hands-on learning and expert-led discus sions. The day included Copeland compres sor troubleshooting, Vilter industrial compressor technology and Copeland refrigeration and building management

their careers and how much enthusi asm there is for learning from industry leaders. Copeland is excited to invest in these apprentices to support the growing need for skilled workers in the HVACR trade.” Bryant Marks 10 Years of “Bryant Women in HVAC” B ryant Heating & Cool ing Systems recently celebrated a decade of “Bryant Women in HVAC,” a career support initiative

that has empowered women across the heating and cool ing industry since 2015. The theme for this year’s recognition was “Own the Momentum,” as a tribute to the progress that has been made by women throughout the HVAC industry, and an encouragement for women to keep moving forward in achieving career goals. There are currently 829 women in

Attendees for Bryant’s recent “Bryant Women in HVAC” event.

Jodie Rukamp SCS Engineers Gary Struhar, CMS Retired Nate Torres, CARO Resource Compliance Harrison Travis, CMS Retired

the Bryant network, united by a shared commitment to leadership, growth and community. The “Bryant Women in HVAC” annual event features keynote speakers, breakout sessions, peer panels, and roundtable discussions designed to foster leadership and personal growth.

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Daikin Applied Begins Laboratory Construction

RectorSeal Acquires MARS Parts T ools and accessories manufacturer, RectorSeal, has acquired MARS Parts, composed of both Global,

MARS supplies premium motors, components, and service parts for the HVAC aftermarket and leading origi nal equipment manufacturers. Global has driven innovation in the HVACR space, introducing products such as the Turbo200 Universal Capacitor and AmRad Capacitors. The Source is Motors & Armatures, Inc.

the Source, and MARS's parts and acces sories division. The acquisition broadens RectorSeal’s offering of high-performance components and further strengthens its commitment to delivering innovative technologies and reliable solutions for the professional trades.

Craig Childress Wins National HVAC Competition F or the third consecutive year, Craig

get my hands on and attended as many in-person trainings as possible. That drive to learn and grow has stayed with me ever since.” Childress said he found the diagnostics portion of the compe tition to be the greatest challenge.

D aikin Applied recently announced it will build a research and develop ment testing laboratory at its Plym outh, MN, headquarters. The team has begun phased commis sioning of nine test cells, with full facility completion and opening planned for 2027. The 71,000 sq. ft. lab will advance product innovation for data center cooling by repli cating the operating extremes of modern hyperscale environments. Four test cells will also focus on next-generation airside tech nologies to address emerging market trends and evolving customer needs. This expanded capability will further support product development across Daikin Applied’s tradi tional cooling and heat pump segments.  and for my future in the field. What I appreciate most about my career is that it’s one where I’m always learning. The manufacturers are always changing and updating the equipment, and the industry changes its regulations, so I’m continu ously learning new things every day, which is really exciting.” Reeser said the most challenging part of the competition was going up and down on the stand with the heat recovery venti lator. “Cutting the pipe and installing it was easy. It was the up-and-down that was the difficult part,” said Reeser. Reeser was followed by Kirby Hess of Flora, IN, who received a $10,000 prize, and Nathaniel Magner of Boston, VA, who placed third, for a $5,000 prize.

Childress took first place in the profes sional division of the 2025 ServiceTitan HVAC National Championships powered by Trane and American Stan dard Heating and Air

Craig Childress

Conditioning. The Massachusetts-based plumber rose above his competitors in a series of head-to-head challenging and skill-testing events in the annual competi tion, and won a $40,000 prize. Childress competed alongside nine other professionals in the final rounds of the championships, conducting diagnos tics checks and installing Trane residential equipment in an intense, fast-paced envi ronment that demonstrated their precise skills, excellent service and unparalleled knowledge in HVAC. Childress told RSES Journal he began his career in the trades as a plumber while attending a vocational high school. He then began a course in HVAC. “After a decade in plumbing, I had the chance to take an accelerated two-week HVAC training program at Ultimate Technical Academy in Arkansas. This was a unique opportunity that opened a new career path for me,” Childress said. “When I returned to the company I was working for, I was responsible for launch ing an HVAC department. There was a lot for me to learn in a short period of time. I read every HVAC book I could

“They created fully-functional Trane equipment setups for us to troubleshoot. What made it even more interesting was how they tailored the difficulty based on whether it was the professional or appren tice competitions. It was a great way to incorporate service into the finals and make the competition very well rounded,” said Childress. Alex Ivey of Ocean Springs, MS, was the runner-up in the Professional Division, and he received a $15,000 prize, followed by Scott Savidge of Pavilion, NY, who placed third and pocketed $10,000. In the apprentice division, Braden Reeser of North Platte, NE, battled against nine competitors and took first place, with a $20,000 prize. Reeser told RSES Journal he entered the HVAC industry upon graduating college in 2023. He received his train ing at Mid-plains Community College in North Platte, NE. He chose HVAC because he saw it provided long-term career opportunity. “AI is a concern for many in the work force, but HVAC needs a human element, so I felt confident going into this career 

WINTER 2025 RSES Journal 7

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“SAFER” REFRIGERANTS REVISITED

Leak detection and safe handling practices are as important with alternative refrigerants as with the refrigerants they are replacing.

BY BILL LAPE, CARO, CIRO, CRST

O n Tuesday, October 17, 2017, three people died due to an ammonia leak at an ice rink in Fernie, British Columbia, Canada. While the Fernie inves tigation 1 was still ongoing there were calls to replace all ice rink ammonia refrigeration systems in Canada with "safer" alternatives. Since the Fernie incident, there have been several additional fatal accidents involving ammonia refrigeration systems, including the Lineage Logistics inci dent in Statesville, NC, U.S. in January 2020, and the Arctic Glacier incident in Kamloops, British Columbia, Canada, on May 26, 2022. These continuing incidents only serve to increase the calls for “safer” refrigerants. Several articles found on the internet point to Freon refrigerants as a safer alter native. But, what the articles fail to point out is that not only are these refrigerants being phased out, but that they too have their own inherent risks. Chlorofluorocarbon refrigerants are being phased out as part of the 1987 Montreal Protocol due to their tendency to deplete the ozone layer. Hydrofluoro carbons, or HFCs, are being phased out due to their "Global Warming Poten tial," or GWP, as part of the Kyoto Protocol. Safety Applies to All Gases Ozone depletion and global warming are broad, long term, risks, however, refrig erants continue to pose more immedi ate risks. While not caustic like ammonia, CFCs and HFCs will, like ammonia, cause frostbite on bare skin. When exposed to high temperatures, CFCs and HFCs will decompose into toxic byproducts, including halogen acids such as hydrofluoric acid.

While the exposure limits for these refrig erants are significantly higher than ammo nia, they will displace oxygen with no warning outside of specialized sensors. There have been documented cases of deaths due to asphyxia from entering a space where a CFC or HFC refrigerant leak was occur ring. 2 This is perhaps the most critical safety concern with these types of refrigerants. Some of the newer refrigerants taking the place of CFCs and HFCs have odors to indicate a leak, but the majority of them are moderately to highly flammable even at low airborne concentrations. This makes leak detection and mitigation all the more critical. Carbon dioxide, while not toxic or flammable, also displaces oxygen and is undetectable without sensors. Carbon diox ide systems also operate at much higher pressures than other refrigerant systems, which can lead to other hazards, such as catastrophic ruptures, if unproperly maintained. Many of the new Hydro-Fluoro-Olefin (HFO) and Hydro-Chloro-Fluoro-Olefin (HCDC) refrigerants are both moderately flammable and have possible long term envi ronmental and health effects. The HCFO and HFO refrigerants decompose rapidly in the atmosphere, resulting in little to no buildup in the atmosphere, thus having a substantially lower ozone depletion potential than traditional CFC and HCFC refriger ants. However, some of the chemicals that these new refrigerants break down into, such as trifluoroacetic acid (TFA), are toxic to aquatic life; and its effects on humans has yet to be fully understood. It is also important to note that TFA is classified as a “forever” chemical by some agencies in the same class as PFAS (Per- and Polyfluoroalkyl Substances). The long-term health effects of

PFAS exposure are only now being publicly recognized after 50 years. Responsible Stewardship a Safeguard Regardless of the refrigerant used, there will always be hazards associated with their use. The only true safeguards are proper system design and installation, allocation of sufficient resources for proper opera tion and maintenance of the system, and proper training in safe system operation, system maintenance and leak response. This includes proper training in a facility's emer gency action plan, not only for employees, but also for visitors. In an industrial setting, facilities always try to educate their visitors on the emer gency action plan. What about non-indus trial facilities? Do these facilities explain to visitors what the facility alarms are and what to do when they go off, or is the expectation that they will read the sign next to the alarm (if there is one) and do what it says? When training is insufficient to the point that someone gets burned trying to siphon an ammonia-water mixture by mouth, 3 one has to wonder if training will be sufficient such that no injuries or fatalities will occur with these "safer" refrigerants. Bill Lape is a Project Director for SCS Engi neers. Bill is a Certified Industrial Refrig eration Operator, a Certified Refrigeration Service Technician, and the current Presi dent of RETA-RSES. This article appeared in the July 2018 edition of Psiktikos and the Jan.-Feb. 2018 edition of the RETA Breeze. 1 Fernie-Investigation-Report-TSBC.pdf. 2 https://bit.ly/3WwbBcV; https://bit.ly/refrigaccident 3 https://bit.ly/ammoniaincidents

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BOOK LAUNCH

THE FOUNDATION TO YOUR HVACR FUTURE

Contents include: • Fundamental safety requirements for HVACR professionals • Details for basic installation of HVACR equipment • Deeper dives into heating and cooling systems • & much more!

Printed version or eBook available on our website!

Want more info? Call 800-297-5660 • Email general@rses.org • Visit www.rses.org

Optimizing AHU Performance with Winter Maintenance

Air handling units play a vital role in commercial building performance—from supporting energy efficiency to enhancing indoor air quality and maximizing occupant comfort. That is why it is critical to keep them running properly.

BY MARK MILLER & JEREMY FITZE

A s the airside portion of many commercial heating, ventilation and air conditioning systems, air handling units (AHU) condition and circulate ventilated air through the build ing’s duct system. The equipment pulls in return air from the conditioned building through the return duct system or plenum. Depending on the design, return fans can help to recirculate a portion of the return air back to the AHU, while the exhaust system removes the remainder from the building. A portion of that exhaust air may then be exhausted from the building through exhaust dampers or fans to help maintain proper building pressure and indoor air quality (IAQ). The AHU introduces outside air through a series of modulating dampers, mixing it with the return air in a mixing plenum, and then passing it through a filtration system. Filtered air is then heated and/or cooled, often by a chiller, boiler, or variable refrig erant flow (VRF) system, where humidity levels may also be adjusted, and then finally distributed through the building via supply fans. Economizers may also be integrated to enable energy-efficient free-cooling when ambient conditions are suitable. Proper equipment maintenance is key to ensuring optimal AHU performance, espe cially when the equipment is located on the

Photo courtesy Johnson Controls/YORK.

roof where it can be exposed to extreme weather conditions, outdoor contami nants and debris. A proactive maintenance approach can help ensure proper airflow is maintained while mitigating premature system wear and unplanned downtime. Although maintenance protocols can

vary based on geographic location, appli cation requirements and manufacturer’s guidelines, the winter season is an ideal time to prioritize AHU service. Making the Case for Maintenance Winter can be especially taxing on roof

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THE FIRST SIGN OF AN UNDER

top equipment like AHUs. Extreme temperatures can interfere with mechanical components, causing dampers, coils or condensate drains to freeze. Cold air and accumulated ice or snow can disrupt airflow. The first sign of an underperforming AHU is often noted by building occupants who may report temperature swings, reduced airflow or a “stuffy” feeling within the building. If neglected, these condi tions can lead to unhealthy IAQ levels, which can decrease productivity and increase the spread of illness-causing airborne viruses and bacteria. As performance slippage progresses, operators may notice longer HVAC system run times, higher motor amper age, frequent cycling and a decreased ability to meet design setpoints. Exces sive fan noise, increased vibration, signs of water and building automa tion system (BAS) alarms may also follow. As these issues escalate, they often manifest in the form of increased energy consumption and rising operat ing costs. In fact, the Department of Energy estimates that organizations can save as much as 20% in operational expenditures by following a preventa tive HVAC maintenance schedule. 1 Winter Maintenance Best Practices Referring to the original equipment manu facturers’ (OEM) installation, operation and maintenance literature and recom mended schedule is a critical first step before beginning service. Additionally, ASHRAE Standard 180 for Inspection and Maintenance of Commer cial Building HVAC Systems provides an excellent baseline of best practices. ASHRAE Standard 62.1 is also a valuable resource for AHU operations as it outlines "Ventilation for Acceptable Indoor Air Quality". If service is related to a system issue, running recent performance and fault reports from the BAS can help identify trending issues and prioritize work based on concerns. As technicians develop their AHU winter maintenance protocols, the follow ing key steps can also be helpful:

5. UV Lights and Humidification— Replace UV bulbs following the manufacturer’s recommended replacement schedule, then test safety switches and controls. Ensure the humidification distribution is clean and undamaged, then test the safety and operation of the steam supply system. 6. Controls and Sensors— Check cali bration of temperature and humid ity sensors, exercise dampers and actuators, validate safeties and review setpoint schedules. 7. Airflow and Performance Verifica tion— Measure static pressures, airflow and supply/return tempera ture differentials and compare the outcomes to design and baseline readings. 8. Final Startup and Documentation— Confirm BAS communication, store trending data, complete main tenance log and provide recom mended next-step items. Safety During AHU Service Safety and preparation are the highest priority for any maintenance practice. When accessing rooftop equipment during winter conditions, first confirm the area is free of weather-related hazards such as ice or snow accumulation. Most Occupational Health and Safety Admin istration (OSHA) standards require fall protection for sites that are at least six feet above ground level. Requirements may vary depending on the location of equipment, so it is important to evaluate the build ing’s safety systems, including guardrails, and plan accordingly. Additionally, some equipment and maintenance materials may require rigging to be arranged. Performing proper lock-out/tag-out (LOTO) procedures is a critical step that must be taken before beginning service. During this process, technicians should ensure control power, fans, heaters and variable frequency drives (VFDs) are de-energized and cannot be turned on during service. Insulated tools should be used during LOTO or when equipment cannot be de-energized. Personal protec

1. Inspection and Verification— Visually inspect the condition of the equip ment’s exterior, access panels, elec trical panels, control panels, hoods, roof and door seals. Verify motor and alignment, vibration baseline and belt condition. 2. Air Filtration and Coils— Replace or clean filters, coils, energy and heat wheels, heat exchangers and other heating elements. 3. Drains and Freeze Protection— Clear or freeze-stat on coils and clean pans. Validate freeze protection concentration in the water system. 4. Fans, Motors, Drives— Lubricate bearings per OEM specifications, measure motor currents, check belt tensions and confirm VFD param eters or soft-start settings. PERFORMING AHU IS OFTEN NOTED BY BUILDING OCCUPANTS WHO MAY REPORT TEMPERATURE SWINGS. REDUCED AIRFLOW OR A 'STUFFY' FEELING WITHIN THE BUILDING. condensate drains, check traps, and verify the operation of the heat trace

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ESTABLISHING AN OSHA COMPLIANT LOCKOUT/ TAGOUT PROGRAM

employers must inspect the lockout/ tagout program on a regular basis (at least once a year) to ensure that the procedures are being carried out cor rectly and that they are still effective in limiting employee exposure to hazard ous energy. LOCKOUT SEQUENCE 1. Notify all affected employees: When it is time for servicing or maintenance, warn all employees that the machine must be shut down and locked out before the maintenance or servicing chores may be performed. Take down the names and job titles of all employ ees who are affected. 2. Know the machine's power source: The authorized employee in charge of the lockout/tagout procedure must be aware of potential energy threats and be able to control energy. OSHA empha sizes that the procedure must describe what employees must know and do to properly control hazardous energy. 3. Turn off the machine: If the machine is already running, stop it using the normal procedure; pressing the stop button, closing the valve, opening the switch and so on. 4. Deactivate energy-isolating devices: Separate the equipment from its energy source.

5. Lockout: Use individually assigned locks or programmed lockout mecha nisms to disable the energy-isolating device. 6. Release the stored energy: Stored en ergy must be discharged or restrained. This can be accomplished by ground ing, blocking, bleeding down, reposi tioning and so on. 7. Remove the device from the power source: This is done by first making sure no one is exposed; and then run ning the machine through its startup procedure, and making sure it does not start to confirm the machine is isolated from the energy source. It is not locked out if the device is left turned off. LOTO SAFETY Lockout/tagout (LOTO) procedures are essential for the safety and well-being of workers. By instating a LOTO program, em ployers can prevent serious harm and even death. By providing adequate training and equipment, conducting frequent equipment inspections, upgrading LOTO policies, and regularly enforcing LOTO standards, work ers are safe, and accidents are prevented. For additional information on LOTO safety, visit https://bit.ly/43au7LJ .

tive equipment (PPE) should include safety glasses, gloves, hearing protection and flame-resistant clothing, if required. Staging service tools and standard replacement parts can help to make processes more efficient and reduce time on the roof. Some equipment manufactur ers may include a scannable QR code on the equipment, providing a digital knowl edge source without the added paperwork. These resources may include model-specific information like technical guides, wiring diagrams and fault code descriptions to Communication is a critical, but often overlooked, component for successful building system maintenance. As service orders become increasingly digitalized, opportunities to consult in person may become less frequent. However, this face to-face interaction is a prime opportunity to review operators’ concerns and share system knowledge. By building strong rela tionships with building teams, technicians further streamline service. Driving Service Success OSHA specifies what actions to take when creating a lockout/tagout program. Accord ing to OSHA, the first step is to establish and standardize energy-control processes. These procedures explicitly outline the steps for disconnecting machines' energy supply and installing lockout/tagout devices on energy-isolating devices to prevent re-en ergization. The process must also address how to deal with stored or re-accumulated energy. To stay OSHA-compliant, employers must train staff on the energy-control program, including safe application, usage of lockout/ tagout devices and energy-control removal. Employees must be able to understand the following: • Instructions on how to carry out the steps. • Steps to specifically turn off, isolate, block and secure machines. • Specific instructions for the proper installation, handling and transfer of lockout/tagout devices, including who is in charge of them. Specific specifications for testing equipment to determine if lockout/ta gout devices work as intended. Lastly, •

Courtesy of OSHA

When accessing rooftop equipment during winter conditions, first confirm the area is free of weather-related hazards such as ice or snow accumulation.

can develop a better understanding of their unique building requirements and tolerance for downtime. When combined with manufacturers’ recommendations and ASHRAE guide lines, this information can be leveraged to develop a proactive AHU maintenance schedule that helps building teams meet their goals.

1 U.S. Department of Energy, Better Buildings™, Better Plants (August 2022), “Preventative maintenance for commercial HVAC equipment” https://betterbuildingssolutioncenter.energy.gov/solutions-at-a glance/preventative-maintenance-commercial-hvac-equipment Mark Miller is Product Warranty & Tech nical Support Manager, AHU Airside at Johnson Controls. Jeremy Fitze is AHU Product Techni cal Support Engineer at Johnson Controls.

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Next-level Maintenance Drives Winter Residential Heating Success

Proactive maintenance is essential to avoid breakdowns in the coldest months.

BY CASEY MCCONNAUGHY

W inter conditions can be taxing on furnaces and heat pumps. Proactive maintenance can help to ensure these preferences are met while also confirming equip ment is operating within the manufacturer’s intended performance and efficiency range. The Refrigeration Service Engineers Society (RSES) has devel oped an extensive collection of training and certification programs for HVACR professions. This training features detailed train ing programs, including Technical Institute manuals and focused course units, industry-specific certification and reference materials, and online, self-paced training courses and DVD resources. Each contractor must also develop and apply their own level of expertise, to help drive successful furnace and heat pump maintenance this season. Preparing for Service Proactive maintenance provides an opportunity to catch minor issues before they escalate. Winter service can look different based on client expectations, regional climates and weather conditions. Whether a seasonal tune-up is being conducted as part of an annual service contract, or a customer has requested an inspec tion, every site visit should begin by having a conversation with the homeowner, to learn of any home comfort issues. Before arriving on-site, confirm the make, model and age of the system to ensure the appropriate supplies, like filters, are stocked. Taking an inventory of tools before service can also help to ensure efficiency on the job. In addition to common hand tools, a small vacuum with attachments, a wire brush, extra-fine steel wool, an ohmmeter and an inspection camera are helpful devices. Inspect Key Components for Peak Performance The heat exchanger is central to safe and efficient furnace perfor mance. Visually inspect the unit looking for signs of cracks, corro sion and contaminants. Gas burners should be taken out, wire brushed and vacuumed to remove debris. Flame sensors and spark ignitors should be carefully cleaned using extra-fine steel wool— more abrasive materials, like sand cloth or emery cloth, will cause damage, as they can leave silica imbedded in the flame sensing rod, which acts as an insulator. They can also damage the rod by leaving scratches in it, causing it to get dirty faster. Once the components are clean and reinstalled, an ohmmeter can be used to measure the electrical continuity within the hot surface ignitor and safety switches. Safety switches should regis ter as closed, showing very low resistance when tested, while hot surface ignitors have specific resistance ranges that vary depending

on their type. By measuring each component’s electrical resistance, the reading can be compared to the manufacturer’s specs to deter mine if it is close to failure or in working condition. In an electric heat pump or dual fuel systems , inspect the outdoor coil for signs of corrosion and debris. If debris is present, clean the coil, as proper heat transfer is key to equipment operation. Check ing the static pressure across the indoor coil can also provide an indication of equipment health. By comparing the pressure drop against the manufacturer's installation manual, it is an option to determine if the coil is restricted and needs to be cleaned. In both furnaces and air handling units, it is crucial to inspect the blower wheel. Debris that passes beyond the filter can build up on the blower, limiting airflow and requiring more electricity to move the motor. A malfunctioning or dirty blower wheel can result in temperature loss or cold spots within the home as well as lost efficiency, which can lead to increased heating bills. Air leakage is another area that can negatively impact heating efficiency and lead to premature wear on both furnaces and heat pumps, as well as higher utility bills and occupant discomfort. Inspecting the complete ductwork system manually or by using an inspection camera provides a clear picture of the ductwork design to determine where there may be inefficiencies or signs of damage. Airflow will always take the path of least resistance. It is also important to inspect the system itself for additional areas of air leakage. This can occur between equipment components such as the furnace and indoor coil or filter rack. These areas can be easily sealed using foil tape to enhance airflow and efficiency. Additionally, inspect where the thermostat meets the wall for potential air leaks, which can cause inaccurate temperature readings. Deliver Lasting Benefits Through Proactive Seasonal Maintenance Seasonal inspections provide an important opportunity to ensure equipment remains reliable, efficient and safe. For homeowners, this can translate to measurable cost-savings over the lifespan of the system. Routine maintenance is also often necessary to main tain manufacturers’ warranties. While the winter season often prompts homeowners to think about their home comfort system, bi-annual inspections are often ideal for year round performance. During each check, documentation of all inspected areas and recommendations help to build trust during all seasons. Casey McConnaughy is regional technical service manager for Bosch Home Comfort Group and currently serves on the RETA-RSES Board of Directors.

WINTER 2025 RSES Journal 13

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Use of airflow measuring instruments brings with it key protocols and best practices. PROPER USE OF AIRFLOW & AIR VELOCITY MEASURING INSTRUMENTATION

BY JIM HALL, P.E., TBE

I t is extremely important that the HVAC technician understands the different types of instruments used for air veloc ity/airflow measurement; best practices for properly selecting and using them; and knowledge of proper airflow standards. Right out of the gate, the technician must understand the different types of instruments used for air velocity/airflow measurement, including anemometers, rotating vane anemometers, flow hoods and more. Thermal Anemometer A thermal anemom

Digital Rotating Vane Anemometer The rotating

Pitot Tube

vane is sensed by a magnetic or optical pickup; and the signal is converted to a direct feet per minute (ft/min). TSI Instruments

The pitot tube senses the total pressure and static pressure in the duct or plenum. It is a double wall tube, the inner tube senses total pressure and the outer tube senses static pressure. The difference between the two is the velocity pressure. The velocity pressure is converted to velocity in ft/min. The pitot tube is used with a digital micro manometer or inclined manometer. Flow Hood/Capture Hood The flow hood/ capture hood

Velocity Grid/Matrix

The velocity grid/matrix

eter uses a heated probe element that is inserted into an airstream. Air speed can then be inferred from the heating power necessary to maintain the probe

uses a Digital Micromanom eter to convert the pressure measurement across the grid/matrix to a ft/min measure ment. Kanomax Airfoil/Airflow Probe

directs the airflow across the flow sens ing grid/matrix. The grid/matrix senses the total pressure and the static pressure,

at a temperature elevation. This power should be some way proportional to air speed. Jim Hall Mechanical Rotating Vane Anemometer

The airfoil/airflow probe uses a digital micro-manometer to convert the pres sure measurement across the airfoil/ airflow probe to an ft/min measure ment. The airfoil/

which are combined to a single differential pressure. This differential pressure is trans mitted to the digital micro-manometer for conversion to a direct airflow readout. There are various sizes to accommodate the variety of outlets/inlets. By definition, the flow hood/capture hood is a propor tioning device. Manometer Best Use Condition A standard air condition for using a manometer is 29.92 in. of mercury (inHg) at 70°F, representing the standard atmo

The mechani cal rotating vane utilizes a revolu tion counter that is engineered and calibrated to read air velocity directly in feet of air. (Sometimes

probe amplifies the velocity pressure signal for increased sensitivity at low velocities. The lee side pressure port is not equivalent to the static pressure port of a pitot tube.

referred to as intrinsically safe.)

14 RSES Journal WINTER 2025

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Mechanical Rotating Vane Anemometer

Digital Rotating Vane Anemometer

Typical Specification

Thermal Anemometer

Velocity Grid/Matrix

Airfoil-Airflow Probe

Flow Hood- Capture Hood

Pitot Tube

25–2500 CFM (1500 CFM exhaust)

Measurement Range

200–10,000 ft/ min

0–6000 ft/min

50–6000 ft/min 25–2500 ft/min 25–5000 ft/min 50–8000 ft/min

Temp. range

40°F–113°F

40°F–113°F

40°F–140°F

40°F–140°F

40°F–140°F

40°F–140°F

±5% of reading or ±5 ft/min, which ever is greater

±1% of reading or ±4 ft/min, which ever is greater

Micro-manom eter will report negative value Micro-manom eter will report negative value Face velocity (grill, lab/kitchen hood, filter, coil); traverse; point air velocity; low velocities

±3% of reading ±7 ft/min

±3% of reading ±7 ft/min

±3% of reading ±7 CFM

Accuracy

Micro-manom eter will report a “NegPitot” or “Error”

Micro-manom eter will report negative value

Micro-manom eter will report negative value

Reports positive in both directions

Vane will rotate backwards

Vane will rotate backwards

Airflow direction

Face velocity (grill, lab/kitchen hood, filter, coil); traverse; point air velocity

Face velocity (grill, lab/kitchen hood, filter, coil)

Face velocity (grill, lab/kitchen hood, filter, coil)

Face velocity (grill, lab/kitchen hood, filter, coil)

Duct Traverse; plenum traverse

Diffuser, outlet grill, etc.

Applications

Typical specifications for various manufacturers are noted. Consult individual manufacturer for specific technical data. Location of an instrument within the airstream, velocity profile and application of instrumentation will affect velocity measurement.

spheric pressure at mean sea level accord ing to the Inter national Standard Atmosphere (ISA). This value serves as a universal reference for pressure-related calcu lations and instru ment readings. Test and Balance (TAB) density correc tions shall be made when temperatures

Electronic manometers from Shortridge and Evergreen Telemetry.

are greater than or less than 30°F of stan dard air, or if the altitude is greater than 2000 ft above sea level. Applying density correction factors allows technicians to convert indicated cubic feet per minute (CFM) readings to the actual CFM under standard condi tions, ensuring that the system is operat ing according to its design specifications. The best practice is to make a 2% correc tion for each 1000 ft above sea level, and a 1% correction for each 10°F above or below 70°F. Proper Instrument Application The technician’s goal when using airflow testing instruments is to record accu rate and repeatable measurements. This requires proper use of the instruments, an understanding of instrument operation and limitations; reliable system design and operation; and a good velocity profile.

Acceptable and unacceptable velocity profiles. Reprinted from “AMCA Publication 201-90, Fans and Systems.” Reprinted by permission from AMCA.

WINTER 2025 RSES Journal 15

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