HVAC School - For Techs, By Techs

HVAC School is the ever growing online source for real training topics for technicians in the Air-conditioning, Heating and Ventilation Fields. In the podcast, we will share recorded training, tech ride alongs, share challenging diagnostic scenarios. All to help make the industry, your company, and your truck a better place to be.

Building Science at the Kitchen Table: Using Testing to Close the Sale 04/02/2026

Building Science at the Kitchen Table: Using Testing to Close the Sale Recorded live at the 7th Annual HVACR Training Symposium, this episode brings together Roman from HVAC School and building science practitioner Brynn for a deep-dive conversation on one of the most pressing challenges in the HVAC industry: how contractors can use building science principles not just to solve problems, but to communicate value and close sales at the kitchen table. With 26 years of industry experience and 15 years of consistently applying building science in his contracting business, Brynn shares the process his team has refined to help homeowners understand their comfort problems — and confidently invest in the right solutions. Central to the conversation is the idea that testing — not guessing — is the foundation of a great HVAC business. Brynn outlines his team’s “big three” diagnostic approach: starting with indoor air quality testing, followed by a load calculation using a LIDAR tool, and finishing with a duct evaluation. These three steps give technicians the data they need to tie findings directly to a homeowner’s stated concerns. Rather than overwhelming customers with spreadsheets and raw numbers, the goal is to present information in a way that connects with their lived experience — validating that their hot rooms, cold spots, or humidity discomfort are real, measurable problems with real, measurable solutions. Brynn’s team can complete a full load calculation in as little as 20 minutes on-site, a capability that routinely impresses homeowners and sets them apart from competitors. The episode also tackles the business case for slowing down. Rather than rushing technicians through six to eight calls a day, Brynn’s company reduced daily call volume to two to four, giving technicians time to perform thorough diagnostics. The result? Ticket sales increased, replacement opportunities grew organically, and install callbacks dropped to a remarkable half of one percent, compared to an industry average closer to ten percent. Roman and Brynn agree that adopting building science practices isn’t about overhauling your business overnight. The key is to start with one skill — like combustion testing or airflow measurement — master it, embed it in company culture, and build from there. Over time, these small habits compound into a business that delivers on its promises every time. Beyond the technical content, the conversation wraps with a heartfelt discussion about workforce development and the GRIT Foundation, a nonprofit working to reintroduce skilled trades exposure to young people. With shop classes having largely disappeared from schools across the country, Brynn and Roman emphasize the importance of giving children the chance to discover a passion for hands-on work. Brynn’s team hosted a GRIT camp in Detroit, and one participant has since enrolled in HVAC college — a reminder that sparking curiosity early can change the trajectory of a young person’s life. Contractors interested in Brynn’s training programs and building science bootcamps can find more information at HVACTrain.com. Topics Covered The culture and community of the HVACR Symposium and why first-time attendees always come back Why building science can feel intimidating to contractors — and how to simplify it for customer conversations Brynn’s “big three” on-site diagnostics: indoor air quality testing, load calculation, and duct evaluation How to ask the right questions first — understanding the customer’s pain before running tests Using data to validate homeowner concerns (hot rooms, cold spots, humidity issues) rather than dismissing them Completing a full load calculation in 20 minutes using LiDAR tools and tablet software Presenting test results with third-party references (EPA, American Lung Association) to build trust Why oversized HVAC equipment is the rule, not the exception — and what the data shows across thousands of homes The business case for slowing down: fewer daily calls, better diagnostics, higher ticket sales, fewer callbacks Reducing install callbacks from an industry average of ~10% to just 0.5% through building science practices How to implement building science incrementally: start with one practice, make it a habit, then build from there Using platforms like measureQuick and Smart Probe for ongoing performance verification Mitigating legal and financial risk on larger residential and multi-family projects through proper documentation Building a word-of-mouth reputation that eliminates the need for active marketing The GRIT Foundation: reintroducing skilled trades to young people and inspiring the next generation of HVAC professionals Where to find Brynn’s contractor bootcamps, online classes, and workforce development seminars at HVACTrain.com Learn more about Brynn's education opportunities at . Have a question that you want us to answer on the podcast? Submit your questions at . Purchase your tickets or learn more about the 7th Annual HVACR Training Symposium at . Subscribe to our podcast on your or . Subscribe to our channel. Check out our handy here or on the HVAC School Mobile App for and . /episode/index/show/hvacschool/id/40504125

Hard Lessons w/ Roman, Tim D., Nathan O. and ELK 03/31/2026

Better Seen than Viewed w/ Jim Bergmann 03/26/2026

Better Seen than Viewed w/ Jim Bergmann In this heartfelt and wide-ranging episode, host Bryan reconnects with Jim Bergmann of measureQuick after nearly three years apart. The reunion is anything but ordinary — Jim opens up about a serious battle with non-Hodgkin's B-cell lymphoma that sent him through not one but two rounds of chemotherapy, ultimately requiring a cutting-edge CAR-T cell immunotherapy treatment at the Cleveland Clinic. Jim shares the remarkable medical journey of having his T cells extracted, genetically modified in a Maryland lab, and reintroduced into his body to permanently attack cancer cells. Now past the critical six-month remission milestone, Jim is back, healthy, and more motivated than ever to push the HVAC diagnostics industry forward. From his medical comeback, the conversation transitions naturally into what Jim loves most: the world of HVAC diagnostics and the evolution of measureQuick. After years of defending a per-use pricing model that the market simply didn't embrace, Jim candidly admits the old model wasn't working. With the help of business partner Eric Preston (formerly of TruTech Tools), the team overhauled the software's pricing structure in February — a move that has since driven 90%+ customer retention and accelerated growth significantly. The new focus is squarely on "time to value," streamlining workflows so technicians reach key diagnostic reports faster than ever before. A significant portion of the episode dives into how measureQuick is thoughtfully integrating artificial intelligence. Rather than chasing AI trends, Jim and his team — including AI specialist Ben Reed — took a deliberate approach: identifying the precise areas where AI genuinely helps technicians without creating distractions. The standout use case is label identification, where AI reads equipment labels and auto-populates system profiles. Jim is refreshingly candid about AI's limitations in HVAC diagnostics, explaining that the field variability of real-world systems (varying line set lengths, mismatched equipment, non-standard airflow conditions) makes purely AI-driven diagnostics unreliable. Instead, measureQuick leans on first-principle modeling and non-dimensional mathematics to generate objective, data-driven results. The episode closes with a thought-provoking discussion about the state of the HVAC industry at large. Bryan and Jim tackle the growing influence of private equity consolidation, the persistent problem of technicians skipping probe deployment, the difference between clearing faults and actually fixing them, and the importance of commissioning and retro-commissioning equipment to manufacturer design intent. Throughout it all, the conversation is anchored by a shared belief: that measuring everything — in business and on the job — is the foundation of genuine, lasting improvement. It's a must-listen for any HVAC professional or business owner who wants to understand where the industry is headed. Topics Covered Jim's cancer diagnosis: non-Hodgkin's B-cell lymphoma and the progression from standard chemo to aggressive relapse CAR-T cell immunotherapy explained: how T cells are extracted, genetically modified, and reintroduced to fight cancer permanently Jim's recovery at the Cleveland Clinic and surpassing the critical six-month remission milestone Neurotoxicity as a side effect of CAR-T therapy and what that experience was like The pivot away from measureQuick's per-use pricing model and the dramatic improvement in retention after switching The "time to value" philosophy driving measureQuick's new hybrid workflow interface How measureQuick is integrating AI — and where AI falls short in real-world HVAC diagnostics Label identification as the most practical current AI application in field diagnostics Why AI is highly sycophantic and the danger of relying on subjective, internet-sourced training data for HVAC decisions The power of measureQuick's proprietary measurement data and target zones as a foundation for AI summaries First-principle modeling and non-dimensional mathematics: why brand-agnostic diagnostics work The importance of deploying all nine probes on every air conditioning service call Benchmarking vs. commissioning vs. retro-commissioning: the three layers of equipment assessment Design temperature difference: measuring evaporator and condenser delta-T as engineering benchmarks How ECM motors mask airflow problems — and why that leads to premature motor failure and higher energy costs The two "elephants in the room": incomplete probe deployment and clearing faults without fixing them Why clearing a fault in measureQuick without addressing the root cause is like putting duct tape over a check engine light How poor installation practices in high-growth markets (Florida, Texas, Arizona, Las Vegas) have created widespread system deficiencies The role of private equity in HVAC consolidation and why many PE firms add cost without adding value Why implementing field measurement systems like measureQuick is the missing link for PE-owned and independent shops alike The legacy mode vs. new mode toggle in the upcoming measureQuick update — no forced UI changes for existing users How measureQuick helps newer technicians become productive faster and helps seasoned technicians be more consistent The importance of presenting diagnostic findings to homeowners and helping them understand what the numbers actually mean Learn more about measureQuick at . Have a question that you want us to answer on the podcast? Submit your questions at . Purchase your tickets or learn more about the 7th Annual HVACR Training Symposium at . Subscribe to our podcast on your or . Subscribe to our channel. Check out our handy here or on the HVAC School Mobile App for and . /episode/index/show/hvacschool/id/40499595

Symposium - What Good Techs Do Different W/ Data 03/24/2026

Heat Recovery from Data Center w/ Jeff Staub 03/19/2026

Heat Recovery from Data Center w/ Jeff Staub In this episode of the HVAC School Podcast, host Bryan sits down with Jeff Staub, Director of OEM Sales for Danfoss North America, to explore one of the most rapidly evolving frontiers in the HVAC and refrigeration world: thermal management for AI data centers. With nearly 30 years of industry experience spanning technical support, application engineering, and product development, Jeff brings deep expertise on how the explosive growth of AI chip technology is reshaping data center cooling architecture — and creating major new opportunities for HVAC professionals, contractors, and facility managers alike. A central theme of the conversation is heat recovery — specifically, how the enormous amounts of heat generated by high-density GPU chips in modern data centers can be captured and repurposed rather than simply rejected into the atmosphere. Jeff explains that while heat recovery itself is not a new concept (supermarkets have used reheat coils and heat reclaim for decades), its application in AI data centers presents fresh challenges and possibilities. The heat coming off liquid-cooled server chips typically runs around 90 to 100 degrees Fahrenheit — useful, but not immediately at the temperature needed for most end applications like domestic hot water or space heating. Boosting that heat using heat pumps or feeding it into district energy systems, boiler pre-heat loops, vertical farms, or multifamily housing developments are among the most promising strategies being explored around the world. Jeff highlights a significant contrast between Europe and the United States in how heat recovery is being adopted. In Europe, where district energy networks are widespread, data centers can plug directly into community heating infrastructure — and projections suggest that 80% of European data centers will incorporate heat recovery in the near future. In the US, the picture is more fragmented: while opportunities exist at universities, hospitals, urban mixed-use developments, and facilities co-located with nuclear power plants, the economics are trickier. Key sticking points include who owns the capital expenditure for heat recovery modules and heat pumps, and who ultimately benefits from the recovered heat. Bryan and Jeff discuss how innovative ownership models — with landlords, municipalities, or co-tenants sharing infrastructure — are beginning to unlock these opportunities, and how co-generation arrangements with power stations present exciting long-term potential. The episode wraps up with highly practical guidance for HVAC contractors and facility managers looking to break into the data center space. Jeff encourages technicians not to be intimidated: the fundamentals of vapor compression, chiller systems, and fluid flow that HVAC professionals already know transfer directly to data center work. The key additions are familiarity with large centrifugal and screw compressors, variable frequency drives on pumps, glycol loop management, and central distribution unit (CDU) architectures. Bryan emphasizes that the boundary between HVAC and plumbing will continue to blur as secondary fluid pumping becomes more prevalent — and that staying curious and investing in ongoing training (through manufacturer programs like Danfoss Learning, Carrier University, and others) is the best way to ride this wave rather than get left behind. Both hosts agree: AI data centers are not going away, and the technicians who keep them cool will be indispensable. Topics Covered The evolution of data center cooling — from direct vapor compression on chips, to air-conditioned server rooms (CRAC units), to today's liquid cooling and chiller-loop architectures Why AI GPU chips generate unprecedented heat densities, with individual server racks approaching 250 kW to 1 MW of heat output What heat recovery means in the data center context: capturing hot water (90–100°F) off chip cooling loops instead of rejecting it to outdoor air The concept of 'heat quality' — why low-temperature waste heat is abundant but difficult to use directly, and how heat pumps solve the temperature-lift challenge Real-world heat recovery applications: district energy systems, boiler pre-heat, vertical farms, multifamily housing, hospitals, and universities Europe vs. the US: why district energy adoption makes heat recovery far more common in European data centers, and what the US can learn Business model challenges: who pays for heat recovery infrastructure, and how co-location, municipal incentives, and landlord ownership models can unlock value Co-generation opportunities: feeding recovered heat back into steam turbines at co-located nuclear or power plants How heat recovery makes heat pump technology more viable by raising the source temperature and reducing compression ratio Danfoss's role in data center thermal management — from compressors and drives to plate heat exchangers, CDU flow control, and prepackaged heat recovery modules Refrigerant transitions and what they mean for data center cooling (R-410A to R-454B, CO2 transcritical systems, potential two-phase refrigerant direct-to-chip cooling) The convergence of HVAC and plumbing trades in a world of secondary fluid pumping and isolated refrigerant charges Absorption chiller technology as a potential future use case for low-grade waste heat Advice for contractors: how existing chiller and refrigeration skills translate to data center work, and what new competencies to build Career and training resources: Danfoss Learning, manufacturer universities (Carrier, Trane, McQuay), and leveraging AI tools for self-education The importance of redundancy and uptime in mission-critical data center environments — and what that means for service response expectations Learn more about Danfoss at Have a question that you want us to answer on the podcast? Submit your questions at . Purchase your tickets or learn more about the 7th Annual HVACR Training Symposium at . Subscribe to our podcast on your or . Subscribe to our channel. Check out our handy here or on the HVAC School Mobile App for and . /episode/index/show/hvacschool/id/40303125

All About ESCO with Renee Tomlinson and MeasureQuick's Latest Features with Jim Bergmann 03/17/2026

All About ESCO with Renee Tomlinson and MeasureQuick's Latest Features with Jim Bergmann In this short episode, the HVAC School team members talk with Jim Bergmann (measureQuick) and Renee Tomlinson (ESCO) about the latest and greatest that they brought to their booths at the 7th Annual HVACR Training Symposium. First, JD Kelly spoke with Renee about ESCO Institute's educational offerings. ESCO offers a mix of books and online training content, including new training for A3 refrigerants, a new CO2 (R-744) training manual, and the newly released second edition of System Performance. ESCO has been working with Visual 3D Academy to bring augmented reality (AR) training to the market. Beginners and advanced techs alike can find training material to benefit their careers, as ESCO offers courses on fundamentals for beginners and specialized knowledge for those with more industry experience. ESCO's HVACR Learning Network allows you to access all ESCO courses with a monthly subscription package or purchase access to individual courses, such as if you only need one or two courses of specialized training. Then, Roman Baugh spoke with Jim Bergmann about the latest developments to measureQuick, especially as it has expanded in both breadth AND depth. The unlimited-use subscription has been a positive development that has been well-received, and Jim Bergmann's latest update in development aims to make the value even better with improvements to workflows (creating a hybrid between regular and guided workflows). Developments have also included improved support for VRF systems and all of those systems' operational considerations. The core function of measureQuick is to bring visuals to data, and measureQuick is implementing AI to reduce user errors, such as when it comes to label-reading and ensuring that pressure-temperature data matches the system. User testing is also rigorous to ensure that the software works as intended and to minimize tech support calls for the app itself, and Jim has spent the past several months on user testing in advance of the update's rollout. Have a question that you want us to answer on the podcast? Submit your questions at . Purchase your tickets or learn more about the 7th Annual HVACR Training Symposium at . Subscribe to our podcast on your or . Subscribe to our channel. Check out our handy here or on the HVAC School Mobile App for and . /episode/index/show/hvacschool/id/40446005

Building Tools & the Trade w/ Tony G. from Fieldpiece 03/12/2026

Building Tools & the Trade w/ Tony G. from Fieldpiece Recorded live on the third day of the AHR Expo 2026 in Las Vegas, Nevada, this episode of HVAC School brings together host Bryan and longtime friend of the show Tony Gonzalez, Director of Training at Fieldpiece Instruments. The conversation kicks off with some light-hearted banter about trade show survival tips — including the classic trick of hanging around near closing time to score free gear from exhibitors who don't want to ship anything home. Tony, who spent much of the show working the Fieldpiece booth, shares what it's like to be on that side of the expo floor, while Bryan admits he stopped by the booth but somehow managed to avoid saying hello. One of the highlights of the episode is a hands-on look at Fieldpiece's brand new analog manifold gauge set — a surprise addition to their lineup. Bryan gives his first impressions live on the mic, noting the heavy-duty build quality, four-port design, dual-scale display for popular refrigerants including R-22, R-32, R-454B, and R-410A, and high-pressure ratings. The standout feature that catches Bryan off-guard is a built-in pressure marker ring — what Tony jokingly calls a "fidget spinner" — that allows techs to mark a pressure point on the gauge dial during standing pressure tests, replacing the old wax pen or Sharpie workaround. Bryan makes a compelling case for why every truck should carry a set of analog gauges as a reliable backup, especially for dirty systems, long-term standing pressure tests, or situations where digital probes or batteries fail. Tony shifts the conversation to something he's deeply passionate about: Fieldpiece's commitment to tackling two of the biggest challenges facing the HVAC industry today — low-quality workmanship in the field and the growing skills gap as experienced technicians retire. Fieldpiece has launched a formal School Partnership Program, developed after extensive conversations with trade school directors and union leaders to understand their real needs. The program offers in-person support, supplemental training materials focused on best practices, prizes for top graduates, tools for labs and classrooms, and student discounts. Tony also unveils Fieldpiece's mobile training trailer — a fully-equipped 35-foot rig with live HVAC equipment, including a variable-speed heat pump and furnace — designed to bring hands-on training directly to contractors, distributors, and schools. Bryan passionately echoes the importance of repetitive, hands-on practice, arguing that reading books or watching videos will never replace actually pulling vacuums and executing best practices over and over again. The episode wraps up with Tony sharing details about Fieldpiece's revamped rewards program, where technicians and contractors can earn points by registering products, attending events, and completing free courses on Fieldpiece University — Fieldpiece's online learning platform offering continuing education credits. Bryan encourages small contractors to leverage Fieldpiece University as the backbone of an in-house apprenticeship program without needing a big budget. Tony also teases some exciting future developments, including a new office and learning facility under construction in Heber, Utah, near Park City, a larger state-of-the-art training facility coming to Tustin, California, and a fully redesigned website expected to launch within the next couple of months. Topics Covered Trade show tips: how to score free gear at the end of the last day Tony Gonzalez's personal life update First look at Fieldpiece's new analog manifold gauge set Refrigerant compatibility: R-22, R-32, R-454B, R-410A display on the new gauges The built-in pressure marker ring — a clever replacement for the wax pen trick Why every HVAC truck should have a set of analog gauges as a backup Use cases for analog gauges: dirty systems, long-term standing pressure tests, dead batteries Fieldpiece's two-pronged approach to the HVAC industry: reducing low-quality work and closing the skills gap The Fieldpiece School Partnership Program — resources, in-person support, student prizes, and lab tools Fieldpiece's 35-foot mobile training trailer: bringing live equipment to schools, contractors, and distributors The importance of hands-on, repetitive practice for trade skills — not just classroom learning Fieldpiece's new and expanded training facilities in Tustin, CA, and Heber, UT The revamped Fieldpiece Rewards Program — earning points for swag through product registration, events, and courses Fieldpiece University: free online courses with continuing education credit How small contractors can use Fieldpiece University to build internal apprenticeship programs A shoutout to the GRIT Foundation and their shared mission in workforce development Upcoming redesigned fieldpiece.com website Tony's trailer driving lessons — and a certain "learning opportunity" involving a sharp turn Learn more about Fieldpiece's School Partnership Program at , Fieldpiece University at , and Fieldpiece's products at Have a question that you want us to answer on the podcast? Submit your questions at . Purchase your tickets or learn more about the 7th Annual HVACR Training Symposium at . Subscribe to our podcast on your or . Subscribe to our channel. Check out our handy here or on the HVAC School Mobile App for and . /episode/index/show/hvacschool/id/40216015

Symposium - Do Inverters Suck? 03/10/2026

Recovery Pro Tips w/ Jesse from NAVAC 03/05/2026

Recovery Pro Tips w/ Jesse from NAVAC Recorded live on the floor at the AHR Expo 2026, this episode of the podcast brings together host Bryan and his guest Jesse, National Training Manager at NAVAC, for a candid, high-energy conversation about professional best practices in the HVAC/R trade. The two have a long-standing friendship and professional rapport that makes the discussion feel both educational and genuinely entertaining. Jesse brings a unique background to the table — from underground coal mining in West Virginia to becoming a lineman, then pivoting to HVAC through vocational school and a contractor-sponsored apprenticeship program. His path to becoming a national trainer is a testament to the value of investing in yourself and being open to learning at every stage of a career. The core of this episode centers on refrigerant recovery and charging best practices — a topic that might sound routine but quickly reveals how many technicians, even experienced ones, are cutting corners that cost their clients and their companies money. Bryan and Jesse dig into the problems caused by unnecessarily opening sealed systems, the refrigerant lost every time a technician gauges up a system without need, and why the HVAC industry needs to shift its mindset to treat equipment more like a home refrigerator: a sealed system that should run for years without needing to be cracked open. Jesse makes a compelling case that many so-called "mysterious leaks" are actually caused by repeated unnecessary gauge hookups removing small amounts of refrigerant each time. A significant portion of the conversation focuses on the transition away from manifold gauges toward digital probes and modern recovery setups. Jesse isn't dismissive of manifolds — he acknowledges their place in the classroom and as a backup tool — but he makes a strong case that eliminating restrictions throughout the recovery and charging process is one of the single most impactful things a technician can do to improve efficiency, protect equipment, and deliver better results for customers. Topics like pulling Schrader cores, using 3/8" hoses, Rapid-Y fittings, and the importance of using a filter dryer inline with the recovery machine are all covered with practical, field-tested advice. Bryan and Jesse also tackle some timely and emerging issues facing the industry, including the equalization behavior of R-454B blends and the growing challenge of refrigerant recovery in extreme cold climates as cold-climate heat pumps become more widespread in northern markets. These aren't hypothetical — they're problems technicians are encountering right now, and Bryan's theory about refrigerant fractionation showing up on thermal imaging cameras offers a genuinely fascinating technical angle. The episode closes with Jesse's overarching message: eliminate restrictions wherever you can, take pride in your craft, and never stop learning. Topics Covered Jesse’s background: coal mining, lineman work, HVAC vo-tech, contractor apprenticeship, and path to becoming a national trainer The sealed system philosophy: why unnecessarily opening refrigerant circuits causes more problems than it solves Manifold gauges — their appropriate role in training and as a backup vs. the case for moving to digital probes How repeated gauge hookups can introduce refrigerant loss and fake “mystery leaks" — the 3.5 oz. per hose problem Restrictions as the enemy of efficient recovery: pulling Schrader cores, using core removal tools, and proper hose sizing The importance of recovering liquid first and how restrictions cause flash gas that slows recovery and adds heat Hose size trade-offs: why 3/8" hoses are the recommended sweet spot between flow rate and refrigerant retention Using a filter dryer inline with the recovery machine as cheap insurance against acid contamination and machine damage Why recovered refrigerant should generally NOT be reused — dirty recovery tanks, fractionation, and the limits of a single filter pass Scales as a non-negotiable tool: weighing refrigerant in AND out, and why techs who estimate by feel are guessing Diagnosing overcharge and undercharge situations using scale data before making repairs Airflow first, charge second: the importance of confirming CFM before adding refrigerant to a struggling system The R-454B equalization issue: refrigerant fractionation in new blends and Bryan’s thermal imaging theory Cold-climate heat pump recovery challenges at sub-zero temperatures and strategies for adding heat to the system Heat pump maintenance best practices: testing defrost cycles and what happens when they haven’t been checked in years Word of mouth as the most powerful (and dangerous) form of advertising in the service industry Recovery cylinder safety: the dangers of overfilling tanks and the 80% rule Learn more about NAVAC's products and resources at . Have a question that you want us to answer on the podcast? Submit your questions at . Purchase your tickets or learn more about the 7th Annual HVACR Training Symposium at . Subscribe to our podcast on your or . Subscribe to our channel. Check out our handy here or on the HVAC School Mobile App for and . /episode/index/show/hvacschool/id/40201465

Symposium - What is the House Trying to Tell Me? 03/03/2026

Don't Die! w/ Louise from UEi 02/26/2026

Don't Die! w/ Louise from UEi In this episode, recorded live at AHR Expo 2026, Bryan sits down with Louise from UEi Test Instruments for an in-depth conversation about one of the most underestimated dangers in the HVAC trade: carbon monoxide. Rather than treating CO as just another checkmark on a safety list, Bryan and Louise dive into the full history of the gas — all the way back to early publications from 1922 and 1923 that were already studying the effects of low-level CO exposure. One of the most fascinating takeaways from their discussion is just how long the industry has known about the dangers of carbon monoxide, yet how frequently it remains misunderstood, misdiagnosed, and overlooked on the job site. Louise breaks down the science behind CO poisoning in a way that is both accessible and eye-opening. Unlike high-level acute poisoning — where symptoms are immediately obvious — low-level, chronic carbon monoxide exposure is an entirely different beast. It can mimic the flu, chronic headaches, early-onset Alzheimer’s, and even heart attack symptoms. Because CO is colorless, odorless, and tasteless, it is notoriously difficult to diagnose, and victims often have no idea what is causing their illness. Compounding the problem is the cumulative nature of CO toxicity: the gas builds up in the bloodstream over time and can linger in the body for days, months, or even years after exposure ends. Bryan draws an entertaining but sobering historical connection between the prevalence of carbon monoxide poisoning during the Victorian era — when gas lamps were common inside homes — and the widespread reports of ghost sightings, fugue states, fainting spells, and the spiritualist movement of the time. It was almost certainly CO poisoning, not the paranormal. The conversation then shifts to practical, on-the-job guidance for technicians and contractors. Bryan and Louise walk through the proper process for combustion analysis: starting your analyzer outside in fresh air, identifying test ports on furnaces, boilers, and water heaters, and understanding what readings at steady state actually mean. They emphasize that CO production is not limited to furnaces alone — ranges, ovens, dryers, fireplaces, water heaters, and even propane-powered forklifts are all legitimate sources. One of the most critical points they make is that carbon monoxide hazards are often intermittent and condition-dependent. A system can appear to be working perfectly during one visit and be producing dangerous levels the next time a door is closed or a vent is accidentally blocked. Visual inspection, awareness of combustion air sourcing, and thoughtful analysis are just as important as having the right instruments. On the product side, Louise introduces two exciting new offerings from UEI. The first is the UEI Clip, a compact personal CO detector that clips onto a bag, belt, or lanyard, activates automatically at 20 ppm, and is designed as a set-it-and-forget-it safety device with a two-year sealed battery lifespan. Priced under $100, it is an affordable way to outfit an entire team with a baseline layer of personal protection. The second highlight is the new High Accuracy Clamp Meter (HAC), a commemorative product celebrating the United States’ 250th anniversary. This meter excels at wattage measurement — particularly with low-draw ECM blower motors where most meters fall short — and Bluetooth integration with MeasureQuick is on the horizon. Louise also walks through UEI’s revamped combustion analyzer recertification program, UEI Service Plus, which offers same-day turnaround on standard recertifications at their Indianapolis facility, extended warranties with each annual service, and transparent, upfront pricing directly on their website. Topics Covered The history of carbon monoxide research dating back to publications from 1922 and 1923, and a 1923 patent for a hot water heater that sparked a friendly debate between Bryan and Louise about terminology. How low-level, chronic CO exposure is underdiagnosed and can mimic conditions like the flu, chronic headaches, early-onset Alzheimer’s, and heart attack symptoms — and why CO builds up cumulatively in the bloodstream. The fascinating historical theory connecting widespread Victorian-era reports of ghosts, fugue states, and fainting spells to chronic carbon monoxide poisoning from indoor gas lamps. CO safety thresholds: residential standard (9 ppm), World Health Organization guideline (4 ppm), first responder evacuation threshold (35 ppm), and how UL-rated home alarms may not trigger until 70 ppm sustained for 1–4 hours. Sources of CO that technicians often overlook, including ovens, ranges, dryers, fireplaces, water heaters, propane forklifts, generators, and vehicles idling near garages. Proper combustion analysis procedure: starting the analyzer outside in ambient air, identifying or installing test ports, running tests at steady state, and interpreting O2, CO, and stack temperature readings. Industry CO standards for furnaces: official standard (400 ppm), HRI recommendation (200 ppm), industry best practice (100 ppm), and modern high-efficiency benchmarks (50 ppm or less). How combustion air sourcing — and changes to it (new roofs, blocked vents, swapped doors) — is one of the most commonly missed risk factors for CO production. Why even “heat pump markets” like Florida still need combustion analysis, since over 90% of homes have at least one fuel-fired appliance. Introduction of the UEi Clip personal CO detector: set-and-forget, activates at 20 ppm, sealed 2-year battery, priced under $100, and its unexpected popularity among refrigeration technicians. Introduction of the UEi High Accuracy Clamp Meter (HAC) commemorative edition: exceptional accuracy at low current draws (ideal for ECM blower motors), full accessory kit included, and upcoming measureQuick Bluetooth integration. UEi’s Service+ combustion analyzer recertification program: same-day turnaround at their Indianapolis lab, extended warranty with each annual service, prepaid UPS shipping labels, and transparent pricing on their website. A brief spotlight on UEi as a family-owned business founded by Michael Kane’s parents, with their own manufacturing operations in the UK and Korea. Learn more about UEi's new and longstanding products, as well as the Service+ guarantee, at . Have a question that you want us to answer on the podcast? Submit your questions at . Purchase your tickets or learn more about the 7th Annual HVACR Training Symposium at . Subscribe to our podcast on your or . Subscribe to our channel. Check out our handy here or on the HVAC School Mobile App for and . /episode/index/show/hvacschool/id/40152730

Heat Exchanger Crack Comment - Short #280 02/24/2026

Dehum Innovations and Essentials w/ Nikki K. 02/19/2026

Dehum Innovations and Essentials w/ Nikki K. In this live episode recorded at the AHR Expo 2026 Podcast Pavilion in Las Vegas, host Bryan sits down with longtime friend and industry expert Nikki Krueger of Santa Fe and AprilAire. Nikki brings over 15 years of experience in indoor air quality and whole-home dehumidification to the conversation, having started her career with AprilAire before moving to Santa Fe (formerly Ultra Aire) — and now coming full circle as the two brands have integrated under the AprilAire umbrella as of January 1st of this year. The episode dives deep into a topic close to both hosts’ hearts: how to properly manage indoor humidity, and what role a whole-home ventilating dehumidifier plays in a comprehensive HVAC system strategy. Bryan and Nikki lay out a holistic framework for tackling moisture problems, emphasizing that a dehumidifier should be the last tool added — not the first. Before reaching for dedicated dehumidification equipment, contractors need to assess the building envelope for air leaks, evaluate whether the air conditioning system is properly sized (oversizing is a major contributor to poor latent removal), confirm that the AC is set up with the right airflow and sensible heat ratio, and take into account the ventilation strategy and occupant behavior. The pair discuss real-world scenarios ranging from elderly residents in Florida who keep their thermostats at 80°F, to a project in Barbados where overcooling caused interstitial condensation in walls and ceilings. The message is clear: humidity control is a systems problem, not a single-product fix. A significant portion of the episode is dedicated to proper installation practices for whole-home dehumidifiers. Nikki explains why Santa Fe recommends pulling from a dedicated return and discharging into the supply side of the AC duct — rather than tying into the return side — because the heat generated by dehumidification (roughly 1,054 BTUs per pint of water removed) can warm the AC evaporator coil and reduce its latent removal capacity. Bryan adds nuance around dew point management when routing outdoor air ducts, and both hosts agree that fan operation strategy (continuous low-speed vs. intermittent) matters more in tight, low-load homes where mixing is harder to achieve naturally. They also clarify a common misconception: a ventilating dehumidifier is not a dedicated outdoor air system (DOAS) and does not automatically condition incoming ventilation air before it enters the home. The conversation wraps up with an exciting look at Santa Fe’s newly launched Ultra V Series, which features an upgraded 8-inch ventilation duct (up from 6 inches), a more powerful fan for handling higher static pressure in retrofit applications, a new digital control panel, and a wired remote humidity sensor that can be placed in the living space for more accurate readings. Nikki and Bryan also field audience questions on topics like short-cycling risks from oversized dehumidifiers and why Santa Fe chose a wired sensor over wireless (accuracy, reliability, and fewer callback headaches). Bryan closes by noting that rising dew points across most U.S. markets over the last 20 years make whole-home dehumidification more relevant than ever — and that any region where you can see green grass outside is a candidate for a more advanced moisture control strategy. Topics Covered Introduction to Nikki Krueger and the merger of Santa Fe and AprilAire under one brand The purpose of whole-home ventilating dehumidifiers and how they fit into an overall HVAC system strategy Latent vs. sensible heat loads explained — and why both matter for comfort and moisture control Geographic reach of humidity problems — why dehumidification isn’t just a Florida or Gulf Coast issue Ken Gehring (“Teddy Bear”), inventor of the whole-house ventilating dehumidifier, and his framework for diagnosing moisture problems The four-factor checklist before deploying a dehumidifier: building envelope, AC sizing, AC setup/airflow, and ventilation strategy How occupant behavior (thermostat preferences, activity levels, large households) creates latent load variability The dangers of overcooling — how setting thermostat too low can cause interstitial condensation in walls, ceilings, and attics Sensible heat ratio (SHR) and its role in a system’s ability to remove moisture — targeting ~350 CFM per ton in humid climates Why dehumidifiers should connect to a dedicated return and discharge into the supply — not tie into the AC return side How dehumidifier heat output (~1,054 BTUs per pint) can reduce AC coil efficiency when ducted incorrectly Fan-on strategy debate: when running continuous low-speed circulation helps vs. hurts humidity control Tighter homes, smaller systems, and the importance of air mixing strategies (including ceiling fans) Ventilating dehumidifiers vs. dedicated outdoor air systems (DOAS) — clearing up a common misconception about how ventilation air is conditioned Dew point management for outdoor air ducts — preventing condensation inside duct runs Using dehumidifiers to address sweating ductwork in multi-story homes Rising dew points over the past 20 years and what “green grass climates” means for dehumidification demand Heat pump oversizing challenges in colder climates and the downstream impact on AC latent removal Santa Fe’s new Ultra V Series: 8-inch ventilation duct, stronger fan, digital controls, and wired remote humidity sensor Why proper dehumidifier sizing matters: short-cycling risks, moisture reservoir release, and uneven RH throughout the home Why Santa Fe chose a wired humidity sensor — accuracy, reliability, and reducing contractor callbacks Audience Q&A: oversizing consequences, short-cycling mechanics, and sensor placement best practices Learn more about Santa Fe Dehumidifiers at . Connect with Nikki Krueger on LinkedIn or Instagram @nikkikruegerIAQ. Check out the work of Ken Gehring ("Teddy Bear") or ask him a question on the HVAC Talk Forum: . Have a question that you want us to answer on the podcast? Submit your questions at . Purchase your tickets or learn more about the 7th Annual HVACR Training Symposium at . Subscribe to our podcast on your or . Subscribe to our channel. Check out our handy here or on the HVAC School Mobile App for and . /episode/index/show/hvacschool/id/40091100

Lifetime of HVAC/R w/ John Pastorello - Short #279 02/17/2026

Lifetime of HVAC/R w/ John Pastorello - Short #279 In this short podcast episode from AHR Expo 2026, Bryan sits down with John Pastorello for a discussion about the latter's lifetime of HVAC/R. John was a chemist and an HVAC technician before founding Refrigeration Technologies in 1987, and he received the HVAC Tactical Lifetime Achievement Award in 2026. Prior to entering the trade, John was a chemist in a lab. He applied for and was hired by an HVAC company when he realized the financial opportunity in the trade. He eventually owned a contracting business, but he didn't truly make his HVAC/R chemistry debut until 1987 with Big Blu. When he noticed problems with existing liquid leak reactants and inaccurate electronic leak detectors, John developed Big Blu in his kitchen (with the help of his local library and patent office for research) and tested it in the field. Big Blu was the first Refrigeration Technologies product, and it was the only one for a while. He then developed Nylog in the early 1990s while developing a different product. After falling down research rabbit holes and doing lots of trial and error, he eventually realized the product's potential as an assembly lubricant, and Nylog became an official Refrigeration Technologies product. Even as Refrigeration Technologies continues to grow and has received several purchase offers, it remains a family business. John's son, Mike, became a mechanic but eventually decided to return to the business, and he runs it to this day. John's career culminated with the HVAC Tactical Lifetime Achievement Award, which is a testament to the service, education, and mentorship he has shared with the HVAC/R industry. Have a question that you want us to answer on the podcast? Submit your questions at . Purchase your tickets or learn more about the 7th Annual HVACR Training Symposium at . Subscribe to our podcast on your or . Subscribe to our channel. Check out our handy here or on the HVAC School Mobile App for and . /episode/index/show/hvacschool/id/40087480

Vapor Injection + Modulation Innovation w/ Copeland 02/12/2026

Vapor Injection + Modulation Innovation w/ Copeland In this live episode from the AHR 2026 Podcast Pavilion, Bryan sits down with Copeland's Josh Souders (Manager of Commercial Unitary Product Management) and Jeff Kukert (Compression Senior Technical Trainer) to dive deep into Enhanced Vapor Injection (EVI) technology and its transformative impact on HVAC systems. This conversation offers both technical professionals and industry newcomers a comprehensive look at how vapor injection is revolutionizing heat pump performance, particularly in challenging climate conditions. The discussion centers on how EVI technology addresses one of the industry's most persistent challenges: maintaining high heat pump capacity in extremely low-temperature conditions. Josh and Jeff explain that vapor injection can deliver up to 20% added capacity and 10% improved efficiency while simultaneously enhancing compressor reliability. This technology, which has been a staple in refrigeration applications for years, is now becoming increasingly prevalent in commercial and residential HVAC systems, especially as cold climate heat pumps gain traction across North America. The guests make the complex topic accessible by breaking down how the system works—taking liquid refrigerant from the condensing line, running it through an expansion device and brazed plate heat exchanger (economizer), and injecting the cooled vapor directly back into the compressor scroll at a specific intermediate point. What makes this episode particularly valuable is the practical guidance offered for field technicians. The conversation moves beyond theoretical explanations to address real-world implementation challenges and troubleshooting strategies. Josh and Jeff emphasize the importance of understanding operating envelopes, pulse-width modulated (PWM) valves, pressure transducers, and modern control systems. They introduce Copeland's latest product developments, including the YAW variable speed vapor injection platform (1.5 to 25 tons) and the upcoming YAB two-stage vapor injection system launching later in 2026. The discussion also touches on applications beyond traditional HVAC, including commercial water heating and boiler replacement systems where high discharge temperatures are crucial. Throughout the episode, the guests maintain an encouraging tone toward technicians who may feel intimidated by these advancing technologies. They stress that while EVI systems may appear complex with additional tubing, heat exchangers, valves, and sensors, the underlying thermodynamic principles remain the same. The key is familiarizing oneself with new components like PWM valves and modern controllers, and leveraging tools like Copeland Mobile to verify system performance against operating envelopes. This episode serves as both an educational resource and a call to action for HVAC professionals to embrace these emerging technologies that are rapidly becoming industry standard. Topics Covered Enhanced Vapor Injection (EVI) fundamentals – How EVI works, its history in refrigeration, and why it's now critical for commercial and residential HVAC applications Capacity and efficiency benefits – Achieving up to 20% capacity boost and 10% efficiency improvement, particularly in low-ambient heating conditions Compressor reliability improvements – How injecting cooled vapor into the scroll set manages discharge temperatures and extends compressor life under high compression ratios Operating envelope management – Understanding compressor operational limits and using tools like Copeland Mobile to verify field conditions stay within safe parameters Cold climate heat pump technology – Meeting DOE's Cold Climate Heat Pump Challenge requirements for 100% capacity at 5°F ambient conditions System architecture and components – Detailed explanation of economizers (brazed plate heat exchangers), pulse-width modulated (PWM) valves, pressure transducers, and advanced controllers Compression ratio challenges – Managing the increased work required when outdoor temperatures drop while indoor condensing temperatures remain constant New Copeland product platforms – Introduction to YAW variable speed vapor injection (1.5-25 tons), YAB two-stage vapor injection (launching 2026), and tandem variable speed configurations Applications beyond traditional HVAC – Water heating systems, commercial boiler replacement, and managing high discharge temperatures for Legionella protection Technician training and tools – Practical advice on learning PWM valves, thermistors, transducers, and system controllers; emphasis on using Copeland Mobile for dynamic performance analysis Market trends and adoption – How vapor injection is becoming standard in premium residential systems and increasingly common across commercial rooftop units and dedicated outdoor air systems Installation and service considerations – Proper system design to avoid oversizing, humidity control in hot-humid climates, and troubleshooting techniques for complex control systems Have a question that you want us to answer on the podcast? Submit your questions at . Purchase your tickets or learn more about the 7th Annual HVACR Training Symposium at . Subscribe to our podcast on your or . Subscribe to our channel. Check out our handy here or on the HVAC School Mobile App for and . /episode/index/show/hvacschool/id/40078585

TXV vs. EEV - Short #278 02/10/2026

TXV vs. EEV - Short #278 In this short podcast episode, Bryan breaks down the differences between a thermostatic expansion valve (TXV) and an electronic expansion valve (EEV). He highlights their strengths and weaknesses. In the basic refrigerant circuit, the metering device drops the pressure. TXVs and EEVs are both metering devices that cause the liquid refrigerant to drop in pressure and become a liquid-vapor mixture; they control evaporator feeding and maintain a constant superheat. TXVs achieve this by mechanical means; the bulb responds to suction line temperature and evaporator pressure at the valve. They are self-contained and easy to diagnose with basic refrigeration measurements. However, they are prone to mechanical failures, including clogged orifices and screens, cracked capillary tubes, and powerhead leaks. Installation errors are also easy to make, and TXVs can hunt in low-load conditions. Overall, failures are often mechanical and refrigerant-related. They win in the simplicity department. EEVs receive inputs from sensors and modulate in response to those digital signals. They have a wider modulation range and maintain stable control in low-superheat applications, and they do well in conditions with highly variable loads or where coordination across multiple coils is required. EEVs come in two types: stepper motor (small, discrete steps) and PWM (controlled solenoid valves). Stepper-style EEVs excel at fine positioning, and PWM-style EEVs are in applications that require a more robust valve (like CO2 refrigeration). EEV failures are often electromechanical or related to sensor control. They win in the controllability department. There is no "best" metering device; they merely have different strengths that make them better suited to different applications. However, EEVs are the future due to the greater degree of controllability we will need in newer equipment. Commissioning and airflow are also crucial for getting the most out of both metering device types in terms of longevity and reliability. Have a question that you want us to answer on the podcast? Submit your questions at . Purchase your tickets or learn more about the 7th Annual HVACR Training Symposium at . Subscribe to our podcast on your or . Subscribe to our channel. Check out our handy here or on the HVAC School Mobile App for and . /episode/index/show/hvacschool/id/39992630

Electric Heat Talk w/ Bert 02/05/2026

Electric Heat Talk w/ Bert In this informative episode, host Bryan welcomes guest Bert for an in-depth discussion on the often-overlooked but critically important topic of electric heat in HVAC systems. The conversation takes listeners through both the common and uncommon issues that arise with electric heat installations, offering practical insights drawn from years of field experience. Bryan and Bert balance technical expertise with relatable storytelling, making complex electrical concepts accessible to both HVAC professionals and homeowners interested in understanding their heating systems. The discussion begins with some of the more dramatic (and rare) scenarios, including tales of objects left on heat strips during installation—from instruction manuals to spray glue cans—that have led to fires and property damage. These cautionary tales serve as memorable reminders of the importance of proper installation practices. The conversation then shifts to the far more common issues technicians encounter regularly, particularly loose electrical connections. With electric heat strips drawing substantial continuous amperage—often 20 amps per 5kW or more—poor connections can quickly lead to melted wire nuts, damaged terminal blocks, and potentially dangerous situations. Bryan and Bert emphasize that these connection problems often don't manifest until the heating season begins, making proper installation and inspection critical. Bryan and Bert also address widespread confusion around emergency heat versus auxiliary heat, explaining why emergency heat settings are largely obsolete in most modern heat pump applications. They clarify that in typical residential installations with 5-10kW heat strips, the electric backup cannot efficiently heat an entire home on its own, making the emergency heat function impractical. Instead, auxiliary heat should work in tandem with the heat pump to supplement heating during extremely cold conditions or defrost cycles. The hosts advocate for implementing lockout controls that prevent auxiliary heat from activating unless outdoor temperatures drop below 40 degrees, helping homeowners avoid unnecessarily high electricity bills while still maintaining comfort. The technical discussion extends to critical safety mechanisms, including interlocks, thermal overloads, and fusible links that prevent catastrophic failures. Bryan provides historical context on how interlock systems have evolved from high-voltage relay-based designs to modern control board logic, while warning against improper retrofitting that can create new hazards. The episode concludes with practical guidance on proper sizing, voltage considerations, airflow requirements, and the economics of electric heat versus other fuel sources. Throughout the conversation, Bryan and his guest stress that while electric heat is simple and reliable, it demands respect for proper electrical practices and thoughtful system design to ensure both safety and cost-effectiveness. Topics Covered Installation Horror Stories and Safety Hazards: Objects left on heat strips causing fires, including the infamous spray glue can incident Loose Electrical Connections: The #1 issue with electric heat systems and why continuous high amperage makes proper connections critical Wire Sizing and Breaker Matching: Common mistakes when replacing furnaces with heat pumps and the dangers of undersized wiring Emergency Heat vs. Auxiliary Heat: Why emergency heat is largely obsolete in modern residential applications and when auxiliary heat should actually engage Heat Output Calculations: Understanding BTU production per kilowatt (3.41 BTUs per watt) and why 5-10kW strips can't heat most homes alone Lockout Controls and Outdoor Thermostats: Implementing temperature-based restrictions to prevent unnecessary auxiliary heat operation above 40°F Interlock Systems Evolution: How blower/heat strip safety interlocks have changed from relay-based to control board logic Thermal Overloads and Fusible Links: The two types of safety devices that prevent overheating and fire hazards Defrost Cycle Operation: How auxiliary heat integrates with heat pump defrost sequences Balance Point and Dual Fuel Considerations: Economic and operational factors in choosing between electric and gas backup heat Voltage Variations and Sizing: Working with different voltage ratings (208V vs. 240V) and how they affect heat output Diagnostic Techniques: Using Ohm's law and resistance measurements to verify heat strip operation and specifications Airflow Requirements: Why proper air movement is critical for preventing overload trips and premature failures Electrical Safety Practices: Avoiding dangerous shortcuts like bypassing thermal limits or using undersized relays Energy Efficiency and Economics: Comparing the true cost-effectiveness of electric heat versus gas and heat pump operation Have a question that you want us to answer on the podcast? Submit your questions at . Purchase your tickets or learn more about the 7th Annual HVACR Training Symposium at . Subscribe to our podcast on your or . Subscribe to our channel. Check out our handy here or on the HVAC School Mobile App for and . /episode/index/show/hvacschool/id/39798560

Vapor Diffusion Ports, Hygric Buoyancy, and Fruit - Short #277 02/03/2026

Vapor Diffusion Ports, Hygric Buoyancy, and Fruit - Short #277 In this short podcast episode, Bryan talks about some building science concepts, including vapor diffusion ports, hygric buoyancy, and... fruit packaging? Much of building science wisdom over the past couple of decades has dealt with air sealing (just seal it tighter!). However, building tightness has a darker side: more difficulty drying. When buildings can't dry, moisture accumulates and leads to rot. Air leaks and vapor diffusion are NOT the same thing. Vapor diffusion refers to water vapor diffusing through surfaces into the home (through the materials of walls, floors, etc.). Air moves much more water than vapor diffusion, so air leaks are a bigger problem in terms of moisture. Therefore, air barriers matter more than vapor barriers... until the air barrier battle has been won. Hygric buoyancy refers to moist air's lower density than dry air, so wet air rises toward the attic (and then the attic peaks). While sealed attics are excellent, moisture can accumulate at the roof deck, especially when the roofing cools at night. The condensation is worsened by using open-cell foam, as open-cell foam is air-closed but vapor-open (whereas closed-cell foam is air-closed AND vapor-closed). Drying isn't needed if you can KEEP the moisture out of closed-cell foam. Open-cell foam requires a place for vapor to go. Vapor diffusion ports are airtight, controlled vapor-open outlets at the highest points of sealed attics. A cap protects them from bulk water, and they consist of a membrane that blocks air but allows vapor to exit. Unlike a ridge vent, ventilation is not the goal of a vapor diffusion port; it is drying by diffusion rather than airflow and acts as a controlled pressure-relief valve for moisture. Vapor diffusion ports have been proven to be effective at drying and preventing roof rot in humid climates (but NOT ALL climates). They do not work against bulk water intrusion, in cold climates, or when used as vents. Vapor diffusion ports work like fruit packaging, which is designed to let oxygen in and CO2 out, while controlling moisture and slowing decay. Have a question that you want us to answer on the podcast? Submit your questions at . Purchase your tickets or learn more about the 7th Annual HVACR Training Symposium at . Subscribe to our podcast on your or . Subscribe to our channel. Check out our handy here or on the HVAC School Mobile App for and . /episode/index/show/hvacschool/id/39937200

Gas & Combustion Safety w/ Bert 01/29/2026

Gas & Combustion Safety w/ Bert In this informative episode, Bryan and Bert dive deep into gas appliance safety and combustion analysis from the unique perspective of Florida HVAC technicians. While they humorously acknowledge that Florida's mild winters mean they don't work on gas furnaces daily, they make a compelling case that this actually makes their training even more critical. When technicians only encounter gas appliances occasionally, the stakes are higher—which is why they've developed rigorous protocols to ensure safety every single time. The conversation covers everything from the basics of gas leak detection to the nuances of carbon monoxide monitoring, combustion air zones, and proper venting. Bryan and Bert share real-world stories of dangerous situations they've encountered, from exploding pool heaters to improperly capped gas lines at vacation rentals. Their approach emphasizes that every gas leak is your problem when you're on site, regardless of why you were originally called out. This episode is packed with practical wisdom for both seasoned professionals working in gas-heavy markets and those who encounter these systems less frequently. Throughout the discussion, the hosts stress fundamental safety principles that apply across all markets: using your nose to detect leaks, understanding the difference between unspent gas and carbon monoxide, ensuring proper combustion air zones, and never ignoring warning signs like delayed ignition or flame rollout. They also tackle common misconceptions about equipment like flexible gas connectors, orphaned water heaters, and the real risks of cracked heat exchangers. The conversation wraps up with important reminders about company lockout/tagout procedures, the critical importance of low-level carbon monoxide detectors, and the tools every technician should carry. Bryan and Bert's candid, no-nonsense approach makes complex safety topics accessible while never losing sight of how serious the consequences can be when gas work goes wrong. Topics Covered Gas leak detection and response protocols - Why every gas leak on site becomes your responsibility, using your nose as the first line of defense, and never leaving a leak for someone else to fix Carbon monoxide safety and monitoring - Understanding CO as a combustion byproduct, the limitations of standard UL-rated detectors, and the critical importance of low-level CO monitors Combustion air zones and depressurization - Identifying risks from sealed spaces, return air leaks, exhaust fans, and other equipment that can create dangerous negative pressure Delayed ignition and flame rollout - Recognizing warning signs, understanding causes, and why you should never ignore scorched wires or tripped rollout switches Proper gas line assembly and materials - Selecting appropriate materials for different environments, avoiding flexible connector failures, and ensuring proper sizing Combustion analysis fundamentals - Measuring CO levels in the flue, targeting air-free CO under 100 ppm, and understanding when adjustments are needed Natural draft vs. induced draft systems - Differences in safety considerations, orphaned water heaters, and the myth of oversized flue pipes Venting requirements and back drafting - Identifying improper venting, looking for evidence of back draft on water heaters, and ensuring proper flue design Gas pressure testing and adjustment - When to adjust and when not to, reading data tags, and understanding that most flame problems are air-related, not gas pressure Cracked heat exchangers in context - Why they're less common in warm climates, the role of proper airflow, and focusing on actual safety risks vs. edge cases Tools and equipment recommendations - Combustion analyzers, personal protective CO detectors, combustible gas detectors, precision manometers, and low-level CO alarms Lockout/tagout procedures - Following company protocols, communicating clearly with customers, and balancing safety requirements with homeowner autonomy Have a question that you want us to answer on the podcast? Submit your questions at . Purchase your tickets or learn more about the 7th Annual HVACR Training Symposium at . Subscribe to our podcast on your or . Subscribe to our channel. Check out our handy here or on the HVAC School Mobile App for and . /episode/index/show/hvacschool/id/39785990

WHY SQUARE FOOTAGE ≠ TONNAGE - Short #276 01/27/2026

WHY SQUARE FOOTAGE ≠ TONNAGE - Short #276 In this short podcast episode, Bryan dives a bit into equipment sizing rules of thumb and why square footage does NOT equal tonnage in today's world. Many rules of thumb exist in the industry, and one is a load calculation rule stating that you can size the HVAC for a house at 500 square feet per ton. Old houses are leaky and poorly insulated compared to new homes, which results in large energy loads but allows the homes to dry themselves out, as moisture could leak out before it could cause trouble indoors. Large loads and leaky envelopes made 500-600 square feet per ton a sensible rule. Homes built within the last few decades have a lot more insulation and are tighter, and they have smaller sensible heat loads. However, they're a lot more moisture-prone, especially when moisture can't escape via proper ventilation paths. The 500 square-foot rule of thumb overshoots the latent capacity and leads to short cycling due to oversized equipment. Enter ACCA Manual J, which presents a load calculation method that is very good, but it has barriers to entry; it is very rigorous, has a learning curve, and can be a hassle. One thing is clear, though: load management is key, especially latent load management. At this time, we measure energy efficiency in terms of metrics like SEER, but the future is pointing to peak load management as the answer: getting the right power draw at the right moments instead of high general efficiency. Modernizing hot deck-cold deck systems with steady-state, constantly running systems might be the way to go, especially if we utilize energy storage and modern variable-speed technologies. The new rule of thumb is to think like a building scientist and apply new tools to concepts that have stood the test of time. Low peak loads and steady-state operation are often the way to go with high latent loads in homes built to the most recent building codes and standards. Have a question that you want us to answer on the podcast? Submit your questions at . Purchase your tickets or learn more about the 7th Annual HVACR Training Symposium at . Subscribe to our podcast on your or . Subscribe to our channel. Check out our handy here or on the HVAC School Mobile App for and . /episode/index/show/hvacschool/id/39501475

EPRs and Rack Refrigeration w/ Matthew Taylor 01/22/2026

EPRs and Rack Refrigeration w/ Matthew Taylor Matthew Taylor delivers an expert-level presentation on EPRs, building on his previous work on parallel rack systems. While his earlier content focused on the similarities between air conditioning and refrigeration, this session explores what makes commercial refrigeration unique—particularly the critical role of EPRs in maintaining optimal operating conditions across multiple evaporators running at different temperatures. This presentation was shared at the 6th Annual HVACR Training Symposium. The discussion begins with a fundamental review of the refrigeration cycle in a typical supermarket setting, where 30 to 80 evaporators may share a common suction line. Matthew explains why EPRs are essential: when multiple cases need to operate at different temperatures (ranging from -13°F for frozen foods to 24°F for fresh products) but all connect to the same compressor rack, EPRs become the solution that makes this possible. Without them, cases would cycle on and off constantly, creating efficiency nightmares, oil management problems, and potential food safety issues. Matthew walks through the mechanical principles of various EPR types, from the high-efficiency Sporlan SORIT valve with its pilot-operated design to the Parker A8 valve that can be installed directly in the store. He also addresses the industry's shift toward electronic EPRs, particularly the CDS modules that offer temperature-based control rather than just pressure regulation. Throughout the presentation, Matthew emphasizes practical considerations: how EPRs affect compressor staging, oil system pressure, defrost cycles, and ultimately, the core product temperatures that determine food safety. The session includes real-world troubleshooting insights and addresses common misconceptions about setting superheat on systems with EPRs. This technical presentation provides HVAC professionals with the knowledge needed to understand, diagnose, and service EPR-equipped refrigeration systems confidently. Matthew's approach demystifies a component that many technicians find intimidating, breaking it down into understandable principles while highlighting the critical role EPRs play in modern commercial refrigeration efficiency and reliability. Topics Covered Basic Refrigeration Cycle in Supermarket Applications – Understanding parallel rack systems with 30-80 evaporators sharing common suction and liquid lines Oil Management Systems – Oil separators, oil reservoirs, oil regulators, and the critical pressure differential required for proper oil flow Compressor Staging and Capacity Control – How parallel rack compressors operate as multi-stage units to match system load efficiently Saturated Suction Temperature (SST) – Why racks are designated by temperature (e.g., "13-degree rack" or "-13 degree rack") and how this relates to the coldest evaporator requirement Temperature Difference (TD) Engineering – The relationship between evaporator temperature and case leaving air temperature, typically 10 degrees in traditional systems EPR Fundamentals – Why EPRs are necessary to maintain different evaporator pressures on cases operating at various temperatures while connected to a single rack Mechanical EPR Types – Comparison of Sporlan SORIT valves (pilot-operated, low pressure drop) versus Parker A8 valves (self-contained, higher pressure drop) Electronic EPR Systems – Modern CDS modules and other electronic controls offering pressure control, temperature control, or hybrid approaches System Stability and Load Management – How proper EPR settings prevent compressor hunting, reduce energy consumption, and protect oil management systems Subcooling Requirements – Why liquid receivers eliminate natural subcooling and how mechanical subcoolers restore it before expansion devices Core Product Temperature – The critical relationship between runtime, EPR settings, and food safety in refrigerated cases Dual-Temperature Applications – Converting medium-temp cases to low-temp operation (like holiday turkey displays) using EPR pilot solenoids Superheat Setting Procedures – Why EPRs must be overridden to 50-100% open position when setting TXV superheat High Glide Refrigerants – Special considerations for setting EPRs with refrigerants that have significant difference between dew point and bubble point temperatures Troubleshooting Philosophy – Understanding EPRs and TXVs as independent systems that don't directly affect each other due to non-critically charged liquid receiver systems Pressure Drop Considerations – How EPR pressure losses (0.5-2 psi depending on type) affect compressor suction setpoints and energy efficiency Electronic Control Integration – Various controller brands and approaches to managing electronic EPRs, from pressure transducers to temperature sensors and PID algorithms Have a question that you want us to answer on the podcast? Submit your questions at . Purchase your tickets or learn more about the 7th Annual HVACR Training Symposium at . Subscribe to our podcast on your or . Subscribe to our channel. Check out our handy here or on the HVAC School Mobile App for and . /episode/index/show/hvacschool/id/39552825

Combustion vs. Compression - Short #275 01/20/2026

Combustion vs. Compression - Short #275 In this short podcast episode, Bryan covers the history of the great heating debate: furnaces vs. heat pumps or combustion vs. compression. He also gives a breakdown of each other's strengths and gives his two cents on the winner of the debate. Fire kept humans warm for much of history, but engineers developed a way to move heat by manipulating refrigerant pressures. Early heat pumps got a bad rap because they didn't live up to the hype; they had frequent operational issues, didn't heat effectively, and were largely unable to be serviced effectively by technicians. However, heat pumps have evolved and now outperform furnaces in many areas. Ones with COPs between 2 and 5 can be anywhere from 200-500% efficient in terms of watts in, BTUs out. They also have many safety benefits over gas furnaces, including no risk of flame rollout, carbon monoxide poisoning, and gas leaks; removing the gas meter and all its risks entirely is a possibility. Nevertheless, some people still insist that combustion is king due to its comfort, as furnaces' heat is more intense than that of heat pumps. Furnaces also require little electricity, making them more sensible in markets with weak or dirty electrical grids. Combustion appliances also only need to work part of the year, meaning they run fewer cycles and experience less mechanical wear over the same period of time as heat pumps (thus may have longer lifespans). Dual fuel allows you to get the best of both worlds; it allows the heat pump to handle the cooling and most of the heating for the energy efficiency benefits, and the furnace can step in when more intense heat is needed. Ultimately, the "winner" of this debate, at least to Bryan, is the most sensible solution for energy costs, safety, comfort, and reliability; the real answer will depend on the climate, infrastructure, and other factors. Have a question that you want us to answer on the podcast? Submit your questions at . Purchase your tickets or learn more about the 7th Annual HVACR Training Symposium at . Subscribe to our podcast on your or . Subscribe to our channel. Check out our handy here or on the HVAC School Mobile App for and . /episode/index/show/hvacschool/id/39431005

HVAC In the Northeast w/ Leo & Paul Sharkey 01/15/2026

HVAC In the Northeast w/ Leo & Paul Sharkey In this engaging episode of the HVAC School podcast, host Bryan Orr sits down with Leo and Paul Sharkey, a father-son duo of mechanical engineers who made the leap into the HVAC business. Leo and Paul share their remarkable journey of purchasing an HVAC company in September 2020 and quadrupling its revenue within five years. Their engineering backgrounds bring a refreshing, data-driven perspective to an industry that often relies on rules of thumb and outdated practices. The Sharkeys operate in the challenging Northeast market, where homes can date back to the 1600s and 1700s. They discuss the eye-opening discovery that traditional HVAC sizing methods—like the simplistic "one ton per 400 square feet" rule—fail dramatically in older housing stock. Their commitment to running thousands of Manual J calculations has transformed their approach, often resulting in smaller, more efficient systems than competitors propose. The conversation dives deep into the unique challenges of working with centuries-old New England homes, including extreme infiltration rates, non-linear heat loss curves during harsh winters, and the complications of mixing modern additions with ancient construction. Beyond sizing, Leo and Paul tackle the practical realities of heat pump installations in cold climates. They explain why turndown ratio is critical, how they handle homes with heat loads that triple their cooling loads, and when backup heating systems are truly necessary. Their consultative approach rejects the "one-size-fits-all" mentality that has flooded the market with incentive-chasing installations. They candidly discuss the problems created by Massachusetts' generous rebate programs, which have attracted fly-by-night operators who prioritize rebate qualifications over proper design and long-term performance. The episode also explores the balance between ductless and ducted systems, revealing when each approach makes economic and technical sense. The Sharkeys share fascinating case studies, from a 1748 house with the equivalent of a full-size door's worth of air leakage to underground concrete dome homes requiring specialized dehumidification. Their willingness to take on complex projects that other contractors avoid demonstrates how engineering thinking, combined with trade expertise, can solve challenging HVAC problems. This conversation is essential listening for anyone serious about understanding cold climate HVAC design, building science principles, and what it takes to deliver quality comfort solutions in real-world conditions. Topics Covered Engineering background transition to HVAC - How mechanical engineering experience in semiconductors and manufacturing informed their HVAC business approach Manual J calculations and proper sizing - Running 7,000-9,000 Manual J calculations over five years and why they typically specify smaller systems than competitors Old New England housing challenges - Working with homes from the 1600s-1700s, extreme infiltration rates, and heat loss characteristics of ancient construction Heat load vs. cooling load imbalances - Managing homes where heat loads can be triple the cooling loads and how this affects system design Heat pump turndown ratios - Why equipment turndown capability is critical for shoulder seasons and preventing short cycling in cold climates Cold weather performance and derating - Equipment capacity loss at low ambient temperatures and the importance of proper backup heat sizing Ductless vs. ducted system economics - When to choose multi-zone ductless over ducted systems based on home layout, infrastructure, and cost Retrofit complications in mixed construction - Dealing with homes that combine 200-year-old sections with modern additions on the same heating system Massachusetts incentive programs - How Mass Save rebates (up to $25,000 financing + $10,000 rebates) have impacted market quality and contractor behavior Installation challenges at low temperatures - Field issues including undersized ductwork, poor equipment placement, defrost cycle complications, and electric backup heat requirements Building science fundamentals - Blower door testing, weatherization impacts, infiltration effects on heat load, and wind loading considerations Consultative sales approach - Rejecting one-size-fits-all solutions and customizing system recommendations based on home characteristics and homeowner needs Backup heating strategies - When and why fuel-based backup systems are necessary, including power outage considerations and client comfort levels Complex project examples - Case studies including underground concrete dome homes, storage closet air handler installations, and severely under-designed retrofit corrections Learn more about Leo and Paul's business, Jay Moody HVAC, at . Have a question that you want us to answer on the podcast? Submit your questions at . Purchase your tickets or learn more about the 7th Annual HVACR Training Symposium at . Subscribe to our podcast on your or . Subscribe to our channel. Check out our handy here or on the HVAC School Mobile App for and . /episode/index/show/hvacschool/id/39476435

Superheat in Heat Mode: Why Heat Pumps Get Weird - Short #274 01/13/2026

Superheat in Heat Mode: Why Heat Pumps Get Weird - Short #274 In this short podcast, Bryan answers a listener-submitted question and explains why heat pumps get a bit weird: when it comes to superheat in heat mode. He also explains how we can move heat from outdoors to indoors, even in temperatures below freezing (cold temperatures just have less heat, not zero heat). In order to move heat in very cold conditions, we need very low suction pressures and cold coils, which gives us a high compression ratio. Superheat will be affected by these conditions. Remember: superheat that is too low can cause floodback, and superheat that is too high can cause the compressor to overheat. Superheat is easy to check in cooling mode, but it's harder in heating mode, especially since the suction line is at the outdoor unit. In heating mode, we can only measure superheat between the coil outlet and the reversing valve inlet, which is a very short run of tubing. The superheat will also be less stable in heat mode in cold weather, and it will have a wider range of "normal" values than cooling mode, depending on the conditions. Superheat could even drop to zero with some fixed-orifice metering devices (which would cause floodback). That's why many of these heat pumps have accumulators, which collect liquid refrigerant to protect the compressor. Even though TXVs attempt to maintain superheat, you may still see some variation in heat mode during cold weather. EEVs are common in ductless systems and are highly controllable but maintain relatively low superheats by design; fast metering control, intelligent logic, accumulators, and low refrigerant charges allow them to avoid floodback in low temperatures. In any case, spikes and drops in temperature can cause the superheat to jump or collapse because the load changes (as the outdoor coil is the evaporator). Frost buildup on the coil also inhibits airflow and heat transfer, causing the superheat to change as the evaporator pressure and temperature drop. Defrost also introduces chaos to the equation. All of these should influence your judgment when checking superheat to diagnose or commission a system in heat mode. Have a question that you want us to answer on the podcast? Submit your questions at . Purchase your tickets or learn more about the 7th Annual HVACR Training Symposium at . Subscribe to our podcast on your or . Subscribe to our channel. Check out our handy here or on the HVAC School Mobile App for and . /episode/index/show/hvacschool/id/39411915

What We Learned From NCI Duct / Balancing Training 01/08/2026

What We Learned From NCI Duct / Balancing Training In this engaging and informative episode, Bryan sits down with Elliot to discuss his recent training experience with the National Comfort Institute (NCI), covering two intensive courses on duct system optimization and residential air balancing. The conversation offers valuable insights for HVAC professionals looking to improve their technical skills and provide better service to their customers. With a mix of technical expertise and practical field experience, this episode breaks down complex HVAC concepts into actionable strategies for contractors and technicians. Elliot shares his key takeaways from the NCI training, emphasizing how the courses filled critical knowledge gaps about the "invisible stuff" in HVAC systems—the air itself. The discussion reveals a common industry problem: most HVAC professionals focus heavily on equipment while neglecting proper duct design and air balancing. Elliot explains how he learned to move beyond guesswork in duct design, discovering that flex duct has actual CFM ratings and that proper system design requires understanding static pressure, equivalent length of fittings, and the science behind airflow. The conversation highlights the importance of oversized return air systems—a point both hosts stress repeatedly—and explains why Florida (and possibly the entire nation) suffers from chronically undersized returns. The hosts discuss various duct system approaches, from traditional trunk lines to the flex-and-fitting systems, acknowledging that different markets require different solutions based on climate, building construction, and supply chain availability. Throughout the episode, Bryan and Elliot tackle practical installation challenges that technicians face daily. They discuss the importance of proper flex duct installation, explaining how compressed or sagging ductwork dramatically reduces airflow efficiency. The conversation covers the critical role of balancing dampers in every branch run, the impact of proper duct strapping, and how simple adjustments like straightening kinked flex duct can immediately improve CFM delivery. The hosts also address the limitations of builder-grade installations, noting that most new construction lacks the dampers necessary for proper air balancing. They emphasize a practical, process-based approach to HVAC work that focuses on getting clients measurable results without requiring perfect conditions or unlimited budgets. The episode concludes with a strong endorsement of the National Comfort Institute's training programs and tools, particularly the TrueFlow Grid and measureQuick technologies that simplify complex air balancing calculations. Bryan and Elliot stress the importance of ethical, high-performance contracting that delivers real value to customers rather than just marketing sizzle. They encourage HVAC professionals to invest in training and proper tools, acknowledging that while the initial investment may seem steep, the ability to provide superior service and reduce callbacks makes it worthwhile. The conversation serves as both a technical deep-dive and a call to action for contractors to elevate their skills and focus on the whole system—equipment, ductwork, and building envelope—to truly solve customer comfort problems. Topics Covered NCI Training Experience - Elliot's overview of the duct system optimization and residential air balancing courses, including instructor quality and course relevance to Florida's HVAC market Duct Design Fundamentals - Moving from guesswork to calculated design using CFM ratings, square footage calculations, and proper system output considerations Static Pressure Management - Understanding static pressure drop across coils, the importance of variable speed fans, and strategies to reduce total external static pressure Return Air Systems - Why bigger returns are always better, the critical importance of oversized return grills, and the impact of filter face velocity on system performance Equivalent Length of Fittings - How fittings add "phantom" duct length to runs, techniques to reduce equivalent length, and the dramatic impact of turning vanes on 90-degree turns Flex Duct vs. Trunk Lines - Comparing different duct system approaches across various markets, the pros and cons of metal, duct board, and flex systems, and the flex-and-fitting methodology Proper Flex Installation - The importance of stretching flex duct correctly, proper strapping techniques, and how sagging or compressed flex drastically reduces airflow Air Balancing Techniques - The necessity of balancing dampers in every branch run, methods for achieving proper air distribution, and using velocity comparisons for troubleshooting Throw and Mixing in Rooms - Understanding that grills, not duct size, control air throw and mixing, and the role of Manual T in selecting appropriate terminal devices Practical Installation Tips - Simple improvements technicians can make during service calls, like straightening kinked ductwork and adding straps to reduce sag High-Performance Tools - The TrueFlow Grid, measureQuick app, hot wire anemometers, and other technologies that simplify complex air balancing calculations Building Performance Perspective - Moving beyond equipment-only focus to consider the entire system: ductwork, building envelope, and how they all interact Ethical Contracting - Delivering real value to customers, avoiding the "all sizzle, no steak" approach, and providing solutions that work within real-world budgets and constraints Learn more about NCI's training opportunities . Have a question that you want us to answer on the podcast? Submit your questions at . Purchase your tickets or learn more about the 7th Annual HVACR Training Symposium at . Subscribe to our podcast on your or . Subscribe to our channel. Check out our handy here or on the HVAC School Mobile App for and . /episode/index/show/hvacschool/id/39410725

HVAC Systems for Architects: Making Sense of the Alphabet Soup - Short #273 01/06/2026

HVAC Systems for Architects: Making Sense of the Alphabet Soup - Short #273 In this short podcast, Bryan answers a question submitted to HVAC School by an aspiring licensed architect who wanted to learn more about the many different types of HVAC systems. The three main buckets of HVAC systems are air-to-air, water-source, and air-to-water. Air-to-air systems move air around to remove heat from one space, and that heat is rejected to the air somewhere else. Water-source systems move water around the building and use water as the heat rejection medium. Air-water hybrid systems condition the load with water and may use air for ventilation; water or air may be used as the rejection medium. Systems may be direct-exchange (DX) and may transfer heat directly to refrigerant, or they may flow the air or water over a coil with water or glycol, utilizing a secondary fluid. Systems may also have separate indoor and outdoor architecture (split systems), or all components may be rolled into a single box (package unit). Package units include window units, PTACs, and RTUs. When it comes to forced-air systems, constant air volume (CAV) systems maintain the same volume of airflow (though the temperatures will change). Variable air volume (VAV) systems use one stream of cold air in a main duct, and each zone has a VAV box that functions as a damper to control zones individually. Dual duct systems have one cold duct and one warm duct that run parallel to each other and mix at each zone. Packaged rooftop units (RTUs) are self-contained with ducts that run down into the space and are common in retail spaces. Air-to-water systems use fan coil units (FCUs) fed with chilled or hot water. Air moves locally inside the space, so there is less ductwork and good zone control, but there are many units to manage. Chillers make chilled water, and that water is pumped around the building and sent to individual air handler units (AHUs). These are highly efficient and have large amounts of piping. They need mechanical rooms and dedicated personnel to maintain them. Variable refrigerant flow (VRF) systems are DX systems that are becoming more popular and consist of multiple indoor units with one or more outdoor units. Some of these can be used for heat recovery, meaning one space can be cooled while another is heated. Heat pump types include air-source, water-source, and ground-source. Air-source heat pumps absorb heat from the air via one unit and reject it via the other; the outdoor and indoor units can swap functions. Water-source heat pumps are common in commercial applications and have multiple heat pumps tied into a water loop that tries to stay within a given temperature range via boilers and cooling towers. Ground-source or geothermal heat pumps pick up heat from the earth's stable temperature and are highly efficient, but they have high installation costs. Passive systems come in all sorts of varieties and reduce the HVAC system's loads but don't replace HVAC systems in North America. Mechanical systems consist of straight-cool (air conditioner with electric heat), furnaces (gas, propane, or oil combustion), or heat pump (reversible air conditioners) systems. Have a question that you want us to answer on the podcast? Submit your questions at . Purchase your tickets or learn more about the 7th Annual HVACR Training Symposium at . Subscribe to our podcast on your or . Subscribe to our channel. Check out our handy here or on the HVAC School Mobile App for and . /episode/index/show/hvacschool/id/39409940

Sizing Breakers and Conductors (for HVAC) – Have Things Changed? 01/01/2026

Sizing Breakers and Conductors (for HVAC) – Have Things Changed? In this essential episode, Bryan Orr sits down with Elliot, the residential install supervisor at Kalos Services, to unpack a critical issue that's causing confusion among HVAC technicians, electricians, and inspectors alike: the new standards for breaker and conductor sizing on inverter-driven equipment. The conversation was sparked by Elliot's frustrating experience of having two inspectors in the same county fail the same installation for opposite reasons—one for an oversized breaker and another for an undersized breaker. This contradiction led to a deep dive into recent changes in UL standards and how they affect everyday HVAC installations. The heart of the issue stems from the transition to low-GWP refrigerants and the updated UL 60335-2-40 Edition 3 standard, which replaced the 1995 certification approach. This new standard introduced more conservative calculations for electrical characteristics, particularly affecting equipment using A2L refrigerants. The result? Data tags now show higher Minimum Circuit Ampacity (MCA) ratings than before, even though the equipment itself hasn't changed—only the math used to calculate these values has shifted. This has created a puzzling situation where the MCA can be higher than the recommended breaker size, which seems counterintuitive to anyone familiar with traditional electrical principles. Bryan and Elliot clarify the fundamental rule that still applies: size your wire to the MCA and your breaker to the MOCP (Maximum Overcurrent Protector). The confusion arises because manufacturers like Mitsubishi are now including "recommended breaker" sizes on data tags that are lower than the MCA—a courtesy to contractors, not a code requirement. The higher MCA reflects conservative safety margins that account for extreme operating conditions, but in practice, inverter-driven systems have multiple built-in protections that prevent them from ever actually reaching these calculated amperage levels. The key takeaway is that contractors can safely install breakers at the recommended size without safety concerns, as long as the breaker's lugs are rated to accept the wire size required by the MCA. The episode also explores how inverter-driven equipment fundamentally differs from traditional PSC motors, particularly regarding locked rotor amps (now more accurately termed "inverter input") and voltage drop considerations. Unlike conventional motors that simply run slower with reduced voltage, inverter-driven compressors and ECM motors compensate by drawing more current to maintain performance, creating a potential compounding effect with voltage drop that installers need to understand—even though voltage drop itself isn't an enforceable NEC code requirement. Topics Covered: New UL 60335-2-40 Edition 3 standards and their impact on electrical calculations for HVAC equipment The relationship between MCA (Minimum Circuit Ampacity) and MOCP (Maximum Overcurrent Protector) and why they can now seem contradictory Recommended breaker sizes on modern data tags and why they may be lower than the MCA Handling inspector conflicts and failed inspections related to breaker sizing Differences between inverter-driven equipment and traditional PSC motors in electrical behavior The transition from "locked rotor amps" to "inverter input" terminology for modern equipment Voltage drop considerations with inverter-driven systems (NEC 210.19A and 215.2A) Why inverter-driven equipment draws more current at lower voltages compared to traditional motors Proper wire and breaker sizing for A2L refrigerant equipment (454B systems) NEC Section 440 requirements specific to air conditioning and refrigeration equipment Breaker lug ratings and ensuring they can accept the required wire size Practical advice for communicating with inspectors and resolving code disputes Read the tech tip on this topic . Have a question that you want us to answer on the podcast? Submit your questions at . Purchase your tickets or learn more about the 7th Annual HVACR Training Symposium at . Subscribe to our podcast on your or . Subscribe to our channel. Check out our handy here or on the HVAC School Mobile App for and . /episode/index/show/hvacschool/id/39387115

Absorption Cooling - The Rise and Fall and Rise - Short #272 12/30/2025

Absorption Cooling - The Rise and Fall and Rise - Short #272 In this short podcast episode, Bryan goes on another history journey, retelling the story of the rise and fall and rise of absorption cooling. Some of the first HVAC/R engineers cooled buildings with fire; they used absorption refrigeration, which ran on heat instead of electricity. In the early 1800s, French scientist Michael Faraday showed that gases like ammonia could absorb heat as they evaporated. Instead of compressing the vapor, engineers looked for a way to absorb the heat from the vapor and drive it back out. In 1859, Ferdinand Carré invented a machine that boiled ammonia, absorbed the vapor into water, and reheated the mixture to desorb the ammonia, creating a self-contained refrigeration machine powered by heat alone (including waste steam from boilers). This ammonia-water absorption machine could freeze water and chill brine, and it became popular in the 1880s. An absorption system has an evaporator that boils refrigerant, which is then absorbed into another liquid and creates a strong solution. Heat drives refrigerant back out of the solution as a vapor, where it is then condensed back to a liquid and metered. However, while they were reliable, they were heavy, expensive, and slow to respond. In the 1920s and 1930s, the rise of practical sealed electric compression systems began replacing absorption refrigeration infrastructure. By the mid-1900s, absorption chillers were replaced in all but a few applications. Absorption didn't completely vanish, in part thanks to Servel, which continued manufacturing absorption refrigeration systems for industrial applications and rural areas with unreliable electricity. By the 1960s, Japan and Europe refined the design with lithium bromide instead of ammonia. Absorption chillers are still present, but their complexity, maintenance demands, and poor efficiency still make them impractical for most refrigeration purposes. However, with concerns about the electrical grid and decarbonization initiatives on the rise, absorption refrigeration in hybrid systems with improved efficiency and a heat source obtained from gas turbines and biomass boilers looks promising. Have a question that you want us to answer on the podcast? Submit your questions at . Purchase your tickets or learn more about the 7th Annual HVACR Training Symposium at . Subscribe to our podcast on your or . Subscribe to our channel. Check out our handy here or on the HVAC School Mobile App for and . /episode/index/show/hvacschool/id/39258235

Combustion Analysis w/ Tony G. 12/25/2025

Combustion Analysis w/ Tony G. In this comprehensive training session from the symposium, Tony Gonzalez, Training Director at Fieldpiece, delivers an engaging and practical guide to combustion analysis for HVAC technicians. With 25 years of experience at Fieldpiece—from warehouse worker to training director—Tony brings both technical expertise and real-world application to this 50-minute interactive session focused on the company's CAT 85 combustion analyzer. Tony emphasizes that combustion analysis serves four critical purposes: safety, efficiency, equipment specification verification, and liability protection. He makes a compelling business case for investing in combustion analyzers, noting that preventing just two callbacks or one liability lawsuit can pay for the equipment ten times over. The training walks attendees through the complete process, from properly warming up the analyzer in fresh air (allowing sensors to calibrate to ambient oxygen and zero carbon monoxide) to generating professional PDF reports that can be shared with customers or integrated into work order management systems like ServiceTitan. The session provides detailed guidance on interpreting key measurements, including stack temperature, oxygen percentage, carbon monoxide levels, and draft pressure. Using design parameters from the National Comfort Institute, Tony demonstrates how to diagnose issues by comparing actual readings against acceptable ranges for different furnace types (atmospheric, 80% induced fan, and 90+ percent condensing). He walks through practical troubleshooting scenarios, showing how measurements like high oxygen combined with low stack temperature can point to specific problems like low gas pressure that technicians can then verify and correct. Throughout the presentation, Tony emphasizes proper technique and best practices, from creating test ports at least 12 inches above the inducer fan to the importance of plugging test ports after completion. He also highlights innovative features of Fieldpiece's analyzers, including the hydro cycle pump that eliminates traditional water traps, sensor vault technology that extends sensor life to four years, and built-in wireless connectivity allowing technicians to view measurements on their mobile devices through the Job Link app. Topics Covered: Why perform combustion analysis: Safety verification, efficiency optimization, OEM specification compliance, and liability protection Business benefits: Reducing callbacks, improving OEM relationships, enhancing professional image, and protecting against lawsuits Proper startup procedure: Warming up analyzers in fresh air for accurate oxygen and CO sensor calibration Ambient CO testing: Using combustion analyzers vs. dedicated walk-around detectors for carbon monoxide detection in living spaces Test port installation: Proper placement at least 12 inches above inducer fans and away from 90-degree elbows Key measurements explained: Stack temperature, oxygen percentage, CO PPM, CO air-free, draft pressure, and efficiency calculations Equipment type selection: Choosing correct settings for atmospheric, 80% induced fan, or 90+ percent condensing furnaces Diagnostic interpretation: Using National Comfort Institute parameters to identify issues like excess combustion air or low gas pressure Advanced features: Built-in dual port manometer for gas and static pressure, wireless Job Link app connectivity, and hydro cycle pump technology Report generation: Creating professional PDF reports with company branding for customer documentation and CYA protection Maintenance tips: Checking particle filters, understanding sensor vault technology, and the importance of annual calibration Sensor longevity: Four-year sensor life warranty and field-replaceable sensors without sending equipment for service Have a question that you want us to answer on the podcast? Submit your questions at . Purchase your tickets or learn more about the 7th Annual HVACR Training Symposium at . Subscribe to our podcast on your or . Subscribe to our channel. Check out our handy here or on the HVAC School Mobile App for and . /episode/index/show/hvacschool/id/39241610

Give Until it Hertz - The Battle Over Frequency - Short #271 12/23/2025

Give Until it Hertz - The Battle Over Frequency - Short #271 In this short podcast episode, we go back into the history of the trades, namely the battle over frequency (and how each side had to give until it hertz). The low hum of motors is alternating current: electricity moving back and forth through copper 60x per second (in the USA and Canada, at least). In another version of history, that pulse could be 50x per second instead (as in much of the remainder of the world). The forgotten frequency war is the lesser-known sequel to the war of the currents. Tesla's AC power prevailed over Edison's DC, but different motor and generator companies chose different alternating current frequencies. Westinghouse chose 60 cycles per second, whereas General Electric experimented with 25-40 cycles per second, and Europe-based Siemens and AEG standardized around 50 hertz. These different frequencies set the rhythm for everything that turns or glows, and electric parts that didn't match often failed. Nevertheless, the engineers of the companies defended their own frequencies. In the 1910s, the US began merging electrical grids to set a single standard. Westinghouse had the most dominant technology at the time, and 60 hertz became the norm in the USA. However, across the pond, 50 hertz made more sense for the European infrastructure that was in place and being rebuilt after WWI, and it was solidified by the rebuilding efforts of WWII. As a result, roughly 2/3 of the planet uses a 50-hertz frequency. The two frequencies are incompatible because motors will travel at a different speed than their design while drawing the same current, leading to reduced capacity or overheating. In the 1960s, international companies produced dual-rated compressors and motors, but global trade is still complicated by different frequencies, and moving entirely to a single frequency is impractical due to the infrastructure disruption required. However, modern VFDs and inverter technology can change frequencies as they enter the motor, thus solving the battle over frequency and reminding us that flexibility is the real future. Have a question that you want us to answer on the podcast? Submit your questions at . Purchase your tickets or learn more about the 7th Annual HVACR Training Symposium at . Subscribe to our podcast on your or . Subscribe to our channel. Check out our handy here or on the HVAC School Mobile App for and . /episode/index/show/hvacschool/id/39200860

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