Episódios

  • Compressor Ohm Mistakes w/ Bert

    Compressor Ohm Mistakes w/ Bert
    May 22 2025
    In this episode, Bryan and Bert dive into the often misunderstood world of compressor testing, focusing on common mistakes technicians make when using ohmmeters, compressor testers, and megohm meters. The conversation highlights how diagnostic errors can lead to unnecessarily condemned compressors and wasted time and resources. The hosts begin by discussing fundamental concepts like the difference between "open" and "short" conditions, emphasizing that a path doesn't necessarily indicate a short circuit—it simply means there's a low-resistance path. They explore how many technicians get confused when testing terminals, mistakenly thinking that normal winding-to-winding measurements indicate a problem. Through practical examples from their field experience, they illustrate why understanding normal readings is crucial before taking any measurement. A significant portion of the discussion centers on proper testing techniques for scroll compressors, which often show different measurements to ground compared to other compressor types due to their design, with windings submerged in refrigerant and oil. Bryan and Bert explain why standard motor testers can lead to false diagnoses when they indicate "bad" at threshold levels like 20 megohms—a reading that would be normal for many functional scroll compressors. They recommend proper megohm meters calibrated to appropriate voltage levels for accurate testing. Key Topics Covered: The difference between "open" circuits and "shorts" and how to properly interpret ohm readingsCommon mistakes when testing compressor terminals, especially misinterpreting normal winding-to-winding measurementsHow to properly check for shorts to ground and the importance of clean connectionsWhy scroll compressors naturally show different resistance-to-ground readings due to their design with submerged windingsProblems with inexpensive compressor testers that give false "bad" readings on functional equipmentThe "redneck test" for isolating a compressor to determine if it's truly the source of breaker tripsThe importance of understanding meter auto-ranging and correctly interpreting readings in ohms, kilohms, and megohmsWhy a reading below 0.5 megohms to ground is the general threshold for concern with scroll compressorsDifferences between megohm meters, high pot testers, and standard multimetersThe misconception that winding-to-winding shorts are common without corresponding shorts to ground Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool. Purchase your tickets or learn more about the 6th Annual HVACR Training Symposium at https://hvacrschool.com/symposium. Subscribe to our podcast on your iPhone or Android. Subscribe to our YouTube channel. Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android
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    35 minutos
  • Motor Ambient Rating - Short #241

    Motor Ambient Rating - Short #241
    May 20 2025

    In this short podcast episode, Bryan talks about what the ambient rating means on a motor. These ratings can be found on both condensing fan motors and blower motors. They have Cs in their rating, which represents the maximum ambient temperature the motor can handle in degrees Celsius (like 40C or 60C).

    Heat and overvoltage kill motors, and motors with higher ratings can withstand higher temperatures and last longer in hot conditions. Be careful not to confuse this rating with the insulation class (which is classed by letters and corresponds to temperature limits). You could have a condition where you exceed the insulation's rating but not the ambient rating.

    Air over operations (especially in the case of TEAO motors - totally enclosed air over motors) also play a role. The airflow helps cool the motor, and airflow restrictions like dirt and soil can create conditions that cause the motor to exceed its rating.

    Motor bearings also matter. Ball bearings tend to last longer and withstand higher temperatures than sleeve bearings, but they are noisier. Many motors use sleeve bearings, and replacing a sleeve bearing motor with a motor that uses ball bearings may negatively affect the homeowner's comfort due to the noise, so that's a conversation you'll want to have with the customer and set realistic expectations.

    Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool.

    Purchase your tickets or learn more about the 6th Annual HVACR Training Symposium at https://hvacrschool.com/symposium.

    Subscribe to our podcast on your iPhone or Android.

    Subscribe to our YouTube channel.

    Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android
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    5 minutos
  • Superheat Talk w/ JD Kelly

    Superheat Talk w/ JD Kelly
    May 15 2025
    In this episode of the HVAC School podcast, host Bryan discusses superheat with guest JD, who recently co-authored an article on the topic with Ty Branaman. The conversation explores the often misunderstood concept of superheat, its importance in HVAC diagnostics, and common misconceptions technicians have when measuring and interpreting it. Bryan begins by sharing how superheat was initially taught to technicians in the late 1990s and early 2000s, primarily as a method for charging fixed metering device systems. He explains how this limited view led to problems, as technicians would often add or remove refrigerant based solely on superheat readings without considering other system factors or giving the system time to stabilize. JD points out how the industry shifted when TXVs (Thermostatic Expansion Valves) became standard, with many technicians abandoning superheat measurements altogether in favor of subcooling measurements, missing crucial diagnostic information in the process. The discussion then evolves into a more sophisticated understanding of superheat as an indicator of evaporator coil "fullness." Bryan explains that lower superheat indicates a fuller evaporator coil, while higher superheat suggests a starved coil. They discuss the importance of measuring superheat in the correct location, noting that TXVs control superheat at the evaporator outlet, not at the condensing unit where technicians often measure. This misunderstanding leads to many incorrect diagnoses of "bad TXVs" when the real issues might be related to airflow, heat pickup in line sets, or other factors. Both experts emphasize the value of measuring superheat both inside at the evaporator outlet and outside at the condensing unit to get a complete picture of system operation. Key Topics Covered: Definition of superheat and its importance in HVAC diagnosticsHow superheat indicates evaporator coil "fullness" (flooded vs. starved conditions)The distinction between charging by superheat and using superheat as a diagnostic toolCommon misconceptions about superheat measurement on TXV systemsWhy measuring superheat location matters (evaporator outlet vs. condensing unit)How to properly diagnose TXV issues using superheat measurementsThe relationship between airflow problems and superheat readingsNormal superheat ranges for residential systems (7-14 degrees at evaporator outlet)How superheat affects both system capacity and compressor safety"Exercising" TXVs as a troubleshooting techniqueHow line set conditions and installation factors can impact superheat readingsSystem behavior during "hot pull down" conditions when starting with high indoor temperatures JD and Ty's superheat tech tip and worksheet: https://hvacrschool.com/solving-superheat/ Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool. Purchase your tickets or learn more about the 6th Annual HVACR Training Symposium at https://hvacrschool.com/symposium. Subscribe to our podcast on your iPhone or Android. Subscribe to our YouTube channel. Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android
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    29 minutos
  • How to Deal w/ Too Much - Short #240

    How to Deal w/ Too Much - Short #240
    May 13 2025

    In this short podcast, Bryan talks about how to deal with too much at work and in life. He gives some practical tips to help you when you feel overwhelmed.

    One of the best ways to get ahead is to wake up early, exercise, get sunlight, stay hydrated, eat healthy, and get enough sleep. Taking care of yourself and giving yourself ample opportunities to set your mind and body up for success can ensure that you have the energy to tackle the challenges at work and in other areas of your life.

    When you're in the middle of an overwhelming mix of tasks, it helps to take a small break and take some deep breaths. Some people take smoke breaks. Once you have an opportunity to step back and clear your head, try to document all of the things you need to do. You can use a Google Doc with the help of ChatGPT to lay everything out. Once you have all of your tasks in front of you, pick 3-5 things that must get done today and then use your calendar, silence your notifications, and use all the tools at your disposal to focus on those things.

    Perfectionism and people-pleasing can also get in the way of achieving all of your tasks. You have to be able to accept work that isn't perfect and say no to meetings or unnecessary tasks. You can use tools like Loom to document quick notes instead of holding a meeting. When you can't avoid meetings, try to batch them all at once. Batching, delegating, and automating tasks also come in handy, especially before tasks pile up and spiral out of control.

    Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool.

    Purchase your tickets or learn more about the 6th Annual HVACR Training Symposium at https://hvacrschool.com/symposium.

    Subscribe to our podcast on your iPhone or Android.

    Subscribe to our YouTube channel.

    Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android
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    12 minutos
  • Delta T Talk w/ JD Kelly

    Delta T Talk w/ JD Kelly
    May 8 2025
    Bryan from HVAC School interviews JD Kelly, known as "student of HVAC" on Instagram, about Delta T measurements in HVAC systems. This episode dives into the fundamentals of Delta T, common misconceptions, and proper measurement techniques. JD explains that Delta T is simply a temperature difference between two points of the same medium, which is often misunderstood in the industry. Many technicians are taught to measure between return grills and supply registers, but this approach can lead to inaccurate readings due to external factors like duct leakage or heat gain from attics. The proper measurement should be taken directly at the equipment to evaluate how the evaporator coil is performing. Humidity plays a significant role in Delta T measurements, which JD discovered when researching the fundamentals. Bryan elaborates on this point, explaining that in high-humidity environments (like Florida), more energy goes toward removing moisture (latent heat) rather than cooling the air (sensible heat), resulting in lower Delta T readings. This is why a newly repaired unit in a humid house might initially show lower readings but improve as the home dries out. The discussion highlights why the common "20-degree Delta T" rule of thumb isn't universally applicable and requires context. Key Topics Covered: Definition of Delta T: Temperature difference between two points of the same mediumDifference between Delta T and TD (temperature difference)Proper probe placement for accurate Delta T readingsImpact of humidity on Delta T measurementsHow regional differences affect expected Delta T valuesRelationship between CFM (airflow) per ton and Delta T readingsCommon mistakes: Adjusting equipment based solely on Delta T readingsChallenges of applying Delta T in heat pump heating modeHow temperature dead spots can affect readingsWhy Delta T readings must be considered alongside other diagnostic testsThe danger of making unnecessary adjustments to HVAC systemsWhy high Delta T isn't always good and low Delta T isn't always bad JD's Delta T tech tip: https://hvacrschool.com/solving-delta-t/ Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool. Purchase your tickets or learn more about the 6th Annual HVACR Training Symposium at https://hvacrschool.com/symposium. Subscribe to our podcast on your iPhone or Android. Subscribe to our YouTube channel. Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android
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    34 minutos
  • Fire Sprinklers - Short #239

    Fire Sprinklers - Short #239
    May 6 2025

    In this short podcast episode, Bryan talks about fire sprinklers and how to avoid setting them off on job sites.

    Fire sprinklers have an element in the center that expands when exposed to heat (like a TXV sensing bulb) and breaks the glass. When the glass breaks, the fire sprinkler starts pouring out water. In some cases, fire sprinklers are linked to a larger fire suppression system in which several may go off at once, but most of the time, only a single fire sprinkler will go off if bumped or exposed to heat.

    If you're using torches or doing any form of hot work in a closet or other location with a fire sprinkler, make sure to keep torches away from the heat-sensitive bulb or at least cover the sprinkler with a wet rag (and follow your company's guidelines). Blunt force is another possible issue, so we want to avoid hitting the sprinklers with lifts, ladders, or building materials like studs. Keep clearances in mind, and watch out for your colleagues.

    You can get some specialty-built cages to protect the sprinklers, but awareness is one of the best ways to protect fire sprinklers. If possible, make sure signage is posted or that you alert other people in the area about the fire sprinklers.

    If the fire sprinkler does go off, make sure you can quickly reach the person(s) who can access the fire shutoff or direct you to the fire shutoff. While fire sprinklers won't pose much of a personal safety hazard, property damage is a major concern. Training and awareness are the keys to preventing property damage due to fire sprinklers.

    Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool.

    Purchase your tickets or learn more about the 6th Annual HVACR Training Symposium at https://hvacrschool.com/symposium.

    Subscribe to our podcast on your iPhone or Android.

    Subscribe to our YouTube channel.

    Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android
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    8 minutos
  • The PATH to High Performance HVAC w/ David Richardson

    The PATH to High Performance HVAC w/ David Richardson
    May 1 2025
    In this engaging session, David Richardson breaks down the concept of high-performance HVAC, offering a clear roadmap for industry professionals looking to elevate their craft. Richardson argues that the HVAC industry has long been focused on equipment rather than complete systems, leading to widespread inefficiencies. The average system delivers only about 57% of its rated capacity into buildings, while even code-approved systems barely reach 63%. By implementing high-performance HVAC principles, contractors can achieve up to 88% efficiency while improving safety, health, comfort, and energy performance. Richardson presents a practical framework using the acronym "PATH" - Pressure, Airflow, Temperature, and Heat (BTUs) - as a step-by-step approach to implementing high-performance HVAC. He emphasizes starting with static pressure testing, which he calls "the foundation of airflow" and one of the most misunderstood principles in the industry. Just as doctors check blood pressure as a vital sign during every visit, Richardson advocates for measuring static pressure on every call, or at minimum, when encountering "red flag" issues like repeated equipment failures. From there, professionals can progress to measuring airflow, temperature, and finally BTU delivery to create complete system diagnostics. The presentation offers a journey-based approach, acknowledging that implementation takes time and requires breaking old habits. Richardson introduces the "one degree principle," suggesting that change happens incrementally, with small improvements eventually leading to breakthrough moments. He urges contractors to apply this methodology not just to equipment, but to extend testing into duct systems and even the building envelope. By making these changes visible through measurement, contractors can prove value to themselves, their teams, and ultimately their customers, transforming the way HVAC work is perceived and delivered. Key Topics Covered: The definition of high-performance HVAC: getting back to craftsmanship, challenging the status quo, and confirming work through measurementThe industry problem: focusing on equipment instead of complete systems, resulting in just 57% of rated BTU capacity reaching conditioned spacesThe PATH framework: Pressure, Airflow, Temperature, and Heat as building blocks for system diagnosticsHow to implement static pressure testing as the foundation for airflow diagnosticsThe importance of measuring at both equipment and register/grille locationsBreaking down implementation into three areas: equipment, ducts, and building envelopeSTEPS approach: Show, Teach, Equip, Promote, with application to yourself, your team, and your customersThe "one degree principle" for making incremental changes that lead to breakthrough resultsCommon obstacles to implementation and how to overcome resistance to changeHow measurements make your work transparent and lead to better performance Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool. Purchase your tickets or learn more about the 6th Annual HVACR Training Symposium at https://hvacrschool.com/symposium. Subscribe to our podcast on your iPhone or Android. Subscribe to our YouTube channel. Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android
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    55 minutos
  • Estimating Tips and Software

    Estimating Tips and Software
    Apr 30 2025
    In this episode of the HVAC School Podcast, host Bryan sits down with Phil, the executive electrical team leader at Kalos who has transitioned into the world of estimating. Phil shares his extensive background in electrical work dating back to 1994, from his high school electrical elective to running his own business for eight years before joining Kalos and eventually establishing their estimation department. The conversation delves deep into the fundamentals of estimating in the trades, contrasting traditional qualitative approaches with more rigorous quantitative methods. Phil emphasizes that good estimating is about "finding the truth" - understanding the actual costs of materials and labor for a project. They discuss how traditional estimating often relies on heuristics and past experiences with similar jobs, while more detailed estimating involves comprehensive takeoffs and assembly-based counting. The pair explores how estimation isn't just about producing a final number but should provide valuable information that transfers to the production phase. A highlight of the episode is Phil's introduction of his self-developed estimating software called Unity Build. He explains how his interest in AI technologies led him to learn programming and eventually create this cloud-based solution that integrates AI assistance while maintaining the fundamental tools needed for thorough estimating. The software allows for collaboration between team members, is entirely browser-based, requiring no downloads, and is priced at $125 per month per seat. Bryan emphasizes that this is Phil's own business venture that he's taken an interest in, and they both stress that potential users should buy it for what it currently offers, not future promises, though they are committed to continuous improvement. Topics Covered: Phil's 30+ year journey in electrical work and how he learned estimatingThe difference between qualitative (heuristic-based) and quantitative (detailed takeoff) estimating approachesUnit pricing vs. assembly-based takeoffs in estimatingHow good estimating transfers value to the production phaseThe workflow of detailed estimating from information gathering to closeoutLabor factoring and how it affects cost calculationsPhil's development of Unity Build estimation software using AI integrationCloud-based advantages of the new software, including collaboration capabilitiesHow Unity Build facilitates handoff from estimating to productionPricing model ($125/month per seat) and target customers (small to mid-sized contractors)The importance of estimating honesty and finding the "truth" in project costs Check out Unity Build Estimation at https://unitybuildestimation.com/. Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool. Purchase your tickets or learn more about the 6th Annual HVACR Training Symposium at https://hvacrschool.com/symposium. Subscribe to our podcast on your iPhone or Android. Subscribe to our YouTube channel. Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android
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    46 minutos