HVAC School - For Techs, By Techs

Bryan Orr
  • 0.0 (0)
  • Careers
  • Updated weekly

Real training for HVAC ( Heating, Ventilation, Air Conditioning and Refrigeration) Technicians. Including recorded tech training, interviews, diagnostics and general conversations about the trade.

  1. 11 hr ago

    Filters - MERV 13, Myths & More

    In this episode of the HVAC School Podcast, Bryan sits down with Kelsey Hei and Andy Fox from 3M Filtrete to pull back the curtain on what really goes into a quality air filter. Most homeowners — and even some contractors — think of air filters as simple screens that catch dust, but as this episode makes clear, modern filter technology is anything but simple. From proprietary nonwoven fiber structures to electrostatic charging that turns fibers into "magnets" for microscopic particles, the science behind a great air filter is both fascinating and critically important for equipment health and the air we breathe every day. The conversation digs deep into why MERV 13 has become the gold standard recommendation from organizations like the EPA and CDC — especially in the wake of COVID-19 and worsening wildfire seasons across the country. While higher MERV ratings deliver better particle capture, they can also mean higher pressure drop, which strains HVAC equipment. This is where Filtrete's MPR 1900 filter stands out: it achieves MERV 13 performance while maintaining a pressure drop comparable to most MERV 8 filters — roughly half that of leading competitors. That balance between filtration efficiency and airflow resistance is something 3M has spent over 35 years engineering. One of the most compelling segments focuses on real-world testing. Rather than relying solely on lab data, 3M runs extensive in-home studies — placing filters in dozens of homes during Minnesota winters, then retrieving and analyzing them to measure real-life efficiency and pressure drop. This commitment to real-world validation ensures Filtrete's claims hold up in the messy, variable conditions of actual homes, not just controlled lab environments. Bryan and the guests also discuss how overloaded or collapsed filters can cause serious equipment issues, including frozen coils and system shutdowns in extreme cases — underscoring why filter quality and regular replacement matter enormously. The episode wraps with practical advice for contractors and homeowners alike: if you're installing a new system, push for a four- or five-inch filter slot to maximize surface area, lower ongoing pressure drop, and extend filter life. For existing one-inch slots, the MPR 1900 is the top pick. The Filtrete Smart App is also highlighted as a handy tool for setting filter change reminders and monitoring local air quality — making it easier than ever for consumers to stay on top of their indoor air health. Topics Covered ·       3M Filtrete's history — 35+ years of indoor air quality innovation, owning the full manufacturing value chain from raw fiber to finished filter ·       The three pillars of air filter design — Efficiency, pressure drop, and air filter lifetime — and how they must be balanced ·       Nonwoven media explained — Why random fiber orientation captures particles more effectively than woven fabrics ·       Electrostatic charging technology — How fibers are engineered to attract and trap microscopic particles ·       Charge stability over time — Shelf life testing and real-world in-home studies to verify long-term performance ·       Why MERV 13 matters — EPA, CDC, and ASHRAE recommendations; effectiveness against bacteria, viruses, allergens, and wildfire smoke ·       Pressure drop and airflow — How high-resistance air filters strain equipment, raise energy bills, and can cause system failures ·       MPR 1900 spotlight — MERV 13 filtration at MERV 8 pressure drop, with publicly available data through the California Energy Commission ·       California Energy Commission database — Publicly available pressure drop and efficiency data on every filter sold in the U.S. ·       Pleats and surface area — Why having more pleats equals better dust-holding capacity and a longer filter life ·       Frame strength and bypass prevention — How structural integrity affects real-world performance over the filter's lifespan ·       MPR rating system explained — Microparticle Performance Rating: Filtrete's system focused on capturing the smallest, hardest-to-catch particles ·       Exceeding ASHRAE minimums — Filtrete's MERV 11, 12, and 13 filters all capture significantly more fine particles than the minimum standard requires ·       One-inch vs. four/five-inch filters — Why thicker filters are ideal for new installs and how to maximize one-inch slot performance ·       Energy consumption impact — How pressure drop affects fan wattage, system efficiency, and real annual utility costs ·       The Filtrete Smart App — Set filter change reminders at 30/60/90 days, store filter sizes, and get local air quality alerts   Learn more about Filtrete's air filters at filtrete.com or download the Filtrete Smart App on your Android or iOS smartphone.  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 8th 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.

    36 min

  2. 2 days ago

    From High Performance Medicine to High Performance HVAC - Short #290

    In this short podcast from the 8th HVACR Training Symposium's Bry-X stage, Ken Davis shares his experience as an HVAC contractor who has brought vital experience from high-performance medicine to High-Performance HVAC. Ken's experience comes from developing high-reliability organizations (HROs). An HRO has a low fail rate in an industry where high fail rates aren't tolerated due to catastrophic consequences, such as in medicine, nuclear, and aviation industries. This model can also be applied to relatively low-risk industries, like HVAC, to help businesses perform better. Ken had the idea to use the HRO model when he witnessed a traumatic medical emergency and co-founded an air medical program that brought trauma management methods from the hospital to the field. These methods bought time to transport patients to the hospital and improved survivability outcomes; they could also be applied to relatively low-stakes HVAC work and produce better outcomes. One of the key aspects of developing an HRO is to use checklists for complex tasks. Interactive checklists help people think through the procedure and see what they may have forgotten. They also make mistakes visible and show how change is possible; the HVAC professional just needs to have the desire to do better, which can be screened for during the hiring phase by searching for work ethic and personality over experience.  As HVAC professionals, in addition to creating detailed checklists, we can start by getting better at the basics, such as evacuation, airflow measurement, and utilizing software tools like measureQuick. Load calculations are also important, as is the use of software to make sure they're accurate and aid with proper equipment selection. Improving ductwork also has the potential to produce much better outcomes for customers, regardless of whether you use flex or sheet metal ductwork. We can also use advanced tools and testing methodologies (like zonal pressure diagnostics and blower door tests) to sell upgrades that verifiably improve customer indoor air quality, such as dehumidification and better filtration.   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 7th 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.

    27 min

  3. 11 Jun

    Training The Next Generation of HVACR Technicians w/ Lenny Diaddario (Copeland)

    In this episode of the HVAC School Podcast, host Bryan sits down with Lenny from Copeland to explore how one of the most respected names in HVAC and refrigeration is actively investing in the next generation of technicians. Lenny leads Copeland's aftermarket demand creation efforts, which includes everything from working with wholesale networks and trade shows to educational partnerships with schools and nonprofit organizations. The conversation covers a wide range of initiatives aimed not just at recruiting people into the trades, but at giving them the tools and confidence to thrive long-term in the industry. A major theme throughout the episode is Copeland's belief that workforce development is a shared responsibility across the entire industry chain — from manufacturers and parts suppliers to contractors and educators. Lenny describes how Copeland partners with organizations like SkillsUSA, Skills Canada, and the NC3 (National Coalition of Certification Centers) to provide hands-on training opportunities and industry certifications to students in trade and tech schools. Copeland sends trainers to these competitions with mobile refrigeration simulators, where students troubleshoot real-world fault scenarios and receive detailed feedback afterward — making it both a competitive and educational experience. The episode also dives deep into Copeland's Train-the-Trainer program, a cornerstone of their work with NC3 partner schools. Rather than simply handing schools a curriculum and walking away, Copeland brings educators through an intensive one-week program covering HVACR system fundamentals, troubleshooting, and compressor operation — complete with hands-on activities, refrigeration simulators, and even compressor teardowns. The goal is to ensure that instructors can confidently deliver accurate, field-relevant material to their students. Lenny emphasizes that Copeland intentionally avoids "death by PowerPoints," preferring interactive, application-based learning that mirrors what technicians actually encounter on the job. On the technology side, the conversation highlights the newly unified Copeland Mobile app, which now integrates White-Rodgers tools alongside the existing Copeland suite. Features like Check and Charge, PT Pro, and Fault Finder help technicians quickly diagnose system issues in the field, while the AI-powered Scout tool allows users to query Copeland-approved engineering bulletins and product data for fast, accurate answers. Lenny and Bryan discuss why this kind of tightly controlled, manufacturer-backed AI is genuinely valuable — cutting through information overload so a tech on a rooftop can get the right answer quickly. The episode wraps up with details on the HVACR Tech Appreciation Day sweepstakes happening April 1 through June 30, where Copeland is giving away approximately $3,000 worth of tools as a thank-you to technicians across the industry. Topics Covered Lenny's role at Copeland and the scope of their aftermarket and education work How Copeland approaches workforce development as an industry-wide responsibility Copeland's involvement with SkillsUSA and Skills Canada — booths, judges, and mobile refrigeration training simulators The NC3 (National Coalition of Certification Centers) partnership and how it connects trade schools to industry certifications Copeland's three-part curriculum: HVACR system fundamentals, troubleshooting, and compressor operation The Train-the-Trainer program — how Copeland educates educators to deliver consistent, field-ready instruction Hands-on learning philosophy: refrigeration trainers, scroll teardown kits, and compressor-in-a-suitcase tools available to schools Virtual reality scroll teardown in development to bring factory experiences to the classroom The newly integrated Copeland Mobile app — combining White-Rodgers and Copeland tools in one platform App features: Check and Charge, PT Pro (with altitude settings), Fault Finder, and the 30-year products catalog Scout — Copeland's AI tool that searches approved engineering bulletins and product data to answer field questions fast Why manufacturer-controlled AI is a practical and trustworthy resource for technicians The importance of retaining new technicians by giving them support systems so they aren't overwhelmed and don't wash out HVACR Tech Appreciation Day — June 22nd — and the sweepstakes giving away ~$3,000 in tools (vacuum pump, recovery unit, core removal tool, gauge sets) How to reach Copeland's Educational Services team: educationalservices.coldchain@copeland.com Accessing educator resources on Copeland's website and the Copeland Mobile app   Copeland's Resources: Sweepstakes: Enter Copeland's HVACR Technician Appreciation Sweepstakes before June 30th, 2026 at hvacrschool.com/copelandsweepstakes.  Copeland Mobile App: apps.copeland.com/copelandmobile  Educator Resources: https://www.copeland.com/en-us/training-support Educational Services Email: educationalservices.coldchain@copeland.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 8th 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.

    34 min

  4. 9 Jun

    Communications Might Be Your Best Tool - Short #289

    This short episode is Andy Holt's session from the Bry-X stage of the 7th Annual HVACR Training Symposium: Communications Might Be Your Best Tool. In this session, Andy covers some key communication and customer service principles that can help you become a better technician. In the end, customers won't remember your technical knowledge; they will remember how you made them feel, and that's why good communication is so important. Andy's core philosophy is that we aren't in the HVAC business; we are in the people business and just happen to fix HVAC systems. In many cases, technicians can control the way customers perceive them; while some technicians may not care about how the customer perceives them, owning and being aware of our mannerisms and way of speaking can go a long way to build good relationships. Having a clear process that is open to adaptation is the key to creating a good first impression when you greet the customer.  Be cognizant of your mindset when meeting new people as well, as a positive outlook will make it easier to speak pleasantly (verbal communication) and show welcoming body language (nonverbal communication). Nonverbal communication is a huge part of communication, including tone of voice, gestures, and eye contact; attentive but variable eye contact, a solid handshake, a friendly tone of voice, and especially a smile can do a lot to put customers at ease and make them feel satisfied with your service.   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 7th 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.

    16 min

  5. 4 Jun

    All About Airflow Testing w/ Eric Kaiser

    In this session from the 7th Annual HVACR Training Symposium in Florida, Eric "Elk" Kaiser delivers a comprehensive workshop on airflow testing and measurement. Eric opens by challenging technicians to think beyond simply pointing an instrument at a duct and reading a number. Before selecting any tool, he argues, professionals must understand exactly what they are measuring — whether that is velocity, pressure, volume (CFM), or the mass weight of air — and why each of those values matters for designing ductwork, sizing equipment, and delivering comfort to customers. The session sets the stage for a deeper technical conversation about the physics of air and how those physics affect measurement accuracy in the real world. A significant portion of the presentation focuses on air density and how it affects the accuracy of common industry formulas. Eric walks through the origin of the widely-used 1.08 and 4.5 airflow constants, explaining that they are derived from a theoretical "standard air" condition of sea level pressure (14.7 PSIA) and 0% relative humidity — conditions that virtually no technician encounters in the field. He demonstrates how changes in altitude, temperature, and humidity all shift air density, causing those constants to become variables. For technicians working at elevations above 2,500 feet, the density difference can exceed 10%, enough to significantly skew BTU calculations and equipment performance assessments if left uncorrected. Eric also walks through a real-world scenario involving measurements taken across an operating evaporator coil, where a 3.4% density shift between return and supply could easily be misread as duct leakage. The workshop then moves into a thorough survey of airflow measurement instruments and the specific conditions each one is best suited for. Eric covers vane anemometers (large and mini), hot wire anemometers, pitot tubes, flow hoods (passive and active/fan-powered), flow boxes, the temperature rise method, and the digital TrueFlow grid. For each tool, he discusses accuracy considerations, density correction requirements, velocity limitations, placement requirements, and common mistakes. He is candid about the limitations of manufacturer performance charts, sharing a behind-the-scenes look at how one manufacturer evaluated static pressure using a six-foot plenum and four averaging probes — conditions that bear no resemblance to a cramped residential closet with a coil slammed on top of the furnace. The takeaway is that no chart, regardless of source, should be trusted without understanding the conditions under which it was created. Throughout the session, Eric emphasizes a core professional philosophy: understand your instruments, understand their limitations, and understand what level of accuracy is truly needed for the job at hand. He introduces the concept of stacked inaccuracies — where instrument error combines with density correction error to produce readings that can mislead technicians into diagnosing problems that do not exist, or missing ones that do. He concludes with a strong endorsement of the digital TrueFlow grid for residential applications, highlighting its app-based forecasting feature that allows technicians to predict whether a new piece of equipment will work on an existing duct system before the installation begins. The session closes with audience Q&A covering topics such as using density-correcting instruments to compare supply and return readings, and measuring airflow in systems with multiple filter grilles. Topics Covered What airflow measurement actually captures: velocity, pressure, volume (CFM), and mass weight of air — and why the distinction matters The origin and limitations of the 1.08 and 4.5 airflow constants, and when technicians must correct for non-standard air conditions How air density changes with altitude, temperature, and humidity — including a 22% density drop from sea level to 5,000 feet elevation Real-world example: how a 3.4% density shift across an operating evaporator coil can be mistaken for duct leakage Instrument selection overview: large vane anemometers, mini vane anemometers, hot wire anemometers, pitot tubes, and in-duct flow devices Passive vs. active (fan-powered) flow hoods — accuracy differences and the importance of using residential hoods for residential applications Proper probe placement for in-duct measurements: ASHRAE guidelines, straight-run requirements, and how turbulence affects readings Duct traverses: log Chebyshev point averaging vs. timed traverse methods, and best practices for each Manufacturer performance charts and external static pressure testing: how lab conditions differ from field conditions and why charts can mislead Motor types (PSC, constant torque ECM, constant airflow ECM) and how motor behavior affects static pressure measurement and airflow setup Manometer selection: resolution, accuracy, auto-zeroing features, and why a precise-looking display does not equal an accurate reading Temperature rise method for estimating airflow: appropriate uses with electric heat, and limitations with gas furnaces Digital TrueFlow grid: application for residential retrofit work, CFM forecasting, and evaluating existing duct systems before equipment replacement Audience Q&A: density correction on supply vs. return readings, multi-grille TrueFlow workflows, and commercial system setup strategies   You can watch the flow hood comparison video by TruTech Tools HERE. You can also check out all of the great free downloads and other resources TruTech Tools has to offer at https://trutechtools.com/resources.  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 7th 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.

    1hr 8min

  6. 2 Jun

    The Deep End with Roman Baugh: Live Call, Grounded Compressor, Mitsubishi Mini-Split

    In this short podcast, Roman Baugh takes over with his new series, "The Deep End," where he shares tech support conversations. This time, Roman is on the other end of a live tech support call about a grounded compressor with an existing Mitsubishi mini-split (Mr. Slim heat pump). The unit in this case had an unclear service history due to the homeowner moving in recently. In this issue, the compressor kicked on and kicked off immediately. After the technician in this scenario told tech support that he had no continuity from the compressor to ground, tech support asked him to check the resistance (which was 43 ohms from black to ground and 43 from white to ground). Tech support concluded that the compressor was grounded, and it needed to be replaced (along with the PCB). However, the resistance disappeared mid-call, and intermittent resistance readings don't always indicate a failed winding; it's worth noting that cool ambient temperatures that enable liquid refrigerant to migrate into the compressor could potentially skew electrical readings. Roman recommended shutting the system down and trying to get the system to run. His rationale was that if the unit ran and didn't keep stopping, the system may have been overcharged or lacking a crankcase heater. However, that did not show any improvement in operation; the compressor rattled for about a second and shut off. A resistance test confirmed that the compressor was grounded, pointing to a mechanical issue with the compressor and not just a one-off instance of refrigerant migration. This type of failure can happen when there are repeated instances of liquid refrigerant in the crankcase over time.   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 7th 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.

    15 min

  7. 28 May

    Add Duct Renovations to Your Product Offerings

    In this episode, HVAC veteran Adam Mufich of National Comfort Institute (NCI) pulls back the curtain on one of the industry's most overlooked problems: the majority of residential HVAC systems in the United States are not delivering the correct amount of airflow. Drawing on decades of hands-on experience, Adam opens up about his own journey from confident installer to humbled diagnostician, sharing the moment he started measuring his systems and realized how much he had been getting wrong. His candor and expertise make this a must-listen for any HVAC professional serious about doing better work. Adam walks listeners through a sobering picture painted by a Department of Energy study covering 44 research projects across the country. The data reveals that between 50 and 93 percent of systems tested moved less than the minimum 350 CFM per ton of capacity, and between 67 and 100 percent of systems leaked more than 100 CFM to the outside. Equipment oversizing is rampant, with some studies showing that up to 93 percent of systems exceed what Manual J calculations would call for. The ripple effects are enormous: compressor failures, blown blower motors, cracked heat exchangers, wasted energy, and homeowners who are simply not comfortable in their own homes. Adam argues that the single most powerful fix is also the most underused one — properly sizing the equipment in the first place. The bulk of the episode dives into two distinct approaches NCI teaches for addressing these problems. The first is the Air Upgrade, a targeted set of repairs focused near the equipment to reduce static pressure and increase fan airflow. This includes reworking the filter system (a commonly undersized 16x25x1 filter can triple the allowed pressure budget on its own), improving duct fittings with lower equivalent lengths, cleaning evaporator coils and blower wheels, adjusting fan speed, and sealing duct joints. The second approach is full Duct Optimization, a more comprehensive renovation that addresses the entire duct system, incorporates Manual D calculations, installs balancing dampers, improves insulation, and uses tools like flow hoods and MeasureQuick to verify that every room in the house is receiving the correct airflow and BTUs. Adam also spends time on the practical and human side of this work — how to talk to homeowners, how to prioritize what matters to them, and how to overcome the very real obstacles that keep technicians from doing thorough airflow work. He addresses everything from fear of opening walls (his solution: build relationships with drywall contractors and offer turnkey repairs) to the simple but powerful mindset shift of treating airflow as something to be measured, not felt with your hand. His closing message is clear: the tools and methods exist, the training is available, and virtually every house in the country has a problem worth solving. The only thing standing in the way is the willingness to do it right. Topics Covered The current state of the HVAC industry based on a DOE meta-analysis of 44 studies Why equipment oversizing is the number one contributor to airflow problems and how to address it How a 50 percent oversized AC system can increase energy consumption by up to 91 percent (per the ASME Journal of Sustainable Buildings) Tools for proper load calculations, including Ample Energy and Conduit apps Why most systems are not moving enough airflow and what the consequences are (heat exchanger failures, compressor failures, comfort complaints) Duct leakage to the outside and its effects on comfort, indoor air quality, and building pressurization The four pillars of NCI's approach: safe, healthy, comfortable, and efficient systems The Air Upgrade approach: targeted repairs near the equipment to reduce static pressure and increase fan airflow The Duct Optimization approach: full duct system renovation with balanced airflow to every room Static pressure profiling: taking four measurements (before/after filter and before/after coil) to pinpoint restrictions Static pressure budgets and how to use them to identify which part of a system is the biggest problem Fan Law 2 as a planning tool to predict system performance before making changes The TrueFlow Grid and its forecasting feature for planning equipment changes Filter sizing and its massive impact on total external static pressure Duct fitting equivalent lengths and how to reduce resistance near the equipment Sealing duct joints and why it adds static pressure that must be planned for The importance of rechecking and adjusting refrigerant charge after any airflow improvement Air balancing with a flow hood to verify delivered CFM at every register Measuring delivered BTUs using tools like MeasureQuick, JobLink, and NCI's ComfortMax workflow Overcoming obstacles: technician buy-in, access to ducts in walls, attic space limitations, and homeowner hesitation Building relationships with drywall contractors to offer turnkey duct repair solutions Why airflow is invisible and why measuring it is non-negotiable   To learn more about NCI and its training offerings, visit https://www.nationalcomfortinstitute.com/. Watch Adam Mufich's previous symposium session, Fan Law 2 for Techs, at https://www.hvacrschool.com/videos/fan-law-2-for-techs-with-adam-mufich/.  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 7th 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.

    40 min

  8. 26 May

    Refrigeration Pulse Valves - Short #288

    In this short podcast from the Bry-X stage of the 7th Annual HVACR Training Symposium, Matthew Taylor from Kalos Services introduces refrigeration pulse valves, which started as a solution for CO2 refrigeration systems and are now common in commercial refrigeration as a whole. He briefly explains how they work and describes their role in the refrigeration systems (and possibly commercial HVAC systems in the future!). Refrigeration systems have moved away from electronic expansion valves (EEVs), which have been adopted by residential HVAC systems only recently, and have been using pulse valves instead. Pulse valves are also electronic expansion devices with fewer parts than EEVs (which often have stepper motors and complex electronics) and lower failure rates as a result. Pulse valves have a pressure transducer and a temperature sensor that go on the suction line to calculate the superheat; these report to a controller that takes the data from those parts, calculates the superheat based on the refrigerant and programming, and controls the valve like an EEV. However, there are only two wires, and the controller turns the valve on or off (like a solenoid) instead of sending pulses out. Solenoids just open or close completely, but pulse valves have a port (oversized fixed orifice) through which liquid refrigerant passes; when the load changes, the controller merely sends power to open the valve when the load goes up and stops sending power to close the valve when the load goes down. The valve is open for a certain percentage, and the on/off function is open for that amount of time in a six-second duty cycle (and off for the remaining time); this is pulse-width modulation. They also work well with refrigerants that have glide. However, pulse valves have some challenges. They may have issues in cases where we have very long evaporators, as there are delays between what happens between the inlet and outlet. Having multiple, shorter evaporators is a common solution to this problem, and these designs are more efficient in general (especially when they can be used with efficient refrigerants that move slowly through the evaporator). Pulse valves also require a computer (though EEV ones are similar), and are less serviceable than other valves; some may require technicians to take the valve apart to take the screen out, which requires replacement O-rings and gaskets. They are also noisy enough for customers to hear them.   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 7th 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.

    21 min
See All (918)

Hosts & Guests

About

Real training for HVAC ( Heating, Ventilation, Air Conditioning and Refrigeration) Technicians. Including recorded tech training, interviews, diagnostics and general conversations about the trade.

Information

You Might Also Like