HVAC School - For Techs, By Techs
752 episodes - English - Latest episode: 5 days ago - ★★★★★ - 943 ratingsReal training for HVAC ( Heating, Ventilation, Air Conditioning and Refrigeration) Technicians. Including recorded tech training, interviews, diagnostics and general conversations about the trade.
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Episodes
Short #44 - Myth - Time as a Tech Equals Pay
March 05, 2019 12:00 - 16 minutes - 22.9 MBIn this short podcast episode, we talk about the myth that time at a job or in the business equals or deserves pay increases. Many people believe that showing up for a long time justifies a raise. They aren't necessarily progressing in their field, but they think they've spent enough time to warrant a raise. A business relationship is an agreement that you will perform specific tasks for a specified rate. If you don't go above and beyond or progress, then there's no reason for that pay r...
Chiller and Cooling Tower Cleaning w/ Goodway
February 28, 2019 12:00 - 41 minutes - 57.5 MBIn today's podcast episode, Mark Roth from Goodway talks about chiller and cooling tower cleaning best practices and techniques. Goodway makes industrial maintenance equipment for the HVAC industry, especially tube-cleaning equipment. A chiller has water running through the tubes, and debris from the cooling tower can build up in the tubes. When scale or debris buildup occurs, heat exchange becomes much less efficient. Water hardness can also interfere with heat transfer; harder water wi...
Short #43 - Is IAQ a Joke?
February 26, 2019 12:00 - 13 minutes - 19 MBIn this short podcast episode, we address the myth that IAQ is a joke. We also discuss how to think about IAQ correctly in HVAC work. Indoor air quality is NOT a joke. However, it has a bit of a bad reputation in our field due to the overuse of accessories and bells-and-whistles to solve whole-home air quality issues. (Oxidizers, UV lights, etc. can help IAQ issues, but they are not a fix-all.) We don't want completely sterile air, just as we like to have a beneficial microbiome inside...
Propane Refrigerant - A Tech Perspective w/ Chris Stephens
February 21, 2019 12:00 - 36 minutes - 50.4 MBChris Stephens from HVACR Videos joins us to talk about his experiences with and perspective on R290 (propane) refrigerant in restaurant refrigeration. Chris sees R290 propane on a daily basis, and his perspective as a tech differs from that of an R290 equipment manufacturer. While the temperature sensitivity contributes to flammability, R290 is also under pressure in a system. Therefore, propane refrigerant systems require a lot of caution. R290 equipment must undergo thorough redesig...
Short #42 - Myth - Flame Rods
February 19, 2019 12:00 - 7 minutes - 9.99 MBIn this short podcast episode, we discuss the common myth about cleaning flame rods/sensors/rectification devices. Flame sensors or rectification rods are NOT the same as thermocouples or thermopiles. Thermocouples and thermopiles use two dissimilar metals to create a temperature differential. So, we do not clean thermocouples and thermopiles because the heavy abrasives in cleaners can damage and reduce the effectiveness of those devices. However, you don't have to worry about that sort ...
Installing Central Air From Scratch w/ Eric M
February 14, 2019 12:00 - 40 minutes - 55.4 MBIn this podcast episode, Eric and I discuss his new home and his plans for installing central air the Eric-Mele way. Eric's home doesn't have an attic, crawlspace, or basement. So, designing and installing central A/C will be a challenge, especially since Eric doesn't like high-wall ductless systems. Eric considered using an air handler with exposed ductwork, but he doesn't want the noise issues associated with that design. He also considered using a package system, but it has the same n...
Short #41 - Context in Education
February 12, 2019 12:00 - 10 minutes - 14.8 MBIn today's short live podcast, Bryan discusses the importance of context in education and the challenge presented by information. When we learn, we do ourselves a disservice by searching for information alone. Just-in-time education allows us to "search instead of research," and it works in a limited and inefficient way. Instead, we'd be much more effective if we knew how to learn efficiently. To learn efficiently, we need to bring context to the learning process. Instead of focusing o...
VRF/VRV Design w/ Jordan Cummings
February 07, 2019 12:00 - 1 hour - 90.4 MBIn this episode, Jordan Cummings comes on the podcast to review application-based system selection considerations for VRF/VRV systems. A VRF/VRV system works a bit like a hydronics system, but it provides hot or cold air to various zones in a space, not water. The key to having a reliable and long-lasting VRF system is a good installation. Proper maintenance practices, including pulling deep vacuums for dehydration, will also improve the performance and life of a VRF system. When you ch...
Short #40 - Specifically Relative
February 05, 2019 12:00 - 8 minutes - 12.2 MBIn today's short podcast episode, we talk about specific gravity, also known as relative density. We explain why it matters to technicians. When we talk about specific gravity, we're actually talking about density. We're actually using that value to assess how a vapor or liquid's density compares to air or water, respectively. Regardless, we are working with the pressure conditions of 14.7 PSIA, or atmospheric pressure. In the case of liquids, we're relating them to water is at its den...
R290 (Propane), What you need to know w/ Embraco
January 31, 2019 12:00 - 26 minutes - 37.2 MBIn this episode, we speak with Embraco about R290 (Propane) refrigerant, hydrocarbons, and what you need to know about them. Embraco is primarily focused on compressors and is involved in the residential and light commercial market. The greater demand for natural refrigerants or hydrocarbons has made R290 popular. Hydrocarbons have hydrogen and carbon chains; although these refrigerants are very similar to grill propane, they are much drier and purer. R170 is another hydrocarbon for very l...
Short #39 - Tricky Amperages
January 29, 2019 12:00 - 11 minutes - 16 MBWe talk about measuring tricky amperage on a blower and condensing fan motor. We also cover why you may be measuring inaccurately, resulting in a misdiagnosis. When measuring amperage on a PSC blower motor, you may have noticed that amperage on the common is higher when the panel is off. Conversely, on ECM or X13 motors, the amperage is generally lower with the panel off. When measuring amperage, we recommend using a Bluetooth ammeter to take readings without letting the panels interfere...
Beacon 2 Refrigeration Talk Through
January 24, 2019 12:00 - 32 minutes - 45 MBIn this service manual talk-through episode, Eric Mele helps us discuss the Heatcraft Beacon 2 refrigeration system. We talk about what it can do and what it entails. The Heatcraft Beacon 2 is a refrigeration system with more electronic controls than electromechanical. However, it is quite user-friendly, and it allows you to see what the system is doing at almost all times. The monitor doesn't allow you to adjust anything in the system, but it lets you see valve position, superheat, time u...
Short #38 - Low Ambient Cooling
January 22, 2019 12:00 - 16 minutes - 23.3 MBThis short podcast episode covers the why and the how of low ambient cooling and refrigeration. Low ambient cooling refers to operating A/C equipment during low outdoor ambient conditions. Typically, the cap of operation is around 55 or 60 degrees. However, some commercial facilities need cooling when the outdoor temperature is cold. For example, those facilities may have to cool electronics or large volumes of people. In buildings that don't have economizers, running the A/C in cold amb...
VRF in Real Life w/ John Oaks
January 17, 2019 12:00 - 52 minutes - 71.7 MBIn today's podcast, I talk to John Oaks about his experience as a VRF tech in the field, including branch boxes and two-pipe vs. three-pipe technology. John primarily works on the troubleshooting and service side rather than the installation and programming side of the field. Variable refrigerant flow (VRF) systems, also called VRV systems when manufactured by Daikin, are commercial HVAC systems. VRF systems work best in commercial buildings with some degree of fragmentation, like office...
Short #37 - The Trade Skills Gap: A Manifesto
January 15, 2019 12:00 - 14 minutes - 20.3 MBThis is a voice-over audio presentation of the article of the same title on the HVACRschool.com website ("The Trade Skills Gap: A Manifesto). The manifesto discusses the value of technicians and the trades in modern society. It also covers the plague of snobbery that we are all too familiar with in the world. You can read "The Trade Skills Gap: A Manifesto" HERE. Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you hav...
Short #37 - The Trade Skills Gap a Manifesto
January 15, 2019 12:00 - 14 minutes - 20.3 MBThis is a voice over audio presentation of the article of the same title on the HVACRschool.com website
Furnace Sequence Of Operation
January 10, 2019 12:00 - 41 minutes - 57.6 MBJason Obrzut comes on the podcast and talks us through his furnace sequence of operation training: "Take It Slow, It's Gonna Blow!" There are 6 main steps in Jason's furnace sequence of operation training. The phrase, "Take It Slow, It's Gonna Blow!" should help you remember the sequence (Thermostat, Inducer motor, Safety switch, Igniter, Gas valve, Blower motor). The first component in the furnace sequence of operation is the thermostat, which initiates the call for heat. So, the thermo...
Short #36 - Stack Effect
January 08, 2019 12:00 - 7 minutes - 9.93 MBIn this short podcast episode, we talk through stack effect. We explain what it is and what sorts of comfort issues it can cause in a home. Most of us understand that hot air rises even though heat itself doesn't rise. The stack effect is precisely a version of that piece of common knowledge; hotter air is less dense than cooler air, so it floats above the cooler air. In hotter air, the molecules move a lot faster than they do in cooler air, so they can start to separate from each other, w...
The Future of App Based Diagnosis w/ Jim Bergmann
January 03, 2019 12:00 - 50 minutes - 69.2 MBJim Bergmann gives us a year-end review of all that is happening at MeasureQuick and his predictions for the future of app-based diagnosis. He also covers what's been going on with Redfish, BluFlame, BluVac, Supco, Testo, and Fieldpiece. Diagnostic tools only work if the buyers understand how to use them. When apps can assist the tool buyers and users with diagnosis, the tool manufacturers can focus more on improving the technology; they can leave the software and education to mobile appli...
Short #35 - Resolution, Precision & Accuracy
January 01, 2019 12:00 - 12 minutes - 17.4 MBWhat is the difference between accuracy, precision, and resolution? In today's short podcast, Jim Bergmann explains the differences and why they matter. People commonly confuse accuracy and precision. Accuracy refers to how close a measurement is to the correct value, but precision refers to the consistency of values. For example, you can get several infrared thermometers to measure the difference between circuit breakers, and the thermometer readings all come out close to the same value. ...
Ventilation w/ John Semmelhack
December 27, 2018 12:00 - 47 minutes - 65 MBJohn guides us through all aspects of ventilation and system design. He gives us a review of point ventilation, ASHRAE 62.2, whole-home strategies, and much more. Nowadays, construction protocols instruct builders to make houses tighter than the builders of the past. The goal of building tighter homes is to give us more control over the temperature, quality, and energy impact of the outside air we bring into our homes. Common sources of ventilation are local exhaust systems, including ...
Gas & Combustion Tools w/ Bill Spohn
December 20, 2018 12:00 - 49 minutes - 68.9 MBBill and Bryan discuss gas and combustion tools. These tools include manometers, combustible gas detectors, personal CO detectors, draft gauges, and combustion analyzers. Manometers measure gas pressure, and they require calibration but are usually quite accurate. Before using a manometer as a diagnostic tool effectively, you must understand your targets and resolution. Some digital manometers come with BlueTooth technology, so you can log, convert, and store your data on mobile devices....
Short #34 - Heat Pumps
December 18, 2018 12:00 - 15 minutes - 21.6 MBIn this short podcast episode, Bryan speed-talks through all the basics of heat pumps and how they function. Heat pumps are not physical pumps or components on an A/C system. A heat pump is an HVAC unit that is also capable of heating a home by reversing the refrigeration cycle. When that reversal happens, the traditional indoor "evaporator" coil acts as a condenser that rejects heat in the home. As such, the traditional outdoor "condenser" acts as an evaporator that absorbs heat from th...
EPA Regulation Uncertainty w/ Jason Obrzut
December 13, 2018 12:00 - 43 minutes - 60.5 MBJason from ESCO and Cengage comes on to talk about the varying landscape of EPA 608 regulations with what you need to know for now (circa 2018). The EPA has proposed to roll back some regulations regarding HFC refrigerants, including leak rate and leak repair mandates. There are also questions about the regulation of refrigerants that do NOT have ozone-depleting substances, not just HFCs. This choice reinterprets language within the guidelines put forth in 2016 and the Clean Air Act. How...
Short #33 AMA - Business Tips
December 11, 2018 11:00 - 12 minutes - 17.5 MBIn this short podcast episode, Bryan shares his experience as an entrepreneur and his tips for anyone who wants to run and grow a successful business. When growing a business, the best thing you can do is listen to others who have started a business. It's especially useful to listen to those who have already "made it" in the business world. Growing a business requires you to stay focused. While you may have to work in your business, you also want to make time to work on the strategic par...
AMA#1 - State of the HVAC School Union
December 06, 2018 12:00 - 37 minutes - 52.2 MBIn our first ever ask-me-anything (AMA) podcast, we talk about the trade as a whole and answer random questions about Kalos and myself. Some people ask me if I'd encourage my children to get into HVAC/R. In my opinion, the trade offers plenty of good opportunities and room for growth. So, I will definitely encourage my children to get into the trades, but I will not pressure them into it. I think more of us should encourage our children to consider a career in the trades and understand t...
Short #32 - "It's Undersized"
December 04, 2018 12:00 - 14 minutes - 20.1 MBWhen we replace equipment, we sometimes wonder if the old unit was undersized. Here are some things to consider before replacing that old A/C with a bigger one. When we do load calculations, we figure out how much heat to remove or add to a home based on the building's design. We need to account for how much heat is entering or leaving a building and heat gains on the inside of a space. Heat gains can come from human body heat or electronics running, and heat losses are quite rare. Those f...
Short #31 - U-Factor and R-Value
November 27, 2018 12:00 - 7 minutes - 9.97 MBWhat is the difference between r-value and u-factor? Why should we care about the differences? In this short podcast, we'll explain what those differences between the two are and why you should care. R-value and u-factor are actually pretty close to the same thing; they are inverse coefficients of the same phenomenon. R-value is the resistance to heat energy moving through conductance. R-value is not concerned with radiant gains, such as the sun's UV rays passing through a window; the he...
Friction Rate and Duct Design w/ Dr. Bailes
November 21, 2018 12:00 - 37 minutes - 52.3 MBThis episode is very exciting to me because we get to have Dr. Allison Bailes on the show. Today, he shares his knowledge about friction rate and duct design. Allison got his start teaching college-level physics before getting into the building design industry. If you have a forced-air system that blows heated or cooled air through a duct system, that blower creates a pressure difference. Some of the pressure is used up on the filter, registers, and dampers, so you will see pressure drops....
Critical and Triple Point w/ Rusty Walker
November 15, 2018 12:00 - 42 minutes - 58.9 MBRusty Walker with Hill-Phoenix comes on and talks about CO2 triple and critical points. He also covers some best practices for refrigeration techs working with CO2. The triple point is the temperature and pressure at which a substance can exist in all three phases of matter. CO2 has a very high triple point, and CO2 refrigeration equipment can reach its triple point during operation, unlike most other refrigerants. Solid CO2 is dry ice, and it sublimates by becoming a gas and bypassing t...
Short #30 - Braze or Solder Anything
November 13, 2018 12:00 - 12 minutes - 17.2 MBIn this short podcast episode, we cover what you need to consider before you solder or braze any type of joint in HVAC/R work. We want to give special thanks to Solderweld; you can learn more about their products at solderweld.us. When you braze or solder anything, you need to know your base metal. The base metal's temperature and composition will determine which type of flux you will use. For example, if you are working with steel, you can't use fluxing agents with phosphorus. Instead, yo...
Hot Gas Reheat Dehumidification w/ Eric Mele
November 08, 2018 12:00 - 36 minutes - 50.5 MBEric Mele is back on the podcast. This time, we cover hot gas as a reheat dehumidification strategy with all of the broad strokes you should be aware of. One common dehumidification strategy is the hot gas bypass; this strategy allows you to operate under low load. Hot gas reheat is when you add discharge heat back to the conditioned space. When you use reheat for dehumidification, you cool for the purpose of dehumidification and then add sensible heat to remove moisture on the coil. So,...
Short #29 - 3 Quick Tips to Level Up Overnight
November 06, 2018 12:00 - 9 minutes - 12.6 MBIn this short podcast episode, Bryan covers three things you can do to level up and make you a much better tech tomorrow. Everyone will notice your improvement. Also, no matter what level you're on, you can become even better by remembering the following three tips: 1. Use a full-system diagnostic process. Every application should have a full-system diagnostic process, whether you're working on a residential ductless mini-split, a commercial chiller, or a walk-in refrigerator. Instead of...
Combustion Analysis w/ Jim Bergmann
November 01, 2018 11:00 - 1 hour - 121 MBIn this episode, Jim Bergmann does a deep dive into combustion analysis. He covers everything you need to know to keep a furnace running safely and efficiently. When you go into a home, one of the first things you should do is perform an ambient CO test to check how much carbon monoxide is in the home. Combustion analyzers can typically measure CO, or you could use a dedicated CO meter. When it comes to checking for spillage, you'll want to make sure you check anything that is connected ...
Short #28 - The Magic Heat Absorber
October 30, 2018 11:00 - 7 minutes - 10.2 MBThis short podcast episode is about a simplified way to explain the basic refrigerant circuit to new techs. By explaining a component as an absorber, rejector, increaser, or dropper, you may help lock in the basic idea of absorbing and rejecting heat. The goal of refrigeration is to remove heat from a place. Whether that place is a grocery case or a house, we're moving heat. The overall function is pretty straightforward, but the components can get a little bit complicated. At Kalos, we've...
Do you even CAZ test? w/ Jim Bergmann
October 25, 2018 11:00 - 36 minutes - 49.9 MBIn this first part of the two-part combustion analysis series, Jim Bergmann covers CAZ testing or worst-case draft pressure testing in detail. He also explains why it matters to techs and customers. Once again, MeasureQuick will come in handy if you do CAZ testing in the field; Jim Bergmann is working on automating the testing process in his app. CAZ (combustion air zone) testing will benefit the customer in both safety and efficiency. A proper CAZ test will also likely increase the furnace...
Short #27 - Commissioning Mindset
October 23, 2018 11:00 - 10 minutes - 15.1 MBIn this short podcast episode, we talk about the commissioning mindset and what it REALLY takes to set up and commission a new system properly. We commonly check airflow and the refrigerant charge during commissioning. There is a difference between mere startup and commissioning. When you commission a system, you ensure that it is working according to design. Think about how the system lines up with the manufacturer's specs and how appropriately it fits its application. In Florida, our des...
3 Flavors of CO2 w/ Rusty Walker
October 18, 2018 15:30 - 1 hour - 95.9 MBIn this podcast episode, Rusty Walker from Hill Phoenix talks us through the three most common types of market CO2 systems and how they work: secondary, cascade, and booster. Carbon dioxide (CO2) is one of the oldest refrigerants; it is a natural refrigerant that came about when toxic refrigerants like ammonia were common. In the 1980s, we began to rediscover the benefits of CO2 in market refrigeration, including its high latent heat capacity, low costs, and low global warming potential....
Short #26 - Temperature Mistakes
October 16, 2018 11:00 - 11 minutes - 16.5 MBCan you really trust that temperature reading? In this short podcast episode, we talk about some common mistakes techs make when making temperature measurements and what to do about it. Many heat pumps use heat strips as a source of auxiliary heat. However, it takes some time for the heat strips to integrate with the air. So, your superheat, subcooling, and pressures will look fine on a system that isn't cooling well enough. When you take air temperature measurements in the ductwork, try t...
Analog & Digital Manifolds w/ James Bowman
October 11, 2018 11:00 - 41 minutes - 56.8 MBJames Bowman returns to the podcast to talk about analog vs. digital manifolds. He also explains why both of them may still have a place in the industry. Pricing is a key difference between analog and digital manifolds. Analog manifolds tend to be less expensive and will suffice just fine for techs who don't require readings with a lot of detail. While digital manifolds will be more expensive, they can also give you more precise, detailed readings. So, digital manifolds have a slight leg-u...
Short #25 - A Costly Screwup
October 09, 2018 11:00 - 7 minutes - 10.8 MBIn this short podcast episode, we share some quick tips about keeping panels and insulation in place to avoid a costly screwup. Often, technicians will use an impact driver too aggressively. If you feel it begin to clutch, that means that the driver is actually impacting, and that means you're going too far. When that happens, you can strip out the screws, which can be a serious problem on larger equipment. On RTUs and other large commercial equipment, panels can fall off if you strip ou...
Are Refrigerant Additives OK?
October 04, 2018 11:00 - 1 hour - 85.1 MBJohn Pastorello, the HVAC chemist, comes on the podcast and discusses refrigerant additives such as acid inhibitors, oil enhancers, dyes, and leak sealants with his knowledge and some things to consider. Acid neutralizers are refrigerant additives. Oil works best in a slightly acidic environment, and these additives can change the pH of the system. If the pH becomes neutral or alkaline (basic), then the system will not operate as it should. Acid scavengers won't change your pH, but they ar...
Short #24 - Hard vs. Soft Copper
October 02, 2018 11:00 - 7 minutes - 10.5 MBMany technicians use hard or soft copper without thinking about which application is best for which. In this short podcast, Bryan talks about where to use each. He also covers some hanging and strapping strategies. Residential service technicians typically work with soft copper. Conversely, commercial techs are probably much familiar with the hard variety. Both hard and soft types are good for specific applications. If you need to work the copper, then the soft type is best for that. You...
How to Make a Flare That Won't Leak
September 27, 2018 16:00 - 36 minutes - 49.8 MBKevan Mayer with NAVAC comes on and talks all about flaring best practices step by step. From cutting to reaming to torque wrenches, we cover how to make a flare from start to finish. The goal of making a good flare is to reduce leaks as much as possible, especially on ductless units and in commercial HVAC/R. When you make a flare, you have to make sure the depth is correct and consistent, especially on R-410a systems. NAVAC makes various flaring tools, including fast battery-powered ones,...
Chilled Water Air Handlers
September 20, 2018 16:00 - 20 minutes - 28.6 MBIn today's podcast, Eric Mele and Bryan talk about chilled water air handlers, their valve configurations, and some key things to look out for. In a chilled water system, we don't have the traditional evaporator and condenser in our HVAC system. Instead, we merely have a hot coil and a cold coil. We don't work with a direct-expansion refrigerant that changes state. We merely move water. These chilled water systems can be used in residential and commercial applications. With almost all a...
Short #23 - Intangible Soft Skills
September 18, 2018 11:00 - 13 minutes - 19.1 MBIn this short podcast episode, Bryan gets feedback on a podcast topic from Andy Holt. Per Andy's request, we discuss some intangible soft skills required to be a top-level technician in the HVAC trade. Overall, a technician needs to be aware of the people and things in their surroundings. These techs are in tune with their customer's emotions, the pets, and the space where they work. A good technician is thoughtful but has the ability to let things go and not let their bad experiences ov...
Refrigeration Temperature Controls w/ Chris Stephens
September 13, 2018 11:00 - 54 minutes - 74.8 MBChris Stevens from HVACR Videos on YouTube comes onto the podcast and talks about some refrigeration temperature controls basics. You can check out his YouTube channel HERE. Although we have temperature controls in HVAC work, we will see slightly different ones in refrigeration work. The biggest difference is really the temperature itself; we're attempting to bring the box temperature down, so we will be dealing with much lower temperatures in refrigeration. The box and evaporator coil t...
Short #22 - Mineral & POE Oil
September 11, 2018 11:00 - 11 minutes - 16.7 MBBryan talks about the differences between mineral oil (MO) and POE oil, the advantages and disadvantages of using them, and when to use them. Mineral oil (MO) is what we've used for a long time. We like using it because it's very stable; it may have an affinity for moisture, but it is not nearly as hygroscopic as POE oil. Vacuum pump oil is a highly refined mineral oil, and it works so well because it's able to lock in moisture as those non-condensables get sucked out of the system. It is ...
Small Refrigeration Maintenance Procedure
September 06, 2018 11:00 - 34 minutes - 48.1 MBEric Mele returns to the podcast to discuss quality cleaning and maintenance procedures for small refrigeration systems. These small refrigeration systems include reach-in refrigerators and open-air cases on grocery sales floors. Filthy condenser coils are problems in many HVAC applications, but they're exceptionally nasty in some small refrigeration applications; proximity to food residue (grease, sugar, etc.) makes condensers get dirty quickly. Use plastic-bristle brushes to clean the bu...
Short 21 - Leak Detectors
September 04, 2018 11:00 - 10 minutes - 14.8 MBBryan talks about the top refrigerant leak detectors, the best refrigerant leak detection practices, and some good leak detection tips. Leak detectors require some flow through them. Otherwise, they won't detect leaks. So, these tools have small pumps inside of them to move air through them for sampling. Leak detectors also require some time to warm up, so keep that in mind when you approach a job. One type of leak detector is a heated diode (sometimes called a heated pentode). It is a h...