HVAC School - For Techs, By Techs

This podcast episode is one of Alex Meaney's HVACR Training Symposium presentations: HVAC Design Backwards, Forwards, and In Between. Load calculation factors in all three means of heat transfer: conduction, convection, and radiation. It doesn't directly tell you the tonnage; it just tells you how many BTUs (sensible and latent) are entering or leaving a structure. When designing systems after doing load calculations, we need to be mindful of industry standards and their pitfalls, as well as the climate conditions and the difficulty of obtaining manufacturer data. Equipment selection by tonnage is only part of the picture when it comes to HVAC design; we also need to factor in airflow and duct design, especially duct sizing. However, many rules of thumb and poorly explained terms are counterproductive to a thorough understanding of HVAC design. In some cases, the best way to design a system may seem "backward," especially when starting with blower selection instead of ductwork. Duct design is particularly difficult, especially when software identifies several problems with designs that seemed to look good on paper. However, the software points out areas where you can adjust the duct size and manage restrictions to allow the fan to do its job without being derated by friction. Alex also covers: Insulation and efficiency ratings CLTD Groups Tricky radiant gains and losses The relationship between BTUs and tons AHRI ratings Shortcomings of Ductulators in duct design education Pressure vs. friction in ductwork Static pressure vs. velocity pressure Measuring friction with pressure Regulations vs. reality Furnace static pressure range Differences between commercial and residential duct design Oversized and under-ducted systems Variable-capacity systems ACCA manuals and tables Check out Alex Meaney's consultation business at https://www.meanhvac.com/. Learn more about the HVACR Training Symposium or buy a virtual ticket today at https://hvacrschool.com/symposium. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

This podcast is the Santa Fe Panel from the 4th Annual HVACR Training Symposium. The panel focused on dehumidification, was moderated by Nikki Krueger, and featured Andy Ask and Ken Gehring. "Matchmaking" a residence to the climate requires us to design and install equipment that keeps occupants healthy and comfortable. HVAC contractors need to focus on the dew points, especially as they remain high at night and in the shoulder seasons. Humidity loads tend to hold steady (even peak dew points), while sensible loads increase and drop, making it difficult to control latent heat loads the same way we control sensible loads. The equipment will typically be less efficient if you focus on long runtimes to remove latent heat under partial load conditions and maintain 50% humidity. Dehumidifier efficiency is determined on a pint per kilowatt basis, but a constantly running dehumidifier will do its job a lot more efficiently than one that starts and stops regularly. The dehumidifier adds heat to the house and should only come on when the HVAC system is having trouble maintaining the desired humidity load; the dehumidifier has a reheat effect, but the HVAC system will need to deal with the increased heat load. When you add a whole-house dehumidifier, adding a fresh air ventilation component is highly recommended. Nikki, Ken, and Andy also cover: Infiltration and exfiltration Variable-speed technology and supplemental dehumidification Fresh air ventilation Air conditioner vs. dehumidifier latent heat removal Net zero HVAC, electrification, and decarbonization initiatives Air mixing in the ductwork Standalone dehumidifiers Vapor pressure and buoyancy Sizing for peak dehumidification loads Dehumidifier supply and return tie-ins Static pressure and "injection" dehumidification Fan cycling Learn more about the HVACR Training Symposium or buy a virtual ticket today at https://hvacrschool.com/symposium. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

In this short podcast, Bryan talks about where to place the micron gauge during evacuation and how to think about micron gauge positioning. Evacuation (deep vacuum) doesn't remove solid contaminants, and vaporizing liquid water is a time-consuming process; its main purpose is to remove water vapor, air, and nitrogen gases from the HVAC/R system. When you pull down below 500 microns and hold that pressure, we can make sure we have a clean, dry, and tight (leak-free) system. As we started using R-410A and POE oil, water in the system became a much bigger issue than it was with mineral oil (it was never to have water in the system, but it breaks down POE oil). Before we start pulling a vacuum on the system, we need to attach our micron gauge to the pump while it's isolated to make sure the pump is working. A modern vacuum pump should pull down below 100 microns in 30-60 seconds; if your pump can't pull down to 100 microns in under a minute when isolated, then you'll want to change the oil (possibly multiple times). Be sure to change the oil regularly and store it properly. When you pull a vacuum on a system, you'll want to attach your micron gauge as far away from the pump as possible to get an accurate indicator of your vacuum. Use core remover tools to isolate the system and make sure the far side of the system is brought below 500 microns during evacuation. The time it takes to pull down a system and the time you'll hold the vacuum will depend on your application (residential vs. commercial). Check out Review of Vacuum for Service Engineers (revised by Jim Bergmann and Bryan Orr, 2020) at https://www.trutechtools.com/accutools-review-of-vacuum-for-service-engineers.html. Learn more about the HVACR Training Symposium or buy a virtual ticket today at https://hvacrschool.com/symposium. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Brett Wetzel joins the podcast to talk about his journey from resi tech to industry-leading refrigeration trainer. Brett is best known for his educational content, but he is also the manager of technical troubleshooting and training at CoolSys. The skills gap is widening, and CoolSys was inspired to create a solution to that problem. Brett's goal is to offer training that provides education and a sense of community all at once. Since he likes to keep his training simple and establish a solid foundation for his students, one of Brett's favorite training practices includes going over a system's P&ID diagram with his students before even looking at it. He focuses on classroom engagement and keeping trainees interested. Brett does regional training sessions and has written technical documentation to help technicians. As he has shifted from a field role to a full-time educator role, he has noticed that he has had more time at home. CoolSys focuses on commercial and industrial refrigeration, including system components, racks, and controls. The transition from residential HVAC to commercial HVAC and refrigeration requires an inquisitive mind and a drive to keep learning. Independent learners tend to do particularly well. There is an additional step that people will have to take when they move from fieldwork to education; communication skills and an ability to keep students engaged are crucial. Brett and Bryan also cover: CoolSys's training plans First lessons for refrigeration and HVAC trainees Keep It Simple, Stupid (KISS) in training New technologies and energy efficiency in CoolSys training Reading and independent learning The ever-changing nature of the HVAC/R trade Mentorship Practical skills and training CoolSys technical library Check out CoolSys at https://coolsys.com/ to learn about the company and some job opportunities. You can also email Brett at [email protected] or listen to the Advanced Refrigeration Podcast (YouTube channel: https://www.youtube.com/@advancedrefrigerationpodca9389). Learn more about the HVACR Training Symposium or buy a virtual ticket today at https://hvacrschool.com/symposium. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

In this short podcast episode, Bryan gets into some oil talk, covering some common refrigerant oil terms and types. Esterification is the process by which organic acid and alcohol come together to form polyolester (POE) oil and water. Hydrolysis refers to the decomposition of a substance when it comes into contact with water; when POE mixes with water, it will break down into esters, organic acids, and alcohol. Once POE oil undergoes hydrolysis, the process can't be reversed to get the same original oil. POE oil is also hygroscopic; hygroscopicity refers to the ability of the oil to absorb moisture. Miscibility refers to the ability of an oil to mix with refrigerant and be carried with it. In the context of refrigerant oil, "polar" refers to a molecular structure with an uneven distribution of electrons; oils with polar structures attract water molecules. Solubility refers to how well one compound can dissolve into another. Mineral oil is a product of the distillation of crude oil and was common in systems that used CFC and HCFC refrigerants. Mineral oil isn't as miscible with new refrigerants that lack a chlorine molecule. Alkylbenzene (AB) is a synthetic oil used in some commercial refrigeration systems that is compatible with mineral oil. Polyolester (POE) oil is one of the most common synthetic oils we use in systems that use HFC refrigerants; its main downside is its high hygroscopicity and tendency to undergo hydrolysis. Polyalkylene glycol (PAG) oil is common in automotive A/C systems (R-134A) and is more hygroscopic than POE oil but does not undergo hydrolysis. Polyvinyl ether (PVE) oil is used as an alternative to POE oil; it is more hygroscopic but does not undergo hydrolysis. Learn more about the HVACR Training Symposium or buy a virtual ticket today at https://hvacrschool.com/symposium. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

In this short podcast episode, Bryan talks about using a megohmmeter on a scroll compressor (or "megging" a scroll). Scroll compressors are among the most common compressor types nowadays, and they come with their unique needs and best practices. You can't pump them down into vacuums (in many cases, you can't do that anyway due to internal protections), run them in a vacuum, or run a high-voltage megohmmeter or hipot test. Scroll compressors differ from reciprocating compressors. A scroll compressor's motor is located at the bottom of the compressor, meaning it is immersed in refrigerant and oil when the system is operating AND when it is off; when the compressor is off and cold, there is a chance that there will be liquid refrigerant at the bottom. Compared to reciprocating compressors, scrolls tend to have a more compact and balanced design, and there could be a higher risk of internal arcing due to the tighter electrical tolerances associated with the design. Many inexpensive megohmmeters will say that any measurement below 10-20 megohms indicates a short, but some scrolls will have acceptable readings as low as 0.5 megohms to ground; these readings will typically show up on the smaller kilohm scale. You must only use a megohmmeter to ground, not from winding to winding. Moisture contamination, metallic debris, and lubrication issues can also cause a lower ohm reading than acceptable, so it's best to have historic data and track readings over time to make a diagnosis. Many modern multimeters can help you determine if a compressor is shorted to ground; you don't necessarily need a megohmmeter. You may also read the following tech tip to learn more: https://hvacrschool.com/scroll-compressor-pump-down-megohm-test-fusite-plugs/ Learn more about the HVACR Training Symposium or buy a virtual ticket today at https://hvacrschool.com/symposium. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Matt Bruner joins the podcast to talk about what it's really like being an HVAC creative. Matt is a young HVAC business owner who has recently written several HVAC School tech tips and pursued creative interests in the trade. Being creative in any industry or aspect of life requires us to be aware of what's around us and think deeply about how things can be better. Creativity requires us to channel our dissatisfaction into finding a solution, not just complaining, similar to how children channel boredom into projects. While the industry relies on processes and procedures to establish consistent standards, an over-reliance on processes can remove opportunities for HVAC professionals to be creative in their careers. However, creative solutions still need to be based on a solid understanding of the scientific and safety fundamentals of the trade. In many cases, processes get better when people are allowed to be creative and tweak existing models and ways of doing. There is plenty of room for creativity in the design and installation of residential HVAC systems. Common problems, including the need for dehumidification, require creative solutions from smart people in the trade. Solving these challenges is fun for creative-minded people, especially those who acknowledge that they don't have all the answers. The HVAC industry has so many jobs that require creativity through hands-on problem-solving. Matt and Bryan also discuss: How Matt ended up in the HVAC industry "Poor" creativity Institutional and self-imposed constraints AI and data models What it really means to "do things better" Unteaching and unlearning bad habits Asking the right questions Self-awareness The evolution of "the right way" of doing things Learn more about the HVACR Training Symposium or buy a virtual ticket today at https://hvacrschool.com/symposium. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

In this short podcast episode, Bryan talks about TXVs and their impacts on energy efficiency ratings (EER and SEER). EER (Energy Efficiency Ratio) is calculated based on fixed conditions (an outdoor temperature of 95 degrees Fahrenheit and an inside temperature of 80 degrees with 50% RH). EER is a ratio of cooling-only capacity in BTUs per hour to the total electrical input in watts. SEER (Seasonal Energy Efficiency Ratio) is the ratio of an HVAC system's cooling output during a typical cooling season to the seasonal electrical input in watts. Both energy efficiency ratios use non-proportional units (BTUs to watts), but SEER is supposed to account for a wide set of conditions (even though the climates of regional markets can vary quite wildly). EER2 and SEER2 are new standards based on updated equipment testing protocols with more realistic static pressures. TXVs and EEVs can modulate to control the amount of refrigerant going into the evaporator coil. TXVs maintain a set superheat at the evaporator coil outlet, which it detects with a sensing bulb mounted to the suction line. These sorts of modulating metering devices can boost system efficiency by adjusting the amount of refrigerant it feeds into the evaporator coil. Underfeeding can lead to inefficiency, and overfeeding can cause system damage. Non-bleed TXVs shut tight once the compressor shuts off, which prevents refrigerant migration during the off cycle and pressure equalization, thus protecting the compressor and reducing the cyclic degradation coefficient. The compressor may have to start a little bit harder, but the effects of the hard shutoff can improve the SEER rating by about 0.5. TXV systems are, overall, more efficient than systems fixed-orifice metering devices. Learn more about the HVACR Training Symposium or buy a virtual ticket today at https://hvacrschool.com/symposium. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Jim Ball from NCI joins the podcast to talk about high-performance maintenance contracts and agreements. A high-performance maintenance agreement requires you to take system measurements and present solutions to maximize performance accordingly and exceed customers' expectations, not just make assumptions about the performance parameters. Key measurements we should know include the charge levels, total external static pressure, filter & coil pressure drop, and CFM per ton. Many HVAC contractors and technicians don't really believe in maintenance procedures; some contractors merely want to keep customers or secure work during the shoulder months and don't aim to optimize the homeowners' systems. Maintenance procedures provide technicians and contractors the opportunity to improve the health and comfort of their customers. To perform a quality maintenance procedure, we need to establish company-wide processes that produce consistent results. When we standardize maintenance and installation procedures, we want to think about what an ideal system would look like and make our processes meet those expectations. Scheduling is an important aspect of maintenance agreements, and your ability to commit to a schedule can make or break your maintenance program. Pricing is also critical, and customers tend to be educated on their options; many of them understand that a higher price will often indicate higher standards. As we perfect our maintenance procedures and take advantage of technology, we can embrace monitoring in our maintenance programs. Jim and Bryan also discuss: Jim's history in the industry SEER ratings vs. real efficiency The value of historical measurements Craftsmanship and quality standards "Unteaching" poor practices Communication practices with customers Roleplay as a training tool Monitoring as the next step for high-performance maintenance programs Learn more about NCI and high-performance HVAC at https://nationalcomfortinstitute.com/. You can email Jim at [email protected] or call him at (440)-670-8783. Learn more about the HVACR Training Symposium or buy a virtual ticket today at https://hvacrschool.com/symposium. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

This episode of the HVAC School podcast Steve Coscia's symposium presentation: HVAC Soft Skill Training Resources. Likability is a superpower in any job that requires you to interface with customers or students. Every word and mannerism your customer or student sees will matter, and it's important to be likable. Those impressions can heavily influence their decision-making. Making a good first impression is one of the most important areas where we can focus our soft skills, and being on time is an easy way to make a good first impression on customers. When we are pleasant and convey mastery of our craft, we become more likely to earn appreciation and respect from customers and fellow tradespeople. Delegating the authority of the class is a soft skill that is important for instructors, as it encourages participation and lets a student be recognized by their peers. Telling a "signature" story, using props, and making the classroom interactive also help you convey useful information to your students and keep them interested. The objective is to get students to talk, and applying the "rule of 10" with these methods should help keep students' attention. Whether you're leading an employee meeting or training a class, don't be afraid to embrace your unique brand of teaching or leadership. Steve also covers: Lessons learned as a writer and instructor "Overpreparation" Humility Using action-oriented language and being honest Cleanliness and organization skills Sharing information with coworkers The Silo Effect Editorializing and saying too much Using proper grammar and positive words Congruency Integrity, self-control, and proactivity Buying time and convenience-oriented customers Learn more about Steve's training at https://www.coscia.com/, and be sure to check out his training series on ESCO Institute's HVACR Learning Network at https://hvacr.elearn.network/pages/coscia-communications. Learn more about the HVACR Training Symposium or buy a virtual ticket today at https://hvacrschool.com/symposium. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Roman Baugh returns to the podcast to talk about the time he installed an A2L system and lived to tell the tale. Roman used most of his same R-410A tools to install the first A2L-based ductless mini-split in Florida. Flare blocks, wrenches, and torque wrenches will all stay the same; you just have to be sure that your vacuum pumps and recovery machines are rated for use on A2L refrigerants. A2L-based mini-splits use flared fittings with no brazing necessary; this is currently the A1 status quo. Purging and flowing with nitrogen will be required of A2L systems. Purging refers to a higher flow rate and flowing refers to a very low flow rate (2-5 standard cubic feet per hour). If a pipe may have refrigerant inside of it, we will need to cut the pipe with a copper cutter, not use a torch. You will need to store A2L refrigerant tanks upright and locked in your van. You'll want the tanks to avoid being banged around or struck by other objects in the van. Although A2Ls are non-toxic, they still displace oxygen if a valve opens. Bryan and Roman also discuss: "Mildly" or "slightly" flammable Purging vs. flowing nitrogen Deep evacuation Flammable substances in the automotive industry Will there be reverse-threaded connections? The ever-changing HVAC industry Lower charge amounts Resources: You can learn more about A2L refrigerants in general on the ESCO Institute e-learning network by checking out training courses at https://hvacr.elearn.network/. Check out Opteon's new A2L refrigerant, XL41 (R-454B), at https://hvacrschool.com/xl41. You can find Daikin's R-32 resources at https://www.r32reasons.com/. Learn more about the HVACR Training Symposium or buy a virtual ticket today at https://hvacrschool.com/symposium. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

In this short podcast episode, Bryan talks about motor speed and other basic electrical topics as they relate to motors in HVAC equipment. In a typical single-phase PSC-type (induction-driven) motor, the speed is primarily determined by the electrical cycle rate, also known as the hertz. The hertz represents the speed at which the electrical current changes direction (positive to negative) per second; in the USA, that number is typically 60 hertz. Unless we're dealing with ECMs and VFD-driven motors, the motor speed will be partially influenced by the hertz or frequency as determined by the utility company or a generator. Motor speed is also determined by the number of magnetic poles in the motor. A motor doesn't make a complete revolution per cycle; a cycle only refers to the distance between two poles. The more poles we have, the shorter the distance needs to turn per cycle. A two-pole motor rotates all the way every cycle, resulting in 3600 RPM under no-slip conditions (synchronous speed). A four-pole motor has half the RPM, and an eight-pole motor has 1/4 of the RPM of a two-pole motor. Speed taps add winding resistance between run and common to create slip and slow the motor. A six-pole motor has 1200 RPM synchronous, but 1075 is the effective speed with slip factored in. Each speed has a different level of winding resistance, which slows the motor as you move from high to low; the lower-speed tap has higher resistance than high-speed taps. ECMs and VFD-driven systems convert the frequency and don't depend on the electrical frequency from the utility or generator. Learn more about the HVACR Training Symposium or buy a virtual ticket today at https://hvacrschool.com/symposium. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Trevor Matthews returns to the podcast to talk about growing in productivity and confidence as a tech to avoid feeling stuck in your career. They talk about personal development within your organization and in communities or training courses beyond your organization. Confidence and productivity work hand in hand, and techs can grow in both areas when they prioritize the one that matters most to them. In many cases, repetition helps build confidence, especially in the trades and other professions where you work with your hands. Scheduling is another strategy that improves your productivity, which can boost your confidence in the long run. As humans, we tend to fixate on fears and problems. We can build our confidence by reframing our fears, giving ourselves (and others) grace when we make errors, and focusing on building our skills to work through challenges. It's also important to find people in your organization who will uplift you, not hold you back. Developing unhealthy habits is a possible consequence of over-focusing on work, and it could be detrimental to your personal and professional life. Your physical and mental health are also important to your productivity and progress. Trevor and Bryan also discuss: Using a calendar to manage productivity Learning new skills to build confidence Communicating with your employer and building a relationship Training programs Self-assessment and going out of your comfort zone Caring about yourself to care about others Some of Bryan and Trevor's favorite books on the topic: Soundtracks by Jon Acuff Atomic Habits by James Clear Good to Great by Jim Collins Check out Trevor's Refrigeration Mentor program at https://refrigerationmentor.com/. Learn more about the HVACR Training Symposium or buy a virtual ticket today at https://hvacrschool.com/symposium. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

This podcast episode is Alex Meaney's 2023 HVACR Training Symposium session: "The Art of Unteaching." We may have flawed understandings of HVAC concepts, including the understanding that "heat rises." Our world is constantly shaped by the things we see and believe, and we are hard-wired to defend our observations and beliefs if we feel that those are threatened by new information. Instructors need to be sneaky about "unteaching" flawed ways of understanding the scientific principles of HVAC. When we communicate concepts to others, we need to watch our language and make sure our messages are clear; the subtext is as important, if not more important, than the actual material. Humility also goes a long way when teaching, though teachers need to be especially careful of imposter syndrome. Teachers can be most effective when they find a point of common ground between what their students already know and what they want to teach their students; avoiding jargon is a good way to make sure everyone can start on the same page before you teach them the vocabulary. When teaching, think about filling in the gaps without students realizing that those gaps have been filled; some teaching techniques, like inversion, can help with this process. Group settings also make it easier for students to process new information. Alex also covers: Pitfalls of the 12,000-BTU rule Bridge vs. bedrock foundation Pedantism and cognitive dissonance Repeating and rephrasing answers The "forgot to know it" approach Humility and the "reset button" Fallacies and heuristics Being able to understand when you're wrong Check out Alex's design consultation work at https://www.meanhvac.com/. Learn more about the HVACR Training Symposium or buy a virtual ticket today at https://hvacrschool.com/symposium. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

In this short podcast episode, Bryan talks about compression ratio and efficiency, particularly how floating or fixed suction and head pressure affect those things. Compression ratio (absolute head pressure divided by absolute suction pressure) closely correlates to efficiency in all sorts of compression-refrigeration HVAC/R systems; the most efficient systems have high mass flow with less compressor work. High compression ratios indicate a greater differential between the head and suction pressures. A lower compression ratio is desirable, but the number has to be realistic; a compression ratio of 1 indicates that the system is off. Medium-temp refrigeration compression ratios are typically around 3:1, whereas low-temp refrigeration can have higher compression ratios (6:1). In commercial refrigeration applications, we can help control the compression ratio with floating suction and head strategies. Floating the suction and head pressures allow the equipment to achieve lower compression ratios and higher equipment efficiency. Old strategies for controlling compression ratio would involve having a fixed evaporator temperature and suction pressure. In a parallel rack system, floating suction allows the suction pressure to float up when the case maintains temperature; this strategy helps close the gap between the absolute suction and absolute head pressures and reduces the compression ratio. Floating suction strategies allow the suction to "float" up by allowing the evaporator coil temperature to rise a little bit when the box temperature is under control. Floating head strategies, on the other hand, allow the head pressure to float down in low-ambient conditions. We can look at ambient temperature and discharge pressure to determine how much we can float down the head pressure. Learn more about the HVACR Training Symposium or buy a virtual ticket today at https://hvacrschool.com/symposium. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

This podcast episode is Nikki Krueger (Santa Fe Dehumidifiers) and Bryan's 2023 HVACR Training Symposium session about how we can optimize dehumidification and efficiency to create an HVAC design and humidity utopia. While we attempt to achieve comfort and high indoor air quality in humid climates, we may find challenges integrating these with the HVAC system and getting customers to understand the need for proper dehumidification. Older homes that are built "leaky" allow for uncontrolled infiltration and exfiltration, but newer constructions are a lot tighter and rely on mechanical ventilation to control where the outdoor air comes from and make sure it is properly filtered and distributed. We deal with both sensible and latent BTUs in a home, and we can't treat them as though they're all equal. Many high-efficiency systems have high sensible heat ratios (SHRs) and are designed to remove sensible BTUs very efficiently, but they're not adequate at removing latent BTUs. Ideally, we would rely on an A/C system or heat pump to dehumidify the air in cooling mode before adding a dehumidifier. However, some of the systems that are best equipped to handle high latent loads will be less efficient. If you wish to install supplemental humidification, the ideal design will have a dedicated return and tie into the main HVAC supply duct. Nikki and Bryan also discuss: Willis Carrier's real invention Strategies for reducing conductive, convective, and radiant gains Understanding relative humidity and dew point Design loads Electrification and energy efficiency incentives Adiabatic heating and cooling Single-stage vs. multi-stage equipment Dehumidification for ductless mini-splits Supplemental dehumidifier designs Learn more about Santa Fe Dehumidifiers at https://www.santa-fe-products.com/. Learn more about the HVACR Training Symposium or buy a virtual ticket today at https://hvacrschool.com/symposium. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

This is the episode for you if you've ever asked, "What the flux?" In this short podcast, Bryan explains the basics of flux in soldering and brazing, as well as magnetism. Flux means "flow." In HVAC, "flux" may have two meanings. It may refer to the substance that helps the molten alloy flow and bond to base metals more effectively when you're soldering or brazing. However, flux may also refer to magnetic flux, which is the lines of force that emanate from a magnet; this concept is important in inductive loads like transformers. In soldering, brazing, and welding, flux is a powder-paste or liquid that you apply to the base metal. You usually apply it directly to the male side of the base metal, or it may be embedded in the brazing alloy. Flux prevents oxides (like rust or the black flakes, cupric oxide) from forming on the surface you're brazing, which commonly happens at higher temperatures. Flux helps you create a proper bond, but it doesn't eliminate the need to clean the base metal before brazing. You typically don't need flux when you use silver-phosphorus or phosphorus-copper brazing rods for copper-to-copper brazing; the phosphorus acts as a fluxing agent, and using flux may increase the risk of contamination. It's also important to remove the flux from the metal after brazing because it may cause pitting; you may use a brush and/or a wet rag. Flux is useful when you use rods with high silver content or when you have other base metals; the appropriate flux will depend on the base metal, especially if you're soldering aluminum. Learn more about the HVACR Training Symposium or buy a virtual ticket today at https://hvacrschool.com/symposium. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Steve Rogers from The Energy Conservatory (TEC) returns to the podcast to discuss the impacts of duct leakage on occupant comfort and HVAC system performance. Duct leakage has more significant negative effects in heat pump systems than in furnace systems, especially in climates with high heating, cooling, or latent loads, due to pressure imbalances and moisture problems. You can measure duct leakage by masking off all supply and return registers, attaching a calibrated fan, and running the duct blaster to pressurize the duct work to 25 Pascals. Exhaust-only ventilation presents many of the same problems as duct leakage, particularly in the humid South. The duct leakage allowable by code (in Florida) is almost equivalent to a 50-CFM bathroom fan. Leakage often happens on the supply side, and it is important to determine whether the leakage is happening on the supply or return side; you may lose significant capacity on the supply side, and you may lose a little less capacity if the leakage is primarily on the return side. That capacity, however, is often heavily latent, leading to potential moisture problems (though less so in cold climates). Duct leakage may go outside or merely into an unconditioned space within the home; you can test the duct leakage outside with a duct blaster and a blower door simultaneously. Steve and Bryan also discuss: Duct leakage problem differences in the North and South Regulations and their effects on changeout practices Using powered flow hoods and a TrueFlow grid to measure duct leakage Duct leakage allowable by code Home construction types and duct configuration Envelope leakage Leakage testing and pricing Low-Income Heating Assistance Program (LIHEAP) Learn more about TEC at https://energyconservatory.com/. Learn more about the HVACR Training Symposium or buy a virtual ticket today at https://hvacrschool.com/symposium. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Tom Lorenz from Sensi joins the podcast to talk about the launch of the Sensi Touch 2 thermostat. The Sensi Touch 2 smart thermostat is compatible with room sensors, which makes it an efficient and effective thermostat. Smart thermostats are becoming more common in homes, especially as we focus on HVAC efficiency. Designers are aiming to make smart thermostats user-friendly, aesthetically pleasing, easy to install, and driven by data (via sensors). Installation is easy for contractors, as it relies on push terminals and cleanly covers up the previous thermostat's installation site. The Sensi Touch 2 requires a common wire, but it has easy-to-use push terminals that allow wires to click into place. It also has dedicated accessory terminals for add-on equipment like dehumidifiers. You can also pair the Sensi Touch 2 with its respective app to program the thermostat. Smart maintenance automatically alerts homeowners about poor performance or efficiency. These sorts of alerts can offer peace of mind for the homeowner. The room sensors allow the Sensi Touch 2 to manage home comfort by collecting data from several locations of the house; you can sync up to 15 room sensors to the Sensi Touch 2 thermostat. As with other Sensi thermostats, the Sensi Touch 2 has contractor branding capabilities. You can get your company name and number programmed into the main display so that the customers know who to call whenever they need something. You can learn more at procontractorbranding.com. Tom and Bryan also discuss: History of Emerson, White-Rodgers, and Sensi controls Personal data and privacy concerns with smart technology Smart thermostat design and aesthetics Energy Star certification Sensi Lite (coming soon) Warranty information Learn more about the Sensi Touch 2 at https://sensi.copeland.com/en-us/for-professionals/touch2-smart-thermostat. Learn more about the HVACR Training Symposium or buy a virtual ticket today at https://hvacrschool.com/symposium. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Eugene Silberstein from ESCO Group returns to the podcast to discuss why and how to create an internal training program for your HVAC/R company. HVAC/R has so many niches, and information and practices are always evolving, so lifelong learning is necessary for the industry. In-house training is a form of education that can come with many benefits, including control over scheduling, building community within the organization, and convenience. However, creating an in-house training program also comes with many challenges, including time and money expenses. For an internal training program to work, there needs to be a clear commitment to lifelong education that is ingrained in the culture. That could include bringing in other educators, setting up mentorship programs, and partnering with local trade schools. Unlike an external training program, an in-house training program also allows you to tailor education to your technicians' goals and needs. A good in-house training program creates an environment of psychological safety; it allows trainees to ask questions without feeling singled out or judged. Some people who know topics well aren't the best trainers; trainers need to know how to teach others, which means understanding how the human mind works. Commitment is ultimately what makes or breaks an internal training program. If your trainees can see that you are investing in them consistently, they will be more likely to give and get the most out of the training program. Eugene and Bryan also discuss: The hunger and need for HVAC/R education Benefits and drawbacks of external training Using mistakes and callbacks as learning experiences Educators who make trainees feel safe Education, engagement, and entertainment Will technicians leave your company if you train them? Casual but deliberate training Learn more about ESCO Group's HVACR learning network at https://hvacr.elearn.network/. Learn more about the HVACR Training Symposium or buy a virtual ticket today at https://hvacrschool.com/symposium. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

In this short podcast, Bryan talks about the times when subcooling is meaningless. It is important to understand subcooling fully before using it as a charging or diagnostic method, particularly in refrigeration systems. When we need to charge TXV systems in residential HVAC, many technicians rely on subcooling to set the charge. However, refrigeration systems don't quite work the same way; charging a refrigeration system by subcooling may lead you to overcharge the system. We take subcooling on the liquid line between the condenser and the metering device. The condenser takes superheated vapor and rejects heat. This process turns the superheated vapor refrigerant into a liquid-vapor mixture midway through and subcools the liquid refrigerant at the bottom of the condenser. That liquid "stacks" at the bottom of the condenser. Adding more refrigerant will cause more liquid refrigerant to stack up at the end of the condenser and increase subcooling. These conditions can cause an increase in head pressure. However, many refrigeration systems have receivers between the metering device and the condenser. Excess refrigerant gets stored in the receiver; it doesn't stack up in the condenser, and it doesn't contribute to additional subcooling. As the liquid line fills and the metering device restricts, the liquid goes into the receiver, not the condenser. Subcooling won't change much until the receiver is full, which is a major problem; receivers should only be up to 80% full, even when pumped down. So, we rely on sight glasses or receiver-level monitors to determine the charge, not subcooling. The goal is to keep the sight glass clear, meaning there is a full line of liquid going to the metering device. (However, sight glasses will also be clear when the system is off or empty.) Learn more about the HVACR Training Symposium or buy a virtual ticket today at https://hvacrschool.com/symposium. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Craig M (AC Service Tech) returns to the podcast to talk about solving work-life imbalance, especially for HVAC/R technicians who have children and families of their own. Our actions tend to be driven by our priorities, which vary at different stages of our lives. Someone's work-life balance could also vary depending on different parts of the year. When we let the right people into our lives and are surrounded by supportive communities, we can reconfigure our personal and career trajectories to keep them in line with our priorities. To create a healthy work-life balance, we must be open to investing in others and letting others invest in us. "Balance" implies a constant state of evenness, but for people who work many hours, own a business, or have a family, their time may not be perfectly balanced at all times. That sort of variety presents a challenge, but it also presents opportunities for us to invite wise counsel and maintain communication to make sure we're on the same page as the important people in our lives. We are imperfect, and in many cases, we make mistakes when we do things we shouldn't do or fail to do things we should do. When we make those mistakes or bad things happen, we can think about practical measures we can immediately implement in our lives to make them more fulfilling in terms of our long-term vision. Craig and Bryan also discuss: Providing for one's family Seeking counsel and wisdom from others How lifestyles and priorities shift as children grow up Intentionality and short-term vs. long-term thinking Making the "right" decision Letting people struggle but supporting them Emotional maturity Authenticity Bringing positivity to communication and relationships Learn more about Craig's books and other educational resources at https://www.acservicetech.com/. Learn more about the HVACR Training Symposium or buy a virtual ticket today at https://hvacrschool.com/symposium. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

In this short podcast, Bryan explains how rules of thumb (ROT) can cause duct issues. He talks about the role of friction rate in duct design as well as its intent and limitations. Friction rate is a value located on duct calculation tools, including Ductulators. We use friction rate to predict the operating static pressure of the system, but it is often misapplied when people design their ductwork around rules of thumb. The friction rate is expressed in inches of water column ("WC), which we also use to measure static pressure. However, the operational static pressure and friction rate are NOT the same things. Ductulators provide information about friction rate based on 100 feet of straight ductwork in the size selected, which we almost never see in the field; fittings and turns add effective length (EL), so the total effective length (TEL) is often more than 100 feet. When duct designers apply rules of thumb, like a 0.1" friction rate, and apply it to the CFM, they don't consider the actual length of the duct. So, the ducts are often undersized and don't properly account for the actual resistance to airflow. If you want to stop using rules of thumb, ACCA Manual D and related software can help you get more precise design parameters and account for other restrictions. The following tech tips contain more information and specific equations to help you find the total effective length: The Friction Rate Chart (and What it Means), What the Heck is a Friction Rate? (Eric Kaiser), How to Determine the Friction Rate for Residential Duct Design (Neil Comparetto). Learn more about the HVACR Training Symposium or buy a virtual ticket today at https://hvacrschool.com/symposium. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Craig Migliaccio (AC Service Tech) returns to the podcast to talk about what it means to have the heart of a teacher. Craig discovered his passion for teaching while instructing apprentices on the job, and he went into institutionalized teaching from there. He chose to overcome several administrative obstacles to become eligible as a teacher at technical schools, and that perseverance is one aspect of the "heart of a teacher." One of the most rewarding aspects of teaching is the investment in others. For Craig, HVAC is a tool for supporting someone's family, and a teacher can find a sense of purpose in helping people be better HVAC practitioners. When good teachers invest in their students or apprentices, they give those people a reason to take pride in their work. The job of a teacher isn't to give students the answer, which can be frustrating for students and the teachers of those frustrated students. People who have the heart of a teacher allow students to learn things themselves and be frustrated when they don't receive the answer immediately. Teachers ultimately care and want to keep improving, and they get their students to ask questions. The most important aspect of teaching is getting students to retain knowledge and build on it, and many students retain knowledge when they get to ask questions on their own and apply their knowledge. Craig and Bryan also discuss: Craig's experience with teaching licensure The intrinsic desire to share knowledge or skills Investing in others during a labor shortage Switching mindsets Monologuing vs. asking questions Continuous improvement as a teacher Impostor syndrome and teaching Making educational content more valuable Limitations of video/audio education Learn more about Craig's books and other educational resources at https://www.acservicetech.com/. Learn more about the HVACR Training Symposium or buy a virtual ticket today at https://hvacrschool.com/symposium. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

In this short podcast episode, Bryan explains why saturation can be CONFUSING and clears up some common misconceptions. Saturation applies to dehumidification and refrigerant inside the system. Generally, saturation is the state at which a substance can no longer hold or absorb any more of another substance. When air is saturated with water vapor and can hold no more, it is at the dew point or 100% relative humidity; it will condense on any surface below the air temperature. Air isn't like a sponge that absorbs water vapor; saturation deals with vapor pressure, particularly the pressure exerted by a vapor in thermodynamic equilibrium with its condensed phases in a closed system. Dehumidification is the process by which we remove moisture from the air; this process improves comfort across a significant portion of North America during the summer months, and it prevents fungal growth inside the home. Air in a dehumidifier or an HVAC system in cool mode makes contact with a surface at a temperature below the dew point. So, moisture comes out of the air and condenses on the coil. Colder evaporator coils, which result from longer runtimes, are more effective at removing moisture. Inside a system, the refrigerant in the evaporator boils as it absorbs heat. The refrigerant can absorb a lot of heat due to the heat required to change state, also known as latent heat (compared to sensible heat, which is the heat required to raise the temperature of a substance). Until the refrigerant completely boils off, it is at saturation. Pressure also dictates the saturation point, and we use refrigerants that can boil under the appropriate temperature and pressure conditions for the HVAC equipment we're working with. Learn more about the HVACR Training Symposium or buy a virtual ticket today at https://hvacrschool.com/symposium. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Kevin Hart from HAVEN returns to the podcast to talk about ventilation in humid climates and some best practices for working on systems that focus on the V in HVAC. HAVEN focuses on IAQ management with the use of software technology. HAVEN started off with its central air monitor, and the company then developed a central air controller to help customers make their homes healthier. Fresh-air ventilation is one IAQ, but humid climates make it tricky to bring that air in; dumping "fresh" air into the structure without taking extra precautions can lead to high indoor humidity and even microbial growth. ERVs, HRVs, and ventilating dehumidifiers are some traditional ventilation strategies for various climates; exhaust ventilation is also quite common but can pull hot, humid air through the building envelope. HAVEN is creating a more templated approach to ventilation; HAVEN uses whole-home in-duct monitoring and local weather data to get ideas of the conditions inside and outside the home to tailor fresh-air ventilation to each individual system's needs. HAVEN has partnered with several ventilating dehumidifier manufacturers, including Santa Fe and AprilAire; many of these manufacturers also use filtration to control the quality of incoming fresh air. Kevin and Bryan also discuss: HAVEN's journey during the COVID-19 pandemic Chemical interactions in our homes (VOCs and CO2) Exfiltration and infiltration The problem with industry standards and regulations Appropriate climates for ERVs, HRVs, and ventilating dehumidifiers Using dew point to control indoor and outdoor parameters Energy savings with HAVEN's technology Does a house need to "breathe?" HAVEN app You can learn more about HAVEN's offerings for HVAC professionals at https://pro.haveniaq.com/ and get a discount on HAVEN's product bundle at https://www.trutechtools.com/ by using the coupon code haven2022. Learn more about the 4th Annual HVACR Training Symposium or buy a virtual ticket today at https://hvacrschool.com/symposium. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Dominick Guarino from NCI joins the podcast to talk about the High-Performance HVAC Summit, an upcoming event hosted by NCI from April 17–20. The National Comfort Institute (NCI) is a training organization that helps technicians learn crucial skills and succeed through high-performance contracting. High-performance contracting is based on the mindset of "don't just promise performance; prove it." To maximize technicians' potential, NCI teaches technicians how to test equipment properly and monetize their skills. Techs can then use their knowledge to teach the homeowner about the system and solve problems with sales; they can earn money while being solutions-oriented. NCI's High-Performance HVAC Summit is a training event geared toward HVAC business owners and contractors. It started as a membership conference for education and networking, and it has since expanded to include like-minded HVAC professionals from all walks of life. Workshops are led by a mix of contractors and NCI staff, and there are breakout sessions and other various session types. This year's High-Performance Summit theme will be "It All Starts With Service." The four focal points of the workshops will be lead generation through service and maintenance, CO safety, the lead handoff from service to sales, and maintenance agreements. One more session will focus on hands-on testing, called "Low-Performance Town" this year, and there will be a panel about the future of high-performance HVAC. Dominick and Bryan also discuss: Dominick and NCI's history in the industry High-performance maintenance Consumers who do their research The HVACR Training Symposium High-Performance Summit Awards Banquet NCI's collaboration with other industry leaders and organizations Visit https://www.gotosummit.com/ to learn more about the High-Performance Summit. If you decide to register for the summit, type HVACSCHOOL in the coupon code section for a $100 discount. Learn more about the 4th Annual HVACR Training Symposium or buy a virtual ticket today at https://hvacrschool.com/symposium. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

In this podcast from AHR 2023, Tony Gonzalez from Fieldpiece joins Bryan to talk about training, combustion, and more. Fieldpiece has a new combustion analyzer that reduces the cost of tool ownership and maximizes the tool's uptime, namely by using a long-lasting sensor. The combustion analyzer's oxygen and CO sensors seal up when the combustion analyzer is turned off, which pauses degradation. The sensors are also field-replaceable and come with a 4-year warranty. The CAT85 also has a built-in dual-port manometer (which can measure static pressure) and can measure a live draft pressure during combustion analysis. Some common misconceptions exist around combustion analyzer sensor lifespans and calibration. The sensor life refers to how long a sensor can output a signal to generate a reading; it doesn't refer to the accuracy of the sensor at the end of its life. Calibration keeps the sensors accurate, especially because sensor accuracy tends to degrade over time. To get the most out of your sensor, yearly calibration is recommended. Fieldpiece is also launching its ambassador program, which is a network of independent trainers with field knowledge who have been trained to become Fieldpiece product experts. Those ambassadors then train contractors and technicians on behalf of Fieldpiece. Tony and Bryan also discuss: Fieldpiece's sensor calibration process Water freezing in combustion analyzer traps Distinguishing your company from the competition with superior tools Technical training from Fieldpiece Fieldpiece leak detectors and new A2L refrigerants Infrared vs. heated diode leak detector sensors Learn more about Fieldpiece tools at https://www.fieldpiece.com/ or ask about training by emailing [email protected]. Learn more about the 4th Annual HVACR Training Symposium or buy a virtual ticket today at https://hvacrschool.com/symposium. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

In this podcast from AHR 2023, Brandon Marshall from Chemours and Chris Forth from JCI talk about the future of refrigerants and Opteon XL41 (R-454B). Refrigerant regulations are changing to pave the way for lower-GWP refrigerants, but M1 is also in full swing. M1 refers to the U.S. Department of Energy's implementation of the new efficiency standards for A/C units and heat pumps (SEER2, EER2, etc.). These standards changed the equipment testing procedure to match field conditions more closely. Opteon is the next-generation portfolio of low-GWP refrigerants for Chemours as a successor to the legacy refrigerants in the Freon product line. These refrigerants are a response to the HFC phasedown outlined in the AIM Act. JCI chose to use Opteon XL41, an HFO, for its equipment due to Opteon XL41's low GWP compared to R-32 and because of the similar operating pressures and temperatures to R-410A. A2Ls are a permanent change in the industry, and their safety considerations and best practices are here to stay. However, even though A2Ls are more flammable than A1 refrigerants, they are nowhere near as flammable as A3 refrigerants. Just about any refrigerant can propagate flame under the right conditions (including A1s), so A2Ls are only a little bit more flammable than those. Brandon, Chris, and Bryan also discuss: Brandon and Chris's industry experience The transition from CFCs to HCFCs to HFCs Refrigerant reclamation Upcoming GWP limits Hydrofluoroolefins (HFOs) A2L refrigerant product testing Staying up to date on A2L training resources Some of the prominent flammable refrigerant trainers Smuggled and counterfeit refrigerants Learn more about the 4th Annual HVACR Training Symposium or buy a virtual ticket today at https://hvacrschool.com/symposium. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

In this podcast from AHR 2023, Jim Bergmann and Joe Medosch talk about measureQuick and the ways it's EXPLODING with growth and new features. They also talk about heat pumps, electrification, and other hot topics in the industry. Jim Bergmann recently released an open letter about heat pumps on LinkedIn; he addressed the shortcomings of the industry from a skill standpoint. The lack of training and standards may be mitigated with proper training (and an understanding of building science fundamentals) or by embracing hybrid systems. Heat pumps may also perform relatively poorly during extreme weather events and may not manage temperature swings well. MeasureQuick has recently been working with ACCA and formed other partnerships to allow for standardization (for companies and the industry as a whole). More companies are also integrating with measureQuick, especially TEC and their TrueFlow Grid; accuracy across brands tends to be pretty consistent, and measureQuick allows you to mix and match tools. The customer-facing side of measureQuick has also received some development, which allows the customer to see the value and quality of their installation. MeasureQuick is keeping up with the growing pains by doing constant testing. Joe and Jim make sure the user experience is seamless, intuitive, and free of problems or inconveniences. Jim, Joe, and Bryan also discuss: Fixing the building envelope Heat pump vs. gas furnace comfort Energy Star certification for installations measureQuick user base milestones Industry leaders, supporters, and partnerships New measureQuick workflows Joe Medosch's role at measureQuick The challenges of the HVAC trade Technology challenges for measureQuick's users Free and paid measureQuick features Learn more about the 4th Annual HVACR Training Symposium or buy a virtual ticket today at https://hvacrschool.com/symposium. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Genry Garcia returns to the podcast to talk about pressures in the building envelope, namely the infiltration skeletons behind closed doors. When doing load calculations (Manual J), we need to know how much of the heat load, especially the latent heat load, comes from leakage in the building envelope and the ducts. Opening/closing doors and windows can also worsen the issues that stem from infiltration due to upsetting the balance of pressures in the home. Smoke pencils and other similar tools can give you an idea of the pressure in a home and how it could change when doors open or close. Since there is a lot of room for inaccuracy in extreme climates (especially those with high latent loads), many HVAC systems are oversized and underperform. Some building design features also exacerbate problems presented by oversized HVAC systems. To get the data we need to design systems that mitigate those issues, we need to do a blower door test. Downsizing the tonnage in retrofits or replacements usually has advantages, but it must be done right, and customers may not always want to do that. It's the contractor's responsibility to give them a choice and educate them about the options and what the thorough diagnostic process looks like, including balancing the home and checking the pressure in relation to the outdoors. Genry and Bryan also discuss: Positive and negative pressure in certain rooms Exhaust ventilation and pressurization Using See Stack to see differences in loads Leaving the fan in the "on" position Useful tools Variables in lab-based testing and field testing Getting hung up on the 3 Pascals rule of thumb Leaky rooms vs. whole-home leakage Learn more about the 4th Annual HVACR Training Symposium or buy a virtual ticket today at https://hvacrschool.com/symposium. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

In this episode recorded live at AHR Expo 2023, Nick from INFICON joins Bryan to talk about leak detectors and how we can improve our understanding of them. Some leak detectors, including the INFICON Stratus, measure concentrations in PPM (parts per million). When measuring PPM, we have to keep in mind that it doesn't indicate the size of the leak or leak rate, but it does help us pinpoint the leak location. In some cases, we also have to watch for automatic zeroing capabilities. Leak detectors come in many varieties, including heated-diode, ultrasonic, and infrared; each type has unique maintenance needs. Heated-diode leak detectors are sensitive, but their sensors wear off with frequent use and will require replacement. Infrared leak detectors use infrared absorption and don't degrade over time the way heated-diode leak detectors do. An ultrasonic leak detector picks up the sound of refrigerant and air leaking out of a hole to pinpoint the leak. It's a good idea to approach leak detection with a plan, including starting high on the coil and moving down (because refrigerant is heavier than air and may set off the leak detector below the actual leak). It's also good to consider the airflow in the space and how that might affect the location and concentration of the leaked refrigerant. Nick and Bryan also discuss: Pressure, hole shape, and leak rate Understanding tool maintenance Infrared leak detector usage and considerations Common causes of leak detector failure D-TEK product line CO2 and hydrocarbon sensors for leak detectors D-TEK Stratus modes (cloud hunting and pinpoint) Applications for D-TEK Stratus leak detectors "False" positives Learn more about INFICON at https://www.inficon.com/. Learn more about the 4th Annual HVACR Training Symposium or buy a virtual ticket today at https://hvacrschool.com/symposium. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

In this episode recorded live at AHR Expo 2023, Dustin and Jim from Copeland/White-Rodgers join Bryan to talk about the use of heat pumps in cold climates. They talk about the history of heat pump innovation and talk about changes to come. Variable-speed and two-stage compressors, as well as advanced controls, make it easier for contractors to control sizing and for heat pumps to perform to acceptable standards in cooler climates. Contractors in cold climates also rely on dual-fuel models that use electric and gas heat, which makes it easier for the system to move the desired amount of heat. Variable-speed and two-stage compressors help the system deal with different heating and cooling capacities; in cooling mode, these technologies can also help with latent removal if the blower is also able to vary with the compressor. Advanced controls, especially universal controls, also help with defrost management, a key component of heat pump performance. When defrost is managed effectively, customers can yield energy savings. The White-Rodgers universal defrost control comes with coil and outdoor temperature sensors (thermistors) to determine when the unit is ice-bound; it also has a thermostat that can control second-stage heat. Dustin, Jim, and Bryan also discuss: Electrification and heat pump sales Vapor injection and compression ratio control Freq drives White-Rodgers universality and nomenclature Timed vs. demand defrost Electric heat vs. gas/oil heat costs WR Mobile app Multi-volt contactors (White-Rodgers SureSwitch) Pool heat pumps and contactors Crankcase heaters, long line sets, and total system charge A2L refrigerant testing Learn more about White-Rodgers products on the WR Mobile app, our partner page at https://hvacrschool.com/partner/emerson-white-rodgers/, or the website at https://climate.emerson.com/en-us/brands/white-rodgers. Learn more about the 4th Annual HVACR Training Symposium or buy a virtual ticket today at https://hvacrschool.com/symposium. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

In this episode recorded live at AHR Expo 2023, Matthew Schlegel, the Commercial Product Manager of Ducted Systems from JCI (Johnson Controls) joins Bryan to talk about rooftop unit (RTU) retrofit facts and considerations. When doing an RTU retrofit, you want to make sure you know the budget before anything else; larger budgets will allow you to implement things like VFDs and even VAV technology. In many cases, you may consider adding an economizer for "free" cooling and energy savings. You also want to know what you will get out of a retrofit in terms of value, especially when it comes to system efficiency and longevity. Some common IAQ upgrades for RTUs include improved filtration, especially with MERV 13 filters. Economizers also allow you to control the amount of outside air with the help of an exhaust system or even barometric relief. UV lighting can also be used in light commercial RTUs. When doing a retrofit, you'll want to pay attention to the existing equipment's footprint. Sticking to that footprint will make the replacement aspect easier. The utility and electrical infrastructure are also important to consider, as you won't want to replace the existing piping, wiring, and connections. With regulations and technology constantly changing, it helps to be able to contact the manufacturer to assist with the retrofit process. Companies like JCI are trying to assist contractors with installations by providing guidance and education in the field. Matthew and Bryan also discuss: Matthew's professional experience at JCI Adding economizers and VFDs Convertible filter racks Cost-benefit analysis resources Changing regulations Interfacing with the manufacturer during the retrofitting process To learn more about JCI, visit https://www.johnsoncontrols.com/. Learn more about the HVACR Training Symposium or buy a virtual ticket today at https://hvacrschool.com/symposium. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Chris Mohalley returns to the podcast to talk about troubleshooting the modern ECM (or EC motor) and give diagnostic tips. ECMs are electronically commutated motors; they are mechanical motors with an electronic control module that dictates everything the motor does. As with all motors, ECMs have inputs and outputs. If the motor is not running, the first step is to check the line voltage and make sure that it is correct and connected continuously, as that's one of the main inputs on all ECMs; there is no relay or switch on the line side. The motor itself is the output, so you will know if the output is correct if the motor is rotating and generating airflow as intended. Constant-speed and constant-torque motors can all be diagnosed with a basic voltmeter. One of the most difficult parts of troubleshooting constant-torque ECMs is knowing how the taps are programmed by the manufacturer; reading the manual and schematic is advantageous during diagnosis, especially as these motors have evolved to use pulse-width modulation (PWM) and have nine speeds instead of five (energizing pin 1 at the same time as another pin, diagnosed with 24v AC). Constant-airflow motors tend to have inputs that are less complicated than the five or nine-speed taps. Chris and Bryan also discuss: Inputs: line voltage and signals TechMate Pro, multimeters, and Genteq TECINspect diagnostic tools Constant-speed vs. constant-torque vs. constant-airflow motors Diagnosing PWM signals with DC voltage Adjusting airflow with DIP switches Are board and motor failures common? Why we don't diagnose the motor separately from the control Learn more about Regal Rexnord's FREE training at https://regal.mmu.com. Learn more about the HVACR Training Symposium or buy a virtual ticket today at https://hvacrschool.com/symposium. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Clifton Beck of ESCO Group returns to the podcast to talk about training for the future. He also talks about how he became an educator, what it's like to be a trades educator with ESCO Group, and how educators can handle the recent HFC phasedown and the rise of A2L refrigerants. Especially with the COVID-19 pandemic, mass media has changed the way the industry thinks about training. Organizations like ESCO have evolved, and that is evident in their curricula; changes are being made to keep up with field tools and equipment to make sure technicians are up to date. A large network of industry experts makes these training curricula possible. Virtual and media education have changed the way we think of educators. Many of the most knowledgeable people in the industry, including people like Craig Migliaccio, work in the field and aren't traditional educators but have a large positive influence on the industry due to social media. Refrigerant regulation changes, including the HFC phasedown, present opportunities for training to focus on combating misinformation and adapting to field conditions. Training should aim to eliminate confusion and anger in these situations. Proper installation and service procedures will make the A2L transition much easier. Clifton and Bryan also discuss: Clifton's professional history HVAC experts and relationship building ESCO Institute and HVAC Excellence The evolution of educators and expectations for them HFC phasedown facts Recovery, recycling, and reclaiming refrigerant appropriately Commercial vs. residential HVAC/R and refrigerant regulations Educators as social media personalities HVAC Excellence Conference Learn more about ESCO Group's resources at https://www.escogroup.org/. You can also check out the ESCO Group YouTube channel at https://www.youtube.com/@escogroup. Learn more about the HVACR Training Symposium or buy a virtual ticket today at https://hvacrschool.com/symposium. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

ECM expert Chris Mohalley joins the podcast to talk about the balance between selecting air filtration and motor performance, also known as "MERV vs. Motors." As the industry realizes that filtration is more important, we're starting to see an interest in filters with MERV ratings of 13 or higher. However, there are some design challenges associated with static pressure drops across filters, motor responses to static pressure, and airflow. If the airflow isn't set properly, that could affect the refrigerant charge and temperature rise. PSC motors' performance directly follows the load; as static pressure increases, the airflow rate produced by the motor decreases. They may also make loud noises when the static pressure is high but satisfactory airflow. However, they are robust and don't typically fail quickly due to high static pressure. Electrically commutated motors (ECMs) are operated by electronic controls and come in constant torque or constant airflow varieties. The former has a performance curve (like a PSC motor) but doesn't appear to suffer from longevity issues when the static pressure is high; the latter can adjust airflow based on static pressure, but it is likely to have issues maintaining airflow during high static pressure conditions. Regardless, there is still an operational envelope; going outside of that envelope will likely result in a capacity and/or efficiency hit if there is high static pressure. Chris and Bryan also discuss: COVID-19 pandemic and the evolution of filtration Face velocity across filters Amps in constant torque vs constant airflow motors Swings in airflow/performance Educating the customer about "upgrading" filters Using performance manuals Learn more about Regal Rexnord's training at https://regal.mmu.com. Learn more about the 4th Annual HVACR Training Symposium or buy a virtual ticket today at https://hvacrschool.com/symposium. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

John Ellis, a business consultant who specializes in IAQ training, joins the podcast to talk about effective filtration, product development, and more. John has recently worked with an OEM to bring field practicality and application to the engineers who design products. Filtration design is a relatively poorly understood concept in the industry; we tend to overlook a filter's ability to remove particulates from the air when we prioritize static pressure drop. We have to understand how the duct design can make higher-MERV filters work and how the face velocity plays into design and comfort. John also talks about bypass HEPA filtration and its appropriate uses and potential for misapplication. Bypass HEPA may be integrated with the HVAC system (but run independently of the system) or installed independently of the HVAC; its effectiveness will be dictated by its runtime, and it doesn't filter everything. IAQ products and strategies need to produce quantifiable results, and our industry needs people to be trained to measure and produce those results, not push products. Education, integrity, and competence are the keys to starting conversations about IAQ methodologies that actually benefit the customer. When we're ready to have those conversations with the customer, we can show the customer that we prioritize their health, safety, and comfort; it's good to use maintenance procedures as times to follow up with the customer and make sure their IAQ needs are being met. Communication is critical here. John and Bryan also discuss: Design, production, and distribution MERV ratings Oversized filter-back returns with media filters Blow-by Charcoal carbon pellets vs. activated carbon Oxidizers and microbiology disruption Sales resistance & being pushed to make more sales Problems with circuit boards Learn more about John's work at https://thenewflatrate.com/ or contact him directly at (505)-652-8119. Learn more about the 4th Annual HVACR Training Symposium or buy a virtual ticket today at https://hvacrschool.com/symposium. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Dr. Allison Bailes from Energy Vanguard joins the podcast to answer the age-old question: do houses need to breathe? He also talks about his new book, A House Needs to Breathe... Or Does It? You can purchase that book directly through the Energy Vanguard site at https://energyvanguardstore.com/ or on Amazon. HVAC professionals can benefit from learning about building science because there is a lot of overlap between the two, and an HVAC technician who knows about building science can set themselves apart in the market. In short, Dr. Bailes doesn't think a house needs to "breathe," especially if a house brings in low-quality air, especially humid air, through gaps and cracks. Some people also use the term "breathe" differently; some may be referring to leakiness, and others may refer to drying out a house. It is necessary for a house to be dry, but we want to make sure that fresh air is controlled. If you build a home tightly, you have to ventilate it correctly. We have to control air, liquid water, water vapor, and heat. Heat is especially complicated, as it has three different ways of moving and can come in sensitive and latent varieties. One way of controlling those is through control layers like vapor barriers, though these aren't always needed; we must understand the vapor flow to determine if a vapor barrier is necessary. Dr. Bailes and Bryan also discuss: Energy Vanguard's resources The chapters of "A House Needs to Breathe... Or Does It?" IAQ - filtration, humidity control, ventilation, and source control Challenges with attic air Dr. Bailes's book-writing process The HVACR Training Symposium and other events w/ Dr. Bailes Keep up with Energy Vanguard, read the blog, and subscribe to the weekly newsletter at https://www.energyvanguard.com/. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

David Holt with the National Comfort Institute (NCI) returns to the podcast to talk about high-performance HVAC and what the heck it even is. High-performance HVAC is all about delivering the highest possible equipment performance out of the box. High-performance HVAC is a key element of NCI's work; equipment should be able to deliver the health, comfort, safety, reliability, and efficiency expected by the occupants, and equipment that can't do that often has root issues we need to troubleshoot and fix. In many cases, the root cause has something to do with airflow issues. As contractors, we can focus more heavily on testing fan airflow to get to the bottom of poor HVAC performance, even when there may not be an apparent airflow problem. We need the proper test instrumentation to measure CFM, a key indicator of performance. We can't expect to maximize system performance until the airflow is correct across the heat exchange surfaces. Many factors that contribute to poor equipment performance actually have to do with building science, including issues like air leakage. Although HVAC contractors can't control that, we can be successful if we have a culture and mindset that makes us put our customers first and work with the circumstances we're given to deliver the best possible solution. David and Bryan also discuss: David's role at NCI Manufacturer, distributor, contractor, technician, and customer relationships How to measure CFM effectively Effects of improperly Issues that arise during building construction Parts vs. equipment vs. systems What makes a good service technician The high-performance mindset Having a classroom vs. a commitment to training If you want to get more involved in HVAC training, you can text David at (706)-332-2212 or visit https://nationalcomfortinstitute.com/pro/. Learn more about NCI's High-Performance HVAC Summit at https://www.gotosummit.com/. Check out the HVACR Training Symposium and order your virtual tickets before, during, or after the symposium (Jan 19-21, 2023) at https://hvacrschool.com/symposium. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Ed Janowiak returns to the podcast to talk about setting realistic customer expectations when designing residential HVAC systems across climates, seasons, and load conditions. Being honest and aggressive is one of the best ways to set realistic expectations, and our load calculations and equipment selection need to reflect that. Manual J calculations must consider non-design days, not just the design conditions, including partial load conditions. Partial load conditions that aren't accounted for may make it more difficult for the HVAC system to control latent heat, potentially leading to moisture problems indoors. We have to set expectations in the summer a bit differently than we set expectations in the winter, and we must account for the equipment type when we create expectations. Heat pumps perform differently than furnaces, and oversized furnaces typically present fewer problems than oversized heat pumps in areas with high latent loads. Clients must also be willing to acknowledge that systems won't perform exactly as designed during partial load conditions. You can put the information in writing and make clients sign the paperwork to ensure that they understand the expectations you've set. Laying out expectations and making clients read them is a good way to prevent conflict or identify clients that may not accept the expectations. Ed and Bryan also discuss: Ed's three "Hate Me" reasons Oversizing furnaces vs. straight-cool A/C units vs. heat pumps Electrification Heat pumps in cold climates Humid vs. arid climates Designing systems with ancillary dehumidification Not being responsible for clients' lifestyle choices ACCA collaboration and industry support Learn more about the training ACCA has to offer at https://www.acca.org. Check out the HVACR Training Symposium and order your virtual tickets before, during, or after the symposium (Jan 19-21, 2023) at https://hvacrschool.com/symposium. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Craig Migliaccio, aka AC Service Tech, returns to the podcast to share his knowledge about mini-split install & service. He also talks a bit about his upcoming book, "Inverter Mini-Split Operation and Service Procedures." Mini-splits are unique because they are compartmentalized in ways that traditional central-air ducted systems are not. Mini-splits come in many varieties, including ducted and ductless types, as well as multi-zone types. Many are inverter-driven and have more electrical efficiency as a result and can vary their capacities based on load variation. Mini-splits have metering devices at their outdoor units, and these devices may be electric expansion valves (EEVs) or capillary tubes. Inverter mini-splits also don't have filter driers because their PVE oil doesn't have the same acid concerns as POE oil, and they don't have traditional liquid lines. Flare connections are also critical when installing ductless systems, especially because you want systems to be tight to prevent leaking and contamination. Craig likes eccentric flaring tools with offset cones, and he recommends using flare nuts from the equipment manufacturer, not the line set manufacturer. He covers other flaring best practices as well. The charge is quite small in mini-splits, so weighing the charge and being careful and deliberate during charging is critical. Refrigerant leaks can also be highly problematic; corrosion and poor flare connections are common causes of leaks. Craig and Bryan also discuss: Hyper-heat systems Coefficient of performance (COP) and BTU output Moving between PSC and ECM or inverter technologies Mini-splits vs. VRF/VRV technologies Pressure testing and leak detection Compressor diagnosis Thermistors and electrical resistance Heat sinks and mounting circuit boards Selecting a location to install a mini-split Things to consider when checking the charge Why measure superheat and subcooling? Cleaning and maintenance best practices Check out Craig's YouTube channel at https://www.youtube.com/@acservicetech. Starting January 1st, 2023, you can buy Craig's book on his website, which has a bunch of other good resources. Visit that site at https://www.acservicetech.com/. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

David Richardson from NCI returns to the podcast to talk about why CO (carbon monoxide) doesn't leak and what it does instead. CO is a highly dangerous gas that is colorless and odorless, and we can keep ourselves safe by staying aware of it with personal low-level CO monitors. However, CO doesn't leak; it spills, especially via backdrafting, a blocked flue, or updrafting. Whenever the flue gas comes back inside the structure unintentionally, there is room for a potential CO problem. With proper testing, we can determine the cause of that spillage and make the best choice to stop it from happening. When there is an excessive draft, there's often turbulence in the draft hoods, which leads to spillage. Spillage commonly happens at the draft hood, but it can also happen near the burner compartment of a gas appliance. Smoke tests won't detect that, but CO testing will. However, we need to look for rising CO levels over the run cycle of the equipment. If you test CO levels in the ducts, you're only seeing how the fans are distributing the CO; you're not checking the likely source of CO. Water heaters often give visual clues of improper venting, especially if there's soot, rust near the venting, or discoloration near the burner compartment. David and Bryan also cover: CO poisoning symptoms CO monitors vs. alarms The roles of stack effect and airflow in CO spillage Air taking the path of least resistance CO testing best practices CO and changes in sinus pressure Combustible gas leak detectors Low-level CO monitors Wind and its effects on pressurization or depressurization Electric appliances, generators, and CO poisoning Learn more about NCI's training courses at http://nationalcomfortinstitute.com/. You can also contact David directly at [email protected]. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Jim Fultz with Emerson White-Rodgers returns to the podcast to talk about one HSI furnace control to rule them all, the 50M56X-843 Universal Single Stage Integrated Furnace Control. The 50M56X does not come with wiring harnesses; the control comes with the plugs that the majority of manufacturers use, making it a versatile and user-friendly universal part. It also works with the White-Rodgers Connect app to help you configure the part with the burners. You can also do some basic configuration when it comes to the blower motor. With the 50M56X and Emerson White-Rodgers Connect app combination, you can quickly and accurately configure the control without wi-fi or a password. An igniter is included in the box with the 50M56X; the igniter must match the control. The control also comes with a three-digit display that communicates the microamp current from the flame sensor, meaning you don't need to use a meter on the flame sensor. So, you can carry less truck stock and complete more calls with this universal part. The device also has some potentially useful extra features. For example, the 50M56X stores error codes for 14 days, not permanently, to prevent causing confusion for future technicians. It also has a bus connector for the thermostat and a dehumidification terminal for thermostats with dehumidification capabilities. Jim and Bryan also cover: White-Rodgers universal vs. aftermarket vs. OEM parts Blower speed and X13, ECM, and PSC motors Near-field communication (NFC) capabilities Cross-referencing Technology and ethical business 50M56X warranty information Integration with Sensi thermostats WR Mobile App (available on Google Play and the App Store) Learn about Emerson White-Rodgers and their featured products on our partner page HERE. Check out the wide array of products and resources Emerson White-Rodgers has to offer at https://emerson.com/universalcontrols. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Yaron Ben Nun from Nostromo Energy joins the podcast to talk about ice banking, a way of using ice to balance energy consumption. Nostromo Energy is an Israel-based company that has recently started working in California. Water has a very high latent heat of fusion, meaning it can absorb and store a lot of energy between its solid and liquid states of matter. By storing ice, Nostromo Energy can support commercial and industrial structures that utilize chiller-type applications by offering a clean and sustainable battery thanks to water and its physical properties. Load balancing or management will be critical as the electrification of heating sources continues. Lithium-ion batteries aren't sustainable solutions in many of these cases, and that's where ice banking can support the grid by providing a thermal battery. Water offers many advantages as a medium for storing energy, especially since it is natural and doesn't have the numerous economic and labor concerns that come with the production of many other batteries. However, there have been some challenges with the widespread adoption of ice banking, especially when it comes to retrofitting and the ability to match the demand for new power stations. Water is also heavy, meaning that it can be difficult to manage in rooftop applications. Nostromo Energy keeps working to solve those problems and increase the coefficient of performance (COP), especially by maintaining a relatively high freezing temperature. Yaron and Bryan also discuss: Yaron's career and Nostromo Energy HVAC equipment and the electrical grid Economic and labor factors of lithium-ion battery production Discharge rates and glycol cycles COP and compression ratio Heat recovery chiller technology Carbon counting, kilowatt-hours, and carbon emission Thermal energy storage and tax rebate eligibility Learn more at nostromo.energy. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Eric Kaiser and Ty Branaman return to the podcast to talk about why we need to pay technicians and field workers better in the HVAC industry and how small and medium businesses can help current employees. When the pay for entry-level HVAC positions can't compete with fast-food, retail, or warehousing jobs, we can't expect people to flock to the industry, especially since so much skill is required. Overtime is also almost unavoidable in many places, and it's a problem that requires a more nuanced solution than getting more trucks on the road. The tricky part about paying more for overtime is that it's challenging to implement pricing structures that charge the end user proportionally. As prices for equipment, fuel, and living essentials go up, the company often has to eat those extra costs if they want to pay their technicians fairly. In some cases, HVAC businesses feel bad for the customer when the cost of everything increases, which could be doing a disservice to the techs who deserve higher wages for their work. HVAC companies can increase their value by setting themselves apart in their markets, such as by performing unique services that benefit customers; effort and skill are required, which can justify higher prices. We have to be realistic about what our competitors are selling and work towards selling comfort, not just parts or systems. Eric, Ty, and Bryan also discuss: Challenges with reducing overtime HVAC sales and higher pay rates Customers' willingness to pay Base pay and incentives How managers can take care of their employees Understanding employee motivation Using profits for personal luxury items vs. reinvesting in a business Knowing our numbers Understanding employee discussions about pay If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Dr. Chuck Allgood from Chemours returns to the podcast to do some refrigerant myth-busting. Many people don't understand why high-GWP HFCs can impact the atmosphere if the refrigerant is heavier than air. High-GWP HFCs exist for a long time, and they last long enough for natural mixing and the wind to distribute their molecules throughout the atmosphere. HFOs, by comparison, are more reactive in the atmosphere and have relatively short lifespans, meaning they have less of an effect on the environment. Even though refrigerants with lower GWPs are entering the market, it's always been our job to keep refrigerants inside the system where they can't harm the environment. However, when leaks occur, these lower-GWP refrigerants break down quickly outside the system but not inside it. Contractors and manufacturers should still work together to reduce leak rates as much as possible, even as we keep innovating. Another common myth is around "natural refrigerants," which are common in some forms of refrigeration, but "natural refrigerants" may be a misleading term; although you find them in nature, they undergo heavy manufacturing and processing before being used in HVAC/R systems. Even "non-toxic" and "non-flammable" labels for A1 refrigerants may be misleading, as they don't capture the full picture of their risks. There are also some myths around oil miscibility; oil still needs the help of refrigerant velocity and volume to move it through a system. POE and PVE oil are great in terms of miscibility and also get entrained in the refrigerant to ensure good oil return to the compressor. Dr. Chuck and Bryan also discuss: Dr. Chuck's recent work and research "Heat rises" and buoyancy Pseudoscience HFO stability and reactivity Trifluoroacetate (TFA), toxicity, "forever chemicals" Education and change in the industry "Future-proof" vs. innovation Phosgene Learn more about Chemours and their A2L training at opteon.com. You can also check out the Chemours/Opteon YouTube channel at https://www.youtube.com/@OpteonProducts/videos. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Ty Branaman and Eric Kaiser return to the podcast to discuss the good, the bad, and the ugly of trade schools. They cover the opportunities and challenges they've observed in trade schools. As with for-profit colleges, for-profit trade schools market programs aggressively and can take people who are at a crossroads in their life and saddle them with debt. In some cases, trade schools are hesitant to fail people and end up passing people who don't have the technical proficiency to be effective tradespeople. Sometimes, trade schools don't emphasize practical skills and contractors' experiences as much as they could, either. The tricky part about trade schools is their allocation of resources, which instructors typically can't control. Sometimes, too much money is spent on equipment, and not enough is spent on the instructors. There needs to be an appropriate balance of both in an effective program. Administrative distractions can also make programs less likely to produce effective technicians. The admission process also doesn't always sort people into appropriate classes; many people with low proficiency are put into classes that are too advanced for them. People are going into trade schools with less mechanical aptitude than in previous generations, and trade schools often skip over the basics of tool use. Students need to know how to use tools before they learn how to fix systems, and that tool proficiency needs to be reinforced. Continuing education is also more focused on paperwork than application and isn't as thorough as it probably could be. Ty, Eric, and Bryan also discuss: First-generation trade school graduates Administrative challenges with trades instructors Motivating students Instructor qualifications "PowerPoint teaching" Automated systems Bringing work experience to the classroom Where does podcasting fit into trades education? If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

John Pastorello from Refrigeration Technologies returns to the podcast to talk about selecting proper cleaners for various HVAC/R jobs. From the beginning, the goal of Refrigeration Technologies has been to make cleaners that are safe but have the same effectiveness as the strong, hazardous varieties in the industry. The more hazardous cleaners are not food safe and may be corrosive, dangerous to inhale, or irritating to the skin or eyes. Some cleaners can also damage components; brighteners aren't recommended for use on aluminum coils for that reason. John is a fan of foaming cleaners because the foam gives the cleaner more contact area and holds the detergent in place for a longer time. Foaming cleaners tend to be good for degreasing. However, if used improperly, the foam can overflow in the drain pan and get messy. Many residential and light commercial HVAC contractors may benefit from keeping Viper EVAP+ for evaporator coils, Heavy Duty for condenser coils, and Brite only when there is an extremely dirty condenser coil. The Viper aerosol coil cleaner can also work well for small systems. The Pan & Drain Treatment also keeps drain sludge and odors at bay inside condensate lines and pans. Instead of relying on harsh chemicals to dissolve microbial growth, Refrigeration Technologies cleaners help use enzymes to dissolve odor-causing biological material in HVAC systems. John and Bryan also discuss: PPE to use when working with cleaners Acid-based cleaners and "non-acid" cleaners Dwell time and contact Dilution ratios NSF registration and what it means to be "food-safe" Viper Venom Packs Watch our 3D video showing how to use several Refrigeration Technologies products HERE. Learn more about Refrigeration Technologies products and resources at refrigtech.com. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Eric Kaiser and Ty Branaman return to the podcast to talk about the progression from technician to service manager and if a good tech always makes a good service manager. They discuss career paths, differing skills between technicians and service managers, and how HVAC/R companies can support techs who wish to remain techs. In many cases, top technicians are pulled into service manager positions to keep them with the company. Sometimes, older technicians who have lost some mobility and strength over the years end up going to managerial positions to stay in the industry. Some people genuinely want to acquire managerial positions. Not everybody is motivated by promotions, and HVAC business managers would benefit from knowing what their employees value and want for their professional lives. Just as we have to teach technicians hard skills to be good at their jobs, we have to teach soft skills to service managers. We can't expect skilled technicians to enjoy or feel comfortable in leadership positions without knowledge of the expectations and required skills. When people genuinely want to go into service manager positions, they can benefit from having a clear path supported by goals and frequent performance reviews to keep them on the right track. However, some people may want to stay technicians; we can do right by them to keep their bodies in good shape so that they can get the most out of their careers and be able to enjoy all types of activities after they retire. Ty, Eric, and Bryan also discuss: Leadership training Setting expectations for positions Keeping technicians happy Residential vs. Commercial HVAC soft skills Taking care of employees over customers Making room for different personalities and providing opportunities for them If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.