HVAC School - For Techs, By Techs

Jim takes us all the way through the history of furnaces, from the Stone Age when he was a child to modern modulating condensing types. The goal of a furnace is to move heat, so a furnace uses heat exchangers to facilitate heat transfer. Furnaces have primary and secondary air. The primary air goes through the burner, and the secondary air goes around the flame and is pulled in around the heat exchanger inlet. So, the flame's heat creates a draft that pulls air in. Natural gas and oil (LP/propane) furnaces are common nowadays, but we initially burned wood and coal in furnaces. The first gas furnaces came into existence by modifying coal, not from the gas lines we see nowadays. Long ago, the flue gases were also exhausted to the basement; CO poisoning was less of a concern back then, as combustion was usually complete. Burning the building was a much more severe risk. The first “gas crisis” in the 1970s forced us to focus on gas furnace efficiency. In that time, we developed spill switches and retrofit kits that converted furnaces over to spark ignition. In the 1980s, we came out with the draft-induced 80% furnaces we see nowadays. We also eliminated standing pilots and draft diverters. Even though the appliances became more efficient, we didn't actually burn the gas any more efficiently. So, despite the technological advancements we've made over the years, we don't actually burn gas any more efficiently than we did in the 1930s. However, our modern furnace technology has eliminated standby losses, controlled ignition, and focused on the role of latent heat in combustion. Jim also discusses: Flame color and types Draft hoods and diverters Products of complete combustion Excess air: a double-edged sword Natural ventilation Efficiency percentages Furnace testing and ratings Turbulators Modulation   Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool.  Purchase your tickets or learn more about the 6th Annual HVACR Training Symposium at https://hvacrschool.com/symposium. Take the HVAC School Industry Pulse Survey by WorkHero at https://hvacrschool.com/workhero.  Subscribe to our podcast on your iPhone or Android.   Subscribe to our YouTube channel.  Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android

In this short podcast episode, Bryan talks about heat exchangers and temperature rise in gas furnaces, especially 80% open-combustion gas furnaces. Temperature rise is the difference between the return air temperature and supply air temperature; in cooling, we usually refer to this difference as a delta T or temperature split. The manufacturer sets a target range on the data plate; high-efficiency furnaces tend to have lower temperature rise targets than mid-efficiency or older furnaces. We want to heat the space and not waste heat on surfaces (like duct surfaces). For that reason, the goal is to stay in the middle of the temperature rise range or slightly on the lower side for peak efficiency, better heat transfer, proper airflow, proper venting, and protection of the heat exchanger.  In mid-efficiency furnaces, we don't want the temperature rise to be too low, as cooler gases can condense. High-efficiency condensing furnaces have a dedicated condensate system, but 80% furnaces do not. That condensation can corrode the heat exchanger, which makes it vulnerable to cracks. Cracked heat exchangers may also happen when the temperature rise is too high, and they are dangerous due to carbon monoxide (CO) leaks; check for abnormal flame movement and color. Lower-temperature air is also uncomfortable if the registers are in locations where blowing air on people is inevitable. We can reduce the temperature rise by increasing the heating airflow, which can sometimes be done by re-tapping constant-torque and PSC motors or changing ECM settings. However, restrictive filters and ductwork may also cause that problem, and they need to be addressed.     Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool.  Purchase your tickets or learn more about the 6th Annual HVACR Training Symposium at https://hvacrschool.com/symposium. Take the HVAC School Industry Pulse Survey by WorkHero at https://hvacrschool.com/industrypulse.  Subscribe to our podcast on your iPhone or Android.   Subscribe to our YouTube channel.  Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android

In this episode of the HVAC School podcast, Bryan shares his "Manufacturer Responsibility Manifesto," a document he wrote over two years ago but held back from publishing until now. The manifesto addresses growing concerns about the burden being placed on HVAC contractors, particularly smaller businesses, due to manufacturing quality issues and warranty policies. The industry has undergone significant changes since the 1990s, including stricter refrigerant regulations and an increase in parts failures. While manufacturers offer longer warranty periods now than in the past (often 10+ years compared to 3-5 years previously), these warranties often don't cover crucial expenses like refrigerant, brazing rods, fittings, and labor costs. This leaves contractors in a difficult position of either absorbing these costs or charging customers and potentially damaging relationships. The manifesto calls for manufacturers to take greater responsibility for their products, particularly during the warranty period. Bryan proposes that manufacturers should reimburse contractors for total costs (including labor) for manufacturer-caused repairs within the first year, and cover parts and ancillary materials (including refrigerant) during the subsequent warranty period. He argues that this would incentivize manufacturers to improve product quality and reduce environmental impact, as they would bear more of the financial responsibility for failures and refrigerant losses. Key topics covered in the podcast: Evolution of HVAC industry regulations since the 1990s Increase in parts failures compared to previous decades Impact of global supply chain issues on part quality and availability Environmental concerns regarding refrigerant leaks and equipment waste Warranty coverage limitations and their impact on contractors Disparity between domestic and overseas manufacturing quality Financial burden on small contracting businesses Need for clear standards to differentiate manufacturer vs contractor-caused failures Proposal for comprehensive warranty coverage including ancillary materials Environmental responsibility and accountability in manufacturing Role of manufacturers in industry sustainability Impact of private equity and large companies on the industry Need for improved quality control in manufacturing Relationship between warranty policies and contractor-customer trust Call for industry-wide collaboration to implement changes   Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool. Purchase your tickets or learn more about the 6th Annual HVACR Training Symposium at https://hvacrschool.com/symposium. Take the HVAC School Industry Pulse Survey by WorkHero at https://hvacrschool.com/industrypulse.  Subscribe to our podcast on your iPhone or Android. Subscribe to our YouTube channel. Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android

In this short Q&A podcast episode, Bryan answers a listener-submitted question and gives some of his tips for moving to HVAC sales from field technician/installer roles. The world of sales has a different pay structure, which makes it an appealing option to many technicians. Salespeople need to be able to have money conversations with confidence and not be afraid to talk about pricing. You can practice these conversations with friends or fellow technicians, including answering questions and responding to objections. Sales confidence is another key to success in sales. Many successful sales techs go into sales with the assumption that the client wants to work with them and aren't timid because they're confident they'll make the sale. Great salespeople also seek out feedback to learn and grow from. Many great salespeople in the HVAC industry also benefit from learning about load calculations, equipment selection, and duct design, particularly via the ACCA manuals and software like Wrightsoft and Kwik Model 3D. The HVAC Grapevine, NCI, and TEC all have great educational resources about building science. Deploying test instruments, including blower doors, duct blasters, and thermal imaging cameras, also gives you vital information about the structure and shows clients that you're going above and beyond for their comfort; you're delivering quality and doing so with integrity. Communication skills are a crucial part of sales, and the best thing you can do to start honing your communication skills is to ask good questions and listen for valuable answers. Empathy is also important in sales, and it's most effective when you can understand your client's priorities.     Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool.  Purchase your tickets or learn more about the 6th Annual HVACR Training Symposium at https://hvacrschool.com/symposium. Take the HVAC School Industry Pulse Survey by WorkHero at https://hvacrschool.com/industrypulse.  Subscribe to our podcast on your iPhone or Android.   Subscribe to our YouTube channel.  Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android

This unique podcast episode is a commentary on the phenomenon of "white shirt techs" in the HVAC industry - a term that refers to technicians who focus heavily on sales and maintaining a pristine appearance rather than technical expertise. While there's nothing inherently wrong with having good sales skills or maintaining a professional appearance, there needs to be a balance with actual technical competency. The episode serves as part of a manifesto series heading into 2025, addressing important industry trends and concerns. There is a delicate balance between sales and service in the HVAC industry, particularly in residential services. Some companies and technicians may prioritize metrics like average ticket price and five-star reviews over providing genuine solutions to customers' problems. While it's important to discuss money and options with clients, we shouldn't resort to fear tactics or make promises that products can't fulfill, particularly in areas like indoor air quality solutions and UV lights. The podcast raises important questions about professional identity and integrity in the HVAC field. Technicians should occasionally step back and think about whether they've lost their passion for actually fixing equipment and solving technical problems in favor of focusing solely on sales. He argues that the best residential technicians maintain their interest in the mechanical aspects of the work, even as they develop their customer service and sales skills. The episode concludes with a call for technicians and companies to invest more time in technical training and to maintain their commitment to solving real problems rather than just selling solutions. Key Topics Covered: Definition and characteristics of "white shirt technicians" The balance between sales skills and technical expertise Problems with fear-based selling and overpromising in HVAC The importance of third-party verification for product claims Discussion of specific products like surge protectors and UV lights The role of maintenance agreements and their value proposition The future sustainability of sales-first business models The importance of maintaining passion for the technical aspects of HVAC Professional appearance versus technical competency The relationship between pricing and actual value delivered The role of customer reviews and their potential manipulation Training priorities: technical skills versus sales techniques   Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool.  Purchase your tickets or learn more about the 6th Annual HVACR Training Symposium at https://hvacrschool.com/symposium. Subscribe to our podcast on your iPhone or Android.   Subscribe to our YouTube channel.  Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android

In this short podcast episode, Bryan answers a listener-submitted question about double flares and their application in the HVAC/R industry. Flare connections are common in certain types of equipment, and they connect the copper to the appliance. As a result, when we make a flare, our goal is to make it leak-free. A regular flare requires you to cut the copper, clean it, put the flare nut on, and make the flare with a flaring block (or a flaring tool). You can also put a little bit of oil on the flare cone to prevent galling. Modern power flaring tools are common nowadays, especially in markets where we install a lot of mini-splits. We also use torque wrenches to tighten the flare connection according to the manufacturer's specs. In mission-critical applications where we have toxic or flammable refrigerants under high pressure, we especially want leak-free connections. Double flares make more sense in these scenarios for extra security (though we may use different connection types). A double flare requires you to use a double-flare die that flares over the edge, though those double-flare dies are more common in older flaring kits and may not exist for power tools or spin tools.    Double flares are usually less practical than other alternatives that exist on the market. For example, some manufacturers make flare gaskets to reduce the likelihood of leaks, and these are functionally similar to a double flare.    Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool.  Purchase your tickets or learn more about the 6th Annual HVACR Training Symposium at https://hvacrschool.com/symposium. Subscribe to our podcast on your iPhone or Android.   Subscribe to our YouTube channel.  Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android

In this episode of the HVAC School Podcast, Bryan interviews Zach about duct coatings and their applications in HVAC systems, particularly focusing on the Hardcast RE500 product. The discussion delves into the importance of proper duct coating applications and their benefits for both contractors and customers. Zach, who has extensive experience in duct cleaning and restoration, shares his expertise on the proper application and benefits of duct coating systems. The conversation explores how modern ductboard comes with a clear coat that offers some protection, but additional coating can provide significant benefits, especially in high-velocity areas near equipment. They discuss how coating creates a smoother, more cleanable surface that's almost comparable to sheet metal in terms of friction resistance. Zach emphasizes that coating should only be applied after proper cleaning, as it's not meant to cover up dirty ducts but rather to protect and improve cleaned surfaces. A significant portion of the discussion centers around the practical applications for HVAC contractors, particularly during equipment changeouts. Bryan proposes the idea of coating the first 5-10 feet of ductwork near equipment during changeouts, as these areas experience the highest velocity and are most susceptible to fiber shedding and moisture issues. The conversation also addresses the cost-effectiveness of coating versus replacement, with the coating being approximately one-fourth to one-fifth the cost of replacement. Key Topics Covered: Hardcast RE500 duct coating product and its applications Benefits of duct coating, including reduced friction, fiber containment, and improved cleanability The importance of proper surface preparation before coating application Comparison between coated ductboard and sheet metal surfaces Drying and curing times for duct coatings The relationship between duct cleaning and coating services Cost comparison between coating and replacement Special considerations for coastal environments NADCA certification and training requirements The importance of proper application techniques and professional certification Health and safety considerations regarding fiberglass ductwork The role of duct coating in preventative maintenance Application methods, including airless sprayer and brush/bucket techniques Quality control and industry standards for duct coating   Learn more about NADCA at https://nadca.com/.  Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool.  Purchase your tickets or learn more about the 6th Annual HVACR Training Symposium at https://hvacrschool.com/symposium. Subscribe to our podcast on your iPhone or Android.   Subscribe to our YouTube channel.  Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android

In this short Q&A podcast episode, Bryan answers a listener-submitted question about metacognition and more about critical thinking, reflective analysis, and challenging biases. Metacognition is the ability to think about thinking; it's about breaking things down, noticing your own thoughts, and understanding the "why" behind their thoughts. Metacognition is beneficial when applied to the "wide" aspects of the "wide-narrow-wide" mindset; it helps with broad analysis and is less useful during the narrow phase when you want a flow state. Unpacking our biases is useful, but it's most important in positions of power. Biases and assumptions have the most widespread effect when they're leveraged on others by authority figures, but they show up in any position of power (or lack thereof). Many of these are baked into us as mental shortcuts called heuristics, which are the same things that tell us not to touch stoves for survival; they're ingrained, but we have to be able to challenge those and unpack the reasons when it comes to assumptions about other people. However, this activity is time-consuming and not best used in situations where immediate action is needed. Humans have a strong proclivity for pattern recognition for survival reasons. However, one of the downsides of strong pattern recognition is the risk of associating correlation and causation without taking the proper investigative steps to confirm the relationship between things. The scientific method exists to test a hypothesis and explore the relationship between things in our world. Learning and being open to complex relationships are components of a great mindset to apply to HVAC work as well, and humility and curiosity are at the forefront.   Franco, Zeno E., Kathy Blau, and Philip G. Zimbardo. "Heroism: A conceptual analysis and differentiation between heroic action and altruism." Review of general psychology 15.2 (2011): 99-113. https://doi.org/10.1037/a0022672 Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool.  Purchase your tickets or learn more about the 6th Annual HVACR Training Symposium at https://hvacrschool.com/symposium. Subscribe to our podcast on your iPhone or Android.   Subscribe to our YouTube channel.  Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android.

In today's podcast, Bryan talks with legendary Hydronics author and trainer Dan Holohan about the history of steam heating and some practical applications of old ideas. Recently, Dan has been working on more novels, having published two of them over the past few months. Steam heating is a “lost art” nowadays; it has become increasingly uncommon and has been disappearing since the Vietnam War. Many people who understood steam heating either retired or died after the Vietnam War. Many elements of steam heating are difficult to understand or surprising. (For example, steam pressure has a surprising relationship with velocity: low-pressure steam moves through piping much more quickly than high-pressure steam.) So, Dan Holohan is on a mission to revive that knowledge and teach the newer generations about the lost art. There are many older steam heating systems still operating today, especially in the older large buildings in New York. Dan learned a lot about steam heating when working on these old systems and optimizing them. Most of the time, he optimized those systems by removing unnecessary accessories, not by adding components like steam traps. Many old boilers used coal as a heat source. Nowadays, many old boilers have been fitted with conversion oil burners with thermostats, but they are still piped for coal. Some systems now have multiple risers or massive vents on the main riser to prevent the thermostats from getting too hot too early and satisfying the thermostat too early. We call that master venting, which reduces pressure and allows steam to move very quickly and efficiently. Dan also discusses: The 2-PSI standard Transportation metaphors for BTUs in steam Harmful renovations for old boilers Replacement vs. restoration mindsets Gaps in steam boiler education Monopolizing the market if you HAVE the education Boiler piping and venting Two-pipe vs one-pipe steam   Find out more about Dan and hydronic heating at HeatingHelp.com. Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool.  Purchase your tickets or learn more about the 6th Annual HVACR Training Symposium at https://hvacrschool.com/symposium. Subscribe to our podcast on your iPhone or Android.   Subscribe to our YouTube channel.  Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android.

In this short Q&A podcast episode, Bryan answers a listener-submitted question about superheat, including what it is and how we measure it. Superheat is the number of degrees a refrigerant is above its saturation point. The saturation point is where you will have a liquid-vapor mix, so superheat only exists when a substance is a vapor. Saturated refrigerant should only exist in the evaporator and condenser, during which it is being boiled or condensed.  We usually measure superheat at the evaporator coil outlet and compressor inlet. The superheat at the evaporator outlet is usually around 5-14 degrees Fahrenheit, and it's often between 10 and 20 degrees at the compressor inlet (compressor superheat). However, many systems try to get lower superheat values, and some manufacturers may require higher superheat values at the compressor inlet to prevent liquid refrigerant from getting into the compressor. Accumulators can help keep liquid refrigerant out of the system as well. We may also measure superheat coming out of the compressor on the discharge line (discharge superheat); this superheat may exceed 100 degrees Fahrenheit. Discharge superheat can let you know if the compressor is overheating the oil and causing breakdown or carbonization. We use superheat to set the charge for fixed-orifice metering devices (as opposed to subcooling for TXVs), as superheat is a measure of how well we're feeding our evaporator coil. When the system is off, the superheat will be 0. A system will equalize, and the refrigerant will be at saturation when that happens.   Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool.  Purchase your tickets or learn more about the 6th Annual HVACR Training Symposium at https://hvacrschool.com/symposium. Subscribe to our podcast on your iPhone or Android.   Subscribe to our YouTube channel.  Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android.

In this episode of the HVAC School podcast, Bryan interviews Zach from Southeast Clean Air Solutions about the intricacies of professional duct cleaning. Zach specializes in addressing duct cleaning challenges specific to the Southeastern climate, with a particular focus on fiberglass-lined ducts. The conversation delves into the complexities of cleaning different types of duct systems, highlighting the significant variations in time, technique, and approach depending on the duct materials and home configuration. The discussion reveals that duct cleaning is far more nuanced than many homeowners realize. A typical residential duct cleaning can take between six to eight hours, with metal ductwork being significantly faster to clean than flexible ducts or fiberglass-lined systems. Zach emphasizes the importance of careful cleaning techniques, especially with delicate flex ducts that can easily be punctured or damaged during the cleaning process. He recommends a two-person approach, with one team member working inside the home and another in the attic or crawl space to ensure thorough and safe cleaning. Beyond the cleaning process, the podcast explores critical maintenance strategies for maintaining clean and efficient HVAC systems. Zach and Bryan discuss the importance of proper filtration, home maintenance, and understanding when duct cleaning is truly necessary. They challenge the common misconception of a fixed cleaning schedule, instead advocating for system assessment based on specific conditions like household dust, humidity, and the health needs of home occupants. Key Topics Covered: Duct cleaning techniques for different duct materials (metal, flexible, fiberglass-lined) Time requirements for professional duct cleaning Challenges of cleaning ducts in various home configurations Importance of proper filtration and maintenance Factors determining duct cleaning frequency Risks associated with poorly maintained duct systems Two-person approach to thorough and safe duct cleaning Specialized considerations for homes in humid climates Post-cleaning sealant application for fiberglass-lined ducts   Learn more about NADCA and find certified duct cleaning contractors at https://nadca.com/.  Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool.  Purchase your tickets or learn more about the 6th Annual HVACR Training Symposium at https://hvacrschool.com/symposium. Subscribe to our podcast on your iPhone or Android.   Subscribe to our YouTube channel.  Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android.

In this short podcast, Bryan talks about electric vehicles and whether EVs present an opportunity for HVAC technicians. The residential sales lead at Kalos recently mentioned that keeping an EV in a conditioned garage is advantageous, and it's an upgrade we can offer our customers. In hot weather, EV battery performance and health can be degraded. On top of that, the vehicle consumes power when the vehicle gets hot so that the A/C can control the climate inside the car and preserve the interior. Most people also charge their electric vehicles in the garage at night, so it would stand to reason that conditioning the garage can yield energy savings and improve vehicle longevity. Attic encapsulation above the garage is also an option to limit warm, moist attic air from leaking into the garage; HVAC upgrades can include using closed-cell foam to encapsulate the attic and install a dehumidifier in there. Conditioning a garage requires you to think about insulation. In our market (Florida), block walls don't insulate very well. Even when we can't do very much with the walls, we can usually use some polyiso boards inside the garage. However, we could get some moisture challenges, and carbon monoxide could be an issue if combustion appliances are in the garage (like furnaces, water heaters, or gas-powered cars). We can recommend using heat pump water heaters, and we should quote a low-level CO monitor in cases when garages have a CO risk.  It's important to make sure the garage remains separate from the rest of the house even when we do these upgrades. Keeping the garage separate helps prevent chemicals from getting into the airstream, especially yard chemicals or cleaners.   Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool.  Purchase your tickets or learn more about the 6th Annual HVACR Training Symposium at https://hvacrschool.com/symposium. Subscribe to our podcast on your iPhone or Android.   Subscribe to our YouTube channel.  Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android.

The podcast delves into the world of HVAC chemical solutions through an in-depth conversation with Becca Stamey, the marketing director at Refrigeration Technologies. The discussion provides insights into the company's unique approach to developing cleaning products, rooted in a commitment to safety, effectiveness, and customer feedback. Founded by John Pastorello, a chemist turned HVAC technician, the company has always prioritized creating products that are non-toxic, non-corrosive, and environmentally friendly. Becca highlights the range of Viper products, from condenser and evaporator cleaners to pan and drain sprays and all-purpose cleaners. Each product is carefully formulated with specific purposes in mind, such as the enzyme-based evaporator cleaner designed to address odor issues and break down biofilm. The conversation emphasizes the company's innovative packaging, particularly the Venom Packs, which offer concentrated, durable, and space-efficient solutions for technicians. The podcast also underscores the company's commitment to quality control, with U.S. manufacturing and personal oversight from the leadership team. The episode provides a behind-the-scenes look at Refrigeration Technologies' growth and dedication to the HVAC community. The company has been named to the Inc. 5000 list of top-growing companies for three consecutive years and is expanding its manufacturing capabilities. Becca discusses the company's social media presence and community engagement, including their "Tech of the Month" program, which highlights and celebrates HVAC technicians who embody the company's values. Key Topics Covered: Viper's chemical product line and unique formulations Condenser and evaporator cleaning solutions Innovative Venom Pack packaging Importance of non-toxic, environmentally friendly cleaning products Company's manufacturing process and quality control Social media engagement and community recognition Recent company growth and expansion Upcoming appearances at industry events like AHR Expo   Learn more about Refrigeration Technologies at https://www.refrigtech.com/. You can also follow Refrigeration Technologies on Instagram, LinkedIn, Facebook, YouTube, and TikTok (ViperHVAC). Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool.  Purchase your tickets or learn more about the 6th Annual HVACR Training Symposium at https://hvacrschool.com/symposium. Subscribe to our podcast on your iPhone or Android.   Subscribe to our YouTube channel.  Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android.

In this short podcast, Bryan talks about evaporator coil placement based on a question submitted by a listener, John. Evap coil placement differs in furnace applications versus air handlers. When we use air conditioners with furnaces, we usually put evaporator coils on the positive side to protect the heat exchanger from rusting out during the summer (due to condensation and the chemical reactions that can occur with the metal heat exchanger). However, when it comes to air handlers, they're usually on the negative side. The coil is usually on the negative side of a fan coil or air handler because it keeps the blower motor cooler (though that doesn't make a huge difference in terms of performance).  The HVAC system will lose fewer BTUs to leakage when the coil is on the negative side, which is better for energy efficiency; those BTUs can reach the conditioned space rather than the closet, garage, or wherever it is stored. Pulling air over the evaporator coil on the negative side, however, could potentially lead to greater turbulence.  We run into challenges with evap coil placement on gas furnaces when we have dual fuel systems (a heat pump and furnace working together). You can't run gas heat over a heat pump coil due to the high head pressure, so a parallel setup would avoid the risks of high head pressure (downstream) or rusted-out heat exchangers (upstream).    Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool.  Purchase your tickets or learn more about the 6th Annual HVACR Training Symposium at https://hvacrschool.com/symposium. Subscribe to our podcast on your iPhone or Android.   Subscribe to our YouTube channel.  Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android.

In this episode of the HVAC School Podcast, Bryan interviews Zachary Ortwine, a duct cleaning professional who provides insights into ethical duct cleaning practices. The conversation delves deep into the complexities of cleaning different types of ductwork, the importance of proper assessment, and the potential challenges in maintaining indoor air quality. Zach emphasizes the critical role of thorough inspection and honest communication with clients. He explains that not all duct systems are equally cleanable, and professionals must carefully assess factors like duct material, contaminant type, and cleaning feasibility. Metal ducts can be cleaned more aggressively, while fiberglass ducts require a more delicate approach. The discussion highlights the importance of understanding the underlying issues that contribute to indoor air quality problems, such as system design, maintenance, and home living conditions. The podcast explores the evolution of duct cleaning technologies and safety considerations. Zach shares insights into modern fiberglass materials, which have improved safety compared to older versions, and discusses the importance of proper cleaning and coating techniques. The conversation also touches on broader indoor air quality challenges, including the impact of tighter building envelopes, ventilation issues, and the potential health risks of prolonged exposure to indoor contaminants. Key Topics Covered: Ethical considerations in duct cleaning Assessment techniques for determining cleanability Different duct materials (metal, flex, fiberglass) and cleaning approaches Indoor air quality challenges in modern homes NADCA (National Air Duct Cleaners Association) standards Importance of technician certification and experience Ventilation and its impact on indoor air quality Proper testing and verification of cleaning results Coating techniques for fiberglass ducts Misconceptions about antimicrobial treatments   Learn more about NADCA and certified professionals at https://nadca.com/.  Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool.  Purchase your tickets or learn more about the 6th Annual HVACR Training Symposium at https://hvacrschool.com/symposium. Subscribe to our podcast on your iPhone or Android.   Subscribe to our YouTube channel.  Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android.

In this short podcast episode, Zach joins Bryan to answer a common duct maintenance question: Should I fog or sanitize my ducts? The National Air Duct Cleaners Association (NADCA) outlines the uses of chemical products. Adding chemicals is usually a last resort in flex or sheet metal (externally wrapped) duct systems; they should NOT be used on ducts with internal liners or are made of duct board or any other material with porous surfaces.  Fog is typically applied while a vacuum is running at the opposite end of the duct. It liquefies on surfaces, and a lot of contractors don't go in and dry off the duct surfaces. It's difficult to coat the entire interior of a duct system with the chemical to make it as effective as possible, and the residue creates a moist, sticky film that actually encourages microbial growth in the ductwork. On top of that, some people may be sensitive to the chemicals.  In many cases, replacing ductwork that has been confirmed to have microbial growth is more reliable. Chemical duct sanitation often has more of a perceived benefit than long-term results. The use of chemical cleaners in ductwork is similar to that of using some line set flushes without forcing a solid pig through the line set to pick up the residue afterward. Ultimately, the customer has to make an informed decision based on the problem and knowledge of the benefits and drawbacks of chemical solutions.   NADCA's white papers, including "Chemical Product Applications in HVAC Systems," are available at https://nadca.com/industry-professionals/nadca-white-papers.  Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool.  Purchase your tickets or learn more about the 6th Annual HVACR Training Symposium at https://hvacrschool.com/symposium. Subscribe to our podcast on your iPhone or Android.   Subscribe to our YouTube channel.  Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android.

Bryan and Craig Migliaccio (AC Service Tech)dive deep into the complexities of managing condensate drainage in high-efficiency (90%+) gas furnaces. The conversation begins with a clear explanation of why these furnaces produce condensate in the first place - they have two heat exchangers that extract so much heat from the combustion gases that water vapor condenses out. This condensate is acidic (pH 3-5) and requires special consideration for drainage and disposal. The discussion explores various challenges contractors face when installing these systems, particularly in cold climates where freezing is a concern. Craig shares practical solutions from his experience in New Jersey, including using larger diameter pipes for exterior drainage and creating air gaps to prevent complete freezing. They address the ongoing debate about whether to combine AC condensate lines with furnace condensate lines, noting that while it's technically possible, there are potential risks and code considerations to keep in mind. A significant portion of the conversation focuses on code compliance and best practices for condensate disposal. The International Mechanical Code (IMC) provides several acceptable options for drainage, including floor drains, utility sinks, and standpipes. However, as Craig points out, local interpretations and requirements can vary significantly, making it crucial for contractors to maintain good relationships with their local inspectors and understand their specific jurisdiction's requirements. Key Topics Covered: How 90% efficient furnaces produce condensate through their dual heat exchanger system The acidic nature of furnace condensate and its corrosion potential Solutions for preventing condensate line freezing in cold climates Pros and cons of combining AC and furnace condensate lines Code-compliant drainage options (IMC 307.2) Use of condensate pumps as a solution for difficult drainage situations Importance of proper trapping and venting in condensate systems Requirements for auxiliary drain pans under furnaces Role of condensate switches and safety controls Challenges with different installation locations (crawl spaces, basements, etc.) Considerations for neutralizer usage when draining into septic systems Best practices for maintaining professional relationships with code officials   Check out some of Craig's great educational books at https://www.acservicetech.com/.  Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool.  Purchase your tickets or learn more about the 6th Annual HVACR Training Symposium at https://hvacrschool.com/symposium. Subscribe to our podcast on your iPhone or Android.   Subscribe to our YouTube channel.  Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android.

In this unique episode of the HVAC School podcast, Bryan interviews Donovan Ryckis, CEO of Ethos Benefits, diving deep into the complex world of healthcare financing and employee benefits. Ryckis shares his journey from financial advising to becoming a healthcare benefits consultant, driven by a mission to expose and transform the inherently problematic healthcare system. The conversation reveals the stark inefficiencies in traditional healthcare models, where insurance companies and healthcare providers often prioritize profit over patient care. Ryckis explains how most employers have been led to believe they cannot control healthcare costs, accepting annual increases as inevitable. By applying a fiduciary approach—similar to financial advising—Ethos Benefits helps companies like Kalos dramatically reduce healthcare expenses while maintaining or improving employee care. A key highlight of the discussion is the innovative strategies Ethos implements, such as negotiating directly with healthcare providers, exposing pharmacy benefit manager markup, and implementing direct primary care. These approaches not only reduce costs but also provide employees with better, more personalized healthcare experiences. The podcast demonstrates that by taking a transparent, data-driven approach, companies can create win-win healthcare solutions that benefit both the organization and its employees. Key Topics Covered: Healthcare financing vs. traditional insurance models Pharmacy benefit manager markup and hidden costs Negotiating medical claims and reducing excessive billing Direct primary care and its benefits Strategies for controlling healthcare expenses Importance of transparency in healthcare pricing The documentary "It's Not Personal, It's Just Healthcare" Challenges in the current healthcare system Empowering employees through better healthcare options   Learn more about Ethos Benefits at https://ethosbenefits.com/ and the Ethos Effect Podcast at https://www.ethoseffectpodcast.com/.   Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool.  Purchase your tickets or learn more about the 6th Annual HVACR Training Symposium at https://hvacrschool.com/symposium. Subscribe to our podcast on your iPhone or Android.   Subscribe to our YouTube channel.  Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android.

Chris Hughes and Steve Rogers from The Energy Conservatory discuss TEC's TrueFlow technology and its crucial role in predicting airflow issues in the sales process, particularly for heat pump retrofits. They explain how the TrueFlow app helps contractors accurately measure both static pressure and airflow in existing systems, enabling them to predict whether proposed equipment changes will work effectively. This is especially vital when considering the growing trend of replacing gas furnaces with heat pumps, as the airflow requirements can differ significantly. The conversation delves into a detailed example of replacing an 80% efficient 48,000 BTU furnace with a heat pump. They demonstrate how the airflow requirement would nearly double from 652 CFM to 1,200 CFM, potentially causing the static pressure to quadruple due to Fan Law 2 principles. This dramatic increase could lead to significant performance issues if not properly addressed during the system design phase. The experts emphasize that using TrueFlow during the sales process allows contractors to identify potential problems and necessary modifications before installation rather than discovering issues during callbacks. The discussion also covers the ideal workflow for system assessment and sales, starting with customer comfort evaluation and proper load calculations. It's important to reduce loads through envelope improvements when possible, particularly in cold climates where heat pump retrofits are becoming more common. Proper system sizing often means going smaller rather than larger, contrary to common industry practices, and the worst HVAC systems are often found in expensive custom homes rather than tract housing. Key Topics Covered: TrueFlow technology and its role in system forecasting Fan Law 2 and its impact on static pressure when changing airflow Heat pump retrofit challenges and considerations The importance of accurate load calculations Dual fuel systems as a solution for cold climates The relationship between airflow and static pressure Sales process integration of technical measurements Common issues with oversized equipment The importance of envelope assessment Methods for reducing system loads Proper duct sizing and modification strategies The role of proper filter sizing and selection The benefits of flat-rate pricing for duct modifications Training resources and support available for TrueFlow users   Check out TEC's YouTube channel at https://www.youtube.com/@energyconservatory, and you can visit TEC's website at https://energyconservatory.com/.   Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool.  Purchase your tickets or learn more about the 6th Annual HVACR Training Symposium at https://hvacrschool.com/symposium. Subscribe to our podcast on your iPhone or Android.   Subscribe to our YouTube channel.  Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android.

In this short podcast episode, Bryan and Mike from DITEK talk about what to do in tricky electrical scenarios, such as when the MCA is 27 and you have a 50A breaker. When you size an HVAC system for compatibility with voltage monitors, like the DITEK Kool Guard, you need to pay attention to the MCA (minimum circuit ampacity), which should not be confused with MOCP (maximum overcurrent protection or breaker size). As long as the MCA is 40 amps or lower, you can attach the HVAC condenser to the Kool Guard. The KG2 also accepts wire sizes up to 6 AWG. The Kool Guard is NOT a source of overcurrent protection; it is a voltage monitor rated for carrying current, which means ratings will be in MCA, not MOCP. MOCP is designed to deal with high starting amps and lets users know the maximum allowable current for a circuit so that it can trip properly when that current is exceeded. According to Section 440 of the National Electrical Code (NEC), motors with internal overload protection allow for a difference between the MCA and MOCP. You may find higher MOCPs on inverter-driven systems.   Learn more about DITEK at https://www.diteksurgeprotection.com/.  Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool.  Purchase your tickets or learn more about the 6th Annual HVACR Training Symposium at https://hvacrschool.com/symposium. Subscribe to our podcast on your iPhone or Android.   Subscribe to our YouTube channel.  Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android.