Explore every episode of the podcast HVAC School - For Techs, By Techs
| Title | Pub. Date | Duration | |
|---|---|---|---|
| How Duct Tape Got Its Name (and Why It Shouldn't Be on Ducts) - Short #264 | 04 Nov 2025 | 00:09:57 | |
In this short podcast episode, Bryan explains how duct tape got its name and why it shouldn't actually be used on ducts. Duct tape is a versatile home DIY-fix tool, but despite its name, it wasn't initially made to seal ducts at all. In 1943, we were in the thick of World War II, and ammo shipments were sealed with wax and paper tape. These were often not durable or difficult to open. Johnson & Johnson developed a tape with rubber adhesive on a cotton duck cloth backing (which was already widely used for military uniforms and tent fabrics). This new tape was nicknamed "duck" tape due to the material and its waterproof abilities (like the waterfowl). A woman named Vesta Stoudt informed President FDR about duct tape, and the War Production Board began using it in wartime supply packaging. After the war, America had a housing boom in the 1950s, which included the demand for forced-air heating and cooling systems. Marketers thought the tape could seal the ducts in those homes, so they changed the color to match sheet metal and rebranded it as "duct tape." In the 1960s, this tape was available in retail outlets with the "duct tape" branding. Unfortunately, in tests by the Lawrence Berkeley National Lab, duct tape failed miserably at sealing the ducts because the rubber adhesive dries out under heat, and dust weakens the adhesive. As a result, many building codes ban duct tape on ducts (spearheaded by California). Instead, UL-listed foil tape and mastic are approved for sealing ducts. However, duct tape still became famous for its versatility as a patching material. It's prevalent in pop culture and has been used in television shows and even in space.
Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool. Purchase your tickets or learn more about the 7th Annual HVACR Training Symposium at https://hvacrschool.com/symposium. Subscribe to our podcast on your iPhone or Android. Subscribe to our YouTube channel. Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android. | |||
| The Art of De-escalation | 30 Oct 2025 | 01:07:21 | |
In this comprehensive discussion, Bryan and Bert tackle one of the most critical yet underdeveloped skills in the trades: conflict resolution and de-escalation. They argue that poor conflict management is one of the primary reasons technicians lose jobs, damage team dynamics, and limit their career advancement. The conversation explores both customer-facing conflicts and internal team disputes, offering practical strategies grounded in real-world experience. The hosts distinguish between rational and irrational customer anger, noting that both require similar approaches—taking clients seriously, listening fully, and resisting the urge to immediately correct or defend. Bert emphasizes the importance of body language, describing how he physically leans into difficult conversations rather than backing away, making eye contact, and allowing customers to repeat themselves until they feel genuinely heard. Bryan adds that the "slow is smooth, smooth is fast" military principle applies perfectly to people problems—rushing to fix the emotional situation often prolongs the conflict, while patient listening typically resolves issues more quickly. When addressing internal team conflicts, they stress going directly to the person involved rather than gossiping or complaining to management. Both hosts acknowledge that ego, the need to be right, and past trauma can trigger fight-or-flight responses that sabotage productive conversations. They advocate for approaching conflicts with humility and a willingness to be wrong, focusing on the single most important issue rather than bringing up a laundry list of grievances. Bert shares that preventing conflict often means letting minor issues go while addressing patterns before they fester into major problems. The conversation concludes with practical advice about maintaining relationships after difficult conversations, recognizing that drawing back creates rejection while intentionally staying connected demonstrates genuine care. They emphasize that mastering conflict resolution isn't just about keeping your job—it's about becoming invaluable in your career and developing skills that serve you in every area of life. Topics Covered:
Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool. Purchase your tickets or learn more about the 7th Annual HVACR Training Symposium at https://hvacrschool.com/symposium. Subscribe to our podcast on your iPhone or Android. Subscribe to our YouTube channel. Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android | |||
| Dehumidify with a Waterfall? - Short #259 | 30 Sep 2025 | 00:08:24 | |
In this short podcast episode, Bryan talks about history and HVAC science: how to dehumidify the air with a waterfall and how cold water became the first air conditioner. In 1902, Willis Carrier worked for a printing company in Brooklyn, New York. There was a huge humidity problem during the summer: the printing plant got damp, causing paper to swell and ink to smudge. Carrier realized that he could wring water out of the air if he brought the air's temperature below the dew point. His solution was to spray chilled water into the airstream; he filed a patent for an invention that would pass air through a mist of cool water, which caused it to cool down and shed its moisture. He called it the "apparatus for treating air." This invention applies basic psychrometric principles. Air holds water vapor up to a certain point. The dew point defines that point. If the air is full of water vapor and its temperature drops below that dew point, excess water vapor condenses to liquid water (such as when it passes over an evaporator coil). In the case of Carrier's invention, the cold water in the spray chamber acted as a giant cooling coil. However, if the water is warm, the opposite effect would happen. We do NOT dehumidify with liquid water due to the requirement for water treatment (to prevent algae and scale buildup). Cold water is less prone to bacterial and algal growth than warm water, but it's still essentially an indoor science experiment. Water is also messy and causes corrosion, and pumping it is expensive. Carrier's experiment evolved to the chilled water coil, which then evolved to the DX coils we see today.
Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool. Purchase your tickets or learn more about the 7th Annual HVACR Training Symposium at https://hvacrschool.com/symposium. Subscribe to our podcast on your iPhone or Android. Subscribe to our YouTube channel. Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android | |||
| Choosing HVAC Cleaners w/ Becca from Viper | 12 Dec 2024 | 00:40:43 | |
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:
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. | |||
| Q&A - Evap Placement - Short #221 | 10 Dec 2024 | 00:07:15 | |
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. | |||
| Can Ducts Be Cleaned Ethically? | 05 Dec 2024 | 00:41:32 | |
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:
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. | |||
| Should I Fog or "Sanitize" My Ducts? - Short #220 | 03 Dec 2024 | 00:09:16 | |
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. | |||
| Condensing Furnace Drain Guidance w/ AC Service Tech | 28 Nov 2024 | 00:38:57 | |
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:
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. | |||
| What Can Be Done About Healthcare? w/ Ethos | 26 Nov 2024 | 00:44:29 | |
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:
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. | |||
| How to Predict Air Flow Issues in the Sales Process | 21 Nov 2024 | 00:46:44 | |
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:
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. | |||
| MCA is 27 and the Breaker is a 50A - Short #219 | 19 Nov 2024 | 00:06:11 | |
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. | |||
| Deploying Surge Protection & Voltage Monitoring w/ DITEK | 14 Nov 2024 | 00:35:32 | |
Bryan discusses surge protection devices (SPDs) with Mike from DITEK, focusing on practical applications for HVAC contractors and how to provide value to clients. Mike emphasizes that surge protection is essential for modern HVAC systems, particularly given that they are typically the most expensive appliance in a home and increasingly rely on sophisticated electronic components like variable-speed compressors and inverter boards. The conversation delves into installation best practices, with a detailed discussion of proper wiring techniques for SPDs. Mike explains that surge protectors should be installed in parallel with the circuit, typically at the disconnect, and addresses common concerns about double-tapping lugs and ground connections. He emphasizes the importance of keeping wire lengths as short as possible and provides guidance for installations both with dedicated disconnects and panel-direct connections. A significant portion of the episode focuses on DITEK's Kool Guard (KG2) product, which represents an evolution in HVAC protection by combining surge protection with voltage monitoring. Mike explains how modern HVAC equipment, particularly inverter-driven systems, is increasingly sensitive to both over-voltage and under-voltage conditions. The Kool Guard monitors voltage on each phase independently and provides visual indication of fault conditions through LED indicators, making it easier for homeowners to identify potential issues without opening electrical enclosures. Key Topics Covered: · Why every modern HVAC system needs surge protection · Installation locations and proper wiring techniques for SPDs · The difference between line-side and load-side installation · Ground connection best practices · How to protect both condensers and air handlers · The evolution from basic surge protection to voltage monitoring · The importance of voltage monitoring for modern inverter-driven equipment · How Kool Guard monitors voltage phase-to-ground vs line-to-line · Common power quality issues beyond lightning strikes · How to discuss surge protection with customers · The limitations of utility-provided surge protection · The impact of aging power infrastructure on power quality · The advantages of USA-made surge protection products · How voltage monitoring prevents damage from brownouts and over-voltage conditions · The pre-programmed voltage protection ranges in Kool Guard · Visual indication features for fault conditions
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. | |||
| Pumping vs. Compression - Short #218 | 12 Nov 2024 | 00:09:32 | |
In this short episode, Bryan clears up the confusion behind pumping vs. compression. Pumping is usually associated with liquid. Liquid, like vapor, is a fluid, but it's a lot denser and is essentially incompressible because the molecules are close together. Liquid volume varies based on temperature and density, but we can't squish the molecules together. That's why compressors with very little axial and radial compliance fail when flooded; they can't compress the liquid. A circulator pump in a hydronic system is an example of a pump that pushes liquid along, but the pressure difference across the pump is minimal compared to that of a compressor; the same is true of liquid vs. vapor CO2. However, vapor molecules are far apart and can be squished together to take up a smaller volume. That's why vapor can go through compressors, which take a fluid of one volume and apply pressure to shrink it to a smaller volume, raising the temperature in the process. Pneumatics, as opposed to hydraulics, utilize compression to move vapor around in a circuit. Recovery machines need to be able to compress vapor refrigerant and pump liquid into the recovery tank. Compressors and pumps can either be positive displacement or non-positive displacement systems. A positive displacement system creates a trap and forces a fixed amount of fluid through a system, like a scroll compressor or a circulator pump. Refrigerant volumes may vary because vapor density varies with temperature and pressure (the volume flow is the same, but the mass flow varies). A condensing fan motor, on the other hand, is dynamic and varies the volume of air it moves in response to pressure, as the mechanism relies on velocity and kinetic energy to move air.
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. | |||
| What are User Requirements? w/ ELK | 25 Sep 2025 | 01:19:21 | |
In this comprehensive session, Eric Kaiser walks through the critical importance of establishing proper user requirements before making equipment purchases. Drawing from real-world experiences in the HVAC industry, he demonstrates how poor upfront planning leads to costly mistakes, buyer's remorse, and multiple equipment purchases. The discussion covers everything from selecting simple tools like screwdrivers to complex HVAC system installations for residential and commercial applications. Eric begins with relatable examples that everyone can understand - like buying screwdrivers that don't do the job you need them for, leading to accumulating multiple tools over time. He then escalates to more serious scenarios, sharing a story about a company that spent significant money switching business software twice because they failed to identify a crucial missing feature upfront. This pattern of inadequate planning costs businesses and homeowners thousands of dollars and countless hours of frustration. The heart of the presentation focuses on a structured approach to equipment selection that prioritizes needs over wants. Eric introduces a step-by-step process that includes defining intended use, conducting thorough assessments, categorizing requirements as needs versus wants, and performing systematic candidate evaluation. He demonstrates this methodology using electrical meter selection, showing how 38 potential options can be narrowed down to just two viable candidates through careful analysis of features like amperage capability, True RMS measurement, and accuracy requirements. The session expands into HVAC system selection, where the stakes are much higher. Participants share valuable insights about customer expectations, from wanting to know when quiet systems are running (leading to flag solutions on registers) to dealing with customers who expect their new heat pump to feel as warm as their old poorly-designed system. Eric emphasizes that understanding customer expectations often differs from understanding their stated wants, requiring skilled questioning to uncover the real requirements for comfort, noise levels, and operational preferences. Key Topics Covered
Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool. Purchase your tickets or learn more about the 7th Annual HVACR Training Symposium at https://hvacrschool.com/symposium. Subscribe to our podcast on your iPhone or Android. Subscribe to our YouTube channel. Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android | |||
| Building Tech Confidence w/ Refrigeration Mentor | 07 Nov 2024 | 00:46:56 | |
Trevor Matthews returns to the HVAC School Podcast to discuss building tech confidence and personal growth in the HVAC and refrigeration industry. The conversation explores the transformative power of self-investment, continuous learning, and maintaining a positive mindset. Trevor shares his personal journey from a hesitant technician to a successful business owner, highlighting the importance of pushing beyond comfort zones and embracing continuous improvement. Some fundamental mindset shifts are necessary for professional development. Trevor candidly discusses his early career struggles, including his initial fear of public speaking and technical challenges. He emphasizes that confidence isn't something that happens overnight but is built through consistent effort, studying, and maintaining a willingness to learn. The key to the growth mindset is to focus on personal progress instead of comparing your achievements to those of others, and it's a perspective that can dramatically impact professional and personal growth. Self-investment consists of dedicating time to learning, staying physically and mentally healthy, and maintaining a positive attitude, and it can open up unprecedented opportunities. Many technicians have transformed their careers by adopting a growth mindset, continuously seeking knowledge, and being willing to step outside their comfort zones. Key Topics Covered:
Recommended Resources Mentioned:
Check out Refrigeration Mentor at https://refrigerationmentor.com/ or email Trevor at trevor@refrigerationmentor.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. | |||
| Molecular Transformator - Short #217 | 05 Nov 2024 | 00:09:11 | |
In this short podcast episode, Bryan talks about the CPS Molecular Transformator and what it does. The Molecular Transformator is a version of a tube-in-shell heat exchanger, which is a method of exchanging heat from one fluid medium to another fluid medium. Tubes containing a fluid pass through a shell containing water or glycol, and there is a heat exchange between that secondary fluid and the fluid being circulated in the tubes. In a Molecular Transformator, the fluid being circulated is recovered refrigerant, and the secondary fluid is water (in a bucket), which absorbs heat from the refrigerant and cools it down to make sure that the refrigerant enters the recovery tank as a liquid. Refrigerant recovery machines have condensers inside of them, but they are quite small and don't hold a lot of refrigerant by design; many recovery machines use microchannel coils. A lot of the time, the refrigerant leaving a recovery machine is a liquid-vapor mix and too high-temperature; a lot of people run a hose over the tank or put it in a bucket of ice. The "Molecular Transformator" tries to settle the vapor molecules down into a liquid; it transforms the vapor molecules using the same mechanism as a tube-in-shell heat exchanger. The main issue is that there will be leftover refrigerant in the Molecular Transformator after recovery. However, you can mitigate this problem with ball valves and proper purging. Do so responsibly to avoid venting refrigerant.
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. | |||
| Surge Protection Basics w/ DITEK | 31 Oct 2024 | 00:39:03 | |
In this enlightening episode, we sit down with Mike, a 20-year veteran from DITEK, a leading American manufacturer of surge protection devices based in Largo, Florida. The conversation begins with a brief discussion about recent hurricane impacts in the Tampa Bay area, where DITEK maintains its 65,000-square-foot manufacturing facility. Mike shares how the company, despite facing challenging weather conditions, continued its operations and maintained its commitment to American manufacturing. The bulk of the discussion centers around surge protection technology and its critical importance in protecting HVAC systems and other electronic equipment. Mike provides an excellent analogy, comparing surge protectors to pressure relief valves for electrical systems. He explains how Metal Oxide Varistors (MOVs) work as semiconductors that create low impedance paths to ground when voltage exceeds certain thresholds. The conversation delves into the evolution of MOV technology, particularly the development of thermally protected MOVs that provide enhanced safety features. The episode also addresses common misconceptions about surge protection, particularly the belief that surge protectors are primarily for lightning protection. Mike explains that while lightning strikes are a concern, especially in areas like Florida, approximately 65% of surges actually originate from within facilities themselves, often from equipment cycling on and off or other power quality issues. He emphasizes the importance of proper installation, particularly regarding ground connections and lead lengths, noting that every six inches of wire length can add about 100 volts to the clamping voltage of the device. Key Topics Covered:
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. | |||
| Q&A - Am I Toxic For Caring? - Short #216 | 29 Oct 2024 | 00:17:10 | |
Bryan answers a listener-submitted question: "Am I toxic for caring?" He gives advice on how to maintain professional relationships while still maintaining very high standards of quality for your own work. Having high standards is great, but it can be frustrating when you perceive coworkers as having lower standards than you. A poor-quality end product is fairly objective, but other ways of judging coworkers' standards are a lot more subjective and may vary by culture, and we end up judging the person rather than the work. While we should care about the objective outcomes of a job, we want to challenge ourselves when we start comparing others' work to our own unfavorably. Judging others' work isn't inherently bad or "toxic," but it has to be controlled and done in service of something greater. When we confront others or judge their work, we need to make sure it comes from a place of professional pride (rather than personal pride) and personal humility. As tradespeople, we don't always do the best work, either. In some mission-critical applications, we need to rely on workarounds to get a quick outcome. In those situations, it's a lot more important to be honest about what we're doing and the value we promise. When we find opportunities for our colleagues to do things better, we can offer advice in service of the job and allow the other person to take it or leave it; we don't get to decide that for others. We also have to acknowledge that people have different natural inclinations, and we'd be wise to respect those differences.
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. | |||
| App Based HVAC Learning | 24 Oct 2024 | 00:32:35 | |
Ruchir Shah joins the podcast to share his journey into HVAC education technology and the founding of SkillCat, a comprehensive training platform for skilled trades. As a five-time entrepreneur in educational technology, Ruchir's path to HVAC was influenced by his earlier work studying the BP oil spill and developing training solutions for oil and gas workers. When COVID-19 hit and many skilled workers found themselves displaced, he recognized a broader pattern of declining income for blue-collar workers over the past 50 years, which led to the creation of SkillCat. The discussion delves into SkillCat's innovative approach to EPA 608 certification, making it more accessible and affordable at just $10 per month. Their platform uses phone-based testing with built-in security measures, achieving a 97-98% pass rate through comprehensive training. This system addresses traditional barriers like high costs, scheduling difficulties, and low pass rates that have historically made it challenging for people to enter the HVAC field. SkillCat and HVAC School have started a partnership. This collaboration aims to transform HVAC School's extensive content library into structured, accredited courses within the SkillCat platform. The partnership represents a marriage of HVAC School's technical expertise and industry insights with SkillCat's educational technology capabilities, making high-quality HVAC training more accessible and organized for both individual technicians and contracting companies. Key Topics Covered:
You can learn more about SkillCat by searching for it in the Google Play Store (Android) or App Store (iOS), or you can visit their website at https://www.skillcatapp.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. | |||
| Q&A - Apps for Doing Proper Loads - Short #215 | 22 Oct 2024 | 00:11:01 | |
In this short Q&A podcast, Bryan answers a listener-submitted question about apps for doing proper loads. Fred specifically asks about apps or charts that can help an HVAC contractor determine the insulation value of a home without assuming numbers or drilling into walls during load calculations. Load calculations account for all the ways that BTUs can enter or leave a home: conduction, convection, and radiation. Insulation prevents heat transfer via conduction, so it's important to the load calculation process. High-end HVAC design software like Wrightsoft and Kwik Model 3D will have these features built into them (based on the age and location of the home). ASHRAE's handbook also has tables and data with R-values and U-factors to help you out with Manual J load calculations. RED Calc is an app that allows you to calculate a wall's R-value with measurements, including surface and air temperatures indoors and outdoors. This RED Calc software is available through the U.S. Department of Energy, as is REScheck. The DOE insulation fact sheet is also quite valuable, as are The Engineering Toolbox and materials straight from the insulation manufacturers. The best way to get a comprehensive load calculation is to have a lot of tribal knowledge about how houses are built in your area, analyze energy bills, and combine tools like RED Calc with building performance tests.
RED Calc is available through the U.S. DOE at https://basc.pnnl.gov/redcalc. REScheck is available at https://www.energycodes.gov/rescheck. ASHRAE's resources are available at https://ashrae.org/technical-resources. Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool. Purchase your tickets or learn more about the 6th Annual HVACR Training Symposium at https://hvacrschool.com/symposium. | |||
| Jim Bergmann & MQ Update from NCI Summit | 17 Oct 2024 | 00:42:14 | |
Bryan sits down with Jim Bergmann at the NCI Summit in Asheville, North Carolina, to discuss the latest developments in HVAC technology, training, and industry trends. The discussion delves into the evolution of MeasureQuick 3.0, highlighting the shift back to a more technician-centric approach. Jim explains how they've redesigned the software to put gauges front and center and implemented an AI-driven system to guide technicians through the process step-by-step. This renewed focus on the end-user experience aims to make the product more valuable for technicians and, in turn, more likely to be adopted as part of standard operating procedures in HVAC companies. Jim and Bryan also explore the importance of understanding HVAC history and fundamentals. They discuss how revisiting old engineering books can provide valuable insights into the core principles of the industry, often explained in more accessible terms than modern textbooks. This approach to learning, combining practical experience with theoretical knowledge, is something both Jim and Bryan advocate for in technician training and development. The conversation then shifts to the challenges and opportunities in the HVAC industry, particularly in light of the push for electrification and the adoption of heat pump technology. Jim emphasizes the critical need for proper evacuation techniques and moisture removal in systems, especially for cold-climate heat pumps. He stresses the importance of standardized processes and documentation to ensure consistent quality in installations and maintenance. Topics covered in the podcast:
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. | |||
| Q&A - System Won't Dehumidify? - Short #214 | 15 Oct 2024 | 00:09:26 | |
In this short podcast episode, Bryan answers a listener-submitted question about an HVAC system that won't dehumidify. This question was submitted by a homeowner with a Carrier heat pump with an attic air handler that cools but won't dehumidify on the hottest days of summer. One of the past companies that serviced the system added charge, but the problem wasn't resolved. This case doesn't seem to be a sizing issue, as the insufficient dehumidification is happening on the hottest days. Normally, sizing issues happen during the edge seasons when temperatures aren't as high as in the summer, but the dew points are still high. Bryan's first recommendation is to use measureQuick to evaluate the delivered capacity and determine the sensible heat ratio (SHR) by comparing sensible BTUs to latent BTUs. High SHRs are associated with less effective dehumidification and more effective sensible BTU removal. Then, we have to determine that airflow is properly dialed in. Typically, lower fan speeds are associated with better dehumidification; 350 CFM per ton is typical of humid climates. In the case of two-speed or variable-speed equipment, we should verify that it is staging up and down properly. On the ventilation side, a duct leakage test is recommended. Proper use of exhaust ventilation, like bath fans and kitchen exhaust, is also critical. Structural leakage and MAD-AIR are also worth checking if a company can measure those, though those are premium services that are usually more expensive.
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. | |||
| What Is Up With Blower Amps & Watts w/ Steve Rogers | 10 Oct 2024 | 00:46:23 | |
Bryan Orr and Steve Rogers dive deep into measuring power consumption in HVAC blower motors, particularly focusing on the differences between PSC (Permanent Split Capacitor) and ECM (Electronically Commutated Motor) technologies. The discussion stems from a question raised at an educators' conference about the accuracy of clamp-on meters in measuring blower motor watt draw, as specified in the ACCA Standard 310. Steve shares insights from extensive testing conducted with different types of motors and power meters. The tests compared PSC motors with constant torque and constant airflow ECM motors across various static pressure conditions. One key finding was that two out of three field-available clamp-on meters tested were capable of accurately measuring true power at levels expected in residential blower motors. However, one meter showed significant inaccuracy at low power levels, highlighting the importance of carefully reviewing meter specifications before use. The conversation delves into the concept of power factor and its crucial role in understanding the true power consumption of ECM motors. Steve explains that ECM motors often have a low power factor (around 0.6), which can lead to misconceptions about their efficiency if only the current draw is measured. The discussion emphasizes the need for proper measurement techniques, including simultaneous voltage and current readings with the blower door on, to accurately assess motor efficiency. Key topics covered in the podcast:
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. | |||
| Q&A - Sizing Heat Pumps for Heat Load - Short #213 | 08 Oct 2024 | 00:09:11 | |
In this short Q&A podcast, Bryan answers a listener-submitted question about sizing heat pumps for heat load in heating mode, something that we haven't talked much about in the past due to the greater need for cooling in our market. In most cases across the country, a heat pump's heating loads will be greater than the cooling loads. There is a greater swing between the desired temperature and the actual temperature in heating mode than in cooling mode (in terms of sensible BTUs). We don't want to oversize for cooling because of its lower efficiency, comfort, and humidity control due to the shorter runtimes. (However, oversizing for cooling loads is far less of an issue in arid climates.) We don't want to oversize the heat pump to meet the heating load when we'll far exceed the cooling load. However, that's not much of a concern for the opposite scenario in which we oversize for heating to meet the cooling load. We can add auxiliary heat, such as electrical heat or natural gas in dual fuel setups, to help us meet the heating load; we don't have those same options in cooling. Variable-capacity systems can also be beneficial in scenarios where heating and cooling loads are massively different. Bryan is excited about future opportunities for standby cooling and heating capacity, such as in the case of a heat pump heat recovery chiller system with buffer tanks. In the meantime, we have to design for vastly different heating and cooling loads and may have to oversize for one or the other.
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. | |||
| Static Pressure is like Blood Pressure - Short #258 | 23 Sep 2025 | 00:10:02 | |
In this short podcast episode, Bryan explains the science behind a common HVAC simile: static pressure is like blood pressure. He covers the similarities and differences between measuring static pressure during a service call or maintenance and a doctor measuring your blood pressure at a checkup. Total external static pressure (TESP) should be measured every time you perform service or maintenance on a unit. The exact test port location will vary between air handlers and furnaces; the coil adds extra pressure drop in furnace applications. You need to pick a coil that has the lowest static pressure drop (same consideration as filters). Typically, the lower the pressure drop, the better. Make sure you use proper ports for static pressure testing when you do make those holes. Static pressure isn't airflow itself. It can help diagnose airflow issues or give indications, but it doesn't measure the CFM. Static pressure is a balloon-type pressure exerted on the walls of the duct. Just as high blood pressure doesn't mean your heart is pumping more blood than it should, a high static pressure doesn't mean your blower is moving a lot of air; both can indicate restrictions. You also don't want an extremely low static pressure, either. It could indicate that airflow is weak, just like a very low blood pressure indicates that the heart isn't pumping as it should. If you want to know your system airflow, you should use TEC's TrueFlow grid. However, static pressure is particularly good at measuring trends so that you can see where the numbers deviate from the norm for each individual system.
Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool. Purchase your tickets or learn more about the 7th Annual HVACR Training Symposium at https://hvacrschool.com/symposium. Subscribe to our podcast on your iPhone or Android. Subscribe to our YouTube channel. Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android | |||
| Water Issues - Spidey Sense | 03 Oct 2024 | 00:41:23 | |
This episode of the HVAC School podcast dives deep into the often-overlooked but critical topic of water issues in HVAC systems. Bryan and Bert discuss the various causes of water leaks and condensation problems, and they explain how to prevent them. They emphasize that water damage is not an inevitable part of HVAC systems and that with proper attention to detail and understanding of the underlying causes, most issues can be prevented. "Spidey Sense" refers to a heightened situational awareness that allows technicians to anticipate and prevent water-related problems. Common water-related problems include drain backups, improper trap depth, and freezing issues, and Bryan and Bert provide practical advice on how to identify and address these problems. The conversation also covers the importance of proper installation techniques, including the correct placement of float switches, insulation of copper lines, and the pitching of secondary drain pans. Bryan and Bert highlight the need for technicians to think critically about the root causes of water issues rather than relying on quick fixes or common misconceptions. They debunk myths such as thermostats being set too low and causing freezing, and they emphasize the importance of addressing underlying airflow problems. They also discuss the challenges of condensation in humid climates and the importance of setting proper customer expectations. Key topics covered in the podcast include:
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. | |||
| Q&A - Cultural Diversity - Short #212 | 01 Oct 2024 | 00:12:09 | |
In this short Q&A podcast episode, Bryan answers a listener-submitted question about cultural diversity in the workplace, especially at an HVAC company. He addresses how we can deal with cultural and language differences in a field where communication is so important. Being open to different demographics of people is great for the industry, especially since we have an aging workforce and need good people in the trade. There are also plenty of opportunities in the trade. However, that doesn't automatically erase the challenges associated with hiring people who don't speak English fluently with English-speaking clients, especially when it comes to money conversations. (However, you can also increase your client base by being able to serve people who speak other languages.) Our operations can aid these people and help them integrate into the workplace by offering ESL classes as a workplace benefit, encouraging everyone to be clear and concise in their communication, embracing other forms of communication (like sharing photos), and offering scripts or guidelines for communicating with customers. Cultures vary, and we can't afford to take a mindlessly xenophobic or excessively open approach. We need to acknowledge what's good for the business and uphold standards, but we need to make space for people of different backgrounds to succeed and contribute to the company and industry. It's also great to get to know people who aren't like us and show interest in other cultures, especially when we get to know them and their families.
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. | |||
| Aux Lockout & Balance Point w/ Sensi | 26 Sep 2024 | 00:25:30 | |
In this informative episode of the HVAC School podcast, host Bryan Orr sits down with Tom Lorenz to talk about some of the Sensi thermostat features, particularly aux lockout and balance point. Tom leads the traditional and smart thermostat lines at Copeland and has over 25 years of experience in the industry. The discussion focuses on two key features of heat pump thermostats: auxiliary lockout and balance point. Tom explains that auxiliary lockout is crucial for energy efficiency, as auxiliary heat (whether electric or propane) is typically more expensive than heat pump operation. All Sensi thermostats now include this feature, which can use internet weather data or a physical outdoor sensor to determine when to engage auxiliary heat. Balance point settings are complex, and there's no one-size-fits-all approach. Factors like heat pump efficiency, home insulation, local climate, and energy costs all play a role in determining the ideal balance point. They emphasize the importance of contractors understanding the specific equipment and secondary heat source when setting up a system for optimal performance and efficiency. The conversation also touches on Sensi's approach to thermostat design, prioritizing ease of use and essential features over feature bloat. Tom highlights Sensi's commitment to user testing and creating intuitive interfaces for both contractors and homeowners. The podcast concludes with resources for listeners to learn more about Sensi thermostats and advanced HVAC control strategies. Key topics covered:
Visit Sensi's site at https://sensi.copeland.com/en-us, and learn more about Sensi's contractor branding at https://hvacrschool.com/sensi. 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. | |||
| Q&A - How to Deploy a Dehum - Short #211 | 24 Sep 2024 | 00:09:24 | |
In this short Q&A podcast episode, Bryan answers Howard's question about how to deploy a dehumidifier (dehum) in a sealed home. He addresses things like location and fresh air requirements in green-grass markets with high dew points. Before deploying a dehumidifier, you will need to know about the climate, the structure, and the client's complaints, budget, and comfort goals. You need to make sure the HVAC system is properly installed; the most common obstacle to proper dehumidification is oversizing. HVAC systems need a cold coil to pull moisture out of the air, and we need adequate (but not too much) ventilation in the structure before deploying a dehumidifier. Common obstacles include leaky structures, venting exhaust air into the attic, and constantly running exhaust ventilation (like range hoods or bath fans). Bryan's preferred setup is to have a dedicated dehumidifier just for the sealed attic, though you can make the HVAC do this if you plan it out during the construction phase. If you bring in outdoor air, you should plan to bring it in through the dehumidifier, but that can interfere with attic dehumidification. You can either use two dehumidifiers or use powered dampers to dehumidify either the attic or house at different times. You can consult the expertise of groups like the HVAC Grapevine and manufacturers like Santa Fe Dehumidifiers. HVAC School also has a range of dehumidifier topics; you can search for videos, podcasts, and tech tips on the topic in the app.
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. | |||
| Leak Detection - Spidey Sense | 19 Sep 2024 | 00:42:02 | |
In this episode of the Spidey Sense series, Bryan and Bert dive deep into the art of refrigerant leak detection, sharing their wealth of experience and practical tips for HVAC technicians. They emphasize the importance of using one's senses and observation skills before relying solely on electronic tools, highlighting how this "Spidey Sense" approach is a hallmark of senior-level expertise in the field. Visual and tactile cues, including warm suction lines, frosted components, and signs of oil, are vital. Different symptoms point to specific kinds of leaks and various scenarios, so you need to understand the behavior of the system. Bryan and Bert also discuss the strategic application of soap bubbles, electronic leak detectors, and nitrogen for pressurization. Each method has limitations, and you'll need to know when to employ them for maximum effectiveness. When detecting leaks, consider recent home renovations or equipment vibrations that might contribute to leaks. Topics covered in the podcast include:
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. | |||
| Q&A - Why Didn't You Notice it Last Time? - Short #210 | 17 Sep 2024 | 00:08:22 | |
In this short Q&A podcast episode, Bryan answers Edward's question about how to deal with customers who ask, "Why didn't you notice it last time?" There isn't an easy answer to that question. The truth is that air conditioning and home health and comfort issues are complicated, and it's entirely possible that an issue simply went unnoticed (or the symptoms simply weren't apparent yet). The HVAC industry doesn't have a standard slate of tests that can give a comprehensive view of everything that's wrong with a system all at once. It's similar to how a doctor can offer a second opinion that differs from the first doctor you saw. You have to determine whether the customer wants to place blame or solve the problem when they ask, "Why didn't you notice it last time?" Sometimes, we need to dig deeper to find the root of the problem. We can offer advanced diagnostics and be honest about what that will entail (including pricing), though it's natural for customers to be apprehensive about being sold options. However, we don't want to avoid pursuing solutions either. There are ways to talk about previous sloppy or incomplete work without placing blame on another technician. The immediate problem is what requires attention, not the last person who worked on the system. Ask the customer to state their goals and the results they want to see, and you can forge a path ahead.
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. | |||
| Q&A - Vacuum Questions Answered | 12 Sep 2024 | 00:20:50 | |
In this episode of the HVAC School podcast, host Bryan dives deep into the topic of vacuum in HVAC and refrigeration systems. He addresses two questions from social media about vacuum, expanding them into a comprehensive discussion of best practices, common issues, and techniques for effective vacuum procedures. Bryan starts by explaining where to ideally locate a vacuum pump when working on a refrigeration system. He emphasizes the importance of pulling from the largest volume locations possible, often at multi-position service valves on the compressor or wherever accessible ports are available. He notes that systems that have been in operation pose unique challenges due to refrigerant dissolved in the oil, which can significantly increase vacuum time. The podcast then covers the "one hose method" for pulling vacuum, detailing the process of using a single large hose connected to the suction side with the core removed, while placing the micron gauge on the liquid side. Bryan explains how this method can be highly effective for new systems but may take longer for systems that have been in operation. He also discusses the importance of valve quality. Key topics covered in the podcast include:
Get your copy of Review of Vacuum for Service Engineers at TruTech Tools HERE. 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. | |||
| Q&A - Drain Traps & Static - Short #209 | 10 Sep 2024 | 00:05:55 | |
In this short Q&A podcast episode, Bryan answers a question about drain traps and static pressure. This question was sent by Stephen with The Comfort Squad when he noticed an uptick in nuisance calls on retrofit systems that kept having their secondary drain pans filled. In negatively pressurized systems (i.e., straight-cool or heat pump units, not gas furnaces), air can pull water back into the drain line. The evaporator coil is under negative pressure because the blower is on top of the evaporator coil. The rule of thumb for trap depth is that it should be greater than or equal to twice the return static pressure (which is why a 1" deep trap is typical for systems with 0.5" return static pressure). However, return static can have some variation, and it's also not a great idea to use the TESP for this measurement because the return static could be greater than the supply. It makes most sense to account for the highest possible return static you will see. 1" is only sufficient if 0.5" return static pressure is the most you will see, so bigger is usually better in all cases. If you can install a 2" or 3" trap, you'll typically have your bases covered without having an excessive trap.
We also wrote a tech tip about this topic: https://hvacrschool.com/drain-trap-depth-and-negative-pressure/ 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. | |||
| How Do You Ramp Up Your Team to Effectively Service and Support CO2 Applications? | 05 Sep 2024 | 00:55:58 | |
In this informative episode, Bryan Orr speaks with Andre Patenaude from Copeland about CO2 refrigeration systems. They dive deep into the unique characteristics and challenges of working with CO2 as a refrigerant, providing valuable insights for HVAC and refrigeration professionals looking to expand their knowledge in this growing field. Andre explains the reasons behind the increasing adoption of CO2 systems, including regulatory pressures and environmental benefits. He details the peculiarities of CO2 refrigerant, such as its high triple point and lower critical point, which create unique operating conditions not seen in traditional refrigerants. The conversation covers the concept of transcritical operation and how it affects system design and efficiency. The discussion then shifts to the infrastructure of CO2 systems, focusing on the transcritical booster architecture commonly used in supermarket applications. Andre breaks down the components and operation of these systems, highlighting key differences from traditional setups. He also touches on the latest innovations in compressor technology from Copeland, including new designs specifically engineered for CO2's high-pressure applications. Key topics covered in the podcast include:
Resources
Tech Tips Podcast Episodes
Videos
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. | |||
| Q&A - Condensating Vents - Short #208 | 03 Sep 2024 | 00:13:06 | |
In this short Q&A podcast episode, Bryan answers Kenton's question about how to stop vents from condensating, especially when sealing and insulation don't do the trick. When approaching a condensation problem, we have to consider the source of moisture and where the condensation is happening. Moisture that builds up on top of the vent comes from attics with a high dew point. (It's not because hot meets cold! Relative humidity and dew point are a lot more important, though hot air is able to hold more moisture.) Warm, moist air with a high dew point hits a colder surface when there is improper sealing and insulation where the duct attaches to the boot. People often attempt to solve condensation issues by adding insulation, which actually has the opposite effect because it reduces the surface temperature; condensation worsens. Some people also increase attic ventilation, but that may cause pressure imbalances that drive moist air into the conditioned space. The best way to control attic conditions is to seal and then dehumidify the attic, though it is an expensive and time-consuming measure. Exhaust vents that end in the attic also add moisture to the attic. Sealing vents and other areas where attic air can seep into the space is another best practice, as is deploying a humidity control strategy. Reducing humidity can happen with a dehumidifier and proper sizing so that the HVAC equipment has long runtimes with a cold evaporator coil (achieved with lower system airflow).
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. | |||
| How To Be a REAL Comfort Consultant | 18 Sep 2025 | 01:10:15 | |
In this comprehensive episode, Bryan Orr sits down with Tim De Stasio to explore the world of comfort consulting and performance contracting in HVAC. Tim, who sold his contracting company to focus on this specialized field, shares his methodical approach to diagnosing home performance issues that go far beyond traditional HVAC troubleshooting. Working primarily in the humid coastal North Carolina market, Tim has developed a thorough process that treats the house as a complete system rather than just focusing on equipment. Tim's journey into comfort consulting began when he recognized the value of comprehensive home performance testing after seeing the work of practitioners like Michael Housh. His approach combines ethical selling with rigorous testing and data collection, allowing him to stand behind his recommendations with confidence. Unlike traditional HVAC service calls that might only involve checking refrigerant levels, Tim's comfort consultations can take an entire day and involve extensive testing protocols that examine everything from building pressure to thermal imaging. The conversation reveals how this type of work requires a fundamental shift in thinking - from being an equipment-focused technician to becoming more like a field engineer or building scientist. Tim emphasizes the importance of having repeatable processes and comprehensive checklists, using tools like Safety Culture app to document findings with photos, notes, and annotations. His methodology starts with a detailed pre-visit questionnaire and includes preparing clients for what will be a very different experience from typical HVAC service calls. Perhaps most importantly, Tim demonstrates how proper diagnostics can lead to ethical sales opportunities. By using tools like blower door tests, thermal imaging, building pressure measurements, and comprehensive system evaluations, he can provide clients with data-driven recommendations prioritized by impact and return on investment. His approach includes a two-week period for analysis before delivering final recommendations, ensuring thoughtful conclusions rather than rushed judgments. Topics Covered
Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool. Purchase your tickets or learn more about the 7th Annual HVACR Training Symposium at https://hvacrschool.com/symposium. Subscribe to our podcast on your iPhone or Android. Subscribe to our YouTube channel. Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android | |||
| Residential & Rack Startup and Commissioning (Part 2) | 29 Aug 2024 | 00:39:16 | |
In this episode, Bryan and Max discuss commercial supermarket startup and commissioning with comparisons to residential HVAC work. Max, who has transitioned from residential air conditioning to supermarket refrigeration, shares his insights on the unique challenges and requirements of this specialized field. The conversation begins by emphasizing the critical importance of safety in supermarket refrigeration work. Unlike residential jobs, technicians often work alone in potentially hazardous environments with high-voltage equipment and large quantities of refrigerant. Hearing protection is stressed as a crucial safety measure due to the extremely loud environments in motor rooms. Max then delves into the complexities of supermarket refrigeration systems, describing the various components involved, including parallel compressor racks, refrigerated cases, and multiple control systems. He highlights the need for adaptability and problem-solving skills, as technicians often encounter unique situations with limited documentation or manufacturer support. The discussion also covers the time-sensitive nature of the work, with many tasks needing to be completed overnight to minimize disruption to store operations. The podcast explores the multifaceted role of a supermarket refrigeration technician, touching on topics such as equipment decommissioning, pressure testing, electrical verification, and programming of control systems. Max emphasizes the importance of developing a comprehensive process and continuously refining it to improve efficiency and effectiveness in the field. Key topics covered in the podcast:
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. | |||
| Q&A - EPR and Pressure Limiting Valves w/ Matthew Taylor | 27 Aug 2024 | 00:29:24 | |
In this episode, Matthew Taylor joins the podcast to dive deep into the world of pressure-limiting valves and regulators used in refrigeration and air conditioning systems. They explore the intricacies of Maximum Operating Pressure (MOP) expansion valves, Evaporator Pressure Regulators (EPR), and Crankcase Pressure Regulators (CPR), discussing their functions, applications, and differences. The conversation begins with an explanation of MOP expansion valves, which are commonly used in low-temperature refrigeration applications and air conditioning systems. Matthew describes how these valves work by using a vapor-charged thermal element to limit the suction pressure, protecting compressors from operating outside their designed range. They discuss the differences between liquid-filled, vapor-charged, and cross-charged valves, highlighting how each type affects system performance and superheat control. The discussion then shifts to larger systems and rack refrigeration, where Crankcase Pressure Regulators (CPRs) are preferred over MOP valves. Matthew explains how CPRs control pressure closer to the compressor, allowing for better superheat control in systems with longer piping runs. The conversation concludes with an explanation of Evaporator Pressure Regulators (EPRs), which are used in multi-evaporator systems to maintain specific evaporator temperatures independently of the overall system suction pressure. Topics covered in the podcast: · Maximum Operating Pressure (MOP) expansion valves · Liquid-filled vs. vapor-charged thermal elements · Cross-charged valves and superheat control · Applications of MOP valves in small refrigeration systems and air conditioning · Crankcase Pressure Regulators (CPRs) for larger systems · Evaporator Pressure Regulators (EPRs) for multi-evaporator setups · Differences between MOP, CPR, and EPR in pressure control · Challenges of pressure control in rack refrigeration systems · Impact of pressure-limiting devices on compressor longevity · Considerations for technicians when working with different types of systems
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. | |||
| Residential & Rack Startup and Commissioning (Part 1) | 22 Aug 2024 | 00:38:37 | |
In this episode of the HVAC podcast, Bryan and Max Johnson from Kalos discuss the critical role of a startup and commissioning technician in the HVAC industry. Max, who has experience in both residential and commercial HVAC, shares his insights on the importance of understanding the scope of work, equipment specifications, and code requirements. One of the key responsibilities of a startup and commissioning technician is to prevent any costly issues that may arise during the installation process. This includes identifying and addressing potential problems with ductwork, refrigerant charge, electrical wiring, and airflow. A comprehensive checklist ensures that no crucial steps are overlooked, such as setting up communicating equipment properly, ensuring the correct accessories are installed, and verifying the drain system is functioning correctly. Proper electrical work is another critical aspect of the startup and commissioning process. Max highlights the importance of using the right connectors and wire sizes to prevent issues like loose connections or overloaded circuits, which can pose fire hazards. Additionally, he stresses the importance of verifying the voltage is within the acceptable range for the equipment, as over-voltage can lead to premature failures. Airflow is another crucial factor that the startup and commissioning technician must address. Setting the correct airflow before charging the system is essential, as it ensures the equipment operates efficiently and effectively removes the necessary amount of latent heat. He recommends using tools like the TrueFlow grid and DG8 manometer to accurately measure and validate the airflow. Follow the manufacturer's charging recommendations closely, as each piece of equipment may have unique requirements. Use a comprehensive calculator, such as the one available on the HVAC School website, to determine the proper charge based on factors like line set length and size. Key Topics Covered: · Understanding the role and importance of a startup and commissioning technician · Developing a comprehensive checklist to ensure no critical steps are missed · Addressing potential issues with ductwork, accessories, and drain systems · Proper electrical work, including connector selection and voltage verification · Importance of setting the correct airflow before charging the system · Following manufacturer guidelines for refrigerant charging
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.
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| Q&A - Stubborn Old Techs - Short #207 | 20 Aug 2024 | 00:09:13 | |
In this short podcast of the Q&A series, Bryan answers a question about "stubborn old techs" (submitted by Luke via Speakpipe). In several cases, old-school techs are "being positional," which means they feel that they have a piece of turf to protect; they see challenges to the status quo as a threat. They may want to defend the way that they do and have always done things. Many of these people also have insecurities and have dealt with a lot of frustration and disrespect over the years, but they also have a lot to offer. Younger technicians can benefit from listening to these people and their experiences and showing empathy. Change is difficult, and "unlearning" or "unteaching" is an art. We can approach it by being open-minded and finding the truth behind the original thought that needs to be unlearned, not by being argumentative. Bryan applies these methods all the time when discussing practices like flowing nitrogen while brazing, which was indeed unnecessary when we used mineral oil but is necessary now that we use POE oil. Speaking with others respectfully is the key; don't speak condescendingly or try to prove them wrong. We all have insecurities and our walls up, and we won't win everyone over, but showing respect and empathy is the key. In the best cases, mutual respect will grow once you prove that you have another person's best interests at heart and that you're not out to get them.
Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool. Purchase your tickets or learn more about the 6th Annual HVACR Training Symposium at https://hvacrschool.com/symposium. | |||
| Modulating Compressors w/ Copeland | 15 Aug 2024 | 00:49:44 | |
In this episode, Josh Souders from Copeland joins the HVAC School Podcast to discuss modulating and variable capacity technologies in HVAC systems. Josh provides an in-depth look at the different levels of modulation available in residential HVAC equipment, from traditional fixed-speed systems to two-stage, multi-stage, and true variable-speed compressors. The conversation covers the benefits of modulating systems, including improved energy efficiency, better comfort, and enhanced humidity control. Josh explains how modulating technologies allow systems to more closely match the actual cooling or heating load of a building, reducing temperature swings and providing more consistent comfort. He also discusses how longer run times with modulating systems can improve dehumidification performance in humid climates. The interview delves into the technical details of how different modulating technologies work, from two-stage scroll compressors with solenoid valves to inverter-driven variable speed compressors. Josh highlights some of the challenges and considerations when implementing modulating systems, including proper sizing, airflow matching, and control strategies. The discussion also touches on cold climate heat pumps and how variable speed technology enables better performance in colder temperatures. Key topics covered:
Arm yourself with knowledge from AC & Heating Connect by Copeland at https://www.ac-heatingconnect.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. | |||
| Q&A - Testing Dehumidifiers - Short #206 | 13 Aug 2024 | 00:09:25 | |
In this short podcast episode of the Q&A series, Bryan answers a question about testing dehumidifiers (submitted by Steven via Speakpipe). Dehumidifiers run air over a cold evaporator coil (to pull moisture out of the air and drain it out) and then reheat it over a condenser coil. The air leaving a dehumidifier is of a higher sensible temperature than the air going in, but there are fewer overall grains of moisture. To see how well a dehumidifier is working, you will need to know the dehumidifier's rating and have the manufacturer's charts at your disposal. You'll also need to be mindful of barometric pressure and know the basics of using a psychrometric chart or app. You'll want to monitor the dew point delta (the difference between the dew point of the air going in and the air going out) to determine how well a dehumidifier is doing its job. Entering air conditions will heavily impact a dehumidifier's performance, and power consumption is another important measure of dehumidifier efficiency. To collect data, you must place one psychrometer at the dehumidifier inlet and one at the outlet; you'll get the dry-bulb and wet-bulb temperatures needed to make a comparative measurement and plot points on the psychrometric chart. You can also measure the condensate output and do the math to determine how much moisture is being removed per hour, but that would hinge on constant operation and consistent entering air conditions.
"Dehumidifier Facts and Troubleshooting" tech tip by Genry Garcia: https://hvacrschool.com/dehumidifier-facts-troubleshooting/ 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. | |||
| Improving Changeout Outcomes | 08 Aug 2024 | 00:30:18 | |
In this episode, we dive deep into the world of residential HVAC installations and improving changeout outcomes with Matt, a senior technician and residential install supervisor at Kalos Services. Matt brings a wealth of experience from both the service and installation sides of the business, offering valuable insights into improving installation processes and workmanship. The conversation highlights the importance of thorough planning and communication in today's HVAC industry. With younger, less experienced technicians entering the field, there's a growing need for detailed instructions and oversight. Matt emphasizes the role of pre-installation videos, photos, and careful site assessments in preventing miscommunications and potential issues during installations. A significant portion of the discussion focuses on quality control and the impact of workmanship on customer satisfaction. Matt stresses the importance of post-installation photos for peer review, allowing for catching errors and improving overall quality. The conversation also touches on the delicate balance of providing constructive criticism to younger technicians while maintaining positive relationships and fostering a culture of continuous improvement. Key topics covered in the podcast:
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. | |||
| Spidey Sense - Airflow - Short #205 | 06 Aug 2024 | 00:13:47 | |
In this short podcast, Bryan talks about how to pay close attention to airflow issues and use your "spidey sense" when you're doing a visual inspection or commissioning a system. He also covers some causes of common airflow problems and some services and upgrades you can offer to your customers. The skill of being able to use your senses and notice when something isn't quite right is a valuable one, especially when you're getting ready to set the charge. Not every technician has access to the tools to do a comprehensive airflow assessment, but every tech can use their senses to determine when something is wrong with the system airflow. Keep an ear out for whistling or other strange noises, and watch out for cabinet shaking, which may indicate an airflow problem. Airflow restrictions are also significant issues. Filter cleanliness (or lack thereof) and improper filter selection are very common causes of airflow issues, including high static pressure drop. Most filters should also not be doubled up (in series). Watch out for furniture blocking vents and registers that are partially (or fully) closed; shutting off registers is NOT a good strategy. Air movement throughout the building is also important, including the presence or absence of returns, open doors, etc., and these things affect MAD-AIR. Watch out for things like leakage as well, which can be around the platform, in ducts around the equipment, and around vents or recessed lighting.
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. | |||
| Preventing Low Voltage Issues | 01 Aug 2024 | 00:43:43 | |
In this episode, Bryan and Bert dive deep into the world of low voltage wiring in HVAC systems. They discuss common mistakes, best practices, and troubleshooting techniques that technicians and contractors should be aware of when dealing with control wiring. The conversation begins with a focus on mechanical issues, such as running wires in places where they can be damaged and poor splicing techniques. Bryan and Bert emphasize the importance of proper wire stripping, both for the outer jacket of control cables and individual conductors. They share tips on how to avoid damaging wires during installation and stress the significance of planning wire placement, especially behind thermostats. The discussion then shifts to common miswiring issues, including incorrect terminal connections and misunderstandings about system configurations. They explore the challenges of wiring heat pumps, straight cool systems, and gas furnaces, highlighting the importance of understanding how different thermostats and equipment interact. The hosts also delve into the complexities of dehumidification control wiring and the need to comprehend how various controllers operate. Bryan and Bert also address communicating systems and offer advice on preventing communication issues. They stress the importance of running new control wiring, considering shielded cable for long runs, and being meticulous about connections. Topics covered in the podcast:
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. | |||
| STOP Overthinking! - QA Short #204 | 30 Jul 2024 | 00:09:05 | |
In this short podcast from our Q&A series, Bryan answers a viewer question and implores you to STOP overthinking in the trade! He also shares a parable and some tips to help stop overthinking, especially if you're just starting out in the trade. In many cases, the simplest assumption is the right one (this is called Occam's Razor). We can always start with the most obvious or simplest possible answer. We can become mindful of our tools, such as by making sure our seals are intact, and we become masters of the obvious. Perfecting little things (and micro-tasks) can help you become more familiar with the tools you use and the equipment you work on, and you start to develop a bigger-picture understanding of your craft. Cleaning the equipment and organizing your tool bag goes a long way; you can unlock the ability to zoom out and spot mistakes that you otherwise wouldn't have thought of otherwise.
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. | |||
| Non-bleed TXVs and Hard Starts - Short #257 | 16 Sep 2025 | 00:10:13 | |
In this short podcast episode, Bryan talks about non-bleed TXVs and whether they need hard starts. A non-bleed (hard shutoff) TXV is a metering device that shuts off during the off cycle; it closes shut when there is no superheat. This strategy prevents refrigerant migration, especially in cases where we have long line sets. Liquid refrigerant stays in the condenser and is kept out of the evaporator, suction line, and compressor crankcase. When we have a non-bleed TXV, the compressor may have a hard time starting under the conditions created by the hard shutoff TXV (high head pressure, low suction pressure). Reciprocating compressors are more likely to have this problem than a scroll or rotary compressor. If you have a short line set, 230+ voltage, and a scroll compressor, you probably won't need a hard start kit. You may need a hard start kit if you have a reciprocating compressor, a longer line set, or 208V power. The OEM will recommend a hard start kit that is suitable for the equipment. Aftermarket hard start kits are okay if a compressor is old and struggling, but they're not the preferred option and should be as close to the OEM's recommendation as possible. Hard start kits typically consist of a start capacitor and a potential relay. Positive-temperature coefficient resistors (PTCRs) also exist, and these have a resistor that heats up and eventually takes them out of the circuit. Hard start kits should not be added to inverter-driven equipment and are not meant to compensate for voltage drop issues; they can cause more harm than good if they're used when they're not necessary or not used correctly.
Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool. Purchase your tickets or learn more about the 7th Annual HVACR Training Symposium at https://hvacrschool.com/symposium. Subscribe to our podcast on your iPhone or Android. Subscribe to our YouTube channel. Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android | |||
| Stewarding Younger Techs | 25 Jul 2024 | 00:36:53 | |
In this podcast episode, Bryan and Dre discuss the challenges and opportunities of stewarding younger techs in the HVAC industry. They explore the growing interest among young people in trades like HVAC, noting a shift away from traditional four-year college paths. The conversation highlights the satisfaction that comes from working with one's hands and the tactile nature of the trade. The discussion delves into the attributes of younger workers, both positive and challenging. They also address the need to help young technicians understand the seriousness and responsibility of their roles, especially when transitioning from less demanding jobs. The podcast touches on the challenge of helping young workers prioritize their work and manage their time effectively, recognizing the natural tendencies of youth to be more focused on short-term feelings and experiences. While acknowledging the benefits of tech-savvy workers who can easily access information and use digital tools, they also discuss the need to manage potential distractions from smartphones and social media. The podcast also explores the evolving expectations around work-life balance, on-call schedules, and the importance of clear communication about job demands and responsibilities. Topics covered in the podcast:
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. | |||
| Duct Smoke Detector Facts and Wiring - Short #203 | 23 Jul 2024 | 00:12:44 | |
In this short podcast, Bryan answers a listener-submitted question about duct smoke detector facts and wiring. He focuses on Honeywell duct smoke detectors (namely the D4120W), but there are some general best practices that can be applied to most duct smoke detectors. The power supply may be 24v or 120v AC or DC and may have multiple inputs. You should not break that constant power source. There are also fan shutdown contacts, which may be normally open (alarm condition) or normally closed (non-alarm condition). Supervisory contacts open to indicate a trouble condition to the panel when something in the circuit isn't working properly (NOT an alarm condition). There is often a resistor at the end of the loop, and the alarm panel recognizes a specific resistance. Alarm initiation contacts close and create a shorted condition when there is an alarm condition (the supervisory contacts open if there is a trouble condition). Smoke detectors in the ducts are different from the ones on ceilings; they usually shut down blowers to prevent the distribution of smoke through the ductwork (and possibly exhaust it to the outside). They are required in duct systems designed for more than (or at least) 2000 CFM per NFPA90 and IMC 606.2.1, though those codes conflict. NFPA90 requires installation in the supply duct, but IMC 606.2.1 requires installation in the return; the AHJ may interpret the code either way. (Smoke detectors in systems >15000 CFM must be in both the return and the supply.) Overall, remember that different detectors are suitable for different velocities. You will want to keep them downstream of bends for at least 18 inches, test them according to the AHJ, and ensure that they are mounted in the right configuration as recommended by the manufacturer.
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. | |||
| Trust the NEW Process: Embracing Evolution in HVAC Technology | 18 Jul 2024 | 00:38:23 | |
In this episode of the HVAC School podcast, host Bryan and guest Jesse Stewart from NAVAC discuss the generational divide in the HVAC industry and the importance of embracing new technologies and processes. They explore the challenges faced by both experienced technicians who may be set in their ways and newcomers to the trade who need proper mentoring. Jesse emphasizes the importance of respecting traditional methods while making way for new techniques. He discusses how bad habits can be passed down from mentors to apprentices, highlighting the need for continuous learning and adaptation in the rapidly evolving HVAC industry. The conversation touches on the importance of treating apprentices with respect and providing them with educational experiences rather than just menial tasks. The podcast delves into specific HVAC practices, particularly focusing on evacuation and recovery processes. Jesse explains the significance of using proper tools and techniques, such as valve core removal tools, high-quality vacuum pump oil, and appropriate hoses for different tasks. He debunks common misconceptions about hose sizes and manifold use, providing practical analogies to help listeners understand these concepts. Topics covered in the podcast include:
Check our NAVAC's entire product line at https://navacglobal.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. | |||