Hvac School - For Techs, By Techs

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 pr

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

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

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 RESche

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 kno

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 bett

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 po

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

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 crit

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 (li

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

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 ou

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: V

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. Howe

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 b

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 pressu

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 fr

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 se

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 limite

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 (