Hvac School - For Techs, By Techs

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 (

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 size

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

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

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

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

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)

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 inte

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/h

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

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 do

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 vacu

In this short podcast episode, Bryan dives into soft start & solar technology, which often work together. He also talks about how we can install ductless systems in homes that rely on solar power. Soft starts are NOT hard starts. Hard starts add more current to the start (auxiliary) winding, which creates a stronger phase shift. Instead, soft starts control the current on the start and run windings and provide just enough of a phase shift to ramp up the motor slowly; it provides a regulated power supply, which means that a slow startup doesn't necessarily cause overheating because there is no locked rotor condition. We can use soft starts on two-stage compressors but need to make sure the compressor goes up to high speed during the starting sequence. Soft starts "learn" the compressor's cycles, so we need to make sure they are trained to reach the high stage, not the low stage. In systems with multiple compressors, we need to have a separate soft start for each compressor. We don't need to use soft starts

In this episode of the HVAC School podcast, host Bryan Orr welcomes Matt Bruner to discuss the concept of a "summer survival guide" for HVAC professionals. They explore strategies for maintaining work-life balance during the busy summer season and share personal experiences on prioritizing family and personal well-being while managing the demands of the HVAC industry. The conversation delves into the importance of intentional planning before the summer rush begins. Matt shares how he and his family implement practices like scheduling an end-of-summer vacation, utilizing daycare services, and outsourcing lawn care to create more family time. Bryan emphasizes the need for financial discipline, avoiding impulsive purchases, and instead investing in services that can alleviate stress and create more personal time. The discussion turns to the challenges of people-pleasing tendencies in the workplace and with clients. Both hosts stress the importance of setting boundaries, learning to say no, and prioritizing one's

In this short podcast episode, Bryan answers a listener-submitted question: How do inverter air conditioners work? Inverter-driven systems have variable capacity to match loads. We can provide cooling or heating BTUs to match the needs of the space without overcompensating or undercompensating and causing temperature swings. Load matching also helps us get better efficiency out of the system. High-humidity climates also benefit from load matching, as equipment doesn't dehumidify well unless it has been running the entire time. When set up and designed properly, variable frequency drives (VFDs) improve comfort, efficiency, and even dehumidification. You can "overclock" your compressor to get more BTUs out of it without oversizing, particularly when you have high heating loads due to the cold weather. Inverter-driven equipment takes AC power in, runs it through a rectifier circuit, and turns it into rough power that resembles DC power. The current is then smoothed out and goes through the inverter bridge circui

In this episode of the HVAC School podcast, host Bryan Orr interviews Tim De Stasio, an experienced HVAC practitioner and consultant. Tim shares his journey in the HVAC industry, from his early days in vocational school to running his own contracting business for 12 years. He now focuses on consulting, design, and contractor training, allowing him to pursue his passion for HVAC while sharing his knowledge with others. The conversation delves deep into the world of dehumidifiers, exploring their importance in modern HVAC systems, especially in humid climates. Tim emphasizes the need for supplementary dehumidification in many homes, particularly during part-load conditions when air conditioning systems may not effectively control humidity. He explains the process of selecting and sizing dehumidifiers, stressing the importance of considering factors such as peak latent load conditions, actual dehumidifier performance under real-world conditions, and static pressure effects on output capacity. The discussion also

In this short podcast episode, Bryan shares some strategies for teaching communication confidence, which may come in handy if you have newer techs who feel nervous or struggle to communicate with other people. The main way to build confidence is to get them to talk in the first place. Scripts and roleplay scenarios during training can help get people used to speaking and give them a reference. Whether we're in sales or not, we have to share information and complete business transactions. Roleplaying those conversations in a controlled, familiar setting allows your more timid team members to put in the reps. The youngest generation in the workforce tends to be exceptionally uncomfortable talking compared to others; they often prefer to communicate via text. These techs can learn a lot from spending time with customer service representatives (CSRs), especially in difficult situations with upset clients. Then, you can address the non-verbal cues that also play a massive role in in-person communication. At Kalos,

This episode focuses on understanding and effectively utilizing various refrigeration system charts and measurements for troubleshooting and diagnostics. Joey Henderson, an HVAC veteran and trainer, shares his wealth of knowledge and experience on this topic. Joey starts by discussing the challenges he faced early in his career when trying to make sense of the confusing charts with arrows indicating high, low, high head, low head, etc. He emphasizes the importance of knowing the "supposed to be" values before attempting any measurements or referencing charts. Without this baseline understanding, the measurements become meaningless. He then delves into specific measurements like subcooling, superheat, evaporator temperature/suction saturation, condenser split, and compressor amperage. For each measurement, Joey explains the ideal range, how to interpret deviations, and how different factors like humidity, airflow, and refrigerant type can affect these values. He also highlights the differences in approaches fo

In this short episode, Bryan talks about wiring in condenser fan motors, including aftermarket motor considerations and the different wire configurations. When condensing fan motors fail, we need to know what to use to replace them. We often use PSC motors, though in cases when we replace a motor with an ECM, we still need to match the horsepower despite the increased flexibility. The motors we typically keep on our truck are 1/3 or 1/6 HP motors.  Frame size (diameter) and depth also come into play; you may encounter a 42-frame motor or a 48-frame motor. You can't replace an 825 RPM motor with a 1075 RPM one because the poles are different (6-pole vs. 8-pole). Single-phase 208/230v will be the most common motors in residential systems, and the phase and voltage must match. You should also know how to reverse a motor if it is reversible. The bearing type will have some tradeoffs; ball bearings last longer but are louder than sleeve bearings.  3-wire and 4-wire condensing fan motors are essentially the same; t