HVAC School - For Techs, By Techs

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. Subscribe to our podcast on your iPhone or Android. Subscribe to our YouTube channel. Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android.

In this episode, 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: Safety considerations in supermarket refrigeration work Components of commercial refrigeration systems (compressor racks, cases, controls) Time constraints and overnight work in supermarket settings Decommissioning old equipment and installing new systems Pressure testing and leak checking procedures Electrical verification and three-phase power considerations Programming and verifying control systems Defrost cycle setup and verification Communication protocols and building management systems Performance audits and client expectations Low ambient controls and regional differences in system requirements Leak detection and walk-in cooler maintenance The importance of developing and refining work processes Transition from residential HVAC to commercial refrigeration Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool. Purchase your tickets or learn more about the 6th Annual HVACR Training Symposium at https://hvacrschool.com/symposium. Subscribe to our podcast on your iPhone or Android. Subscribe to our YouTube channel. Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android.

In this episode, 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. Subscribe to our podcast on your iPhone or Android. Subscribe to our YouTube channel. Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android.

In this episode of the HVAC 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. Subscribe to our podcast on your iPhone or Android. Subscribe to our YouTube channel. Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android.

In this short podcast 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. Subscribe to our podcast on your iPhone or Android. Subscribe to our YouTube channel. Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android.

In this episode, 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: Types of modulating HVAC technologies: fixed-speed, two-stage, multi-stage, variable-speed Benefits of modulation: energy efficiency, comfort, humidity control Technical details of how modulating compressors work Importance of proper system sizing and airflow matching Cold climate heat pump applications Energy efficiency ratings and standards (SEER, EER, HSPF) Federal and local incentives for high-efficiency HVAC systems Upcoming refrigerant transitions to A2L refrigerants Industry trends towards increased adoption of modulating technologies 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. Subscribe to our podcast on your iPhone or Android. Subscribe to our YouTube channel. Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android.

In this short podcast episode 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. Subscribe to our podcast on your iPhone or Android. Subscribe to our YouTube channel. Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android.

In this episode, 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: Challenges in residential HVAC installations, including attention to detail and craftsmanship The importance of thorough planning and communication before installations Using pre-installation videos and photos to improve clarity for technicians Post-installation quality control through photo submissions and peer review Managing younger technicians and providing constructive feedback The role of customer perception in judging installation quality Specific technical considerations for the central Florida market, such as condensate management and voltage regulation The importance of proper system commissioning and documentation Creating a training culture and career pathing for technicians Balancing efficiency with thorough quality checks and testing Adapting to changes in the HVAC workforce and industry practices Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool. Purchase your tickets or learn more about the 6th Annual HVACR Training Symposium at https://hvacrschool.com/symposium. Subscribe to our podcast on your iPhone or Android. Subscribe to our YouTube channel. Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android.

In this short podcast, Bryan talks about 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. Subscribe to our podcast on your iPhone or Android. Subscribe to our YouTube channel. Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android.

In this episode, 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: Proper wire stripping techniques for control cables Common miswiring issues in HVAC systems Thermostat wiring and configuration challenges Dehumidification control wiring complexities Heat pump vs. straight cool/gas furnace wiring differences Communicating systems and preventing communication issues Using shielded cable for long control wire runs Troubleshooting intermittent low voltage problems The importance of reading manuals and understanding system configurations Tips for managing wires behind thermostats and in control panels Using megameters for testing control wires Encouragement for technicians dealing with low voltage issues Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool. Purchase your tickets or learn more about the 6th Annual HVACR Training Symposium at https://hvacrschool.com/symposium. Subscribe to our podcast on your iPhone or Android. Subscribe to our YouTube channel. Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android.