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A2L Refrigerant Sensors: Understanding False Alarms from Off-Gassing
Refrigeration Communication Troubleshooting Using Oscilloscopes
Preventing Heat Illnesses in the BLAZING Summer Heat
What is RS-485 Communication?
A2L Dissipation Boards and Leak Sensors
Oscilloscope Systems and Settings
I’ve Done It This Way for 20 Years – And That’s the Problem
Oscilloscopes 101
Estimating Made Easy with Unity Build
Making Stuff Real – Short #254
Is HVAC School Worth It?
Split-Phase vs. 3-Phase – Short #253
IAQ for the HVAC Technician w/ Brynn Cooksey
Bi-metal & Magnetic Switches – Short #252
Fan Law 2 for Techs w/ Adam Mufich
Understanding Voltage Drop – Short #251
Understanding Airflow: David Bowie, a Used Car Lot, and a 40¢ Tool
Returns – Passive? Active? Sizing? w/ Adam & Matt
#hvac
Tech Tips:
As the HVAC industry transitions to refrigerants with lower global warming potential (GWP), A2L refrigerants like R-454B are becoming more common. These refrigerants are classified as “mildly flammable” and require the installation of A2L leak detection sensors in many applications to ensure safety. While these sensors are essential for detecting actual refrigerant leaks, HVAC technicians […]
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This tech tip is the final installment in our short series on using oscilloscopes to troubleshoot communicating systems. Imagine this scenario: you've got a refrigeration system acting up, and the comms network, whether it's LON or MOD-bus, seems a bit flaky. Let me introduce you to oscilloscopes—more specifically, a PC version called the PicoScope 2204A. […]
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This tech tip about preventing heat illnesses covers information and resources from the Cleveland Clinic, the U.S. Centers for Disease Control and Prevention (CDC), the U.S. Occupational Safety and Health Administration (OSHA), and the National Oceanic and Atmospheric Administration (NOAA). HVAC School is NOT an official OSHA training resource, and although these safety tips are […]
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This tech tip about RS-485 communication is the third installment in a four-part series about oscilloscopes. It's a primer for the final installment about using an oscilloscope for diagnosis. I owe a special thanks to Jeremy Smith for sharing the information on Danfoss and for sparking my curiosity surrounding this type of communication. Let's talk […]
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The HVAC industry's ongoing shift towards eco-friendly solutions continually introduces new challenges and learning opportunities. A2L refrigerants are at the forefront of this transformation, offering a lower global warming potential (GWP) than many of the refrigerants we’ve been using. They’re also mildly flammable, meaning they require some enhanced safety measures. One of these is the […]
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This is part two of our four-part series on oscilloscope fundamentals. Special thanks to Andrew Holden for his contributions. In our last tech tip on oscilloscopes, we learned about some safety basics, waveforms, and measurements. We’re going to dive a little deeper into systems and settings on the oscilloscope in this tech tip. Systems are […]
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Every trade has its favorite phrases. One of the most common in HVAC goes something like: “I’ve been doing it this way for 20 years and never had a problem.” When you hear that—or when you catch yourself saying it—it’s worth stopping to think. Usually, what that sentence really means is: “I’ve been doing it […]
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This tech tip is the first in a four-part series on using oscilloscopes. I'd like to give a special thanks to Andrew Holden for his contributions to this particular tech tip. When we want to measure voltage between two points, we reach for a multimeter. A multimeter can tell us the average electrical potential between […]
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Many of you may already know that our HVAC company, Kalos Services, is also a GC. We do a lot of construction projects with HVAC, plumbing, and electrical scopes of work. Estimating is a crucial part of winning those projects, and those of you who work on HVAC for new construction probably already have an […]
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Videos:
Podcasts:
In this short podcast episode about a bigger-picture topic, Bryan talks about making stuff real. He talks about how to make ideas, businesses, podcasts, and other large projects come to life based on his experiences with HVAC School, Kalos, and several other current and past projects. Understanding yourself and the thing you want to […]
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In this comprehensive discussion, Bryan sits down with Brad Cooper, an experienced HVAC instructor from Arkansas, and JD Kelly, a trade school graduate, to tackle one of the most pressing questions in the HVAC industry: Is trade school worth it? Rather than offering a simple yes or no answer, the trio dives deep into […]
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In this short podcast episode, Bryan breaks down the differences between split-phase and 3-phase power in HVAC systems. Split-phase is a form of single-phase power, and it's common in residential HVAC. Three-phase power is more common in commercial and industrial applications. Single-phase power uses only one of the three phases of power produced by the […]
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In this episode from the 6th Annual HVACR Training Symposium, Brynn Cooksey, a home performance contractor from Michigan and technical training business owner, reveals how indoor air quality (IAQ) testing transformed his contracting business from a commodity service into a profitable specialty. Cooksey shares his proven methodology for turning IAQ into an “instant profit […]
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In this short podcast episode, Bryan covers some basics on bi-metal and magnetic switches. Bi-metal switches are made of two dissimilar metals that are bonded together and are often integrated into motors. When the temperature changes, the metals bend. In an overload circuit, they're designed to bend and open the circuit in an overheat […]
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In this educational session, Adam from National Comfort Institute (NCI) delivers a comprehensive deep dive into Fan Law 2 and its practical applications for residential HVAC systems at the 6th Annual HVACR Training Symposium. Adam begins by establishing the fundamental concepts of CFM (cubic feet per minute) and static pressure, explaining how these measurements […]
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In this short podcast episode, Bryan drops some knowledge to help with understanding voltage drop, a few different causes of it, and NEC recommendations. Voltage is electrical potential or “pressure,” and voltage drop is the reduction in electrical potential energy. We often think of it happening across conductors (which add resistance), but it also […]
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In this enlightening presentation, Alex Meaney breaks down the fundamental concepts of airflow in HVAC systems using practical analogies and real-world examples. Rather than diving straight into complex mathematics, Alex focuses on helping technicians and contractors understand what's actually happening inside ductwork and why traditional design methods may be falling short in modern residential […]
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In this episode of the HVAC School podcast, Bryan Orr sits down with Adam and Matt to tackle one of the most misunderstood aspects of HVAC system design: return air systems. The conversation dives deep into the common myths surrounding returns, particularly the widespread belief that adding returns to rooms will automatically improve comfort […]
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