BACK
Voltage Protection Devices
HVAC in Nuclear Emergencies
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
Psychrometrics and the Magic Line – Short #265
Learning Hydronics, Boilers and Steam w/ Ray Wohlfarth
How Duct Tape Got Its Name (and Why It Shouldn’t Be on Ducts) – Short #264
The Art of De-Escalation
Legionnaires’ Disease: The Cooling Tower Killer – Halloween Short #263
Group Training – What We Have Learned
How Air Conditioning Saved the Movies – Short #262
Just Do it! w/ Chad Simpson
Analyst vs. PM vs. Operations – Short #261
#hvac
Tech Tips:
As HVAC technicians, our responsibilities extend beyond the mechanical and refrigerant systems. The electrical power supply is an often-overlooked factor in equipment longevity. Protecting an HVAC system from damaging voltage fluctuations is a strategic step that reduces service calls and enhances the reliability of our installations. This guide will discuss the importance of voltage protection […]
Read more
This tech tip is based on a podcast episode with Bill Nowicki about the latest DHS guidance on HVAC use in nuclear emergencies. You can listen to that podcast HERE. Bill has 45 years of experience in the nuclear industry, starting with his Naval career, and he also has a few podcasts of his own. […]
Read more
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 refrigerant leak detection sensors in many applications to ensure safety. While these sensors are essential for detecting actual refrigerant leaks, HVAC […]
Read more
This tech tip is the final installment in our short series on using oscilloscopes to troubleshoot communicating systems. This time, we're focusing on troubleshooting communication issues in commercial refrigeration 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 […]
Read more
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 […]
Read more
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 […]
Read more
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. A2L refrigerants are also mildly flammable, meaning they require some enhanced safety measures; one of these […]
Read more
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 […]
Read more
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 […]
Read more
Videos:
Podcasts:
In this short podcast episode, Bryan talks about psychrometrics and the magic line inside a messy-looking chart. The psychrometric chart is a key tool for understanding the relationship between air and water. “Psychrometric” comes from the Greek roots for “cold” and “measurement.” As such, a tool called the psychrometer (with paired wet-bulb and dry-bulb […]
Read more
In this episode of the HVAC School podcast, Bryan sits down with Ray Wohlfarth, a seasoned HVAC contractor and prolific author who has dedicated over 30 years to mastering the art and science of boiler systems. What began as a competitive disadvantage—competitors claiming he knew nothing about boilers—became Ray's driving passion. Through daily reading, […]
Read more
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, […]
Read more
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 […]
Read more
In this spooky Halloween short podcast episode, Bryan tells the story of the cooling tower killer: Legionnaires' disease. In the summer of 1976, the nation celebrated its bicentennial anniversary. The American Legion was holding its 58th annual convention at the Bellevue Stratford Hotel in Philadelphia, PA. In the days following the convention, doctors in […]
Read more
In this episode of the HVAC School podcast, Bryan Orr sits down with Bert and Leanna to discuss Kalos's first official cohort apprenticeship program, dubbed the “Launch Program.” What started as Bryan's persistent idea—one that the team initially resisted as too expensive and logistically challenging—evolved into a transformative three-month training experience that brought 15 […]
Read more
In this short podcast episode, Bryan explores an interesting story in the history of HVAC: how air conditioning saved the movies. In the summer of 1925 in NYC, a new film was set to appear on the big screen… but the theater was stuffy with no fan that could cool down the sheer mass […]
Read more
In this candid conversation recorded live at the NCI Summit in Austin, Bryan Orr sits down with Chad Simpson, owner of Simpson Solutions, for an unexpectedly revealing discussion about the reality of building a successful HVAC business. What makes this episode particularly compelling is Simpson's refreshing honesty about his struggles, failures, and the gradual […]
Read more
In this short business-oriented podcast, Bryan breaks down the differences between three commonly confused positions/roles: analyst vs. PM (project management) vs. operations. When you own or work in a small business, you might wear a lot of hats: estimating, writing proposals, troubleshooting, being a customer or coworker's therapist, etc. This work can be organized, […]
Read more
