Tech Tips

Each commercial rooftop unit (RTU) needs to be mounted to a curb. A curb supports the RTU and provides openings for the supply and return ductwork (which can be massive compared to what we see in residential and light commercial HVAC). Occasionally, we’ll need to do an RTU changeout and put in a bigger or […]

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 […]

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. […]

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 […]

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 […]

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 […]

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 […]

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 […]

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 […]