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Tool Selection: Combustion Analyzers
Tool Selection: Manometers for the Right Job
Condenser Fan Blade Placement
Tool Selection: Analog vs. Digital vs. Probes
Two Ways to Prevent Freezing in 90%+ Furnace Condensate Lines
Decoding Measurement Lingo
History of Thermometry and the Invention of Thermometers
It’s All Relative… Humidity
The Heating Sequence of Operations and Onions
Why VRF Compressors Die w/ Roman
No Serve Situations – Short #243
Locked Compressor Mistakes w/ Bert
When 0V Isn’t Safe – Short #242
Compressor Ohm Mistakes w/ Bert
Motor Ambient Rating – Short #241
Superheat Talk w/ JD Kelly
How to Deal w/ Too Much – Short #240
Delta T Talk w/ JD Kelly
#hvac
Tech Tips:
While gauge manifolds and manometers may only have one main function, some tools take several different measurements and will have more expansive specs. The combustion analyzer is one such example—combustion has so many elements, and we need something that can analyze the concentrations of several different substances as well as temperature. As such, a combustion […]
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Last week, we briefly looked at the spec sheet of a gauge manifold. All things considered, it was quite short; we only had to worry about the refrigerant types, pressure ranges, and hose diameters. However, manometers’ spec sheets are quite a bit longer than gauge manifolds’ because they have resolution and accuracy specs, among other […]
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In a previous article, I talked about wiring permanent split capacitor (PSC) condenser fan motors. While researching the topic, I realized that there isn’t as much information available on condenser motors as there is on their counterpart—the indoor blower motor. I had never really given it much thought, as I assumed that the condenser motor […]
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The original tools of the trade were all analog: electrical meters, gauges, and even manometers (Magnehelic, anyone?). However, digital tools have also become a staple of the skilled trades—where would most of us be without digital multimeters? And then probes also joined the fray with the rapid improvements to smartphone technology over the last 15–20 […]
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This tech tip came from an email sent by Adam Blunkall, a Tennessee-based HVAC technician. He shared some tips to help prevent the issue of freezing in 90%+ furnaces in his market, and we appreciate his insight. Thanks, Adam! If we’re draining our 90%+ furnaces (or any condensing heating system) outside the structure in a […]
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Troubleshooting and commissioning are entirely data-dependent processes. How can you know that a system is undercharged unless you measure the superheat and subcooling? How can you know how much static pressure a blower motor has to overcome? In both cases, we use tools and measurements to help us determine the next steps. However, using the […]
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So, what is thermometry anyway? Thermometry is the scientific study of measuring temperature and has roots that date back to as early as 220 BC. During this time, Philo of Byzantium began to study the effects that temperature had on air. Specifically, he observed expansion and contraction caused by temperature change. He did this using […]
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Florida’s got a lot of great qualities: some pretty neat wildlife, beaches all around, and theme parks. On the flip side, Florida also has hurricanes and a lot of humidity. As much of a pain as it might be for residents and contractors alike, humidity is one of my favorite topics. We see relative humidity (RH) […]
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Just like Shrek, I like to think about the heating sequence of operations as an onion—it has layers. And each layer builds upon the previous one. We have written previously in great detail about gas furnaces, from top to bottom. I want to focus today on why there is a sequence of operations and how […]
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Videos:
Podcasts:
In this episode, Bryan and Roman dive deep into the world of Variable Refrigerant Flow (VRF) systems, focusing on the persistent issue of compressor failures. VRF technology has evolved, and it has seen a major rise in the North American market since the early 2010s. Roman shares his passion for VRF, tracing its origins […]
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In this short podcast episode, Bryan talks about some no-serve situations he's encountered as a technician and HVAC business owner. He also talks about situations that may be unpleasant but aren't quite no-serve situations. Some common and obvious no-serve situations are when a client threatens a technician, especially with lawsuits, bad reviews, or even […]
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In this informative HVAC podcast episode, Bryan and Bert dive deep into the complex world of locked and internal overload compressors, focusing specifically on single-phase residential units. The discussion begins with Bert explaining one of the most common challenges technicians face: diagnosing a locked compressor. He describes how compressors that are locked will typically […]
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In this short podcast episode, Bryan covers some unique electrical cases: when 0v isn't safe. When you measure voltage, you're finding out the electrical potential between two points. Just because there is 0v between one point and another doesn't mean there will be 0v between those points and other points. Non-contact voltage detectors are […]
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In this episode, Bryan and Bert dive into the often misunderstood world of compressor testing, focusing on common mistakes technicians make when using ohmmeters, compressor testers, and megohm meters. The conversation highlights how diagnostic errors can lead to unnecessarily condemned compressors and wasted time and resources. The hosts begin by discussing fundamental concepts like […]
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In this short podcast episode, Bryan talks about what the ambient rating means on a motor. These ratings can be found on both condensing fan motors and blower motors. They have Cs in their rating, which represents the maximum ambient temperature the motor can handle in degrees Celsius (like 40C or 60C). Heat and […]
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In this episode of the HVAC School podcast, host Bryan discusses superheat with guest JD, who recently co-authored an article on the topic with Ty Branaman. The conversation explores the often misunderstood concept of superheat, its importance in HVAC diagnostics, and common misconceptions technicians have when measuring and interpreting it. Bryan begins by sharing […]
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In this short podcast, Bryan talks about how to deal with too much at work and in life. He gives some practical tips to help you when you feel overwhelmed. One of the best ways to get ahead is to wake up early, exercise, get sunlight, stay hydrated, eat healthy, and get enough sleep. […]
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Bryan from HVAC School interviews JD Kelly, known as “student of HVAC” on Instagram, about Delta T measurements in HVAC systems. This episode dives into the fundamentals of Delta T, common misconceptions, and proper measurement techniques. JD explains that Delta T is simply a temperature difference between two points of the same medium, which […]
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