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The Many Uses of Thermal Imaging Cameras in HVAC
Replacing an Evaporator Coil
Different Ignitor Types and How They Work
The VOCs Lurking Under Your Customers’ Sinks (and In Many Other Spots)
Another Ob-NOx-ious Combustion Product
How to Replace a Condensing Fan Motor
Design and Performance Challenges of Air-Source Heat Pumps Across Diverse Climatic Conditions
Brownouts and How They’re Killing HVAC Equipment
CAT Ratings on Electrical Multimeters
Residential vs. Commercial HVAC Sales
When Ammonia Ruled the World – Short #270
Humidity, Airflow, and Refrigeration
The Finned-Tube Coil – Short #269
Are Two Are Better Than One: Understanding Tandem Compressors
The Tech That Tried to Beat the Compressor – Short #268
VRF, Ductless and Humidity Control w/ Roman
The History of the Thermostat – Short #267
Tech Support Highs and Woes w/ Roman
#hvac
Tech Tips:
When most of us think about tools of the trade, a few main ones come to mind: manifold, multimeter, vacuum pumps, recovery machines… the list goes on. One that may NOT come up nearly as often as it probably should is the thermal imaging camera. A few symposiums ago, Bill Spohn and Eric “Elk” Kaiser […]
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Evaporator coil leaks are a fact of life in the industry. (We could have a long and lively discussion about how evap coils aren’t made like they used to be, but that’s for another day.) When you have an evaporator leak on a system, you’ll have two choices to fix the problem: replace the coil […]
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In the furnace sequence of operation, the ignition sequence happens after the safeties have been checked, the inducer fan comes on, and the pressure switch closes. The ignition sequence begins with the ignitor. This part provides the heat needed for combustion (remember: a fire needs heat, oxygen, and fuel), and the ignition process looks a […]
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In HVAC, we have a few infamous indoor air quality monsters that bring terror to our customers’ homes—gases, particles, and organisms that wreak havoc on indoor air quality (and may contribute to moderate to severe health problems). The big one is carbon monoxide (CO), which we all know is deadly. Although not deadly by itself, […]
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As we do fall maintenance and head into the heating season, combustion analysis becomes a big deal. (It’s always kind of a big deal, but now it’s a really big deal.) First and foremost, it tells us how much carbon monoxide (CO) is produced by burning. CO can make people ill, contribute to cognitive deterioration […]
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Service calls about condensing fan motor failure are quite common. Even though fan motor replacement is a standard procedure for residential split systems, it requires careful attention to safety and detail. This article will give you a step-by-step guide showing how to replace a condensing fan motor. Along the way, we will also explain a few […]
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This tech tip was inspired by Alex Meaney and Ed Janowiak’s session at NCI’s High-Performance Summit 2025: “Good Design Isn’t a Buffet: The Importance and Interconnection of Manuals J, S, and D.” Alex is a building science expert who worked at Wrightsoft (now MiTek) for several years before launching his consulting firm, Mean HVAC Consulting […]
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HVAC technicians typically focus on diagnosing issues related to mechanical wear, refrigerant leaks, or control problems within the equipment. However, damage can also originate from external sources. For instance, a failed control board might be attributed to internal shorts or rubouts. Yet, the root cause could be external, such as the voltage spike that can […]
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If you have a multimeter for HVAC work, you most likely have a meter with a CAT III rating on it. Some might also be rated for CAT II at higher voltages or CAT IV at lower ones—or both, like this model of the UEi DL599 from our Multimeter 101 for HVAC 3D video. In […]
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Videos:
Podcasts:
In this candid conversation, Nathan and Bryan dive deep into the often-misunderstood world of sales in the construction and HVAC trades. Nathan, who has transitioned from fieldwork to spending roughly 60% of his time in sales, offers a unique perspective on why sales professionals are necessary despite the skepticism they face from tradespeople. The […]
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In this short podcast episode, Bryan takes us on a history journey back to when ammonia ruled the world. In the mid-1800s, before R-12, many inventors and scientists experimented with vapor-compression refrigeration systems to make ice. They used a variety of refrigerants in their patents, including ether, ethyl ether, carbon dioxide, sulfur dioxide, methyl […]
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In this episode of the HVAC School podcast, Bryan and Nathan dive deep into the challenges of humidity control in grocery stores and other refrigerated environments. While the conversation takes several entertaining detours (including discussions about morning radio shows, Indian weddings with elephants, and imaginary lava-heated homes), the core content provides valuable insights for […]
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In this short podcast episode, Bryan explores the history of the finned-tube coil, which is what we use for heat exchange in air-source air conditioners and heat pumps. Air-source HVAC systems have copper tubes threaded through thin metal fins. This design was optimized to ensure the greatest possible surface area for heat exchange to […]
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In this comprehensive episode of the HVAC School podcast, host Bryan Orr sits down with three experts from Copeland to demystify tandem and trio compressor systems. Joining him are Gina Kahle (Multiples Engineering Manager with 12+ years at Copeland), Tyler Daniels (Product Management team member), and James Stevenson (Technical Sales veteran with 28 years […]
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In this short podcast episode, Bryan tells the story of the technology that tried to beat the compressor… and still may someday. We associate cooling with refrigerant… and all the things that come with it, including compressor noise, oil, recovery machines and tanks, leaks, superheat, and regulations. However, there is a means of providing […]
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In this comprehensive episode, Bryan and Roman dive deep into one of the most challenging topics in modern HVAC: making VRF (Variable Refrigerant Flow) and ductless systems perform effectively in humid climates like Florida. The conversation tackles a common misconception that inverter-driven equipment automatically handles humidity well simply because it can “turn down.” Roman […]
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In this short podcast, Bryan gives another history lesson and goes over the history of the thermostat. Before 1883, automatic temperature control simply did not exist; we shoveled fuel into the furnace and opened windows. If a room got too hot in a commercial building, the janitor would go downstairs to choke the draft […]
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In this candid and comprehensive episode, Bryan sits down with Roman to tackle one of the most frustrating yet crucial aspects of the HVAC industry: technical support. What starts as a conversation about their own tech support nightmares quickly evolves into a deep dive examining the entire ecosystem—from manufacturers and distributors to technicians and […]
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