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HVAC Ghosts of Christmas Past, Present, and Future
Upgrading Time & Temperature Defrost with Demand Defrost for Heat Pumps
Coil Temp Sensors: Thermostats vs. Thermistors
Cabinet Leaks in Air Handlers & Fan Coils
Planning and Installing Condensate Drain Lines
Tandem Compressors and Their Efficiency Benefits
Why the Breaker Size May Be Lower than the MCA (and Why That’s NOT Necessarily a Code Violation)
Set Inverter Technology Up for Success in Humid Climates
Why Airplanes Fog Up Before Takeoff
Lifetime of HVAC/R w/ John Pastorello – Short #279
Vapor Injection + Modulation Innovation w/ Copeland
TXV vs. EEV – Short #278
Electric Heat Talk w/ Bert
Gas & Combustion Safety w/ Bert
Why Square Footage ≠ Tonnage – Short #276
Combustion vs. Compression – Short #275
HVAC In the Northeast w/ Leo & Paul Sharkey
Superheat in Heat Mode: Why Heat Pumps Get Weird – Short #274
#hvac
Tech Tips:
There have been many adaptations of A Christmas Carol over the years, but it all started with a novella written by Charles Dickens in the 1840s. It was early in the Victorian Era, fresh off the heels of the Industrial Revolution. The British were reflecting on past Christmas traditions, like caroling, and exploring new ones […]
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Since heat pumps work by extracting heat from the outdoors to bring it inside, the outdoor coil will almost surely freeze up. To mitigate the freezing, heat pumps enter a defrost cycle in which they run in cooling mode to send hot, high-pressure refrigerant back through the outdoor coil and melt the ice. While the […]
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‘Tis heating season once again. It’s getting colder outside, and the heat pumps are starting to frost up outdoors. The defrost cycle helps get rid of the frost, and there are a few different ways we can do that; the methods themselves may differ between systems (time & temperature vs. demand defrost), as may the […]
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When we think of air leakage, a few common scenarios probably come to mind: disconnected ducts at connections, poorly sealed connections, and air leakage around vents are ones we’ve mentioned quite a bit in tech tips and videos over the years. However, there are a few that we haven’t really talked about, particularly for fan […]
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The condensate drain is the source of many a service call in Florida. A lot of the time, the problem is just a clogged drain; bacterial zoogloea (drain snot) loves humidity, and the all-aluminum coils don’t do us any favors. Other times, there are some clear drain design or installation flaws that present hazards to […]
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This tech tip about tandem compressors was inspired by the recent HVAC School podcast episode with the Copeland team. You can listen to that podcast episode HERE. One compressor is great, but how about two in the same circuit? Or three? We see multiple compressors in rack refrigeration circuits, but the concept isn’t as common […]
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This HVAC system we recently installed has been causing quite a bit of trouble for us with inspectors. If you look at the label, you will see that the breaker size is 25 amps, and the minimum circuit ampacity (MCA or wire size) is 29 amps. The MOCP (maximum overcurrent protection, max fuse, or max […]
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This tech tip about humidity control, particularly as it relates to VRF systems and others that use inverter technology, is a companion piece to a podcast episode with Roman Baugh. You can listen to that podcast episode HERE. Those of you who work in humid climates and install or repair ductless systems are probably well […]
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Every once in a while, especially on humid days, you’ll sit on an airplane waiting for takeoff and see fog pouring from the ceiling vents like a low-budget concert. Someone always panics and asks if something’s on fire. It’s not smoke—it’s condensation. You’re looking at thermodynamics and psychrometrics in action. So, why does it happen, […]
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Videos:
Podcasts:
In this short podcast episode from AHR Expo 2026, Bryan sits down with John Pastorello for a discussion about the latter's lifetime of HVAC/R. John was a chemist and an HVAC technician before founding Refrigeration Technologies in 1987, and he received the HVAC Tactical Lifetime Achievement Award in 2026. Prior to entering the trade, […]
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In this live episode from the AHR 2026 Podcast Pavilion, Bryan sits down with Copeland's Josh Souders (Manager of Commercial Unitary Product Management) and Jeff Kukert (Compression Senior Technical Trainer) to dive deep into Enhanced Vapor Injection (EVI) technology and its transformative impact on HVAC systems. This conversation offers both technical professionals and industry […]
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In this short podcast episode, Bryan breaks down the differences between a thermostatic expansion valve (TXV) and an electronic expansion valve (EEV). He highlights their strengths and weaknesses. In the basic refrigerant circuit, the metering device drops the pressure. TXVs and EEVs are both metering devices that cause the liquid refrigerant to drop in […]
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In this informative episode, host Bryan welcomes guest Bert for an in-depth discussion on the often-overlooked but critically important topic of electric heat in HVAC systems. The conversation takes listeners through both the common and uncommon issues that arise with electric heat installations, offering practical insights drawn from years of field experience. Bryan and […]
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In this informative episode, Bryan and Bert dive deep into gas appliance safety and combustion analysis from the unique perspective of Florida HVAC technicians. While they humorously acknowledge that Florida's mild winters mean they don't work on gas furnaces daily, they make a compelling case that this actually makes their training even more critical. […]
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In this short podcast episode, Bryan dives a bit into equipment sizing rules of thumb and why square footage does NOT equal tonnage in today's world. Many rules of thumb exist in the industry, and one is a load calculation rule stating that you can size the HVAC for a house at 500 square […]
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In this short podcast episode, Bryan covers the history of the great heating debate: furnaces vs. heat pumps or combustion vs. compression. He also gives a breakdown of each other's strengths and gives his two cents on the winner of the debate. Fire kept humans warm for much of history, but engineers developed a […]
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In this engaging episode of the HVAC School podcast, host Bryan Orr sits down with Leo and Paul Sharkey, a father-son duo of mechanical engineers who made the leap into the HVAC business. Leo and Paul share their remarkable journey of purchasing an HVAC company in September 2020 and quadrupling its revenue within five […]
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In this short podcast, Bryan answers a listener-submitted question and explains why heat pumps get a bit weird: when it comes to superheat in heat mode. He also explains how we can move heat from outdoors to indoors, even in temperatures below freezing (cold temperatures just have less heat, not zero heat). In order […]
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