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Confirming Liquid Levels with a Little Thermodynamics
Léon Creux’s Scroll Design: From Initial Failure to an Enduring Legacy
Traditional & Desiccant Dehumidification and When to Use Each (or Both)
Discovering Mental Reference Points
Three Levels of Acid Testing
Dedicated Dehumidifier vs. Electric Reheat Dehumidification – Who Ya Got?
HH vs. EK Filter-Driers: Technical and Field Comparison
3 Ways to Reduce Compression Ratio in a Heat Pump
Best Practices to Conserve A2L Refrigerants in a Shortage
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:
Maintaining the correct vapor-liquid refrigerant balance is crucial for air conditioning and refrigeration system performance. Longer line sets hold more refrigerant, which increases the risk of liquid accumulating in the suction line or entering the compressor during off-cycles. Heat pumps are one common application that requires additional measures. Refrigerant flow reverses during heating, turning the […]
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The HVAC/R industry isn’t short on tragic figures. There’s John Gorrie, whose ice machine showed a lot of promise but didn’t have enough financial backing due to the lucrative ice industry and the death of his business partner. While Gorrie may have died without seeing his vision reach the masses, he was ahead of his […]
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This tech tip about traditional and desiccant dehumidification is based on a conversation with Nikki Krueger and David Schurk. Nikki is a longtime contributor to HVAC School and is a relatively frequent podcast guest and symposium speaker. David Schurk is the Director of Applied Engineering and National Sales Manager at Innovative Air Technologies. Nikki specializes […]
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Trying to wrap your head around HVAC can feel like a constant firehose of new info, right? Whether you're in class or on the job, there's just so much to soak up. And when you finally think you've got one thing down, BAM, here comes another concept. For me, remembering everything can be a real […]
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Anytime we have a compressor failure, we can’t just pull out the bad compressor and drop a new one in. We have to put our detective hats on and find the culprit so that it doesn’t happen again. In many cases, acid is a prime suspect. Whenever there’s acid in the system, the next compressor […]
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This dehumidification tech tip was written by Tim De Stasio. He originally published it on his website, which you can visit HERE. Thanks, Tim! In March of 2024, I set out to better understand the cost of ownership and return on investment for two dehumidification strategies: a dedicated dehumidifier versus using electric reheat dehumidification from […]
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When we think of HVAC system components, the big four come to mind: evaporator, compressor, condenser, and metering device. However, there are several accessories that keep the HVAC system working as intended, and the filter-drier is one we cannot ignore. Filter-driers protect HVAC/R systems by removing moisture, acids, and debris from refrigerant. In typical residential […]
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We’ve talked about compression ratio a lot over the years. Compression ratio is the number you get when you divide the absolute head pressure (PSIG + 14.7) by the absolute suction pressure (PSIG + 14.7). It measures the efficiency of a compressor, and lower numbers indicate that the compressor is moving more refrigerant while consuming […]
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If you own your HVAC company or are involved in management, you may have realized that our industry is currently facing a shortage of new A2L refrigerants, particularly R-454B and R-32. Our own company has faced limited availability and long lead times, mainly due to supply chain disruptions and the increased demand now that our […]
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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 […]
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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, […]
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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, […]
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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 […]
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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 […]
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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 […]
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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 […]
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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 […]
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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, […]
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