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AHRI Performance Data vs. Manufacturer Expanded Performance Data (and When to Use Each)
Field Guide to Crankcase Heaters
What Makes a Thorough Comfort Consultation
Compressor Failure: Diagnosis and Replacement Checklist for Residential and Light Commercial Equipment
Scroll Compressors in a Changing Regulatory Landscape
Ducting Ventilating Dehumidifiers
Measuring RTU Curbs with Adapters in Place
Voltage Protection Devices
HVAC in Nuclear Emergencies
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:
Equipment selection may seem like a pretty straightforward process: look at the data plate, find the tonnage that’s close to your Manual J calculation’s total load, and you’re good to go, right? The problem with that approach is that a 3-ton unit won’t deliver 36,000 BTUs per hour like it says on the data tag. […]
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Crankcase heaters are a critical but often overlooked component in air conditioning and refrigeration systems. Their function is simple but vital: to prevent liquid refrigerant from migrating into the compressor crankcase during the off-cycle. A missing or failed crankcase heater is a leading cause of premature compressor failure. This guide covers why they're necessary, how […]
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This tech tip is based on an HVAC School podcast episode with Tim De Stasio. Tim has written several articles about HVAC design on his blog, several of which he has been generous enough to share with HVAC School. Tim’s focus is on humid climates, and moisture mitigation is one of his main focuses in […]
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Special thanks to Ty Branaman and Bert Testerman for their work and feedback on this tech tip about compressor failure diagnosis and replacement. A PDF checklist that covers all of the procedures in this tech tip can be found at http://www.hvacrschool.com/compressor-replacement-checklist. Important Note Before You Begin Industry data indicates that up to 30% of compressors […]
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This tech tip is based on an HVAC School podcast episode about scroll compressors and new refrigerants with Jeff Kukert and Tom Fesenmyer from Copeland. Jeff is the senior technical trainer, and Tom is the manager of technical services. You can listen to the original podcast HERE, and you can explore Copeland’s vast selection of […]
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This tech tip was written with the guidance of Nikki Krueger, the Director of Marketing & Business Development at Santa Fe Dehumidifiers. Nikki has been a longtime contributor to HVAC School as a recurring podcast guest and presenter at the HVACR Training Symposium. Most of the illustrations and instructions for ducting ventilating dehumidfiers came from […]
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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 […]
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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 […]
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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. […]
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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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