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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
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
The Hidden Cost of Killing Radiant Load – Short #260
Balance Point Explained w/ Jim Fultz
Dehumidify with a Waterfall? – Short #259
What are User Requirements? w/ ELK
Static Pressure is like Blood Pressure – Short #258
How To Be a REAL Comfort Consultant
Non-bleed TXVs and Hard Starts – Short #257
Scroll Compressors & New Refrigerants w/ Copeland
Leaky Ducts = Sweaty Houses – Short #256
#hvac
Tech Tips:
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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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. 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 returned under warranty […]
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This tech tip is based on an HVAC School podcast episode 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 compressors and resources for low-GWP refrigeration […]
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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 came from Santa Fe's Ultra V […]
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Videos:
Podcasts:
In this short podcast, Bryan talks about the hidden cost of killing radiant load, especially when it comes to installing radiant barriers in attics. We sometimes get service calls about ducts sweating when they never used to sweat. If there are no problems with the system (i.e., the refrigerant charge, static pressure, airflow, supply […]
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This comprehensive episode dives deep into one of the most critical yet misunderstood concepts in HVAC: balance point calculations for heat pump systems. Jim and Bryan break down the complexities of dual fuel systems, explaining why proper sizing and balance point calculations are essential for both comfort and efficiency. The discussion moves beyond basic […]
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In this short podcast episode, Bryan talks about history and HVAC science: how to dehumidify the air with a waterfall and how cold water became the first air conditioner. In 1902, Willis Carrier worked for a printing company in Brooklyn, New York. There was a huge humidity problem during the summer: the printing plant […]
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In this comprehensive session, Eric Kaiser walks through the critical importance of establishing proper user requirements before making equipment purchases. Drawing from real-world experiences in the HVAC industry, he demonstrates how poor upfront planning leads to costly mistakes, buyer's remorse, and multiple equipment purchases. The discussion covers everything from selecting simple tools like screwdrivers […]
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In this short podcast episode, Bryan explains the science behind a common HVAC simile: static pressure is like blood pressure. He covers the similarities and differences between measuring static pressure during a service call or maintenance and a doctor measuring your blood pressure at a checkup. Total external static pressure (TESP) should be measured […]
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In this comprehensive episode, Bryan Orr sits down with Tim De Stasio to explore the world of comfort consulting and performance contracting in HVAC. Tim, who sold his contracting company to focus on this specialized field, shares his methodical approach to diagnosing home performance issues that go far beyond traditional HVAC troubleshooting. Working primarily […]
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In this short podcast episode, Bryan talks about non-bleed TXVs and whether they need hard starts. A non-bleed (hard shutoff) TXV is a metering device that shuts off during the off cycle; it closes shut when there is no superheat. This strategy prevents refrigerant migration, especially in cases where we have long line sets. […]
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In this essential episode, Bryan sits down with Jeff and Tom from Copeland to dive deep into the world of scroll compressors and the critical topic of refrigerant compatibility. As the HVAC industry navigates new refrigerant standards and regulations, understanding how compressors are specifically designed and optimized for different refrigerants has never been more […]
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In this short podcast episode, Bryan explains how leaky ducts can lead to sweaty, uncomfortable houses. Moisture issues are common all across humid and “green-grass” climates in the United States. Hot, unconditioned attics and crawl spaces also often have high dew points, which can cause moisture problems in those spaces. Plants also release moisture, […]
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