Vapor Diffusion Ports, Hygric Buoyancy, and Fruit - Short #277
HVAC School - For Techs, By Techs
Release Date: 02/03/2026
The Vacuum Deep Dive: Microns, Moisture, and Molecular Science
HVAC School - For Techs, By Techs
In this action-packed live stream episode of HVAC School, host Bryan is joined by Eric Kaiser, Ty Branaman, and Roman Baugh for a continuation of a deep-dive conversation on vacuum practices — picking up where a previous episode left off with Andrew Greaves and Jim Bergmann. The team sets out to both reinforce the foundational best practices every HVAC technician should follow and to explore some genuinely uncharted scientific territory around how vacuum gauges actually work, how refrigerant contaminates micron gauge readings, and what really happens to moisture inside a system when...
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Surge Protection for HVAC - Short #285
HVAC School - For Techs, By Techs
This short podcast is from the Bry-X stage of the 7th Annual HVACR Training Symposium: Cheryl Klein's "Surge Protection for HVAC." Cheryl is with DITEK, a veteran-owned company based in Florida, and has extensive knowledge of whole-home surge protection and HVAC-specific surge protectors. HVAC systems may have their lifespans reduced by power surges (tens of thousands of volts within microseconds) or sustained overvoltage. Surge protectors specifically protect the equipment from power surges, though DITEK manufactures products that help manage sustained overvoltage (and undervoltage, which...
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20 Years in Family Business from the Kalos Founders
HVAC School - For Techs, By Techs
In this special live panel session recorded at the 7th Annual HVAC/R Training Symposium, the three founders of Kalos Services — Bryan Orr, his father Robert (Bob) Orr, and uncle Keith Huntington — sit down together to celebrate the company's 20th anniversary and answer questions from the audience and online attendees. Hosted by Bert, the conversation blends humor, hard-earned wisdom, and surprising candor about what it actually takes to build and sustain a trades business over two decades. From humble beginnings with $100,000 in startup capital to managing multi-million-dollar commercial...
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Permanent Load Reduction As a Sales Driver - Short #284
HVAC School - For Techs, By Techs
This short podcast episode is Jeremy Begley's Bry-X session from the 7th Annual HVACR Training Symposium: "Permanent Load Reduction in HVAC – The Hidden Driver of Long-Term Sales." Some common customer complaints we hear as HVAC contractors include high humidity, high electric bills, noise, and uncomfortable rooms. The typical HVAC solution is to change the equipment or ductwork, such as by downsizing the unit, adding ancillary dehumidification, or modifying the ductwork. If we can't solve the problem, the customer will ultimately choose a different contractor, no matter how hard we...
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Cold Climate Evacuation Livestream - Pandora's Box
HVAC School - For Techs, By Techs
In this long-awaited live episode of HVAC School, host Bryan Orr reunites with three industry veterans — Jim Bergmann of measureQuick, Roman Baugh (Kalos), and Andrew Greaves of NAVAC — to tackle one of the most pressing and underaddressed challenges in modern HVAC: performing refrigerant recovery and system evacuation in extreme cold-weather conditions. The conversation was sparked by a real-world observation from technician Chris Hughes, who relocated from Louisiana to Minnesota and quickly discovered just how different — and difficult — cold-climate HVAC work can be. What follows is...
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Training Refrigeration: Building Technicians Who Think, Not Just Fix - Short #283
HVAC School - For Techs, By Techs
Training the refrigeration technician is about building technicians who think, not just fix. In this engaging conversation from the 7th Annual HVAC/R Training Symposium, host Trevor Matthews sits down with Billy Carlson to explore what it really takes to develop technicians who think critically and troubleshoot effectively. Billy shares his journey in the HVAC/R industry, from residential air conditioning to commercial refrigeration, and ultimately specializing in supermarket rack systems and CO2 refrigeration. With only five years in the grocery sector, his company now dedicates 70-80% of its...
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Succession in Family Business w/ TruTech & Kalos
HVAC School - For Techs, By Techs
In this special collaborative episode between the Building HVAC Science Podcast and HVAC School, host Bryan Orr sits down with his father and co-founder Robert Orr (Kalos) and Bill and Billy Spohn, the father-son duo behind TruTech Tools, for an in-depth conversation about the realities of running, transitioning, and ultimately passing the torch in a family-owned business. What makes this episode particularly compelling is that both pairs are actively living through their own succession journeys in real time, offering listeners an unusually candid and personal look at the emotional,...
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Adding Plumbing To Your HVAC Business - Short #282
HVAC School - For Techs, By Techs
Looking to Add Plumbing To Your HVAC Business? Learn the critical pitfalls to avoid before you make the leap! In this livestream from the 7th Annual HVAC/R Training Symposium, service plumber and third-generation tradesman Nate Agentis breaks down why adding plumbing to your HVAC business isn't as simple as hiring a plumber and stocking PVC on your trucks. What You'll Learn: Why most HVAC companies fail when adding plumbing services The hidden costs beyond just hiring plumbers Marketing challenges specific to emergency plumbing How to structure your plumbing division for success The...
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Troubleshooting Tips and Tricks w/ Let's Be Techs
HVAC School - For Techs, By Techs
In this episode of the HVAC School Podcast, host Bryan sits down with Johnny, the creator behind the popular social media channel “Let’s Be Techs.” Johnny brings a wealth of hands-on experience to the table, having spent his first 13 years in residential HVAC before transitioning into commercial refrigeration. He shares his unconventional path into the trade—starting out building houses before being recommended to an HVAC contractor—and how the lack of quality mentorship early in his career motivated him to create educational content for technicians. His videos, which began as a fun...
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Heat In....Heat Out: All About Heat Transfer w/ Joe Joe The HVAC Man - Short #281
HVAC School - For Techs, By Techs
Join Joey Henderson LIVE from the 7th Annual HVAC/R Training Symposium in Florida! This essential training breaks down the science of heat transfer into practical field techniques every technician needs. What You'll Learn: Understanding sensible heat (dry bulb) vs latent heat (wet bulb) removal Why airflow matters Heat transfer diagnostics BEFORE pulling out gauges Gas furnace temperature rise troubleshooting How all about heat relates to cooling, heating, and refrigeration Inverter/cold climate heat pump heat transfer principles Target saturated temperatures Key Takeaways: Industry...
info_outlineIn this short podcast episode, Bryan talks about some building science concepts, including vapor diffusion ports, hygric buoyancy, and... fruit packaging?
Much of building science wisdom over the past couple of decades has dealt with air sealing (just seal it tighter!). However, building tightness has a darker side: more difficulty drying. When buildings can't dry, moisture accumulates and leads to rot.
Air leaks and vapor diffusion are NOT the same thing. Vapor diffusion refers to water vapor diffusing through surfaces into the home (through the materials of walls, floors, etc.). Air moves much more water than vapor diffusion, so air leaks are a bigger problem in terms of moisture. Therefore, air barriers matter more than vapor barriers... until the air barrier battle has been won.
Hygric buoyancy refers to moist air's lower density than dry air, so wet air rises toward the attic (and then the attic peaks). While sealed attics are excellent, moisture can accumulate at the roof deck, especially when the roofing cools at night. The condensation is worsened by using open-cell foam, as open-cell foam is air-closed but vapor-open (whereas closed-cell foam is air-closed AND vapor-closed). Drying isn't needed if you can KEEP the moisture out of closed-cell foam. Open-cell foam requires a place for vapor to go.
Vapor diffusion ports are airtight, controlled vapor-open outlets at the highest points of sealed attics. A cap protects them from bulk water, and they consist of a membrane that blocks air but allows vapor to exit. Unlike a ridge vent, ventilation is not the goal of a vapor diffusion port; it is drying by diffusion rather than airflow and acts as a controlled pressure-relief valve for moisture. Vapor diffusion ports have been proven to be effective at drying and preventing roof rot in humid climates (but NOT ALL climates). They do not work against bulk water intrusion, in cold climates, or when used as vents. Vapor diffusion ports work like fruit packaging, which is designed to let oxygen in and CO2 out, while controlling moisture and slowing decay.
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