HVAC School - For Techs, By Techs

In this short podcast from the Bry-X stage of the 7th Annual HVAC/R Training Symposium, Ty Branaman and Leilani Orr talk about how to teach kids the trades. They share lessons they've learned from the GRIT Foundation and over their careers as trades and home educators. Their approaches have evolved over the years, and GRIT has also evolved quite a bit from its beginnings.
Leilani and Ty have found that the Socratic method is great for getting students to think critically; instead of spoon-feeding answers, teachers ask the students "why" and "how" questions. In GRIT Camps, mentors are there to keep students safe and guide them when needed, but mentors ultimately let students make mistakes and figure things out on their own. Students often make leaky joints when they braze for the first time, but it's their first time holding torches and most of the tools used at GRIT Camp.
Making mistakes is crucial to the learning process. The mistakes we (and the students) make with our own hands also stick with us more than being told how to do a task the right way. Then, when students struggle, we can ask if they want to know a shortcut; they give their mentors permission to show them the right way. This method builds curiosity, and it allows students to get excited about a career in the trades or realize that the trades aren't for them but still walk away with hands-on skills and a newfound respect for the trades.
Many tradespeople take the trade skills they learned as children for granted, as many children nowadays don't develop the same hands-on skills. The GRIT Foundation has a course that teaches mentors to teach students those hands-on skills that already seem like second nature to them. Even so, the course is just a guide, not something that needs to be followed to the letter. Many of the concepts taught in the guide and that mentors use at GRIT Camp also apply to apprentices.
 
Learn more about the GRIT Foundation at https://www.thegritfoundation.com/.
Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool.
Purchase your tickets or learn more about the 7th Annual HVACR Training Symposium at https://hvacrschool.com/symposium.
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In this episode, Brad Cooper — second-generation HVAC technician, educator at Arkansas State University-Beebe (ASUBB), and CMHE-certified professional with HVAC Excellence — breaks down geothermal systems for everyday HVAC technicians. Brad brings a grounded, no-hype perspective to a technology that has long intimidated many in the trade. His central message is simple: if you already understand heat pumps and air conditioning, you already have most of the knowledge you need to service geothermal units. The only real difference, as Brad explains, is swapping air for water, a fan for a pump, and a condenser for two heat exchangers.
Brad opens with a compelling real-world story: a customer with two malfunctioning geothermal units called a company for help, but because the technicians were unfamiliar with geothermal systems, they replaced both units with air-to-air equipment — costing the customer $25,000 and stripping them of the significant efficiency benefits geothermal provides. This kind of outcome is exactly what Brad wants to prevent. He urges technicians not to shy away from geothermal work the way past generations were told to avoid flex duct or mobile homes, but instead to approach these systems with the same confidence and diagnostic mindset they bring to any HVAC call.
A major portion of the episode is devoted to practical diagnostics — specifically, how to use a pressure probe and a temperature probe on the water side to calculate GPM flow, BTU output, and system efficiency using a straightforward chart. Brad walks listeners through the math: a gallon of water weighs 8.34 pounds, multiplied by flow rate and delta T, gives you a reliable BTU reading — all without expensive equipment. He also covers the flush cart, the one specialized tool you'll eventually need for water-side work, and explains that most geothermal calls don't require it at all — the majority of failures are standard heat pump issues like bad capacitors, clogged drain lines, or faulty thermostats.
Brad closes with an encouraging, community-minded message: you don't need to go it alone. He encourages technicians to build a network of mentors — someone like a "Paul and a Barnabas" — who can guide them through unfamiliar territory in the field. He also highlights key industry resources, including IGSHPA (International Ground Source Heat Pump Association) for training and certification, GeoFlow for parts and materials, and his brother's company, EDGE Geo Supply, for tools and field training. Brad himself offers his personal phone number and email for anyone with questions, reinforcing that the geothermal community is accessible and willing to help.
Topics Covered
•       Brad's background as a second-generation HVAC tech and his role at ASUBB and HVAC School
•       Why geothermal systems intimidate technicians — and why they shouldn't
•       The core analogy: air-to-air vs. geothermal (air → water, fan → pump, condenser → two heat exchangers)
•       A $25,000 cautionary tale: replacing working geo units out of fear and unfamiliarity
•       Geothermal efficiency: constant EER ratings vs. seasonal SEER ratings and why seasons don't affect geo performance
•       BTU fundamentals: what a BTU is and how to calculate BTU output on the water side
•       Tonnage review: 1 ton = 12,000 BTUs per hour, melting a ton of ice in 24 hours
•       Water weight and flow math: 8.34 lbs/gallon, calculating GPM and BTUs with delta T
•       Using a two-probe setup (pressure + temperature) and a field chart to diagnose water-side performance
•       The flush cart: what it is, when you need it, and why most jobs won't require it
•       Common heat pump-side failures in geo units: capacitors, low-pressure switches, evaporator coils, bad thermostats
•       Common water-side failures: bad pump, low water, dirty water, frozen loop field
•       How antifreeze/glycol affects heating load and BTU output — and when to add it
•       Responding to frozen loop fields during extreme cold events (ice storms in Arkansas and Texas)
•       Humidity control advantages of geothermal in high-humidity climates vs. high-efficiency air-to-air units
•       Selecting the right system: geo isn't for every home or every situation
•       Open-loop options: pulling water from lakes or rivers and utility company incentives
•       Closed-loop installation considerations: drilling costs, lot size, and buried line depths
•       Building a mentor network for field support (the "Paul and Barnabas" principle)
•       Industry resources: IGSHPA for training and certification, GeoFlow, and Edge Geo Supply
 
Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool.
Purchase your tickets or learn more about the 7th Annual HVACR Training Symposium at https://hvacrschool.com/symposium.
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Subscribe to our YouTube channel.
Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android.

In this short podcast, Ruchir Shah and Dan Riggs from SkillCat talk about how to make online training that does not suck! They talk about how to develop training that is relevant to the trades and can be applied in real-world trade work.
The skill gap is widening in the trades, especially as shortages grow when people retire and it becomes more difficult to hire qualified new people. Hiring apprentices with little experience also has costs associated with it, and SkillCat aims to address the training reasons for the skill gap and provide the needed accreditation for trades like HVAC (including EPA 608). After receiving feedback that the curriculum was too theoretical and could do better in the applied learning areas, the SkillCat team has been revamping the training program with a skill map. 
Now, there are partnerships with trade educators, more interactive videos, and interactive virtual activities to create a more relevant learning experience. There are now kits that SkillCat ships out to trainees, and assignments have offline proctors who verify all submitted materials and online activities to ensure that the trainees' submissions align with real field conditions and expectations. The goal is to have trainees who enter the field and can be fully functional helpers with a basic tool kit and enough working field knowledge to identify system components and perform basic tasks, bringing value to employers from day one. SkillCat is going to be piloting a new training program with a mentorship component as well.
 
Learn more about SkillCat at https://www.skillcatapp.com/ and the GRIT Foundation at https://www.thegritfoundation.com/. 
Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool.
Purchase your tickets or learn more about the 7th Annual HVACR Training Symposium at https://hvacrschool.com/symposium.
Subscribe to our podcast on your iPhone or Android.
Subscribe to our YouTube channel.
Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android.

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 temperatures drop below freezing.
A central revelation of the episode is Eric's explanation that modern electronic vacuum (micron) gauges do not actually measure pressure directly — they measure heat transfer and translate it into a pressure reading. Because these gauges are calibrated to nitrogen or air, the presence of refrigerant vapor in a system (which has roughly three times the heat conductivity of nitrogen) can cause the gauge to display a falsely high reading. This means a technician could believe the system still has poor vacuum when it may actually be further along than indicated — or, more concerning, that a system appears to have passed vacuum when contamination is still present. The team acknowledges that controlled experiments are needed to quantify exactly how much refrigerant affects the reading, and they commit to designing those tests.
The conversation then pivots into the physics of water at the triple point — the precise pressure (4,580 microns) and temperature (32°F) at which water can exist simultaneously as solid, liquid, and vapor. Eric walks the audience through a phase diagram built from International Association for the Properties of Water and Steam data, explaining that once pressure drops below the triple point, liquid water no longer exists. Any moisture in the system either sublimes directly from solid ice to vapor or remains frozen. This has major practical implications: a system with ice inside can still pull down to a very deep vacuum, but will not pass a decay test until that ice is fully sublimated — which requires both sufficient vacuum depth and available heat energy. The colder the ambient environment, the deeper the vacuum must go to create the temperature differential needed to drive sublimation.
The episode wraps with an illuminating discussion on refrigerant oils — specifically the differences between POE (polyolester) and PVE (polyvinyl ether) oils and how each interacts with moisture in fundamentally different ways. POE chemically bonds with water through hydrolysis, breaking down into acid and alcohol and permanently degrading the oil. PVE, on the other hand, physically traps moisture through surface tension and can hold up to twice as much water as POE, but remains chemically stable. This distinction affects vacuum strategy, dryer sizing, and long-term system reliability — particularly in VRF and cold-climate heat pump systems where compressor oil management is far more complex.
Topics Covered
Core vacuum best practices refresher: large hoses, removing valve cores, skipping the manifold, using clean pump oil, micron gauge placement, and decay testing
Why micron gauges measure heat transfer — not pressure — and how refrigerant vapor causes false-high readings on the gauge
The impact of refrigerant retained in compressor oil on vacuum accuracy and the potential role of nitrogen sweeps in displacing refrigerant molecules
Triple point science: what happens to moisture when pressure drops below 4,580 microns and why liquid water no longer exists below that threshold
How ice inside a system can allow a deep vacuum pull-down while still failing a decay test, and what that means for cold-climate HVAC work
The role of heat during evacuation: why adding heat accelerates moisture removal and how deep vacuum increases temperature differential to drive sublimation
Cold-climate challenges: vacuum pump limitations, micron gauge accuracy at low temperatures, and the physics of dry air in freezing environments
Triple evacuation and nitrogen purging: whether nitrogen disrupts oil pockets, displaces refrigerant, or both — and why the team wants to test it
Nitrogen tank quality concerns: the possibility that low-grade nitrogen could introduce moisture and whether an inline dryer would help
Using system flush chemicals: why Ty cautions against flushing agents and the risks of adding additional chemicals that break down oil
POE vs. PVE oil chemistry: how POE undergoes hydrolysis when exposed to moisture (creating acid) versus how PVE physically traps water without chemical breakdown
Dryer strategy for large commercial systems, VRF, and VRV: filter dryer sizing, core pulls, oil sampling, and why an "oil dialysis machine" would be a game-changer
Plans for future controlled experiments: testing refrigerant effects on micron gauges, ice behavior at various temperatures, and vacuum performance in cold climates
Industry influence over time: how community-driven knowledge sharing has already shifted vacuum and refrigerant practices over the past decade
Whether you're a residential technician looking to sharpen the fundamentals or a commercial refrigeration specialist wrestling with VRF oil contamination, this episode delivers both practical takeaways and a front-row seat to the scientific inquiry that drives best practices forward. As Bryan puts it: "Don't wait for us — if you want to do the experiment, be part of the conversation."
 
Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool.
Purchase your tickets or learn more about the 7th Annual HVACR Training Symposium at https://hvacrschool.com/symposium.
Subscribe to our podcast on your iPhone or Android.
Subscribe to our YouTube channel.
Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android.

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 surge protectors CANNOT protect against). Nearby lightning strikes and high voltage from the utility company (especially after undervoltage) are common causes of surges. Everyone in the country has risks of power surges, but some areas are exceptionally high-risk, whether due to utility causes or climate (lightning storms).
Degradation is the invisible damage that occurs over time with repeated surges. Destruction can be associated with a specific event, like a direct lightning strike or a blown transformer. Surge protection helps with both; when a surge comes through, the surge protector directs the surge to ground instead of your HVAC equipment. DITEK uses thermally protected MOVs (TPMOVs) to redirect the surge; TPMOVs react to surges and change from a low-impedance state to a high-impedance state, effectively pointing the surges to ground, and only a clamped voltage makes it to the HVAC equipment. However, surge protectors will degrade with each event; DITEK's surge protectors have LEDs indicating their health.
NEC 2020 requires surge protection on all dwellings, so many homeowners have whole-home surge protection already installed. Surge protection on the HVAC unit can still be added as an extra layer, which provides better protection for the HVAC system specifically. HVAC surge protection works at the condenser.
DITEK's KoolGuard2 (KG2) is a voltage monitor that works on single-phase equipment under 40 continuous amps. It cuts power if the power exceeds or dips too far below the typical voltage, and then it restores power after three minutes. It also does not require programming, but it has a few best practices, such as reducing lead length to improve the clamping voltage and keeping protected and unprotected wires in separate conduits. Ground must also be within code have low enough impedance to redirect the surges effectively; the resistance can only be measured properly with a megohmmeter or clamp meter. DITEK also has three-phase surge protection for commercial equipment and has options for BAS systems.
 
Learn more about DITEK's products and DITEK University at https://www.diteksurgeprotection.com/. 
Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool.
Purchase your tickets or learn more about the 7th Annual HVACR Training Symposium at https://hvacrschool.com/symposium.
Subscribe to our podcast on your iPhone or Android.
Subscribe to our YouTube channel.
Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android.