HVAC School - For Techs, By Techs

Some people light up when they find a difficult electrical problem. Others want a wrench in their hand or take real satisfaction in a beautifully planned installation. Those differences can shape how we learn, what frustrates us, and where we find satisfaction in HVAC work.
Bryan and Bert explore three overlapping tendencies in the trades: the technician, the mechanic, and the craftsman. In their framework, technicians gravitate toward diagnosing problems and understanding hidden causes. Mechanics engage with the physical work of repairing and assembling equipment. Craftsmen bring careful preparation, spatial planning, and pride in the finished result. Most people have some of each, and experience can build skills across all three.
The conversation also covers comfort with chaos and Bryan's distinction between moralizers, who feel a strong pull toward how things should be, and normalizers, who work readily with conditions as they are. Both approaches have strengths and blind spots, especially when a job needs a mix of planning, troubleshooting, and execution.
For owners, trainers, and field leaders, the practical question is how to recognize what energizes a person and give them opportunities to use it. Bryan and Bert discuss apprentice training, promotions that move people away from work they enjoy, and the value of building crews with complementary strengths. They close with mentorship and gratitude for the people whose abilities make our own work possible.
Key Takeaways
Observe apprentices across different tasks. Troubleshooting, assembling a training board, and hands-on installation can reveal different interests. Notice the questions people ask, the work they stay absorbed in, and the details they care about.

Separate ability from inclination. A person can develop a skill and still find that work draining. Talk about what brings energy and satisfaction before assuming the next promotion is the right fit.

Pay attention to frustration. Uncertainty, interrupted preparation, repetitive work, and physical challenges affect people differently. Use those patterns to start better conversations about training, support, and job assignments.

Build complementary teams. A crew benefits from people who can diagnose, people who readily tackle the physical work, and people who plan and execute careful details. Recognize the contribution each person makes.

Value mechanical skill alongside technical knowledge. Bryan makes the case that the willingness and ability to get physical work done deserve more recognition as information becomes easier to access.

Make room for mentorship. Experienced tradespeople can multiply their impact by helping others develop similar strengths, even as the physical demands of daily fieldwork become harder to sustain.

Chapters
00:00 — Three ways to thrive in the trades
10:10 — Chaos tolerance and work preferences
12:45 — Moralizers and normalizers
18:15 — What craftsmen care about
22:15 — Ability, energy, and burnout
24:00 — Recognizing strengths in apprentices
31:20 — The changing value of mechanical skills
39:35 — Building teams with complementary strengths
44:25 — Mentorship and a longer career in the trades
46:05 — Appreciating your strengths and your teammates
This episode contains embedded sponsor messages from Refrigeration Technologies, Carrier, NAVAC, Fieldpiece, and the 2027 AHR Expo.
Resources
HVAC School calculators
Submit a podcast question
Learn about the GRIT Foundation
Purchase your tickets or learn more about the 8th Annual HVACR Training Symposium at https://hvacrschool.com/symposium.

A liquid-line restriction should cause high subcooling, right? Not always. In this short episode of the HVAC School podcast, we look at why normal subcooling does not rule out a restriction and why one familiar diagnostic pattern cannot tell the whole story. 
Subcooling describes the refrigerant's temperature margin below saturation at a particular location. It does not directly measure how much refrigerant is stored in the condenser or prove that the metering device is receiving adequate liquid. A thermostatic expansion valve may compensate for a moderate restriction by opening farther, while a receiver can provide another place for liquid to collect. Incorrect charge, poor airflow, and other faults can also exist alongside a restriction.
The practical lesson is to follow the liquid all the way to the metering device. Pressure losses through tubing, filter-driers, valves, and vertical rises can affect liquid delivery even when the reading at the outdoor unit looks normal. Temperature differences across a filter-drier can be useful clues, but a pressure drop may be difficult to detect with temperature clamps while the refrigerant remains subcooled liquid. The episode also discusses flash-gas clues, sight glasses, and the importance of inspecting the actual refrigerant path before settling on a diagnosis.
The key takeaway is that normal subcooling at one measurement point does not clear the entire liquid line. Follow the refrigerant path and consider the equipment, valve response, receiver, and other operating evidence together.
Topics Covered
Why a liquid-line restriction can occur with normal subcooling
Subcooling as a temperature margin rather than a measure of stored refrigerant
How expansion-valve response can mask a moderate restriction
How receivers change refrigerant storage and the diagnostic picture
Why multiple faults can exist at the same time
Pressure losses between the condenser and the metering device
The limits of temperature checks across a filter-drier
Flash-gas clues, sight glasses, and liquid quality versus pressure
Avoiding kinks, excessive line-set rise, and overlooked filter-driers
This episode contains embedded sponsor messages from Refrigeration Technologies, Carrier, NAVAC, Filtrete, and the 2027 AHR Expo.
Resources
Liquid Line Temperature (video)
HVAC School calculators
Submit a podcast question
Learn about the GRIT Foundation
Purchase your tickets or learn more about the 8th Annual HVACR Training Symposium at https://hvacrschool.com/symposium.

In this episode from the 7th Annual HVACR Training Symposium, Alex Meaney delivers a live conference talk he calls "Airflow Serenity," built around the idea of knowing which duct problems are worth chasing and which changes will actually move the needle for a customer.
He opens by describing and reframing how technicians identify airflow problems, including the "complementary failure" situation where both the ductwork and the equipment are improperly sized. The way we communicate with homeowners plays a massive role in how well we can identify these problems. The time spent learning about a homeowner's comfort complaints is a sales tool in itself.
The middle of the talk is where the technical takeaways come in, including how to measure system airflow with anemometers, manometers with static pressure probes & a blower chart, and the TrueFlow Grid. The main engineering takeaway is that friction, not duct size alone, governs airflow, and that friction increases with the square of velocity — so relatively small increases in duct size or reductions in restriction along the path can produce outsized gains.
There are several practical, low-cost fixes technicians can make: pulling slack out of flex duct, adding return capacity, using proper transitions and radius fittings instead of abrupt ones, avoiding compound fittings, and making sure supply plenums have a proper end cap rather than dead-ending against a wall. These can be bundled into a system replacement.
This episode contains embedded sponsor messages from Refrigeration Technologies, Carrier, Copeland, Santa Fe Dehumidifiers, and TruTech Tools.
Resources
Mean HVAC Consulting & Design (Alex's website)
HVAC School calculators
Submit a podcast question
Learn about the GRIT Foundation
Purchase your tickets or learn more about the 8th Annual HVACR Training Symposium at https://hvacrschool.com/symposium.

In this short podcast episode, Bryan talks about compression ratio and compressors, particularly why you see more suction pressure when the compressor unloads and what that means for the HVAC system's operation.
When the compressor drops into low-stage or unloads, the suction pressure goes up. Regardless of the cause of reduced pumping, the head pressure will also drop as the suction pressure rises. If the conditions stay the same and the compressor stages down, the pumping capacity drops; the compressor moves less vapor while the evaporator still needs to absorb the same amount of heat. 
However, if the indoor airflow also drops along with the compressor stage, the load on the evaporator also changes and drops the suction pressure. Dynamic metering devices (such as TXVs and EEVs) also need to equalize and factor into the compression ratio.
We should understand the sequence before condemning a compressor and then use that sequence in diagnosis. To troubleshoot and test staging, we want to identify the equipment and sequence (including how the manufacturer wants us to test staging) and then record everything at each stage or at least a few different points. We want to see how the equipment responds, such as if one part does not respond when the compressor drops to a lower stage.
This episode contains embedded sponsor messages from Refrigeration Technologies, Carrier, NAVAC, TruTech Tools, and the 2027 AHR Expo.
Resources
Compression Ratio (video)
Why Compression Ratio Matters (tech tip)
HVAC School calculators
Submit a podcast question
Learn about the GRIT Foundation
Purchase your tickets or learn more about the 8th Annual HVACR Training Symposium at https://hvacrschool.com/symposium.

In this episode, Bryan welcomes back Louise Kellar of UEi Test Instruments for a deep dive into getting more out of a digital clamp meter than the basic volts, amps, and ohms most techs rely on every day. The tool in the spotlight is UEi's High Accuracy Clamp Meter (HAC), which is accurate when dealing with the low current draws common on modern condenser fan and blower motors and is critical for reliable wattage and capacitor-under-load testing. 
The podcast also walks through a series of lesser-used but valuable meter functions, including microamp measurement for flame rectification testing, diode testing for diagnosing boards on mini-splits, the Low Z setting for eliminating ghost voltage readings and safely bleeding capacitors, and the safety-locking temperature toggle that prevents technicians from accidentally crossing voltage and thermocouple leads.
Bryan and Louise also cover common mistakes, such as not knowing when to use continuity or resistance and auto-ranging mistakes, as well as some crucial takeaways about true RMS measurements, temperature settings, and CAT safety ratings.
This episode contains embedded sponsor messages from Refrigeration Technologies, Carrier, NAVAC, and Filtrete.
Resources
UEi products, manuals, and resources 
HVAC Multimeter Skills: Continuity vs. Resistance & Diode Testing (video)
CAT Ratings on Electrical Multimeters (tech tip)
HVAC School calculators
Submit a podcast question
Learn about the GRIT Foundation
Purchase your tickets or learn more about the 8th Annual HVACR Training Symposium at https://hvacrschool.com/symposium.