HVAC School - For Techs, By Techs

In this live-stream episode, Bryan is joined by Tim DeStasio, John Semmelhack, and Ty Branaman for a deep dive into residential ventilation — the often-overlooked "V" in HVAC. The group opens with quick life updates before launching into a wide-ranging conversation covering the three core ventilation strategies (circulation, extraction, and dilution), how tight home construction changes the ventilation equation, and why there is no single "magic number" that works for every house.
A major theme is the physics of pressurization and depressurization. Tim walks through balanced strategies (ERVs and HRVs), positive-pressure approaches using ventilating dehumidifiers, and exhaust-only setups — explaining why exhaust-only, while still code-compliant, is his least favorite option due to the risk of pulling air from crawl spaces, attics, or combustion appliances. Using REDCalc, Tim demonstrates how even modest airflow can swing a tight house's pressure by ten or more pascals, and the group discusses how wind, stack effect, and seasonal conditions constantly change a home's natural air exchange rate.
Ty brings a service-focused perspective, emphasizing measurement before intervention — checking CO2, carbon monoxide, and other indicators before jumping to solutions like bigger fans or added dehumidification. He shares real-world stories, including a rental home with elevated CO from an unvented gas range, and stresses that building science problems (duct leakage, poorly placed bath fans, depressurized combustion appliances) often hide behind symptoms that look like simple ventilation shortfalls. Large kitchen range hoods get particular attention: hoods moving 1,200 CFM or more can seriously depressurize a house, and the group discusses code thresholds for interlocked and powered makeup air, along with practical products like the Fantech MUAS.
John rounds out the discussion with a walkthrough of a real high-performance home design, showing how an ERV can serve both whole-house outside air and continuous bathroom exhaust, how MERV 16 pre-filtration has become a common upgrade since the 2021—2022 wildfire smoke events, and how an ERV can be configured to boost into a makeup-air role when a range hood kicks on. The episode closes with a look at ventilating dehumidifiers, demand-controlled ventilation, the tradeoffs of leaving blower fans in the "on" position, and recommended resources for anyone wanting to go deeper into building science.
Topics Covered
The three ventilation strategies: circulation, extraction, and dilution
How tight, high-performance construction drives the need for mechanical ventilation
Calculating and understanding natural air exchange rates
Balanced (ERV/HRV), positive-pressure, and exhaust-only ventilation strategies
Using REDCalc to model pressurization and depressurization
Why exhaust-only ventilation can create combustion safety risks
Designing ventilation with flexibility beyond code-minimum rates
Measuring first: CO2, CO, and pollutant levels before choosing a solution
Large range hoods, makeup air requirements, and the Fantech MUAS system
Passive capture and range hood geometry (corner hoods vs. center islands)
A real-world high-performance home ERV design walkthrough
MERV 16 pre-filtration for outside air following regional wildfire smoke events
Using an ERV in a makeup-air configuration for range hood operation
Ventilating dehumidifier strategy and sizing considerations
Demand-controlled ventilation and the new ASHRAE 62.2-2025 guidance
Risks of leaving blower fans in the "on" position, including duct leakage effects
Recommended building science resources: Joseph Lstiburek, Allison Bailes, and TEC classes
 
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 8th Annual HVACR Training Symposium at https://hvacrschool.com/symposium.
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In this short podcast episode, Bryan covers the points to consider when selecting a replacement motor, particularly blower motors and condensing fan motors in residential and light commercial applications. 
Horsepower and amperage both matter for matching, but they are not the only items to consider. We also have to consider phase (three-phase vs. single-phase), voltage, and RPM; those must match exactly (barring VFDs and ECMs with variable RPMs). Frame size, shaft size, mounting, rotation, capacitor (for PSC motors), bearing type, temperature rating, enclosure (or Air Over Motor rating), and operation all matter. The failed motor is also NOT the only source of information; if it is an aftermarket motor, it might not have the correct information, so you are better off using an OEM motor or checking the manufacturer's data.
Single-phase motors are common for residential condensing fan motors and will need a run capacitor. Three-phase motors tend to be more common in commercial settings, and these will not have a run capacitor. Voltages must be appropriate for the application, and if the RPM is fixed, it must match the same general range because it represents the motor speed and is based on the number of poles. However, RPM may be variable in several applications.
Horsepower is the mechanical output rating (ability to do work); we CANNOT use a replacement motor with less horsepower than the OEM motor (and be careful with fractions; 1/3 is greater than 1/4). Amperage is NOT horsepower; amps are electrical input current. We want the amp rating to be close to the original motor, but it won't always match, particularly in the case of ECMs. If it doesn't match, we want to know why that is; if it's an ECM, then it's likely not a problem because ECMs can do the same work as a PSC with fewer watts. Power factor indicates motor efficiency for PSC motors, but the rules aren't quite the same for ECMs, which will have a much lower power factor (or lower wattages with higher amperages). However, if the amperage is off because we have the wrong motor, then that is a problem.  
The physical aspects matter for fitting the motor properly and delivering the right airflow. Rotation should match (though most universal motors can run in either direction). Airflow is especially important for blower motors, so factory replacements or ECM replacements are the way to go in those cases (it's also good to confirm airflow with a TrueFlow grid and by checking static pressure). The speed taps also need to be correct. Noise is also a factor; ball bearing motors tend to be louder than sleeve bearing motors. Temperature ratings also matter because heat can significantly reduce the lifespan of motors, and we need motors that can handle the operating conditions. 
 
Here is the podcast episode about ECM blower amps and watts with Steve Rogers: https://www.hvacrschool.com/podcasts/what-is-up-with-blower-amps-watts-w-steve-rogers/ 
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 8th Annual HVACR Training Symposium at https://hvacrschool.com/symposium.
Subscribe to our podcast on your iPhone or Android.
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In this episode, Bryan welcomes back Trevor Matthews from Refrigeration Mentor for a conversation focused entirely on nailing a job interview in the HVAC and refrigeration trades — whether it's a technician's very first shot at breaking into the industry or an experienced tech looking to move to a new company or specialty. Trevor opens up about his own rocky start, admitting he cycled through roughly 25 different jobs before landing in refrigeration and that he struggled with confidence in early interviews because he assumed he needed a deep resume of experience. What actually got him hired, he says, was being coachable: showing up willing to learn and do what was asked, even if that meant starting by sweeping floors.
For technicians just entering the trade, Bryan and Trevor lay out a practical playbook. Research the company before reaching out — knowing what services they offer, how long they've been in business, and what type of work they do builds instant trust. Cast a wide net rather than sending out only a handful of applications, and don't get discouraged by rejection; both hosts stress "pleasant persistence" as the key to standing out, following up warmly without becoming a nuisance. Trevor shares a story about motivational speaker Les Brown showing up at a radio station day after day until he finally got a chance, as a reminder that repeated, respectful effort pays off. They also recommend creative approaches like recording a video resume tailored to a specific company, and getting ahead on certifications such as EPA 608, confined space, first aid, or defensive driving before ever applying, since these small credentials can make a hiring manager's decision much easier.
The conversation then shifts to technicians pursuing their next opportunity rather than their first. Bryan explains that many larger companies route candidates through HR before they ever speak with a service manager, and that each conversation requires a different tone: HR wants to hear about safety, a clean driving record, and reliability, while a service manager wants to know how you'll bring value to customers and the team. Both agree that driving records have become a surprisingly major factor in hiring, given how much liability and cost a company takes on with every vehicle on the road. They also encourage candidates to ask people already working at a company for an internal referral, since a warm introduction dramatically increases the odds of getting hired, and many companies even offer referral bonuses that make current employees eager to help.
Finally, Trevor and Bryan get tactical about interview performance itself. They recommend using AI tools to generate likely HR and technical interview questions, then practicing out loud with a spouse or friend to shake off the "rust" of not having interviewed in years. Confident humility comes up repeatedly: it's far better to admit "I don't know that term" than to bluff, and to speak with genuine curiosity about the trade rather than reciting a list of accomplishments. Trevor illustrates how a candidate can talk through a hypothetical service call step by step to demonstrate real troubleshooting knowledge, even without hands-on experience in that specific niche. The pair close by touching on soft skills like conflict resolution and building good relationships with dispatch, and Trevor shares where listeners can connect with the Refrigeration Mentor community for more training and support.
Topics Covered
Why Trevor initially struggled with confidence in early job interviews
Researching a company before applying or interviewing
Casting a wide net and using "pleasant persistence" instead of giving up after a few no's
Standing out with a tailored video resume
Getting certifications early: EPA 608, confined space, first aid, defensive driving
Why driving records and vehicle safety matter so much to HVAC/R employers
The difference between talking to HR versus a service manager
Asking a current employee for an internal referral
Avoiding negativity about past employers during interviews
Using AI to prepare likely interview questions, then practicing with a real person
Confident humility: admitting what you don't know instead of bluffing
Demonstrating resourcefulness through podcasts, courses, and industry resources
Talking through a hypothetical service call to show troubleshooting ability
Soft skills, conflict resolution, and building relationships with dispatch
Trevor's own story of landing his first refrigeration job in Australia
Where to connect with Trevor and the Refrigeration Mentor community
 
Learn more about all the great resources Trevor offers through Refrigeration Mentor at https://refrigerationmentor.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 8th 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 episode is Tyler Nelson's Bry-X presentation from the 7th Annual HVACR Training Symposium: Digital Tools and AI - "So Happy Together." Tyler is the Business Development Manager and Global Trainer at Sauermann Americas.
Artificial intelligence (AI) is measured data, not an authority, and it will not replace techs. It may enhance technicians' abilities but must be used responsibly. AI operates on clear logic and supplies pattern recognition, what-if analysis, and decision support (but NOT decision ownership). The technician ultimately owns decision authority and technical judgment, but AI helps save time. Modern AI reinforces best practices, flags inconsistencies, and cross-references industry data, meaning it amplifies experience rather than replacing it.
HVAC technicians' work depends on codes and standards, physics, and diagnostic cause and effect, which all have repeatable workflows; AI provides instant analysis and verification in those key areas. We already have a wealth of data from our tools and manufacturers' literature, and AI connects those to help us make decisions; technicians fear being incorrect or missing diagnostic factors, and AI can help us assimilate data by connecting data sources and ensuring that all angles are covered. It closes interpretation gaps and gives us the framework to make constructive decisions.
measureQuick is an example of a diagnostic app that integrates AI in its workflows; it is leading the way in terms of digital tools and AI integration, and it gives technicians a lot of power in the field. Apps that use AI with digital tools help us navigate the industry as equipment becomes more complex, and they save time by making your work faster and more accurate. These tools come at a cost, but those costs can be spread across flat diagnostic fees and service agreements. Feeding readings from these apps into AI can also help you understand gaps in your own thinking and understand the relationships between the tools' readings and the field reality. AI can also take the data and provide technicians with scripts that are easy for customers to understand.
If you give AI specific prompts and data, including images, equipment data, tool data, and commands to include or exclude certain sources (such as excluding crowdsourced information), you can learn a lot about the system in front of you. It can also help you interpret images or videos. These functions of the tool can help us question our own assumptions, expand our understanding of field problems, and vet our decisions.
 
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 8th Annual HVACR Training Symposium at https://hvacrschool.com/symposium.
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Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android.

In this episode, Bryan leads a live team meeting focused on getting technicians mentally and practically ready for the summer rush. He opens by asking the group to name what makes the season different, and the answers pile up quickly: higher call volumes, hotter attics, more irritable customers, and a nagging pressure to move faster than usual. Bryan distills these observations into a central theme that runs through the entire conversation — the tension between speed and thoroughness, and how the desire to rush during the busy season is the root cause of most costly mistakes and callbacks.
A major thread of the discussion is the idea of "sharpening your ax" before the season's workload hits full force. Bryan pushes the team to build real confidence in their tools rather than assuming they work correctly. He walks through practical habits: verifying that a leak detector is properly calibrated, understanding its components well enough to troubleshoot it, and periodically checking a vacuum pump with a micron gauge so a technician instinctively knows what normal performance looks like. He also shares a story about a mentor named Howard Erskine, using it to illustrate how small, deliberate routines — from hose-rolling technique to truck organization — compound into real speed without sacrificing accuracy.
The conversation then turns to drain lines and diagnostic philosophy, centered on Bryan's "wide, narrow, wide" framework. He explains that rushing tends to collapse a technician's focus into the narrow middle step — fixing only the immediate complaint — while skipping the wide assessment before and after the repair that catches secondary issues like sagging platforms, damaged insulation, or drainage problems before they become bigger failures. A detailed real-world example involving an oversized system in a heavily shaded, lakeside home shows how factors outside a standard load calculation, like mature trees and humidity, can explain why equipment isn't "keeping up" even when nothing is actually broken.
Bryan closes by connecting these technical habits to business outcomes, urging technicians to fully document and resolve issues rather than telling clients to "keep an eye on it." He frames average ticket size, callback rate, and time on call as honest indicators of thoroughness rather than sales pressure, and encourages the team to lean into detailed measureQuick reports, thermal imaging, and clear client communication so that no problem gets punted down the road. He wraps up with an honest, encouraging note about the grind of the summer season, reminding the crew that the long hours are temporary and that consistent, unhurried practices are what ultimately make the season more profitable and less stressful.
Topics Covered
What makes the summer HVAC season uniquely difficult, from heat and call volume to mental fog and burnout
The connection between rushing and increased callbacks, mistakes, and missed opportunities
"Sharpening your ax" — preparing tools and routines before the busy season hits
Properly calibrating and understanding leak detectors, including the H10
Using a micron gauge to verify vacuum pump performance and knowing when to change pump oil
Building personal routines and truck ergonomics to work faster without losing accuracy
Common and costly drain line issues, including float switches, double traps, and pitch problems
The "wide, narrow, wide" troubleshooting framework for full-system diagnosis
A case study on an oversized system in a shaded, lakeside home and how site conditions affect load
Handling clients who report a system "not keeping up," including thermostat lookers vs. comfort-focused clients
Using measureQuick reports and third-party verification to build client trust
Evaluating ductwork, insulation, and equipment sizing as part of a full home assessment
Why documenting a clear path forward beats telling clients to "keep an eye on it"
Average ticket size, callback rate, and time on call as indicators of technician thoroughness
Maintaining a healthy mindset and work-life balance through the demands of summer
 
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 8th 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.