Refrigeration Basics for the AC Guy

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HVAC School – For Techs, By Techs

Real training for HVAC ( Heating, Ventilation, Air Conditioning and Refrigeration) Technicians. Including recorded tech training, interviews, diagnostics and general conversations about the trade.

Recorded live on the floor at the AHR Expo 2026, this episode of the podcast brings together host Bryan and his guest Jesse, National Training Manager at NAVAC, for a candid, high-energy conversation about professional best practices in the HVAC/R trade. The two have a long-standing friendship and professional rapport that makes the discussion feel both educational and genuinely entertaining. Jesse brings a unique background to the table — from underground coal mining in West Virginia to becoming a lineman, then pivoting to HVAC through vocational school and a contractor-sponsored apprenticeship program. His path to becoming a national trainer is a testament to the value of investing in yourself and being open to learning at every stage of a career.

The core of this episode centers on refrigerant recovery and charging best practices — a topic that might sound routine but quickly reveals how many technicians, even experienced ones, are cutting corners that cost their clients and their companies money. Bryan and Jesse dig into the problems caused by unnecessarily opening sealed systems, the refrigerant lost every time a technician gauges up a system without need, and why the HVAC industry needs to shift its mindset to treat equipment more like a home refrigerator: a sealed system that should run for years without needing to be cracked open. Jesse makes a compelling case that many so-called “mysterious leaks” are actually caused by repeated unnecessary gauge hookups removing small amounts of refrigerant each time.

A significant portion of the conversation focuses on the transition away from manifold gauges toward digital probes and modern recovery setups. Jesse isn’t dismissive of manifolds — he acknowledges their place in the classroom and as a backup tool — but he makes a strong case that eliminating restrictions throughout the recovery and charging process is one of the single most impactful things a technician can do to improve efficiency, protect equipment, and deliver better results for customers. Topics like pulling Schrader cores, using 3/8″ hoses, Rapid-Y fittings, and the importance of using a filter dryer inline with the recovery machine are all covered with practical, field-tested advice.

Bryan and Jesse also tackle some timely and emerging issues facing the industry, including the equalization behavior of R-454B blends and the growing challenge of refrigerant recovery in extreme cold climates as cold-climate heat pumps become more widespread in northern markets. These aren’t hypothetical — they’re problems technicians are encountering right now, and Bryan’s theory about refrigerant fractionation showing up on thermal imaging cameras offers a genuinely fascinating technical angle. The episode closes with Jesse’s overarching message: eliminate restrictions wherever you can, take pride in your craft, and never stop learning.

Topics Covered

Jesse’s background: coal mining, lineman work, HVAC vo-tech, contractor apprenticeship, and path to becoming a national trainer
The sealed system philosophy: why unnecessarily opening refrigerant circuits causes more problems than it solves
Manifold gauges — their appropriate role in training and as a backup vs. the case for moving to digital probes
How repeated gauge hookups can introduce refrigerant loss and fake “mystery leaks” — the 3.5 oz. per hose problem
Restrictions as the enemy of efficient recovery: pulling Schrader cores, using core removal tools, and proper hose sizing
The importance of recovering liquid first and how restrictions cause flash gas that slows recovery and adds heat
Hose size trade-offs: why 3/8″ hoses are the recommended sweet spot between flow rate and refrigerant retention
Using a filter dryer inline with the recovery machine as cheap insurance against acid contamination and machine damage
Why recovered refrigerant should generally NOT be reused — dirty recovery tanks, fractionation, and the limits of a single filter pass
Scales as a non-negotiable tool: weighing refrigerant in AND out, and why techs who estimate by feel are guessing
Diagnosing overcharge and undercharge situations using scale data before making repairs
Airflow first, charge second: the importance of confirming CFM before adding refrigerant to a struggling system
The R-454B equalization issue: refrigerant fractionation in new blends and Bryan’s thermal imaging theory
Cold-climate heat pump recovery challenges at sub-zero temperatures and strategies for adding heat to the system
Heat pump maintenance best practices: testing defrost cycles and what happens when they haven’t been checked in years
Word of mouth as the most powerful (and dangerous) form of advertising in the service industry
Recovery cylinder safety: the dangers of overfilling tanks and the 80% rule