HVAC School - For Techs, By Techs

In this short podcast, Bryan answers a question submitted to HVAC School by an aspiring licensed architect who wanted to learn more about the many different types of HVAC systems.

The three main buckets of HVAC systems are air-to-air, water-source, and air-to-water. Air-to-air systems move air around to remove heat from one space, and that heat is rejected to the air somewhere else. Water-source systems move water around the buildi...

In this essential episode, Bryan Orr sits down with Elliot, the residential install supervisor at Kalos Services, to unpack a critical issue that's causing confusion among HVAC technicians, electricians, and inspectors alike: the new standards for breaker and conductor sizing on inverter-driven equipment. The conversation was sparked by Elliot's frus...

In this short podcast episode, Bryan goes on another history journey, retelling the story of the rise and fall and rise of absorption cooling. Some of the first HVAC/R engineers cooled buildings with fire; they used absorption refrigeration, which ran on heat instead of electricity.

In the early 1800s, French scientist Michael Faraday showed that gases like ammonia could absorb heat as they evaporated. Instead of compressing the va...

In this comprehensive training session from the symposium, Tony Gonzalez, Training Director at Fieldpiece, delivers an engaging and practical guide to combustion analysis for HVAC technicians. With 25 years of experience at Fieldpiece—from warehouse worker to training director—Tony brings both technical expertise and real-world application to this 50-minute interac...

In this short podcast episode, we go back into the history of the trades, namely the battle over frequency (and how each side had to give until it hertz).

The low hum of motors is alternating current: electricity moving back and forth through copper 60x per second (in the USA and Canada, at least). In another version of history, that pulse could be 50x per second instead (as in much of the remainder of the world). The forgotten fre...

In this candid conversation, Nathan and Bryan dive deep into the often-misunderstood world of sales in the construction and HVAC trades. Nathan, who has transitioned from fieldwork to spending roughly 60% of his time in sales, offers a unique perspective on why sales professionals are necessary despite the skepticism they face from tradespeople. The discussion tack...

In this short podcast episode, Bryan takes us on a history journey back to when ammonia ruled the world.

In the mid-1800s, before R-12, many inventors and scientists experimented with vapor-compression refrigeration systems to make ice. They used a variety of refrigerants in their patents, including ether, ethyl ether, carbon dioxide, sulfur dioxide, methyl chloride, and ammonia. Each one had tradeoffs, but ammonia was the favorite...

In this episode of the HVAC School podcast, Bryan and Nathan dive deep into the challenges of humidity control in grocery stores and other refrigerated environments. While the conversation takes several entertaining detours (including discussions about morning radio shows, Indian weddings with elephants, and imaginary lava-heated homes), the core content provides v...

In this short podcast episode, Bryan explores the history of the finned-tube coil, which is what we use for heat exchange in air-source air conditioners and heat pumps.

Air-source HVAC systems have copper tubes threaded through thin metal fins. This design was optimized to ensure the greatest possible surface area for heat exchange to occur. However, prior to the finned-tube coil, HVAC coils looked more like plumbing projects with ...

In this comprehensive episode of the HVAC School podcast, host Bryan Orr sits down with three experts from Copeland to demystify tandem and trio compressor systems. Joining him are Gina Kahle (Multiples Engineering Manager with 12+ years at Copeland), Tyler Daniels (Product Management team member), and James Stevenson (Technical Sales veteran with 28 years of field...

In this short podcast episode, Bryan tells the story of the technology that tried to beat the compressor... and still may someday.

We associate cooling with refrigerant... and all the things that come with it, including compressor noise, oil, recovery machines and tanks, leaks, superheat, and regulations. However, there is a means of providing cooling with two pieces of metal and several semiconductors; current runs through it, and...

In this comprehensive episode, Bryan and Roman dive deep into one of the most challenging topics in modern HVAC: making VRF (Variable Refrigerant Flow) and ductless systems perform effectively in humid climates like Florida. The conversation tackles a common misconception that inverter-driven equipment automatically handles humidity well simply because it can "turn down." Roman emphasizes th...

In this short podcast, Bryan gives another history lesson and goes over the history of the thermostat.

Before 1883, automatic temperature control simply did not exist; we shoveled fuel into the furnace and opened windows. If a room got too hot in a commercial building, the janitor would go downstairs to choke the draft damper; this person was responsible for manually controlling comfort.

Warren S. Johnson, a Milwaukee-based college...

In this candid and comprehensive episode, Bryan sits down with Roman to tackle one of the most frustrating yet crucial aspects of the HVAC industry: technical support. What starts as a conversation about their own tech support nightmares quickly evolves into a deep dive examining the entire ecosystem—from manufacturers and distributors to technicians and sales reps—and how each player can im...

In this short podcast episode, Bryan is back for yet another history lesson. This time, the subject is the current war with Tesla, Edison, and Westinghouse.

The current war was fought in the late 1800s with lightbulbs, electrocutions, and a World's Fair that dazzled the entire world. Edison didn't necessarily invent the lightbulb, but he made it commercially viable by inventing the infrastructure needed to make it work; electricity...

In this raw and unfiltered episode, Bryan sits down with Elliot, a senior service tech and newly minted install supervisor, to discuss the realities of working with R-454B refrigerant in the field. What starts as a technical discussion about the new A2L refrigerant quickly evolves into a candid conversation about industry frustrations, manufacturer accountability, and the practical challenge...

In this short podcast episode, Bryan talks about psychrometrics and the magic line inside a messy-looking chart. The psychrometric chart is a key tool for understanding the relationship between air and water.

"Psychrometric" comes from the Greek roots for "cold" and "measurement." As such, a tool called the psychrometer (with paired wet-bulb and dry-bulb thermometers) could measure two different temperatures, and we could use these...