BACK
History of Thermometry and the Invention of Thermometers
It’s All Relative… Humidity
The Heating Sequence of Operations and Onions
Electronic Expansion Valve Troubleshooting
The Best (and Worst) Ways To Duct a Dehumidifier
The Evolving Career of the HVAC Contractor: Embracing Change to Stay Ahead
How To Do a Heat Maintenance That Actually Matters
Technology Trade-offs
3 Tips for Training Apprentices
Q&A – Evap Placement – Short #221
Can Ducts Be Cleaned Ethically?
Should I Fog or “Sanitize” My Ducts? – Short #220
Condensing Furnace Drain Guidance w/ AC Service Tech
How to Predict Air Flow Issues in the Sales Process
MCA is 27 and the Breaker is a 50A – Short #219
Deploying Surge Protection & Voltage Monitoring w/ DITEK
Pumping vs. Compression – Short #218
Building Tech Confidence w/ Refrigeration Mentor
#hvac
Tech Tips:
![](https://hvacrschool.com/wp-content/uploads/2024/10/Featured_Image_Templates_62-300x300.png)
So, what is thermometry anyway? Thermometry is the scientific study of measuring temperature and has roots that date back to as early as 220 BC. During this time, Philo of Byzantium began to study the effects that temperature had on air. Specifically, he observed expansion and contraction caused by temperature change. He did this using […]
Read more![](https://hvacrschool.com/wp-content/uploads/2024/10/Featured_Image_Templates_50-300x300.png)
Florida’s got a lot of great qualities: some pretty neat wildlife, beaches all around, and theme parks. On the flip side, Florida also has hurricanes and a lot of humidity. As much of a pain as it might be for residents and contractors alike, humidity is one of my favorite topics. We see relative humidity […]
Read more![](https://hvacrschool.com/wp-content/uploads/2024/10/Featured_Image_Templates_41-300x300.png)
Just like Shrek, I like to think about the heating sequence of operations as an onion—it has layers. And each layer builds upon the previous one. We have written previously in great detail about gas furnaces, from top to bottom. I want to focus today on why there is a sequence of operations and how […]
Read more![](https://hvacrschool.com/wp-content/uploads/2024/10/Featured_Image_Templates_38-300x300.png)
Electronic expansion valves (or EEVs) are metering devices that you’ll find in a variety of modern HVAC equipment, including heat pumps, VRF units, inverter mini splits, and chillers. This valve is electronic rather than mechanical and can precisely control the flow of refrigerant into the evaporator and optimize efficiency for heating and cooling units. Other […]
Read more![](https://hvacrschool.com/wp-content/uploads/2024/09/Featured_Image_Templates_39-300x300.png)
There are a couple of really important things to understand when ducting a dehumidifier. Getting one or both of these things wrong can throw off your entire dehumidifier install. Instead of just telling you the different ways you can install a dehumidifier, let’s talk through some dehumidifier basics, which will help us understand why it’s […]
Read more![](https://hvacrschool.com/wp-content/uploads/2024/09/Featured_Image_Templates_33-300x300.png)
This tech tip was written by Shelby Breger, co-founder of Conduit Tech. You can check out everything Conduit has to offer and learn more about that interesting platform and how it helps contractors at https://getconduit.com/. Thank you, Shelby! Before starting Conduit Tech, Marisa and I spent a year doing everything we could to learn about […]
Read more![](https://hvacrschool.com/wp-content/uploads/2024/09/heat_maintenance_fi-300x300.png)
I know I’m not the only one who has sometimes felt a little bad doing heat maintenance. I remember many a day when my lead technician and I (as an apprentice) would crawl into an attic, clean the flame sensor, and then play FarmVille on our phones for 15 minutes before crawling down, giving the […]
Read more![](https://hvacrschool.com/wp-content/uploads/2024/09/technology_trade_offs_fi-300x300.png)
As a small business owner in the 21st century, I have recently been exposed to the overwhelming amount of new technologies and processes that I could use within my business. In the last few years, there has been a surge of software and connected tools that are entering the marketplace. All of them promise to […]
Read more![](https://hvacrschool.com/wp-content/uploads/2024/09/Featured_Image_Templates_22-300x300.png)
I hired and trained an apprentice who has worked 2 days a week for me over the last 4–5 months. I've been in business for almost two years, and I had a pretty good sense that I would need some help this summer. Hauling a few air handlers and furnaces into an attic by myself […]
Read moreVideos:
Podcasts:
![](https://hvacrschool.com/wp-content/uploads/2024/12/02_1-300x300.jpg)
In this short podcast, Bryan talks about evaporator coil placement based on a question submitted by a listener, John. Evap coil placement differs in furnace applications versus air handlers. When we use air conditioners with furnaces, we usually put evaporator coils on the positive side to protect the heat exchanger from rusting out during […]
Read more![](https://hvacrschool.com/wp-content/uploads/2024/12/01-3-300x300.jpg)
In this episode of the HVAC School Podcast, Bryan interviews Zachary Ortwine, a duct cleaning professional who provides insights into ethical duct cleaning practices. The conversation delves deep into the complexities of cleaning different types of ductwork, the importance of proper assessment, and the potential challenges in maintaining indoor air quality. Zach emphasizes the […]
Read more![](https://hvacrschool.com/wp-content/uploads/2024/12/Should_I_Fog_or_Sanitize_My_Ducts_-_Short_220_Podcast-01-300x300.jpg)
In this short podcast episode, Zach joins Bryan to answer a common duct maintenance question: Should I fog or sanitize my ducts? The National Air Duct Cleaners Association (NADCA) outlines the uses of chemical products. Adding chemicals is usually a last resort in flex or sheet metal (externally wrapped) duct systems; they should NOT […]
Read more![](https://hvacrschool.com/wp-content/uploads/2024/11/01-2_1-300x300.jpg)
Bryan and Craig Migliaccio (AC Service Tech)dive deep into the complexities of managing condensate drainage in high-efficiency (90%+) gas furnaces. The conversation begins with a clear explanation of why these furnaces produce condensate in the first place – they have two heat exchangers that extract so much heat from the combustion gases that water […]
Read more![](https://hvacrschool.com/wp-content/uploads/2024/11/01-1_2-300x300.jpg)
Chris Hughes and Steve Rogers from The Energy Conservatory discuss TEC's TrueFlow technology and its crucial role in predicting airflow issues in the sales process, particularly for heat pump retrofits. They explain how the TrueFlow app helps contractors accurately measure both static pressure and airflow in existing systems, enabling them to predict whether proposed […]
Read more![](https://hvacrschool.com/wp-content/uploads/2024/11/01-2-300x300.jpg)
In this short podcast episode, Bryan and Mike from DITEK talk about what to do in tricky electrical scenarios, such as when the MCA is 27 and you have a 50A breaker. When you size an HVAC system for compatibility with voltage monitors, like the DITEK Kool Guard, you need to pay attention to […]
Read more![](https://hvacrschool.com/wp-content/uploads/2024/11/Featured_Image_Templates_82-300x300.png)
Bryan discusses surge protection devices (SPDs) with Mike from DITEK, focusing on practical applications for HVAC contractors and how to provide value to clients. Mike emphasizes that surge protection is essential for modern HVAC systems, particularly given that they are typically the most expensive appliance in a home and increasingly rely on sophisticated electronic […]
Read more![](https://hvacrschool.com/wp-content/uploads/2024/11/Featured_Image_Templates_80-300x300.png)
In this short episode, Bryan clears up the confusion behind pumping vs. compression. Pumping is usually associated with liquid. Liquid, like vapor, is a fluid, but it's a lot denser and is essentially incompressible because the molecules are close together. Liquid volume varies based on temperature and density, but we can't squish the molecules […]
Read more![](https://hvacrschool.com/wp-content/uploads/2024/11/Featured_Image_Templates_79-300x300.png)
Trevor Matthews returns to the HVAC School Podcast to discuss building tech confidence and personal growth in the HVAC and refrigeration industry. The conversation explores the transformative power of self-investment, continuous learning, and maintaining a positive mindset. Trevor shares his personal journey from a hesitant technician to a successful business owner, highlighting the importance […]
Read more