HVAC School - For Techs, By Techs Bryan Orr

In this podcast, Bryan Orr and Bert discuss various aspects of pool heaters, focusing on issues that make them different from typical HVAC systems. They cover the basics of pool heaters - the main types (heat pumps and gas heaters) and how they operate similarly or differently from things HVAC techs work on regularly.
The bulk of the 45-minute podcast looks at common service and troubleshooting situations with pool heaters, which are usually installed by pool contractors initially and not HVAC contractors. Bryan and Bert talk through typical causes of common error codes and problems like units frequently going out on high pressure. They cover water flow issues and the role of pressure versus flow switches, the sizing and limitations of heat pumps, low ambient operation challenges, freeze protection, and proper refrigerant charging. There is also a good amount of discussion on gas pool heaters - frequent component failures due to heat and corrosion issues, piping considerations due to their large BTU capacity, and combustion troubleshooting basics.
Throughout the casual discussion, both hosts interject humor and personal stories related to their dealings with pool heater equipment, clients, and installations over the years. The overall message is that while heat pumps and gas pool heaters have some specialized considerations, much of the core knowledge needed to service them comes from foundational HVAC systems understanding combined with an awareness of the unique aspects covered in detail during this episode.
Topics Covered:
Types of pool heaters How heat pump and gas pool heater operation compare to HVAC Typical installation and service providers Key components and design aspects Common high-pressure issues and troubleshooting water flow problems Low ambient operation challenges Refrigerant charging considerations Gas piping sizing for large BTU appliances Corrosion issues and component failures Combustion testing basics  
Learn more about the 5th Annual HVACR Training Symposium at https://hvacrschool.com/Symposium24.
If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.”
Subscribe to our YouTube channel at https://www.youtube.com/@HVACS. 
Check out our handy calculators HERE or on the HVAC School Mobile App (Google Play Store or App Store).

In this short episode, Bryan explains the fundamentals of capacitance, focusing on the unit of measure: farads, including micro and pico.
Farads are named after scientist Michael Faraday and measure capacitance; one farad represents the capacitance of a capacitor in which one coulomb of charge causes a potential difference of one volt across the plates. Farads measure the storage of electrical energy and indicate the capacitor's ability to create a phase shift.
Since farads are large units, our capacitors are rated in microfarads (1/1,000,000 farads). Bigger capacitors have higher microfarad ratings and store more charge.
Capacitors create a phase shift and limit current on the start or auxiliary winding. (You'll read less current across the start winding than the run winding or common when a run capacitor is in the circuit.) The start winding helps get a single-phase motor up and running (but it isn't present on all motors). Three-phase power has three windings, and it has three sine waves 120 degrees out of phase with each other, all of which can apply directional force. A single-phase motor has two windings and only one sine wave, so it doesn't have that phase difference, making it difficult to start a motor. Capacitors charge and discharge at a different point of the sine wave, causing a phase shift.
A picofarad is 1/1,000,000,000 farad, which is smaller than the microfarads we use. However, our meters can auto-range into the picofarad scale if they read a very weak capacitor. You'll have to make sure your meter is reading in the microfarad scale, not the picofarad scale.
 
Learn more about the 5th Annual HVACR Training Symposium at https://hvacrschool.com/Symposium24.
If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.”
Subscribe to our YouTube channel at https://www.youtube.com/@HVACS. 
Check out our handy calculators HERE or on the HVAC School Mobile App (Google Play Store or App Store).

Bryan Orr hosted a live podcast discussion all about 90% efficient furnaces with HVAC professionals Ty Branaman, Adam Mufich, and Matthew Bruner. They covered the basics of how 90% furnaces work compared to traditional 80% furnaces, troubleshooting tips, and best practices for installation and service.
A key difference with 90% furnaces is the addition of a secondary heat exchanger that extracts more heat from the exhaust gases before they go out the flue. This allows the furnace to achieve at least 90% efficiency. The condensing of water vapor in the exhaust also releases latent heat. However, the acidic condensate must be properly drained, and pipes must be corrosion-resistant. Proper airflow is also critical.
The experts emphasized starting any service job by carefully looking over the furnace and venting. Check for any signs of problems like leaks, debris buildup, or animals/pests blocking vents. Verify gas supply and use combustion analysis to optimize performance. When troubleshooting, methodically trace through the sequence of operations. Pressure switches, flame sensors, and airflow issues are common culprits.
The podcast concludes with a reminder that extensive training content on HVAC topics like this is available through HVAC School and other industry experts. Continuing education and an open, collaborative mindset are important for professional growth.
Key topics covered:
How 90% furnaces achieve higher efficiency with a secondary heat exchanger Water condensation and corrosion concerns - importance of drainage and pipe material Verifying gas supply, venting, airflow, and using combustion analysis Troubleshooting tips - visually inspecting, tracing sequence of operations, checking pressure switches and flame sensor Proper installation positioning and intake/exhaust vent sizing per manufacturer specifications  
View the entire livestream with Ty on our YouTube channel HERE.
Learn more about the 5th Annual HVACR Training Symposium at https://hvacrschool.com/Symposium24.
If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.”
Subscribe to our YouTube channel at https://www.youtube.com/@HVACS. 
Check out our handy calculators HERE or on the HVAC School Mobile App (Google Play Store or App Store).

In this short podcast, Bryan breaks down the differences between analog and digital sine waves.
Analog readings deal with an unlimited number of values; they are very precise and can have any number of decimals. As a result, the alternating current (AC) analog sine readings have very smooth curves when we read them on an oscilloscope (in the US, we see 60 peak-and-valley cycles per second because the frequency is 60 hertz). 
Variable frequency drives (VFDs) and ECMs work with digital outputs instead. The alternating current (AC) input is flattened out and then replicated as a direct current (DC) digital output that mimics an analog sine wave using technologies like pulse-width modulation (PWM). Digital outputs appear as a series of steps on an oscilloscope, but PWM doesn't output different "steps" of voltage. PWM just changes the length and frequency according to the duty cycle (percentage of the time energized or unenergized). Digital scrolls turn on and off very often, and the time they spend "on" is the duty cycle, which determines how it stages up and down.
While ECM motor modules usually won't work with regular motors, VFDs can run with typical motors and modify sine waves. These sine waves don't have a smooth curve, but the digital waves can be smoothed out while voltage and current are modified. If VFD-driven motors aren't designed or shaft-grounded properly, electrical discharge machining (EDM) can happen with high-frequency voltage spikes, which can damage the shaft and bearings.
 
Learn more about the 5th Annual HVACR Training Symposium at https://hvacrschool.com/Symposium24.
If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.”
Subscribe to our YouTube channel at https://www.youtube.com/@HVACS. 
Check out our handy calculators HERE or on the HVAC School Mobile App (Google Play Store or App Store).

Bryan Orr interviews Tyler Nelson, an HVAC expert with over 20 years of experience as a contractor. They have an in-depth discussion about combustion analysis and why it is becoming increasingly important for HVAC technicians to utilize this process.
The conversation provides an overview of combustion analysis benefits and why HVAC pros should incorporate it into their standard operating procedures. Tyler offers insightful perspectives from his decades of contracting experience, including his knowledge of how field conditions vary and factory settings may not translate perfectly.
Carbon monoxide poses several dangers to customers and HVAC technicians. Tyler talks about CO poisoning risks and how analyzers can help detect issues. He also covers AHRI Guideline X for cracked heat exchanger testing and emphasizes the need to use combustion analyzers, not just visual inspection, to reliably detect cracks.
Tyler also demonstrates the use of the Sauermann combustion analyzer and mobile app. He highlights key features like replaceable sensors, app control and reporting, and programming for optimum CO sensor protection. He details how combustion analysis allows you to optimize setup, monitor equipment health, and troubleshoot issues.
Tyler and Bryan also discuss:
Why combustion analysis is critical for proper HVAC system installation, maintenance, and diagnostics CO poisoning and risks to HVAC technicians AHRI Guideline X The role of combustion analysis in system commissioning, maintenance, and diagnostics Sauermann combustion analyzer and mobile app Advice for technicians to embrace innovations like analyzers while retaining old-school skills and knowledge  
Read AHRI Guideline X in its entirety at https://www.ahrinet.org/search-standards/ahri-guideline-x-induced-draft-furnace-heat-exchanger-inspection. 
Learn more about Sauermann tools at https://sauermanngroup.com/en-INT, and you can connect with Tyler on LinkedIn HERE.
Learn more about the 5th Annual HVACR Training Symposium at https://hvacrschool.com/Symposium24.
If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.”
Subscribe to our YouTube channel at https://www.youtube.com/@HVACS. 
“Check out our handy calculators HERE or on the HVAC School Mobile App (Google Play Store or App Store).

In this short podcast, Bryan talks about checking the charge of a heat pump in heat mode. This skill will become more critical as ambient temperatures get cooler.
The most reliable way to check and set the charge regardless of operating mode and season is to weigh the charge. This method is most practical during installation and commissioning, and proper commissioning can prevent issues with charge levels later. Weighing the charge is recommended for big repairs, like major component replacements.
But in many cases, we don't need to check the charge by hooking up gauges; we can check for proper operation by taking a few line temperature readings. Before carrying out any tests or taking readings, make sure the heat pump is defrosted and that you've carried out a full visual inspection. You can carry out a full delivered capacity test in either cooling or heating mode (without the electric heat strips energized) to determine how many BTUs the system is moving. Some simpler tests will require you to compare the discharge vapor line and suction line temperatures to the outdoor temperature and the liquid line temperature to the indoor temperature. 
Manufacturers will give specific instructions for their units, including covering the condenser, and they may have charts to help you calculate system pressures based on indoor and outdoor temperatures. If you want to check suction pressure on the low side, you'll always use the common suction port, but you can take either discharge pressure or liquid pressure on the high side.
Bryan also covers:
Critical charge  Ductless system charging practices Some manufacturer-specific practices Indoor temperatures and system pressures R-22 rules of thumb Total discharge superheat Staging and capacity considerations Weighing out when in doubt  
Read the tech tip about this topic at https://hvacrschool.com/checking-charge-heat-pump-winter/. 
Learn more about the 5th Annual HVACR Training Symposium at https://hvacrschool.com/Symposium24.
If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.
Subscribe to our YouTube channel at https://www.youtube.com/@HVACS.
Check out our handy calculators HERE or on the HVAC School Mobile App (Google Play Store or App Store).