HVAC School - For Techs, By Techs

Latest Episodes:

A2L Update With Chemours Live from AHR Feb 01, 2024

Show notes

Don Gillis and Dr. Chuck Allgood from Chemours join the show to discuss their new easy as "1,2,3" branding around the A2L refrigerants R454A, R454B, and R454C. They explain that A2Ls are not actually flammable like hydrocarbons; they are just mildly combustible with much lower burning velocity and energy than propane or butane. The key is that A2L refrigerants can only be used in equipment specifically designed and tested for them.

They outline several equipment changes, like the inclusion of sensors that detect leaks and mitigate risks by shutting down systems. Service ports will be red to denote flammability. Refrigerant cylinders will move away from colors and instead use red bands/markings to signal A2L, along with left-handed threads and updated pressure relief valves. Best practices like nitrogen purging, confined space protocols, and leak repairs will become outright requirements. Tools like recovery machines and leak detectors will need A2L ratings, but most from the past 2 years likely already have them.

In closing, the guests emphasize that A2Ls contain no propane or hydrocarbons and cannot be retrofitted into existing A1 equipment. Contractors should get trained, adopt the solutions coming, and not fear progress. But they should spread the word that A2Ls are not simply being dropped into old equipment.

Topics Covered:

Differences between A2Ls and flammable refrigerants
Required safety features in A2L equipment
Changes to refrigerant cylinders
Updating tools and practices for A2Ls
Retrofitting existing systems with A2Ls (not allowed)
Spreading proper understanding about A2Ls

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).

What is DX? - Short #185 Jan 30, 2024

Show notes

In this short podcast episode, Bryan tackles the following question: What is DX?

In short, DX stands for "direct expansion," which means that you cool the end product via the refrigeration cycle. We blow air over an evaporator coil, which allows the refrigerant to take up heat from the air and directly expand. Chillers, boilers, and chilled water systems are NOT direct expansion systems; they use a secondary fluid like water or glycol to move the heat throughout the structure, not an evaporator to take up heat directly. They also have heat exchangers to move heat from the refrigerant to the secondary fluid.

DX systems tend to be smaller, and chillers and boilers tend to be larger. Chillers are advantageous in cases where we're working with toxic or flammable refrigerants or large refrigerant charges; we can keep the refrigerant charge away from the structure and space or product(s) needing to be heated or cooled.

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).

Vacuum and Recovery in an A2L World with Jesse Stewart Jan 24, 2024

Show notes

In this podcast, Bryan Orr interviews Jesse Stewart from NAVAC about A2L refrigerants and compatible tools and safety procedures.

They discuss how NAVAC has a full line of A2L-compatible tools for evacuation and recovery, including the new NR7 and upgraded models of the NRDDF and NRDD. Jesse explains key features that make tools A2L compatible, like DC motors, sparkless designs, insulated electrical terminations, soft power switches, and fans. He notes that NAVAC has been designing tools this way in preparation for wider A2L adoption.

The conversation covers some evolving questions around A2L systems, like requirements for strike plates to protect line sets and whether existing line sets can still be used. They agree that ongoing questions need to be directed to organizations like ASHRAE to get definitive guidance. Overall, Jesse emphasizes that best practices are now required, not just recommended, when working with A2Ls. He details several examples, like nitrogen purging while brazing, the "10-foot rule" for checking potential ignition sources, and proper confined space protocols.

Topics covered:

NAVAC's line of A2L-compatible tools
Key safety features for A2L tools
Evolving regulations and best practices around A2L systems
Using nitrogen while brazing
The "10 foot rule" before A2L installations
Working in confined spaces with A2Ls
Adapting outdated practices to meet new safety needs

Explore NAVAC's A2L-compatible tools at https://navacglobal.com/a2l-compatible-tools/ or general products at https://navacglobal.com/. You can also ask the experts for help by emailing training@navacglobal.com.

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).

Safe Chemicals are Good Chemicals w/ Mike Pastorello Jan 24, 2024

Show notes

This podcast covers refrigeration technologies' growth and focus on providing safe, high-performing chemicals for HVAC technicians without hazardous ingredients.

Mike Pastorello discusses the 2017 rebranding that gave their products a more modern, cohesive look. He also talks about bringing on new marketing talent like Ashley and Becca to amp up refrigeration technologies' social media presence and connect more directly with end users. Throughout, Mike emphasizes enabling the marketing experts to drive strategy rather than micromanaging.

Regarding products, Mike highlights their priority of keeping technicians safe while effectively doing their jobs. He mentions constantly improving formulas to eliminate skin burns, bad odors, and other issues with traditional chemicals. Bryan shares an example from his contracting company where lax safety practices led to an emergency room visit and realigned his team's commitment to using safer alternatives like Viper products.

They also overview popular refrigeration technologies offerings like Nylog thread sealant and the Venom Packs compact container system. Mike states the Venom Packs will avoid upcoming taxes on traditional gallon jugs. Bryan praises the durable, flexible packaging and smaller nozzle.

Bullet points:

2017 rebrand and modernizing refrigeration technologies' visual identity
Bringing on new marketing talent to expand social media reach
Empowering new hires to take the lead rather than micromanaging
Keeping technicians safe while effectively doing their jobs
Continually improving chemical formulas to reduce hazards
An emergency room visit underscoring the need for safety focus
Overview of Nylog refrigerant thread sealant
Benefits of the durable and flexible Venom Packs

Check out all Refrigeration Technologies products at https://www.refrigtech.com/.

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).

How Better Truck Stock Makes the Trade Better w/ Jim Fultz Jan 24, 2024

Show notes

This live podcast from AHR Expo 2024 discusses the costs of truck rolls for HVAC technicians and how technicians and companies can reduce those costs. Jim and Bryan highlight that every time a tech has to go to the supply house to get parts, the company loses money in potential service calls that could have been completed. They emphasize stocking trucks properly so that technicians can complete repairs efficiently without leaving jobsites.

Jim talks about the White Rogers 50M56X8-43 universal control board, which auto-configures itself to different furnace models. He explains how it simplifies installations and troubleshooting, allowing techs to solve problems faster. Bryan adds that having universal parts encourages techs to thoroughly diagnose issues before replacing components. They also discuss the display showing flame current in microamps, which helps techs benchmark flame rod cleanliness over time.

Later, Jim stresses the importance of techs understanding all the individual components in heating systems rather than seeing units as intimidating beasts with complex wiring. Bryan shares how new controls with better interfaces and indicators help guide techs to increase their skills and knowledge. They agree that improvements allowing faster on-site repairs provide a better, more rewarding experience for both techs and customers.

Throughout, Jim and Bryan sprinkle in jokes, stories, and food references while emphasizing the overarching goal of giving techs what they need to enjoy their work and provide the best service possible.

Topics covered:

Costs of truck rolls and supply house trips
Stocking trucks for same-day repairs
New universal control simplifying installations
Diagnosing issues thoroughly before replacing parts
Display showing useful flame current readings
Understanding all components in heating systems
Improved interfaces and indicators enhancing skills
Faster on-site repairs benefiting techs and customers
Loving your work and helping people

Check out Copeland's trusted products and brands at https://copeland.com.

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).

The VCRT Redesigned + More w/ Fieldpiece Jan 24, 2024

Show notes

In this podcast, Bryan chats with Tony Gonzalez of Fieldpiece about their latest innovations for service tools, including the redesigned VCRT, as well as the training resources they offer.

They start off discussing Fieldpiece's philosophy of developing solutions for technicians' real pain points, not just making products. Understanding workflows and obstacles lets them design better tools. Tony then reveals their new line of valve core removal tools aimed at faster, easier access to system ports. Features include integrated ball valves to isolate gauges, sight glasses to confirm capture of the core, and improved ergonomics for gripping.

Next they touch on Fieldpiece University, their free online learning platform for HVAC best practices. It contains individual courses as well as guided "training tracks" on full applications like combustion analysis. With quality content being critical, Tony aims to continue expanding their offerings this year.

They also briefly discuss A2L refrigerants - while tool compatibility questions persist in the field, most quality equipment made in recent years carries approvals. Technicians mainly need to verify the manufacturer's guidance and adhere to existing best practices.

Key topics:

New valve core removal tools
Enhanced sight glass and isolation
Continual improvement of Fieldpiece University
Clarifying tools and A2Ls

The overarching theme is providing solutions - both through innovative tools and readily accessible education for the industry. You can learn more about Fieldpiece at https://www.fieldpiece.com/.

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).

Absolute vs. Gauge Pressure (Micron Gauge vs. Manometer) - Short #184 Jan 23, 2024

Show notes

In this short podcast episode, Bryan covers the differences between absolute and gauge pressure, as well as measuring pressure with a micron gauge or a manometer.

Compression ratio deals with absolute suction and absolute discharge pressures. Absolute pressure requires us to add atmospheric pressure to the gauge pressure. We usually measure gauge pressure in pounds per square inch (PSI). PSIG is the gauge pressure (zeroed to atmospheric pressure), and PSIA is the gauge pressure plus the atmospheric pressure (usually around 14.7 PSI).

When we measure vacuum pressure, we have "negative pressure" with respect to the atmosphere. We're not measuring less than zero pressure; we are in a positively pressurized environment, but the pressure is negative relative to the atmosphere (not absolutely). We use microns to measure deep vacuums; they are tiny pressure units equivalent to a millionth of a meter of mercury column. Since microns measure absolute pressure, they always dip below atmospheric pressure and approach 0 (but never reach it because we're not in a perfect vacuum). We don't have to zero the micron gauge because it automatically measures with respect to zero.

Manometers measure pressure differentials; they measure pressure in reference to something else, whether that's the room around you (whatever you've zeroed it to) or another point on the system (measured at the other port). In any case, we're not referencing 0 PSIA. Many manometers may pick up readings in the inches of water column scale, and some even measure very small scales like Pascals.

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).

Is Dual Fuel the Answer? w/ Tom Buescher Jan 18, 2024

Show notes

In this HVAC School podcast, Bryan and Tom Buescher with Copeland discuss dual-fuel heat pump systems as an intermediate step towards more sustainable heating solutions.

They talk about the overall goal of reducing greenhouse gas emissions from residential heating and cooling, which accounts for over half of home energy use. While heat pumps can provide higher efficiency, simply switching everyone to electric isn't realistic in the short term. Factors like grid capacity, infrastructure, and consumer comfort have to be considered.

Dual fuel systems allow for a hybrid approach - utilizing heat pumps to provide the bulk of heating, with gas heating as a backup for the coldest stretches. This arrangement allows more heat pumps to be adopted now while still ensuring warmth and meeting consumer expectations. It bridges the gap during this transitional period as grids adapt to more renewable generation.

Key topics covered:

Tom's industry background
The role of location - dual-fuel makes the most sense in northern climates zones 3-5 currently
Electrical factors - service capacity, indoor air temp, wiring
Existing home challenges - ductwork, insulation
Staged operation of dual fuel systems
Role of hybrid approaches during transitions
New universal controls and thermostats enabling these dual-fuel setups

Overall, Bryan and Tom have a nuanced discussion about creating real progress incrementally, meeting consumer needs alongside policy goals. Considering both environmental and practical perspectives is key.

Visit Copeland's website at https://www.copeland.com/en-us and Sensi at https://sensi.copeland.com/en-us. You can also watch our new install video featuring the Sensi Touch 2 at https://hvacrschool.com/videos/sensi-touch-2-install/.

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).

NTC, PTC and Thermocouples - Short #183 Jan 16, 2024

Show notes

In this short podcast episode, Bryan dives into NTC, PTC, and thermocouples. NTC and PTC are two types of thermistors, and all three tools are used to sense temperature.

Thermistors are resistors that change their resistance based on a change in temperature. They must be powered, and the resistance changes the amperage. You can test a thermistor with an ohmmeter at a fixed temperature. The best temperature for testing is the thermistor's rated temperature, typically 77 degrees Fahrenheit.

NTC thermistors are negative temperature coefficient thermistors; as the temperature decreases, the resistance increases, and vice versa. Temperature and resistance are inversely proportional. PTC thermistors are positive temperature coefficient thermistors, and the temperature and resistance are directly proportional. These types of thermistors are usually quite accurate, and they are common in thermostats.

PTCs are common in certain types of hard start kits, in which they help take the start capacitor or start winding out of the circuit. They have the same function as a potential relay. The resistance increases with temperature, meaning the PTC gets hotter and raises its resistance until the circuit opens, but it takes a while to reset because it needs to cool down.

Thermocouples work because they generate a voltage in response to a temperature difference between two dissimilar metals. This phenomenon is called the Seebeck effect. Thermocouples are hardy devices used in temperature-sensing equipment, and they measure over a wider range than thermistors. However, thermocouples tend to be less accurate than thermistors.

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).

How to Save Energy with Grocery Store Refrigeration Jan 11, 2024

Show notes

This podcast episode focuses on practical ways to save energy with grocery store refrigeration systems, with Matthew Taylor from Kalos Services sharing insights from both a technician and business owner perspective. The hosts emphasize that proper, consistent operation and preventing short cycling of compressors can have a major impact as the largest power consumers.

Proper control strategies, like ensuring evaporator pressure regulators (EPRs) are working, maintaining subcooling, and preventing excessive compressor staging and rapid on/off cycling, are critical for reducing energy consumption. Often, technicians troubleshooting issues bypass these controls when they could be tuned and optimized instead. Matthew stresses the financial benefit for owners when technicians understand the original design intent and how to optimize performance, not just apply a band-aid fix to problems. He advises business owners to track power bill anomalies to catch inefficiencies.

Other key factors covered: ensuring clean evaporator coils, properly functioning doors/curtains, humidity control, condensed maintenance, addressing core issues like suction pressure rather than quick fixes, compression ratio impacts, and coordinating refrigeration with HVAC equipment. Implementing complex new networked equipment has trade-offs as well - while offering more data, it requires different skill sets to leverage.

Topics covered: