HVAC School - For Techs, By Techs

Latest Episodes:

Spidey Sense - Airflow - Short #205 Aug 06, 2024

Show notes

In this short podcast, Bryan talks about how to pay close attention to airflow issues and use your "spidey sense" when you're doing a visual inspection or commissioning a system. He also covers some causes of common airflow problems and some services and upgrades you can offer to your customers.

The skill of being able to use your senses and notice when something isn't quite right is a valuable one, especially when you're getting ready to set the charge. Not every technician has access to the tools to do a comprehensive airflow assessment, but every tech can use their senses to determine when something is wrong with the system airflow. Keep an ear out for whistling or other strange noises, and watch out for cabinet shaking, which may indicate an airflow problem.

Airflow restrictions are also significant issues. Filter cleanliness (or lack thereof) and improper filter selection are very common causes of airflow issues, including high static pressure drop. Most filters should also not be doubled up (in series). Watch out for furniture blocking vents and registers that are partially (or fully) closed; shutting off registers is NOT a good strategy. Air movement throughout the building is also important, including the presence or absence of returns, open doors, etc., and these things affect MAD-AIR.

Watch out for things like leakage as well, which can be around the platform, in ducts around the equipment, and around vents or recessed lighting.

Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool.

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Preventing Low Voltage Issues Aug 01, 2024

Show notes

In this episode, Bryan and Bert dive deep into the world of low voltage wiring in HVAC systems. They discuss common mistakes, best practices, and troubleshooting techniques that technicians and contractors should be aware of when dealing with control wiring.

The conversation begins with a focus on mechanical issues, such as running wires in places where they can be damaged and poor splicing techniques. Bryan and Bert emphasize the importance of proper wire stripping, both for the outer jacket of control cables and individual conductors. They share tips on how to avoid damaging wires during installation and stress the significance of planning wire placement, especially behind thermostats.

The discussion then shifts to common miswiring issues, including incorrect terminal connections and misunderstandings about system configurations. They explore the challenges of wiring heat pumps, straight cool systems, and gas furnaces, highlighting the importance of understanding how different thermostats and equipment interact. The hosts also delve into the complexities of dehumidification control wiring and the need to comprehend how various controllers operate.

Bryan and Bert also address communicating systems and offer advice on preventing communication issues. They stress the importance of running new control wiring, considering shielded cable for long runs, and being meticulous about connections.

Topics covered in the podcast:

Proper wire stripping techniques for control cables
Common miswiring issues in HVAC systems
Thermostat wiring and configuration challenges
Dehumidification control wiring complexities
Heat pump vs. straight cool/gas furnace wiring differences
Communicating systems and preventing communication issues
Using shielded cable for long control wire runs
Troubleshooting intermittent low voltage problems
The importance of reading manuals and understanding system configurations
Tips for managing wires behind thermostats and in control panels
Using megameters for testing control wires
Encouragement for technicians dealing with low voltage issues

Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool.

STOP Overthinking! - QA Short #204 Jul 30, 2024

Show notes

In this short podcast from our Q&A series, Bryan answers a viewer question and implores you to STOP overthinking in the trade! He also shares a parable and some tips to help stop overthinking, especially if you're just starting out in the trade.

In many cases, the simplest assumption is the right one (this is called Occam's Razor). We can always start with the most obvious or simplest possible answer. We can become mindful of our tools, such as by making sure our seals are intact, and we become masters of the obvious.

Perfecting little things (and micro-tasks) can help you become more familiar with the tools you use and the equipment you work on, and you start to develop a bigger-picture understanding of your craft. Cleaning the equipment and organizing your tool bag goes a long way; you can unlock the ability to zoom out and spot mistakes that you otherwise wouldn't have thought of otherwise.

Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool.

Stewarding Younger Techs Jul 25, 2024

Show notes

In this podcast episode, Bryan and Dre discuss the challenges and opportunities of stewarding younger techs in the HVAC industry. They explore the growing interest among young people in trades like HVAC, noting a shift away from traditional four-year college paths. The conversation highlights the satisfaction that comes from working with one's hands and the tactile nature of the trade.

The discussion delves into the attributes of younger workers, both positive and challenging. They also address the need to help young technicians understand the seriousness and responsibility of their roles, especially when transitioning from less demanding jobs. The podcast touches on the challenge of helping young workers prioritize their work and manage their time effectively, recognizing the natural tendencies of youth to be more focused on short-term feelings and experiences.

While acknowledging the benefits of tech-savvy workers who can easily access information and use digital tools, they also discuss the need to manage potential distractions from smartphones and social media. The podcast also explores the evolving expectations around work-life balance, on-call schedules, and the importance of clear communication about job demands and responsibilities.

Topics covered in the podcast:

Growing interest in trades among young people
Challenges of managing and mentoring young technicians
The satisfaction of working with one's hands in the HVAC industry
Balancing technology use in the workplace
Adapting to changing work-life balance expectations
Strategies for keeping young technicians engaged and challenged
The importance of building trust and demonstrating care as a manager
Addressing potential boredom and the desire for career progression
The value of mastering skills through repetition and experience
Navigating the rapid promotion of young talent in a growing company
Comparing modern work attitudes with those of previous generations

Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool.

Duct Smoke Detector Facts and Wiring - Short #203 Jul 23, 2024

Show notes

In this short podcast, Bryan answers a listener-submitted question about duct smoke detector facts and wiring. He focuses on Honeywell duct smoke detectors (namely the D4120W), but there are some general best practices that can be applied to most duct smoke detectors.

The power supply may be 24v or 120v AC or DC and may have multiple inputs. You should not break that constant power source. There are also fan shutdown contacts, which may be normally open (alarm condition) or normally closed (non-alarm condition). Supervisory contacts open to indicate a trouble condition to the panel when something in the circuit isn't working properly (NOT an alarm condition). There is often a resistor at the end of the loop, and the alarm panel recognizes a specific resistance. Alarm initiation contacts close and create a shorted condition when there is an alarm condition (the supervisory contacts open if there is a trouble condition).

Smoke detectors in the ducts are different from the ones on ceilings; they usually shut down blowers to prevent the distribution of smoke through the ductwork (and possibly exhaust it to the outside). They are required in duct systems designed for more than (or at least) 2000 CFM per NFPA90 and IMC 606.2.1, though those codes conflict. NFPA90 requires installation in the supply duct, but IMC 606.2.1 requires installation in the return; the AHJ may interpret the code either way. (Smoke detectors in systems >15000 CFM must be in both the return and the supply.)

Overall, remember that different detectors are suitable for different velocities. You will want to keep them downstream of bends for at least 18 inches, test them according to the AHJ, and ensure that they are mounted in the right configuration as recommended by the manufacturer.

Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool.

Trust the NEW Process: Embracing Evolution in HVAC Technology Jul 18, 2024

Show notes

In this episode of the HVAC School podcast, host Bryan and guest Jesse Stewart from NAVAC discuss the generational divide in the HVAC industry and the importance of embracing new technologies and processes. They explore the challenges faced by both experienced technicians who may be set in their ways and newcomers to the trade who need proper mentoring.

Jesse emphasizes the importance of respecting traditional methods while making way for new techniques. He discusses how bad habits can be passed down from mentors to apprentices, highlighting the need for continuous learning and adaptation in the rapidly evolving HVAC industry. The conversation touches on the importance of treating apprentices with respect and providing them with educational experiences rather than just menial tasks.

The podcast delves into specific HVAC practices, particularly focusing on evacuation and recovery processes. Jesse explains the significance of using proper tools and techniques, such as valve core removal tools, high-quality vacuum pump oil, and appropriate hoses for different tasks. He debunks common misconceptions about hose sizes and manifold use, providing practical analogies to help listeners understand these concepts.

Topics covered in the podcast include:

The generational gap in the HVAC industry and its impact on training and practices
The importance of continuous learning and adapting to new technologies
Proper mentoring techniques for apprentices
The "beer can cold" method and other outdated practices
The significance of using the right tools for evacuation and recovery processes
The impact of hose diameter on efficiency in evacuation and recovery
The importance of vacuum pump oil integrity
The differences between service, recovery, and evacuation hoses
Debunking the misconception about the impact of connection size on evacuation and recovery speed
The role of manifolds in modern HVAC practices
NAVAC's approach to developing tools based on customer demand while promoting best practices

Check our NAVAC's entire product line at https://navacglobal.com/.

Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool.

Soft Start & Solar - Short #202 Jul 16, 2024

Show notes

In this short podcast episode, Bryan dives into soft start & solar technology, which often work together. He also talks about how we can install ductless systems in homes that rely on solar power.

Soft starts are NOT hard starts. Hard starts add more current to the start (auxiliary) winding, which creates a stronger phase shift. Instead, soft starts control the current on the start and run windings and provide just enough of a phase shift to ramp up the motor slowly; it provides a regulated power supply, which means that a slow startup doesn't necessarily cause overheating because there is no locked rotor condition.

We can use soft starts on two-stage compressors but need to make sure the compressor goes up to high speed during the starting sequence. Soft starts "learn" the compressor's cycles, so we need to make sure they are trained to reach the high stage, not the low stage. In systems with multiple compressors, we need to have a separate soft start for each compressor. We don't need to use soft starts on inverter-driven or variable frequency drive (VFD) systems.

Soft starts also make sense in systems that rely on solar technology. Solar technology may be on-grid (where we sell back energy during peak times) or off-grid (where energy is banked). Ductless systems can work with solar energy, but they must be connected to the grid or the bank. Banked solar energy doesn't need to be rectified in the same way that AC power from the electrical company does, which may be advantageous for ductless systems that rely on DC-driven technology.

Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool.

Make Summer Work for You w/ Matt Bruner Jul 11, 2024

Show notes

In this episode of the HVAC School podcast, host Bryan Orr welcomes Matt Bruner to discuss the concept of a "summer survival guide" for HVAC professionals. They explore strategies for maintaining work-life balance during the busy summer season and share personal experiences on prioritizing family and personal well-being while managing the demands of the HVAC industry.

The conversation delves into the importance of intentional planning before the summer rush begins. Matt shares how he and his family implement practices like scheduling an end-of-summer vacation, utilizing daycare services, and outsourcing lawn care to create more family time. Bryan emphasizes the need for financial discipline, avoiding impulsive purchases, and instead investing in services that can alleviate stress and create more personal time.

The discussion turns to the challenges of people-pleasing tendencies in the workplace and with clients. Both hosts stress the importance of setting boundaries, learning to say no, and prioritizing one's own family and well-being over excessive work hours or unreasonable client demands. They also touch on the evolution of the HVAC industry, discussing how younger workers are bringing a fresh perspective on work-life balance and how businesses are adapting to these changing expectations.

Key topics covered in the podcast:

Creating a "summer survival guide" for HVAC professionals
Strategies for maintaining work-life balance during peak seasons
Financial planning and discipline to support personal priorities
Setting boundaries with employers and clients
The evolution of work culture in the HVAC industry
Balancing the desire to help customers with personal and family needs
Implementing business practices that reduce stress and improve quality of life
The importance of contentment and avoiding the trap of constant comparison
Adapting service hours and availability to suit personal and family needs
Overcoming the urge to always be available and learning to prioritize personal time

Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool.

How do Inverter Air Conditioners Work? - Short #201 Jul 09, 2024

Show notes

In this short podcast episode, Bryan answers a listener-submitted question: How do inverter air conditioners work?

Inverter-driven systems have variable capacity to match loads. We can provide cooling or heating BTUs to match the needs of the space without overcompensating or undercompensating and causing temperature swings. Load matching also helps us get better efficiency out of the system. High-humidity climates also benefit from load matching, as equipment doesn't dehumidify well unless it has been running the entire time.

When set up and designed properly, variable frequency drives (VFDs) improve comfort, efficiency, and even dehumidification. You can "overclock" your compressor to get more BTUs out of it without oversizing, particularly when you have high heating loads due to the cold weather.

Inverter-driven equipment takes AC power in, runs it through a rectifier circuit, and turns it into rough power that resembles DC power. The current is then smoothed out and goes through the inverter bridge circuit. Unlike an analog AC wave, we rely on pulse-width modulation (PWM) to simulate three-phase power and control the motor speeds according to a space's needs.

We typically troubleshoot residential inverter-driven equipment by following the manufacturer flowcharts and possibly by communicating with tech support. Commercial VFDs are external to the motors and tend to be a bit more universal rather than manufacturer-specific.

Watch the livestream about VFDs & inverters with Matthew Taylor and Corey Cruz HERE, and you can also watch the livestream about cold climate heat pumps with Ross Trethewey and Russ King HERE.

Learn more about NCI's High-Performance HVAC Summit at https://www.gotosummit.com/.

Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool.

How to Size Dehums w/ Tim De Stasio Jul 04, 2024

Show notes

In this episode of the HVAC School podcast, host Bryan Orr interviews Tim De Stasio, an experienced HVAC practitioner and consultant. Tim shares his journey in the HVAC industry, from his early days in vocational school to running his own contracting business for 12 years. He now focuses on consulting, design, and contractor training, allowing him to pursue his passion for HVAC while sharing his knowledge with others.

The conversation delves deep into the world of dehumidifiers, exploring their importance in modern HVAC systems, especially in humid climates. Tim emphasizes the need for supplementary dehumidification in many homes, particularly during part-load conditions when air conditioning systems may not effectively control humidity. He explains the process of selecting and sizing dehumidifiers, stressing the importance of considering factors such as peak latent load conditions, actual dehumidifier performance under real-world conditions, and static pressure effects on output capacity.

The discussion also covers the critical role of proper envelope sealing and ductwork in managing humidity. Tim advocates for addressing these issues before installing a dehumidifier, highlighting the importance of blower door testing and fixing any leaks. The podcast concludes with insights on dehumidifier control strategies, the limitations of ERVs in humidity control, and the potential risks associated with uncontrolled outdoor air introduction into HVAC systems.

Key topics covered in the podcast:

Tim De Stasio's background and transition to HVAC consulting and training
The importance of supplementary dehumidification in various climates
Selecting and sizing dehumidifiers based on peak latent load and real-world performance
The impact of static pressure on dehumidifier output capacity
The necessity of addressing envelope and ductwork issues before installing dehumidifiers
Strategies for controlling dehumidifiers in conjunction with AC systems
Myths about dehumidification, including misconceptions about variable speed equipment and ERVs
The potential risks of uncontrolled outdoor air introduction and the importance of proper ventilation strategies
Resources for learning more about dehumidification and HVAC best practices

Contact Tim at timdestasiohvac@gmail.com or follow him on LinkedIn HERE. You can also follow David Schurk on LinkedIn HERE.

Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool.

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