Jim Bergmann and Michael Housh join Bryan to talk about testing A/C vitals. They discuss the new vitals mode in MeasureQuick and how it works. As with many of MeasureQuick's other functions, vitals mode is an invaluable tool for green and experienced HVAC techs alike. The new vitals mode helps us with charging, airflow, and other staples of A/C testing and commissioning. Vitals mode allows the user to give MeasureQuick some information about the system; when they provide that information, MeasureQuick can instruct them to use the most appropriate charging method. When you add enough refrigerant to create a liquid seal, you will begin to see a temperature drop across the evaporator. At that point, MeasureQuick would inform the user to stop charging and raise the airflow. MeasureQuick's vitals mode guides the user through the commissioning process by focusing on the main drivers: airflow and charging. The app also focuses on secondary drivers, including low-pressure, high-pressure, superheat, and approach. You can get to vitals mode by hitting the "trending" button twice. At the bottom, you can start with the quick charge; you then choose your refrigerant and the charging method. Vitals mode can help several new techs during the cooling season. The weigh-in feature helps prevent overcharging, which is a problem that's all too common. MeasureQuick has been working to fill the gaps in training by helping technicians do jobs correctly and avoid the confusion of listening to many different senior techs or trainers. Jim, Michael, and Bryan also discuss: Subcooling and line length Approach Sensible capacity vs. latent capacity Target temperature split Superheat Trade school vs. field training for charging Increasing the quality of HVAC instruction   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this short podcast episode, Bryan explains how to use liquid line temperature as a quick diagnostic indicator on split A/C systems. Liquid line temperature is one of the first things to check when you approach a system. Checking that temperature is also a great way to get into non-invasive testing. The temperature should be between 4 and 15 degrees warmer than the outdoor temperature (unless it is wet). If the liquid line is cooler than the environment, then there could be a restriction. If there is a restriction, you could have a clogged liquid line drier or a partially closed service valve. When you have a larger condenser coil in relation to your capacity, your liquid line will be closer to the ambient temperature; the refrigerant must be at a higher temperature than the outdoor air to give off heat. You should also not see a pressure drop across the liquid line. An important value is the condensing temperature over ambient (CTOA). On a normally operating piece of equipment, the condensing temperature will be 15-30 degrees above the outdoor temperature. The CTOA is a design feature that sets the differential between the saturation temperature and the ambient temperature. So, before the refrigerant subcools, it will be 15-30 degrees above the outdoor ambient temperature. Subcooling goes below the CTOA. If we have a 30-degree CTOA and subtract 10 degrees of subcooling, then our liquid line will be about 20 degrees above the ambient temperature. If you add up all the numbers and find that the liquid line is warm, then you likely have an airflow restriction (dirty condenser, etc.). You shouldn't see a temperature differential across the liquid line; if you see one, then you likely have a restriction in the liquid line or lines that are too long.   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this live podcast episode, we discuss viruses, bacteria, and fungi. We also explain how they interact with HVAC equipment, their effects on indoor air quality, and how businesses can protect their customers and employees. Since we work with the public, we can minimize the risk of viral transmission by keeping our distance between others and avoid handshakes and other forms of contact. However, we also have to respect the feelings of the customers we're serving. Many people confuse viruses, bacteria, and fungi (mold). All particles are small and would typically pass right through a MERV-8 filter; you typically need MERV-11 or better to catch all three. While our equipment can harbor those particles, the equipment can't create them. While bacteria and fungi can propagate on their own, viruses need a host to propagate.  Viruses can go airborne, but they only grow and propagate inside our bodies. So, we don't need to worry about minimizing growth on surfaces or inside HVAC equipment. We make it harder for bacteria, fungi, and viruses to survive by keeping the relative humidity between 30% and 55%. That is part of the reason why certain viruses become prominent seasonally, though our own immune systems are also a factor. Probiotic cleaners also exist to attack biofilm on surfaces. To achieve that goal, probiotic cleaners promote good bacterial growth to fight the bad growth we want to eliminate. We may expect probiotic technologies to improve even more in the future. However, those won't affect viruses strongly because viruses don't GROW in equipment. We also discuss: Virus transmission Masks and gloves Mobile air scrubbers HVAC technicians as essential workers Microns Legionella COVID-19 vs. influenza HEPA and activated-carbon filtration Photocatalytic oxidation (PCO), bi-polar ionization, and UV lighting Is oxidization effective? Good vs. bad bacteria and probiotic cleaning   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this short podcast episode, Bryan talks about science and how to balance practice and experience with the “why” behind what we do. He also explains how either one can cause an error if you aren’t careful. Science is not just about reading nerdy theories in books; it's all about understanding why the processes in our world. In that sense, many of us field technicians are scientists. When we use problem-solving skills in the field, we try to understand what is going on and why our proposed solutions might fix the issue. We partake in experimentation all the time when we look for solutions, too; we formulate hypotheses about what will happen when we apply a fix, and we test our hypotheses by seeing what happens. However, there has also been a rise in pseudoscience, which uses observation to come to a conclusion WITHOUT the due diligence of experimentation. We see this quite often in brazing; some old-timer technicians use poor brazing practices but still manage to get leak-free joints. While those brazing practices may work on the low side of the system, you can't expect the results to be the same when brazing in a compressor. The methods may "work" in some cases, but they're not backed by scientific understanding, so they can't produce good results under higher-pressure conditions. Science is not perfect and can go wrong, though. When we don't understand the application and the "why" behind the work, we can't expect products and tools to work as they're meant to work. That's when errors pop up. To avoid those errors, investigate the "why" and test out your hypotheses. Bryan also discusses: Multiple ways to do things Thomas Edison vs. Nikola Tesla Poor brazing practices Not pulling a deep vacuum Ozone generators and deodorizers "Hack" work   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

We discuss some of the new, possibly strange-sounding business processes we've decided to implement at Kalos in 2020. First of all, we are going to add terms and conditions that our customers must agree to. These terms and conditions include a "hold harmless" disclaimer regarding viruses, fungi, and bacteria. Florida forbids us from discussing mold, so a "hold harmless" disclaimer protects us from liability for something we aren't even allowed to discuss. We also have to reinforce automobile safety to protect ourselves and our employees. Small fender-benders can spiral into serious legal problems when we lack proper evidence, so we decided to use GPS technology and dashcams in company vehicles. That way, we can collect more data on incidents to see who is really at fault in an accident. We've also clarified safety practices in our employee handbook. New business processes also include changing how we pay people per diem. In our construction and refrigeration divisions, our employees eat and sleep out of town, so they need compensation. We've put new processes in place to reimburse employees for those expenses without taxing that money. We also set rules based on the time of year, zip code, and average food/lodging rates. Overall, most of our new business practices are going into place to make Kalos a safer workplace with more efficient administrative processes We also discuss: Warranties on certain products "Assumption of privacy" Company credit cards vs. gas cards Dispatch/service software IRS "proof of transactions" Nurse triage and dealing with injuries Worker's compensation rates OSHA training and SDS Document signage and subcontractor agreements SambaSafety Slack vs. ServiceTitan Keeping track of parts, inventory losses, and supply house plans "Kaizen"   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

Ben with Infinitum Electric comes on to tell us more about his super-innovative, groundbreaking PCB (printed circuit board) motor technology that we saw at AHR 2020. The Infinitum motor is a relatively simple permanent magnet motor that can also work as a generator. Infinitum got its start with generators, and the groundbreaking new motor technology works quite similarly to generators. These motors can also work with variable frequency drive technology. In this groundbreaking motor, the traditional stator has all of the iron and copper taken out, and copper is etched into the circuit board. When you take the iron out of the equation, you eliminate core losses and get a much more efficient stator. Instead, electromagnetic waves travel through the air via flux transfer over the air gap, which rotates the motor. The machine has low inductance overall. Energy efficiency is the core of Infinitum's philosophy. The original idea for Infinitum's motor came from optimizing performance in specific applications; Infinitum increased the efficiency while keeping the motors small and quiet. After that, the motor outgrew its application and opened the doors to innovation. There is great promise for Infinitum motors in the aerospace industry because they are lightweight, quiet, and highly efficient. However, Infinitum is also interested in short-term applications, including fans, pumps, and compressors in the HVAC/R industry. Ben and Bryan also discuss: Generator vs. motor technology VFD system integration How to operate motors with low inductance Investors and why they choose to invest Development of major automotive and aerospace technology Serviceability of the motors Using printed circuit boards as stators Starting conversations with OEMs   Check out more about Infinitum and its new motor technologies at infinitumelectric.com. Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

Rick from Certified Refrigerant Services joins us to talk about recovery and refrigerant management. He also explains what to look for and do to get the most from your program. A refrigerant management program offers recovery services, reclamation, and other options for processing refrigerants. Rick's company also buys and sells refrigerants. With his line of work, there are also plenty of opportunities to educate contractors. The goal is to reduce refrigerant mixing and keep high-quality refrigerant in circulation. Mixing refrigerants kills their value, though it is sometimes inevitable. On the contractor's side, you can take steps to prevent mixing by diligently using tags and weighing the charge each time. When we commit to careful recovery practices, we can keep high-quality, discontinued refrigerants available for people who have those systems. Contractors can also do injustice to their customers when they recover into dirty tanks, though it can be difficult to understand those tanks' histories. As contractors, we have a lot of difficult decisions to make, but we must always act ethically in terms of EPA guidelines and put the customers' needs first. It's a bad idea (and illegal) to give customers unprocessed recovered refrigerant charges. You can't possibly know if the system has bad refrigerant (such as from a system that burned out) or other issues, so you're probably not helping anyone by giving them unprocessed recovered refrigerant. Quality is the key to the refrigerant management industry, and contractors can both contribute to the cause and benefit from it. Rick and Bryan also discuss: Refrigerant A/C vs. commercial chiller systems and mixing Recycling R-22 EPA refrigerant disposal reports Service vs. recovery cylinders Being proud of being in the HVAC/R trades How much should we really fill our tanks? Life cycle of air conditioners Refrigerant pricing R-410A recovery   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

Chris LaPietra, vice president and general manager of Honeywell Stationary Refrigerants, joins us to talk about some new releases from Honeywell. He also covers refrigerants in general. As our industry reduces its reliance on R-22 (and eventually R-410A), we have turned to more flammable solutions. There is a tradeoff in safety for the lower GWP, though. However, along with some slightly less flammable A2L refrigerants, Honeywell is releasing two new A1 refrigerants: R-466A and R-515B (N-15). These are non-toxic, don't catch fire, and have a lower environmental impact than R-410A and R-22. The Montreal Protocol was a groundbreaking initiative to phase out ozone-depleting substances to help slow down climate change. As a result, R-22 has undergone a phase-out. The Kigali Amendment is the next step, which addresses global warming potential and targets substances with high GWP for a phase-down. So, as R-410A will go in a similar direction to R-22, manufacturers have come on the scene; they are developing alternative refrigerants that address the global climate initiative. Instead of creating new HFCs, manufacturers are inventing new blends and HFOs to replace HFCs. Honeywell wants to avoid creating undue risk in the marketplace. So, they take feedback from their customers and make sure technicians feel comfortable working with their refrigerants. They also keep the best practices pretty similar to those of working with R-410A. Chris and Bryan also discuss: Residential HVAC vs. commercial refrigeration solutions The ZE product line ASHRAE terms and definitions How R-32 is made (and A2L refrigerant blends) Global warming potential (GWP) vs. ozone-depleting potential (ODP) How Honeywell develops new refrigerants Trading off efficiency for lower GWP E-cooling and the potential of the electronics market   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

Eric Kaiser comes on the live podcast to talk through some commonly repeated EPA myths. We also discuss how to get the most from your recovery machine and tanks. The EPA exists to interpret broad laws into specific standards, such as by translating climate initiatives into venting guidelines. One of the most common EPA myths is that you cannot charge a leaking system. If you can repair the leak and get the leak rate below the specified percentage, then you can recharge the system. Not every country allows this procedure. On the subject of refrigerant losses to leaks, making leaks is also NOT a valid excuse to vent refrigerant; the EPA tries to get us to minimize losses as much as possible. De minimis exemptions exist to allow for us to service a system properly, not to give us loopholes for venting. Overall, it's best to use probes to take your readings, not manifolds. R-22 is another controversial subject that gives rise to some EPA myths. R-22 is NOT illegal, but it is no longer being produced or imported. There are limitations based on the amount of charge as well, but recharging a system with R-22 is NOT a crime. When recovering with a recovery machine, you want to prevent junk from getting inside of it (such as from the recovery tank). To protect your recovery machine, it's good practice to run the refrigerant through a filter-drier when returning it to a system, though that won't fully clean the refrigerant. Eric and Bryan also discuss: The ins and outs of new R-22 guidelines Pulling down into a vacuum Low-loss fittings and refrigerant trapped in hoses Whose responsibility is it to keep records? Drop-in refrigerants, mixing refrigerants, and topping off Recovery tank safety basics and cleanliness How recovery machines work Recovering in the liquid phase Heat transfer in recovery PPE   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

Gurminder Sidhu joins us from NATE to talk about what NATE is all about and bring us some news about the new changes and improvements. NATE was created for the industry by the industry; the organization arose from a need to promote education and standardize HVAC qualifications. Today, NATE continues to address the industry's needs by offering education and certification for technicians. NATE also understands the need of explaining the "why" behind our daily work. The people at NATE also believe in continuing education and offer learning materials to techs of all levels, as well as study guides for their exams. People from all sectors of the industry contribute to the study guide content. These people also review it to ensure that everything in the guide is relevant and accurate. The study guides take what technicians have learned in the field and put them into a form that helps them prepare for quizzes. These guides also have practice questions, a glossary, and formulas. Technicians must take a core and specialty exam before the big NATE exam. When it is time for you or one of your employees to take the NATE exam, you can arrange a date and time to take the test at a local testing organization. NATE is currently working on an alternate pathway to certification for those who are new to the industry. This pathway has a series of five smaller exams that people can take in any order. You can take the alternative tests either traditionally or remotely with an online proctor. Gurminder and Bryan also discuss: Four levels of NATE certification The study guide creation process How employers benefit from employing a NATE-certified technician New NATE user interface   Get started or keep up with news from NATE at natex.org. Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

Alex Meaney from MiTek/Wrightsoft joins us at AHR 2020 to talk about some HVAC design myths and how to bust them in your mind. It was a really fun talk with a great guy. One common HVAC design myth worth busting is that we can use a set friction rate with a Ductulator to make duct systems work. The friction rate only applies per 100 feet, and it has different degrees of impact based on duct sizing and fan speeds. We CANNOT guarantee that a system will work if we subtract losses to filters, coils, and grilles until we reach a set friction rate (usually 0.1 or 0.8). We experience most of our pressure losses at the fittings, which the friction rate doesn't account for. To prevent some of these myths, we can move away from manual math and start using more software. However, we have to know what our numbers exactly are and what the performance conditions are. For example, filters can show a static pressure drop rating of 0.1, but that WILL change depending on the CFM. Velocity is a confusing area for techs because we have face velocity and duct velocity. Face velocity refers to the speed of air at the register whereas duct velocity refers to the air speed within the duct. These can get a bit complicated when you throw dampers in, but duct velocity doesn't have that much of an impact on the face velocity; the register has a much greater effect on face velocity than a damper in the middle of a duct. Alex and Bryan also discuss: Starting off by learning the wrong thing 12,000 BTUs per ton Radial duct systems What really is "static pressure?" Oversizing ductwork Creating vs. relieving friction Manual D Ideal velocity Variable-speed technology Efficiency vs. moisture removal Sensible heat ratio (SHR) and Manual S Latent loads   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

Andrew Greaves joins us again from AHR 2020. This time, he discusses what mentors and role models do in our trade and why they're important. Mentors are not just the grouchy senior techs who throw hammers at apprentices. Mentors have an active role in others' professional development; they spend a lot of time with their mentees and actively aid their growth. Not everyone is cut out to be a mentor, as the role comes with a lot of responsibility (and possibly stress). Role models indirectly influence others by doing good work and inspiring others to do the highest quality work; we should all strive to be role models. However, the mentees need to put in a lot of work and must have emotional intelligence. Both mentor and mentee need to ask questions about the work and each other. The relationship is all about involvement and intentionality. Mentors also have to care about their mentees as people, not just as students or technicians. They respect their mentees' values and acknowledge where their own shortcomings are when communicating with their mentees. However, mentors also know when to question and challenge their mentees when necessary. Mentees are entitled to clarity, and a good mentor understands that there has to be mutual understanding and trust in the relationship. Relationships take time, and mentors usually need to give their mentees a chance to prove their work ethic before they commit to the mentorship. As a mentor, you must understand that your mentee doesn't have your perspective, and that's where empathy and expectation management are required. Andrew and Bryan also discuss: Individual learning styles Formalization of mentorship Investment in training vs. mentorship "Multimedia" and internet mentorship Dave Barefoot stories How to start a mentor-mentee relationship Filtering through unsuitable mentees Setting expectations before goals   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this podcast, HVAC School team members Kaleb and Leilani walk the floor and talk to various people about their products and companies at AHR 2020. Bryan also has a quick conversation with Frank from HVAC Outlawz. The newest RectorSeal surge protection (RSH-50 with the 60A disconnect) uses MOVs and gas discharge tubes, which work together to fight off power surges. The effectiveness of the product has allowed RectorSeal to give customers a lifetime warranty on their product. RectorSeal also has a new drain cleaner, Nu Line. Nu Line eliminates the biofilm in drains AND protects the drain from growth after cleaning. One of Bryan's AHR 2020 highlights was speaking with Frank of HVAC Outlawz. Frank wants to push the limits of what we know so that we can perform the best work possible. In his 15 years, he has worked with a wide range of equipment. His experience led him to start creating content on Facebook and Instagram (also with inspiration from Andrew Greaves). He also involves himself in local trades education, which is the key to making our trade accessible to young people. Emerson is also an HVAC titan that participates in events like AHR 2020. Emerson is at the forefront of new HVAC technology and always focuses on doing the right thing for contractors, wholesalers, and industry partners. We also explore: Gas discharge tube technology Various applications for Line Sets Inc. products Measuring duct pressures and velocities with Dwyer Refrigeration Technologies Venom Packs Maintaining building envelope integrity with Friedrich A/C Recovery units with NAVAC Emerson's Sensi Predict and Multiple Thermostat Manager Fieldpiece vacuum pumps and Job Link probes Ultra-Aire dehumidifiers RGF Environmental Group REME Halo LED Women in HVACR Ultravation Synergy   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this live recording from the AHR Expo, Kaleb Saleeby, Nate Adams, Michael Housh, and Steve Rogers discuss building performance. The building science world is an exciting place; we're all excited about improvements to reheat dehumidification, which is when we use waste heat to take care of humidity without cooling. As equipment becomes more efficient, we also look forward to tackling new challenges that make us think more broadly. New people are also stepping up, using new tools, accessing more knowledge, and doing better work. Building performance is becoming more important in HVAC via HVAC 2.0, which focuses on design efficiency. However, the biggest challenge right now is making HVAC 2.0 sustainable and profitable. We must simplify and scale building performance; when we make it accessible, we can work it into the HVAC industry and do more thorough work. One of the challenges to widespread adoption is the lack of experience with building performance. The average technician simply doesn't have the needed exposure to building science concepts and practices. Perhaps the best way to bring people into the building science side of the business is to work on the techs' own homes. We need to bring the personal part of building performance to the technicians and their families if we want to see widespread adoption of HVAC 2.0. We also need to make building performance solutions accessible to the consumers. Although the solutions may be too expensive for many customers right now, the goal is to start holistic comfort conversations. Kaleb, Nate, Michael, Steve, and Bryan also discuss: Tapping into the engineering mindset Economic sustainability Psychrometric charts vs. app-based learning Math vs. software Working with techs and the CSRs The Gulf of Disappointment Contractor relationships Economic and environmental impacts Fossil fuels Upgrading the electrical grid Propane   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

Mike from Refrigeration Technologies talks to us about his journey in business, some new and old products, and how well the business is growing. Refrigeration Technologies tries to make products that do the job correctly the first time and are safe for techs to use. The products are odorless, don't burn skin, and are safe around food. John and Mike Pastorello are passionate about using chemistry to make quality products that make techs' lives easier. Mike joined his father's business full-time when he was 23; he performed a lot of the menial tasks while his father developed the products. Nylog is perhaps one of the most popular yet controversial products. The product is made of refrigeration oil, which is inside the system anyway. While many people may be suspicious of additives to avoid warranty complications, nothing inside Nylog will harm the system. It also won't clog the lines when used properly. Lately, Mike and John have made highly concentrated cleaners that have taken all the excess water out of coil cleaners. These Venom Packs are pure concentrate, meaning that they are very strong but maintain their original cleaners' non-toxic properties. They are also easier to store and come in brightener, all-purpose, evaporator, and condenser varieties. Refrigeration Technologies cleaners also work on tough bacterial zoogloea, a common plague in humid climates like Florida. The Pan & Drain Treatment also works very well to clean out and treat drains. The spray is also tough on odors. Refrigeration Technologies has experienced a lot of growth recently. Most of the company growth happens in John's lab, as the products are constantly getting better. The goal is to improve the quality without raising prices, and improvements to packaging are crucial to that element of growth. The company is also very active on social media and actively takes feedback.   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

Richard Trethewey from This Old House joins Bryan on the podcast and tells his incredible story and shares some encouragement and laughs. Richard works with his sons, Ross and Evan. He has always worked in a family business and then left it to start his own with his sons. Family businesses truly are the backbone of this industry, as our business attracts lots of family-oriented business owners. Richard's sons volunteered to join the business early on. This Old House started off with a phone call from PBS about a home-renovation show idea; Richard had to start the show from scratch with no money, but his father agreed to do the show. The first years of the show were difficult because that was before Home Depot and the internet became popular, so DIY home renovation was still pretty new and unknown; Richard worried about "selling the secrets" of the trade. However, his main concern was with doing good work and setting a positive example for others whenever they watched him. If Richard had to give one piece of advice to young people, it would be to join the skilled trades. Many high-profile jobs have an ebb and flow of good workers, but the skilled trades ALWAYS need good workers. Regardless of where people are or what the market looks like, people will need comfort. One of the most rewarding things about being in the skilled trades is being able to inspire others to obtain the skills to provide for themselves. Nowadays, Richard spends time learning about new technologies and feels excited by the prospect of making American technology even better. He looks to Western European HVAC technologies as an example of what we can do. Richard also looks forward to empowering and inspiring the new generation and getting them to a point where they have pride in their work.   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

This podcast is by Sal at Products by Pros, featuring Bryan Orr of HVAC School. In this episode, Sal asks Bryan all about micron gauges.   Products by Pros Guest: Bryan Orr   What should technicians look at when deciding on a micron gauge? You should look for superior accuracy and resolution, especially if you'll be doing decay testing. You need to see what the trends are in clear detail. (The Bluvac app makes that easy.) Why should a tech even use a micron gauge? You use a micron gauge to verify that you have pulled a proper vacuum. What role does fear or pain play in the use of micron gauges? People respond primarily to pain; most technicians in the field know what they can get away with to avoid the pain of punishment for bad practices. What type of technician doesn’t care about proper vacuum or micron gauges? They typically come from companies that don't care about having clear startup and commissioning practices. What is the cost of adoption for high-end tools? Technicians think in terms of the tyranny of the urgent. They have to take time to learn it, and many of them don't have that time. What are the pressures techs deal with? Scheduling pressures are already immense, and field techs are also under constant pressure to get work done and do their jobs even better. How can techs save time and relieve pressures? Learn how to do things right and become proficient with newer, better tools. How do you pull a proper vacuum? Don't use leaky manifold gauges during evacuation; just use good-quality vacuum-rated hoses. Use core remover tools and keep your micron gauge as far away from your pump as you can get it during evacuation. What are the incentives for techs to do things properly? A common thread among many techs is that they want to avoid blame; if we focus on reducing blame, then techs might feel more encouraged to learn and do things correctly. (There will always be sticks in the mud, though.) What role does integrity play when it comes to business owners doing things properly? Integrity comes in when we show techs how to do procedures right. When you teach techs how to do things right, the work will speak for itself, and your company will earn a positive reputation. What micron gauge from AccuTools would you suggest for technicians? I recommend the Pro for new techs or installers, the LTE for intermediate technicians, and the Micro for pros. Why do you consider AccuTools micron gauges reliable? I consider those products reliable because they work consistently with the typical wear-and-tear that's expected in the field. Except in cases of extreme abuse, they seem to maintain their sensing abilities very well.   Looking to learn more? Go check out hvacrschool.com/evac or the AccuTools YouTube channel HERE. Want to have your local suppliers carry AccuTools? Reach out to [email protected] If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

Rachel and Eric Kaiser join us to talk about connecting STEM concepts to the trades. They also explain how to teach STEM in a way that sticks. STEM refers to science, technology, engineering, and math. In traditional classroom settings, teachers usually tout these subjects as the ones that lead to the most promising careers. However, STEM concepts are not limited to their respective subjects; we use many of those scientific and mathematic concepts in the trades as well. Rachel believes that undergraduate programs would be more effective if they focused more on teaching critical thinking and less on making students meet requirements for degrees. Eric believes that traditional education needs to be more holistic; right now, trades education fixates on details; that approach may help for teaching specific tasks, but it doesn't broaden the students' knowledge. We can start talking about STEM more broadly when we start eliminating stigmas around STEM topics. For example, many students dislike math, but many of those people still use math effectively in several real-world applications without knowing it. We can break down that stigma against math to start having productive discussions and connecting STEM to the trades and other careers. The next step is to spark interest in others so that they seek out new STEM knowledge. The HVAC trade has many scientific concepts in play, even though we focus on diagnostics and field techniques at work. Most of our diagnostic skills are informed by the principles of heat transfer and phase changes. Rachel, Eric, and Bryan also discuss: HVACR Training Symposium Undergraduate vs. graduate programs University research and funding Principles of algebra in real life Gas laws and galvanic corrosion as chemistry concepts in HVAC Theoretical vs. diagnostic vs. instructional applications Continued learning vs. degree programs Applications and limitations Hands-on BEFORE theoretical Choosing to learn Improving safety and productivity through education   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

This short episode is a review of a list of installation reminders made by Kalos manager Jeff Crable. Kalos is doing a bunch of these installs for a commercial customer. Hopefully, the business leaders can take a few things from our checklist and help out their installers. Whenever we do an install for our large commercial customers, we give our installers a long checklist of reminders; that way, they can do the best install possible. Some of those install reminders include: Don't rush the details. Ensure the drain line is clean, pitched correctly, trapped, ventilated, and insulated. Install float switches in the unit and auxiliary pan. Wire in series and test. Replace the auxiliary drain pan or ensure that it's in good condition and has proper sizing. Hang the auxiliary drain pan WITH Unistrut; don't hang with wire. Install a new thermostat. Attach and hang the ductwork properly; silver-tape will NOT support duct board plenums. Replace incorrectly sized breakers (for licensed electrical contractors only). Replace old and faulty disconnects (for licensed electrical contractors only). Ensure that the outside conduit is watertight or replaced. Anchor condensers properly with isolators if the pad is attached to the building foundation. Mark the unit with the correct number using paint and stencils or vinyl stickers. Post pictures of the units and data tag in the appropriate location in our communication software; make detailed notes. Address vertical air handlers and take them as they come. If a unit is in a difficult area, try moving to a more accessible place if you can. Pour gallons of water into the drain pan and observe draining. Listen for noises of concern. All work will be checked by lead techs or managers. Get everything right the first time if you want a full bonus.   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this face-to-face discussion, Bryan and Kaleb share some tips for diagnosing and replacing the reversing valve on a heat pump. These valves may also be known as four-way valves. Kaleb and a trainee recently had to diagnose a heat pump with a scroll compressor. The motor was also over-amping due to a failed capacitor, and the compressor was making a metallic grinding noise. Because reversing valves are pilot-activated, they need a pressure differential to shift, so the scroll plate can sometimes pop up and make noise during bypass. Another possibility was that the compressor could have been running backward, but that wasn't the case. There are some cases when techs misdiagnose a compressor problem as a reversing valve failure; however, in Kaleb's case, there was a problem with the reversing valve that then caused compressor failure. To determine if a system has a reversing valve issue, you should look at the temperature difference across the valve (more than 3 degrees). Another thing to look for is an abnormally low compression ratio (high suction, low head pressure). You also want to watch the compressor amperage, as it will likely be lower than normal. When doing more advanced tests, such as delivered capacity tests, use Bluetooth tools to make your life a lot easier; that way, you can clamp your probes on. When Kaleb replaces a reversing valve, he cuts them out wherever possible. If he can't cut them out, he sweats them out and sweats the new one in. Sometimes, it's also easier to remove the entire condenser coil during replacement. Kaleb and Bryan also discuss: Common suction port Causes of compressor damage Unreasonably hot discharge lines Compressor amperage drop Common suction, common discharge lines Kaleb's compressor replacement Cutting out suction dryers Sweating out reversing valves in Trane units Purging with nitrogen before a pressure test Deburring properly   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this short podcast episode, Bryan talks about the times he has been hoodwinked in his career. It's time to name and shame. One time at a trade show, Bryan came across a product called KVAR. KVAR is already an electrical term for kilovolt-amps reactive; those are volt-amps that show up and generate heat but don't do anything useful, just like foam in a beer mug. So, the product supposedly balanced out the power factor to save energy. However, power companies don't charge based on VA; they charge based on wattage, which already accounts for the power factor. So, the KVAR products made no actual difference; the KVAR motor was simple and very inefficient, which did little to improve energy savings. Bryan was hoodwinked because he didn't ask the right questions. He should have asked about the difference between volt-amps and watts, and he should have asked to see hard data about energy savings. Hoodwinking happens quite often in our industry; the only way we can prevent it from happening to us is to learn more and ask the right questions. So, how do we avoid hoodwinking? The best thing we can do is ask to see the data. Don't accept platitudes, graphs, or name-dropping; ask about the test methodology and specific details. Indoor air quality (IAQ) is an area that has a high potential for hoodwinking. Unfortunately, the IAQ products' data is often incomplete and only tests for a few contaminants. While the products have the potential to do a lot of good, there is potential for deceptive marketing and lazy science. Something to remember, however, is that not everybody who hoodwinks you has bad intentions. They sometimes don't understand what they're doing or are more familiar with marketing than science.   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

This live podcast episode is all about pool heater talk. We cover gas pool heaters and pool heat pumps, explaining how they work and common issues. Pool heat pumps work a lot like air conditioners, but they have heat exchangers that help transfer their heat to the water. Instead of having a typical condenser, a pool heater has a unit that works like a heat pump's outdoor coil in heat mode. There is usually an option to cool the water, but there are almost no cases where someone would want to use that mode. The heat exchanger is the core component of a pool heater, and this part has evolved a lot to improve efficiency and reduce the effects of water chemistry. The old designs were cupronickel tube-in-tube heat exchangers where the refrigerant and water flow in opposite directions. Unfortunately, these corroded and failed easily. Titanium coaxial heat exchangers replaced those, though they can still fail. If heat exchangers fail, water can get into the refrigerant circuit; when that happens, the whole heat pump will fail prematurely. Actuators are also components that commonly cause issues. Gas pool heaters work similarly to gas furnaces, so they tend to work better than heat pumps in low-ambient conditions. However, they have their own set of challenges. They have very short lifespans in Florida and corrode easily because steel, heat, chlorine, and water all interact in the same area. Inducer fans especially tend to rust out easily. We also discuss: Manufacturer quality control Hooking up gauges Water level and flow Low ambient conditions BTUs Float switches Internal thermal overload Heat and water pressure losses Temperature sensor issues on pool heat pumps Pool vs. spa mode Special considerations for indoor pools Flame rollout Cleanliness issues Double-lugging Circuit breaker failure Piping configuration and valves   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

Alejandro Rios from True Refrigeration comes on to talk about self-contained R290. He explains what it is, why to love it, and how to service the sealed system. R290 is pure propane, and it has recently made a name for itself as an emerging refrigerant. It is an A3 refrigerant, meaning that it is non-toxic and highly flammable. As we move away from HFCs and other refrigerants with high global warming potential (GWP), we will encounter more flammable refrigerants, usually A2L and A3 refrigerants. R290 is a natural refrigerant and has a GWP of only 3, making it more attractive than 400-series blends and some A2L refrigerants. You can also vent R290 because it has such a low GWP and an ozone-depleting potential (ODP) of 0. Self-contained systems that use R290 have a relatively small charge. However, they effectively run colder coils. Due to the colder coils, these systems have a net refrigeration effect (NRE) about 30% better than previous equipment models with other refrigerants. R290 is also versatile and can work in medium and low-temp refrigeration. Many of the service procedures are quite similar to other refrigeration systems. However, you have to be EXTRA diligent to check for flammable gas leaks; you must use a combustible gas meter for leak detection, NOT your typical electronic leak detector. Like most self-contained equipment, True's equipment is factory-sealed, and you must braze in your own service ports. However, as long as you vent the refrigerant in open areas and purge the line with nitrogen, you normally don't need to worry about anything catching fire. Alejandro and Bryan also discuss: Regulations for self-contained systems Terminal venting High-efficiency R410A systems Small charges Residual refrigerant and evacuation Adding service ports and sealing them Refrigerant recovery with SHORT hoses POE oil Energy savings   Check out True's YouTube channel HERE. Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this short podcast episode, Bryan explains what happens when your low-voltage circuit puts out a lower voltage than it should. Bryan recently received an email asking about the low voltage on a 20-ton split system with a long control wire; the voltage coming back to the condenser is only 19 volts, so there was some contactor chattering. First, in a case like that, you'll want to figure out why the voltage isn't as high as it should be. The control wire and line sets could be longer than the design specs, which may contribute to the problem. If the distance between components is the main issue, then you can use a relay to mitigate voltage drop and amp draw. You'll also want to check that you've tapped the transformer correctly. Since most transformers are single-phase, they'll probably start off tapped to 240v; when you're dealing with three-phase equipment, you must ensure that the transformer is tapped to 208v. One of the obvious issues to check is the voltage drop. If 26 volts are coming out of the transformer but you're only measuring 19, then you're clearly losing volts and have some resistance. Think about ALL of the conductors; is the drop the same across all of them? If so, then you've likely got a length and wire sizing problem. You can correct that issue with proper wire sizing; you can't always control the length, but if you can, then it's a good issue to address. If there's an issue with only one conductor, then the switch could have a problem, or there might be some wire splices. If the load is drawing higher current than it should, then something could be impeding the motion on the solenoid, contactor, or another electrical component.   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this live podcast from the Castbox app, we talk about codes and common causes for failed inspections. We talk about these topics both broadly and with some specifics. Many of the places where we fail to meet codes are on the electrical side. Electrical components have fire and electrical shock hazards, and codes are stringent for arc and ground fault protection. Leaking current to ground can shock someone, and arcs can cause damage to property and human life. We commonly see failed inspections due to improper marking on the air handler. In the HVAC industry, we have specific wire and breaker-sizing codes for our trade (440 in the NEC). Inspection failures are common in this area, as it's easy to leave the incorrect breaker in place. You also must have a disconnect or easily accessible circuit breaker that can function as a disconnect. In our market, we must also insulate drains and show proper attention to strapping, pitch, float switches, and cleanouts; otherwise, the drains may fail inspection (though it's rare). Clearances also come up quite often and are especially relevant to safety in our industry, as we don't want condensers blocking panels. Obstructed rooms or lack of egress are also common code violations related to safety. Anchorage is another safety-related code category, and there are special requirements in locations that are prone to high winds (like Florida) or earthquakes (California). You can't assume that units installed on rooftops have been anchored correctly, so be sure to check the anchorage. We also discuss: Pulling permits CO detectors PVC primer on condensate drains National Electrical Code (NEC) vs. AHJ Catwalks in attics Duct sealing and mastic vs. metal tape Florida Energy Conservation, Mechanical, and Building Codes Customer complaints Furnace venting and GAMA tables Smoke detectors Locking caps Wire protection Sealing boots   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this live podcast episode from the Castbox app, we have four techs join us to talk about common furnace issues and best practices. Those of us in heat-pump-dominant markets rarely have to worry about common furnace issues related to gas pressure and flow. In that same vein, we also don't have to worry about clocking the gas meter, which is a common practice on gas furnaces. Checking input and performing combustion analysis is critical to the diagnostic process AND can give you an idea of the unit's safety. There is no reason NOT to do combustion analysis when commissioning a furnace. Furnaces also have electrical components with flashing error codes. You must be careful when interpreting those codes, as multiple issues could show up under one code. (Compare it to going out on high pressure; that error doesn't necessarily indicate a pressure switch issue and could entail other problems.) Common codes deal with the flame sensor, but flame sensor failure is rare; the issue could come down to simple maintenance. When cleaning parts, the most important thing to do is make sure the carbon and debris come off; you don't have to overthink the cleaning material. Cracked heat exchangers are common issues that can present unsafe conditions, though they won't always have CO problems. If there is an issue with a cracked heat exchanger, the technician usually CANNOT turn off the system at the gas. (We usually CAN shut off the power at the switch, though.) Only the gas company can typically shut off the gas. We also discuss: Restrictions at ports Adjustments for altitude Carbon monoxide poisoning Proper drain line Clocking the gas meter in commercial settings Gas pool heater problems Parts that commonly need cleaning Steel wool vs. sand cloth High limit codes Clogged burner wings CO-monitoring Venting issues and negative pressurization Intake/exhaust pipe issues Power passing vs. consuming   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

David Richardson with NCI, author of Duct Dynasty, joins us on the podcast to talk about mixed air temperature and more topics of interest. When you bring outside air into the home, you introduce positive pressure into the home. That way, you can offset air lost via mechanical ventilation or through cracks, improving air quality. We often assume that the building will "breathe," but tighter constructions make it difficult for the home to bring in enough fresh air to offset harmful chemicals and VOCs. We need to measure two different kinds of airflow: fan airflow and outside air. When we have these numbers, we must figure out how much air is coming through the outside air intake. The fan airflow represents 100% of the air content after mixing has taken place. You can perform a duct traverse to get the airflow measurement; when you plot the fan airflow, subtract the two to know how much return air you're getting BEFORE mixing with the outside air. Once you have your airflow measurements, you must break those into percentages. You must determine the percentage that matches up with the temperature you want to use for the mixed air. Subtract the outside air from the fan airflow to get the CFM from your baseline. You could get 95% of your airflow from the return and 5% from the outside. Once you know the outside air temperature and the percentage of outside air, you will know how much the outdoor temperature will affect the return air and space temperatures. David and Bryan also discuss: How David got into writing Blown-in cellulose insulation Designed and undesigned leakage Duct traverse tools and procedure Dry-bulb vs. wet-bulb measurement applications SEER vs. AFUE Duct leakage   Learn more about NCI at nationalcomfortinstitute.com. Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this short podcast, Bryan briefly explains why we use a voltmeter to measure “voltage drop” across loads and switches. He also covers some of the differences between passing and consuming power. Many of us are naturals at using voltmeters already. Voltmeters have two leads, and those exist to measure the difference or potential between them. Voltage is a reference to what is going on between the leads; whenever resistance exists, we have a voltage drop. Resistance can sometimes be designed or undesigned. When we think about power passing and consuming, we should note that "consuming" refers to turning energy from a usable form to an unusable one. Stored energy becomes potential energy when it needs to do work. Power consuming results in work; a coil in a contactor or a filament in a lightbulb is a load (the load has resistance). On the other hand, power-passing components do not have resistance, and the charges merely move. We must keep the intended resistance in mind whenever we measure the voltage of energized components; resistance will impact the voltage drop. If you have a high-limit furnace safety, you will want to measure the voltage drop across the limit. There should NOT be a voltage drop across it because it is a power-passing component; there should be no resistance. Of course, you must determine if there is an energy potential present in the first place. Conversely, you SHOULD see a voltage drop when measuring the potential across a heater or fan motor. Overall, wires and switches are power passing components that should not have voltage drops across them. Heaters, compressors, and fan motors are all loads that "consume" power.   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

Ty Branaman from NTI comes on the podcast to share his passion for teaching. He also discusses his approach to impactful HVAC/R instruction. It can be difficult for instructors to create an appropriate balance between teaching theory and practical knowledge. Students and trainees need to have technical skills in the field, but they also need a solid foundation. Impactful HVAC/R instruction requires a balance of the nerdy stuff and physical skills; good instructors put the theoretical parts simply and give students the opportunity to apply theory to hands-on skills. Engagement is another important part of HVAC/R education. If students are sitting down for 15 minutes, that's too long; the students need to be moving and active with the learning material to stay engaged and help the topics stick. Ty emphasizes the importance of spending time in the lab instead of staying in the classroom the entire time. Unfortunately, many trade schools nowadays don't prepare students for fieldwork because there is not enough emphasis on working with equipment in education programs. The best teachers are those who love teaching AND working in the field, and trade schools need more people who are passionate about BOTH. Passionate technicians need to get involved in education by offering to be a substitute or guest speaker or by joining an education advisory board. Ty and Bryan also discuss: Teaching the refrigeration cycle What the current generation values and needs in education Dealing with distractions in the classroom Using mobile apps to supplement learning Teaching newbies effectively Creating an HVAC/R instruction program on a budget Old equipment Getting involved in education How to guide young people in their careers "Thinking outside the box"   Check out Ty's YouTube Channel HERE. Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this short podcast, we take a quick look at Bryan’s take on practical safety improvements. He also discusses the safety year in review at Kalos. Kalos had a great year in terms of safety. As the managers look back on the year, they attribute their success to having a practical approach to safety. To make practical safety improvements, we must be safety-conscious without obsessing over the risks of our job. Our jobs always have an element of danger, and our goal should be to minimize those and abide by OSHA standards. As an industry, we can do a better job of wearing our eye protection on almost every job. Ear protection is also an area we tend to neglect, especially in motor rooms and industrial environments. Ladders also provide a clear source of danger; we need to make sure our ladders are secure (tied off, set on level ground, etc.) and place some responsibility on our customers to give us a safe work environment. Electrical safety is also critical. Especially on commercial jobs, we should use proper lockout-tagout procedures when we can't monitor the power source while we work on equipment. We must also verify that no power is present after we shut off the disconnects. We also experience some fire safety threats, especially while brazing. Eye protection and gloves are critical if you want to keep yourself safe while brazing. (Gloves are also important when cutting sheet metal.) You should also know where fire extinguishers are anytime there is a fire risk on the job. Perhaps our most dangerous work environment is the road. We must avoid texting while driving, drunk driving, and other unsafe practices. We must also drive defensively to avoid accidents with other commuters who partake in unsafe driving practices.   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

Tim Fregeau from Goodway joins us to talk about descaling large equipment. He also discusses best practices and why they matter to you. Scale refers to mineral deposits that build up in any water source. Water can be brackish, rusty, muddy, or otherwise high in mineral content, and those minerals begin to accumulate on heat-transfer surfaces on large equipment. Scale can cause metallic components to weaken and leak, and it can block microchannel coils. The large equipment can't reject the heat efficiently or function as it should when it has scale buildup, so that's where descaling comes in. When it comes to chillers, you can either brush or chemically clean the tubes to remove scale. There will be times when you physically cannot brush the tubes, so you must rely on chemicals to descale the equipment. When you use chemicals, you pump the chemical solution into a low point of the condenser and make it come out of a high point. Factors that influence success are the chemical makeup, flow rate, and pump size. Boilers are quite similar to chillers, but the higher water temperatures come into play. Various chemical agents have different functions. Acids dissolve calcium, and inhibitors protect the base metals. Wetting agents reduce the surface tension and allow the chemicals to spread out. Penetrating agents allow the chemicals to get deeper into the mineral deposit to dissolve calcium and free up the rest of the deposit. Tim and Bryan also discuss: Plate heat exchangers Separating open loops from chillers Goodway clean-in-place systems Chemical selection and dilution Circulation time Why track oil levels and approach temperatures? Compression ratio and system efficiency Common cleaning challenges and mistakes to avoid Water pH Calcium spot tests Goodway products Legionella   Check out Goodway's site HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this short podcast episode, Bryan talks a bit about brazing temperature. He also covers how to heat your copper to the proper temperature. You can use torches with oxyacetylene or air-acetylene tips. Joining two metals with an alloy above 840 degrees classifies as brazing; anything that uses an alloy to join two metals below 840 degrees is technically soldering. When you join two similar metals by melting the base material (not using an alloy), that's welding. Another temperature of interest is 500 degrees; oxygen rapidly bonds to copper at temperatures above 500 degrees, so we will want to flow nitrogen while brazing to prevent cupric oxide (black scale) from forming on the copper. (We always recommend flowing nitrogen even if you are soldering below 500 degrees.) When brazing with a 15% silver alloy (with a phosphorus fluxing agent), you will want to reach a temperature of 1100-1200 degrees. Solidus is when the rod gets a putty-like consistency. However, we want liquidus, which is when the alloy can flow freely into the joint. The color of the copper will be either dark or medium cherry. To be clear, you DO want to see redness when brazing; the color shouldn't be very bright red or orange, but a dark or medium red is ideal. The brazing indicators hold true for copper-to-steel and copper-to-grass brazing as well. Aluminum brazing should stay below 1200 degrees; aluminum also doesn't have the same color indicators as copper, steel, and brass. Steel is complicated because it has a lower melting temperature, but it has much lower thermal conductivity than steel, so it will take longer to heat up and may heat unevenly. You also CANNOT use an alloy with a phosphorus fluxing agent when brazing steel or brass; you need a silver alloy with a separate flux.   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this live episode, we talk about heat pumps, why Bryan likes them, why other people don’t, charging and diagnosing them, and defrost. Even though heat pumps work best in warmer climates, they can theoretically work as long as the temperature is above absolute zero (-460 degrees F). Viewers across the USA install heat pumps in their markets, even in places with cold winters like Wisconsin. Ideally, the discharge line should be around 100 degrees above the outdoor temperature in heat mode. Although this rule of thumb appears to work in many different climates, it is only really applicable on single-stage equipment. When charging heat pumps from scratch, check the manufacturer data in heat mode. Airflow for comfort or efficiency is something else to account for when you're commissioning a heat pump; the CFM should be higher if you want the system to be efficient, but the building will be more comfortable if you have a lower CFM per ton. Airflow is especially important to control in heat mode, as small changes can noticeably affect head pressure. When it comes to defrost, heat pumps typically use a time and temperature strategy. Defrost cycles usually run at a certain temperature for a fixed time period. Heat pump defrost boards usually look a lot more complicated than they really are; when you come across them, stay calm and remember that they're just like any other board. We also discuss: Absolute zero Climate zones “Vapor line” Discharge superheat vs. over ambient W calls Supplementary heat and dehumidification Confirming airflow on a heat pump in heat mode Controlling mean radiant temperature (MRT) vs. blowing hot air Using in-duct psychrometers and manufacturer charts to assess system performance How reversing valves may fail or get stuck Thermal imaging applications Copeland compressors and mobile app Testing defrost boards Carrier vs. Trane & Rheem defrost strategies Demand defrost Suction pressure and compression ratio under frost buildup   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this crossover episode (rantcast), Bryan talks with Gary from HVAC Know It All. They vent about some of the phrases that techs throw around that are often false. Technicians often throw around the phrase, "[X] will void your warranty." However, the truth is that manufacturers can't really void a warranty. Some modifications may go beyond the scope of the warranty, but you don't simply make modifications that "void" the warranty. Techs may say that something voids the warranty to shut down the conversation or to create a selling point (preventive maintenance). In many (but not all) cases, the manufacturer won't even check the installation in the case of a parts warranty; all they want is the returned part, and they will often honor the warranty. Since many manufacturers want to keep their customers, voiding warranties left and right would be a bad business decision; the customer base would opt to work with new manufacturers. However, if there is evidence that the customer, installer, or technician damaged the product, then the manufacturer has a reason to void the warranty. In several cases, the proof must be substantial, and the proof often isn't substantial when using natural additives like Nylog properly. Keep in mind that using additives comes with a calculated risk; you must rely on research and your own judgment to make the best decision for the customer. In this rantcast, Gary and Bryan also discuss: R-22 is not illegal Heat exchanger warranties Lightning and other "acts of God" The Nylog question Why use thread sealants on well-made flares Relationships with manufacturers and suppliers Warranties and original homeowners Putting the customer's needs above the manufacturer's Who really is a hack? How everyone in the distribution chain can take responsibility Complaining respectfully online   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this short podcast, Bryan discusses the differences between air, nitrogen, and oxygen. He also explains why we should only use nitrogen for purging, flowing, and pressurization. You DON'T want to pressurize line sets with air because air contains water vapor and oxygen. Water acts as an oxidizer, and moisture can turn POE oil acidic via hydrolysis. You cannot dry out POE oil, and the acid can lead to compressor burnout. Nitrogen is non-reactive (unlike oxygen) and does not contain water vapor (unlike air). It also does a good job of chasing water vapor out of the lines. Because nitrogen won't react with anything we put in the line sets, it is an ideal medium for purging, flowing, and pressurization. Nitrogen DOES, however, change pressure with temperature; it obeys the gas laws, and you can see it in action when the pressure changes at different parts of the day (with varying temperatures). Oxidation can occur when oxygen reacts with copper to create a black scale called cupric (copper) oxide. It is similar to rust on iron; it is an undesirable form of corrosion. When the black scale comes off, it can get into screens on filter-driers and clog the system. You purge nitrogen to chase all of the air out before brazing. When you've finished purging, you use a flow regulator to reduce the nitrogen pressure (2-5 SCFH) to flow it during brazing. When we pull the vacuum, we only want nitrogen to be in the system; exposure to air should be very short, and any air in the system should be temporary. So, again, it's not a good idea to use air to pressurize the lines.   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this LIVE episode, we talk about diagnosing inverter-driven systems. We also discuss some of the issues and solutions for over-voltage. Inverter-driven systems, also called variable frequency drive equipment, provide comfort control across multiple zones in a building. Some systems may have multiple branch boxes that control various units throughout a building. These systems require a lot of patience; the diagnostic process can last a long time because you must test all of the terminals. Since these systems are very electrical-component-heavy, you may also encounter issues presented by lightning, power outages, or continuous high voltage. Installation errors are also common and can cause performance issues, such as incorrectly torqued-down terminals, nicked wires, and improper wire types. When these systems are on, line voltage runs into a bridge rectifier. So, the equipment takes alternating current (AC) and turns it into a form of direct current (DC). Capacitors smooth out the sine waves before running that current into the inverter, which switches the power into three separate phases, but the power doesn't look like typical three-phase AC power. Many power companies are familiar with single-phase AC equipment, so inverter-driven systems present a challenge. These challenges become clear in equipment near the initial power distribution source; inverter-driven equipment near the beginning of the power line is prone to excessive voltage and failure. We also discuss: Power surges and electrical damage ICM493 Loose connections Grounding Shielded conductor usage Pulse-width modulation (PWM) 230v-rated equipment Multi-stage equipment and airflow Bernoulli's principle Carrier Infinity equipment and locking out stages Ductwork and diffuser sizing Controlling radiant heat loads with multi-stage equipment Ventilation vs. dehumidification vs. heating and cooling R-22 retrofit refrigerants Metal oxide varistors (MOVs)   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

Jim Bergmann is back on the podcast. This time, he talks about common faults with high-efficiency 90+ condensing gas furnaces and their installation. Like A/C units, 90+ furnaces often suffer from clogged drain lines. Other common problems stem from issues with inputs, temperature rise across the appliance, trapping, and venting. On high-efficiency gas furnaces, procedures like clocking the gas meter are much more important than on an 80% gas furnace; you must clock the gas meter to get the proper inputs. To get the furnaces to condense properly, you need to make sure you control excess air and get the temperature rise in the correct range. During the adjustment process, combustion analysis remains important as ever on 90+ gas furnaces. CO poisoning is always a deadly possibility on any sort of gas appliance work, and too many things can go wrong. You must use a combustion analyzer every step of the way. In high-efficiency gas furnaces, you essentially condense water out of the fuel-air mixture. (Think about water dripping out of your car's exhaust pipe in the winter.) Many furnaces counterflow, meaning that the flue gas gets pulled down instead of wandering upward. We need cold return air to meet with cool flue gases for optimal condensate production. Two-stage 90+ furnaces also use two-speed induced draft fans, which normally require an exhaust accelerator. Issues pop up in retrofit systems when we don't update the venting system to prevent the recirculation of flue gases. Two-stage furnaces tend to be very efficient, but they may not be as comfortable as single-stage furnaces. Jim and Bryan also discuss: Chemical causes of premature failure Orifices, fuel pressure, and impingement Heat exchangers Order of operations for checking condensate drainage CO poisoning Byproducts of combustion Energy savings of 90+ furnaces over 80% furnaces Interlocked systems Filtration   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

Bryan explains the core differences between followers and leaders. There is nothing wrong with being a follower, but if you are ready to move into leadership roles, here are his tips. Leaders primarily leverage the work of other people. Conversely, followers have limits to their abilities and their earning potential; the leaders are the ones who set those limits. Good leaders create opportunities for others. Followers who attempt to be leaders are more likely to wait rather than move, complain rather than change, and assume rather than ask. Leaders actively seek out opportunities and tend to act rather than wait and assume that opportunities will come their way. Followers also accept but complain about the status quo, whereas leaders work to change their circumstances. Communication is a major area of difference between followers and leaders. Leaders ask questions, communicate, and propose ideas or solutions; followers typically hesitate to initiate communication and expect others to give them answers and opportunities. Followers also tend to think in terms of what they would do, not what they can actually do; they don't realize their abilities to make a difference and would prefer that the changes happen from the outside. On the other side, leaders seize opportunities to initiate change and create opportunities for other people (even if those are opportunities to fail safely). Moreover, the mark of a good leader is the number of followers who agree with their vision; leaders are also willing to make sacrifices for their followers and manage their resources well. True leaders also know how to listen to others, think broadly, and be kind but truthful; they don't take pride in being "brutally honest" or "knowing it all."   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

Some great live guests join the podcast to discuss the advantages, disadvantages, and challenges of ductless and VRF equipment. We started off working on ductless equipment with Mitsubishi, especially installing them in lanais. Sunrooms have large amounts of radiant heat coming in, and the heat load often warrants getting an A/C system just for the sunroom/lanai. We even began oversizing them a bit (which was a lesson learned). We also learned that mini-split ductless systems tend to have filthy blower wheels because moisture tends to build up on them. However, bib kits make cleaning the blower wheel in place an easy process. High-wall ductless systems also work in houses, not just sunrooms. However, they may have issues dehumidifying effectively. To remove more latent heat, you have to ramp down your blower and ramp up your compressor to get your coil colder. Overall, Bryan is not a large fan of using multi-zone ductless units in residential applications UNLESS they are replacing window units. VRF systems are typically used in commercial applications. The systems typically use cassette-type units or low-static fan coils, unlike high-wall ductless units. Although VRF and high-wall ductless units tend to have different sets of advantages and disadvantages, both of them struggle a bit with humidity and may need supplemental dehumidification. Overall, while VRF and ductless systems are desirable because they can control sensible capacity, those modulation capabilities can also lead to serious problems in wet climates. We also discuss: Condensate pumps Blower wheel set screw issues Ductless and VRF filtration Sensible heat ratio (SHR) VRF serviceability Dehumidification vs. efficiency Regional VRF manufacturing practices EER vs. SEER Daikin dry mode What should HVAC systems really control? Engineering commercial buildings VRF refrigerant loss ICM493 controls   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

Jamie is back on the podcast. This time, he talks about the merits and pitfalls of floating head pressure and why you might care. There is a relationship between floating head and floating suction, though the latter is easier to understand. You can stage fans to come on at certain temperatures, but you'll always be running fans above a certain temperature. When temperatures are below that temperature, you can save energy by not running the fans. However, you still have to worry about feeding the evaporator coil sufficiently. Floating head pressure refers to dropping the pressure differential across the metering device while letting it feed the evaporator coil properly. Allowing the head pressure and temperature to float is beneficial in applications that use large amounts of electricity and have low profit margins, such as grocery refrigeration. This practice is also great for energy savings in mild climates that stay below 80 degrees for most of the year. To use floating head, you first have to look at your metering device capacity. The metering device must have enough capacity to feed the evaporator coil and compressor adequately for the load conditions. Then, you must look at your other components' capacity balance, namely your evaporator and compressor. Sometimes, you also have to use floating suction to combat dehumidification issues that may result when you use floating head pressure. Jamie and Bryan also discuss: Energy efficiency benefits of floating the head pressure Compression ratio Fan staging and variable-speed fans Metering device sizing for load demands Electronic expansion valves (EEVs) vs. TXVs Evaporator and compressor sizing in relation to each other Evaporator pressure controls Oversized condensing units Temporary fixes to save product vs. permanent fixes Ease of locating and purchasing replacement parts   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this short podcast episode, Bryan talks about circuit breaker facts. He also explains why they trip, what they do, and some different types and considerations. Circuit breakers break the circuit during an overcurrent situation. These do NOT handle all overloads, such as locked rotor amps (LRA); these handle significant overloads, such as shorts (when current takes undesigned paths). In air conditioning, we can size our fuses and circuit breakers a bit larger than usual, which prevents tripping from small spikes instead of truly dangerous or prolonged overload conditions. There are thermal and inductive circuit breakers. A thermal circuit breaker uses heat to determine when to trip; these are common breakers but are prone to nuisance trips from poor connections or on days with high ambient temperature. Inductive trip breakers are magnetic and trip at a certain point of inductance; these are not easily affected by ambient temperature but can be expensive. A breaker's temperature can tell you a bit about its condition. Hotter breakers may be closer to tripping. However, arc fault breakers, a type of thermal breaker, can also run hot but work fine, which may confuse technicians. You can use thermal imaging cameras or infrared thermometers to compare breaker temperature. Dielectric grease is a good tool but requires plenty of attention. You need to have the right connectors before you even reach for the grease. The dielectric grease protects the connectors from corrosion (from the outside), and it should NOT go directly on the connectors. Some people also use anti-seize grease; no matter which grease you use, you must be careful and avoid adding resistance. Bryan also discusses: Proper torque settings Measuring voltage drop across the device Using breakers as switches Double-lugging Arc fault vs. GFCI   Learn more about Refrigeration Technologies HERE. If you have an iPhone subscribe to the podcast HERE and if you have an Android phone subscribe HERE.

In this episode from the archives, Dan Holohan joins us on the podcast and talks about his vast experience in the lost art of steam learned from long-dead men. Steam heating is a "lost art" nowadays; it has become increasingly uncommon and has been disappearing since the Vietnam War. Many people who understood steam heating either retired or died after the Vietnam War. Many elements of steam heating are difficult to understand or surprising. (For example, steam pressure has a surprising relationship with velocity: low-pressure steam moves through piping much more quickly than high-pressure steam.) So, Dan Holohan is on a mission to revive that knowledge and teach the newer generations about the lost art. There are many older steam heating systems still operating today, especially in the older large buildings in New York. Dan learned a lot about steam heating when working on these old systems and optimizing them. Most of the time, he optimized those systems by removing unnecessary accessories, not adding components like steam traps. Many old boilers used coal as a heat source. Nowadays, many old boilers have been fitted with conversion oil burners with thermostats, but they are still piped for coal. Some systems now have multiple risers or massive vents on the main riser to prevent the thermostats from getting too hot too early and satisfying the thermostat too early. We call that master venting, reducing pressure and allowing steam to move very quickly and efficiently. Dan also discusses: The 2-PSI standard Transportation metaphors for BTUs in steam Harmful renovations for old boilers Replacement vs. restoration mindsets Gaps in steam boiler education Monopolizing the market if you HAVE the education Boiler piping and venting Two-pipe vs one-pipe steam   Find out more about Dan and hydronic heating at HeatingHelp.com. Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this honest—maybe overly honest—live podcast, we talk about the dark side of white shirt techs. We also discuss ways the industry can make money while doing the fundamentals well. The term "white shirt" refers to a sales technician who prioritizes selling equipment over fieldwork; these technicians don't necessarily sell expensive products, but they lack technical expertise. The surefire way to tell if someone is a "white shirt" is to see if they can solve problems with their hands or if they just pull solutions from a menu of new products. However, "white shirts" do have some skills we can learn from. They are usually great communicators, which is an excellent characteristic in our trade. Honesty is also important, though, and great communication can only be a good thing if it's backed up by honesty. "White shirts" lie, and they make excuses for their lies. Unfortunately, many of us want to do good work and make less than "white shirts." The problem may not be with the white shirt technicians; we contribute to the problem by undervaluing our expertise and quality work. Strangely enough, we rarely ever see white shirt technicians in commercial HVAC. That's because commercial HVAC is a far more expensive, less sales-oriented part of the industry. There is less of a need to push products onto the customer to make money. We also cover: The fine art of setting prices Sales tactics Made-up simplified product names ("heat rejector") Honest, straightforward, non-emotional communication Vetting technicians Deceptive training by salespeople What drives people to sell extra accessories "White shirt" profit margins Labor rates, diagnostic fees, and maintenance prices Hard start kits and potential misunderstandings Bad intentions vs. ignorance Billable time in residential vs. commercial HVAC Buyer's remorse Consulting vs. sales Surge protection   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this podcast episode, Bert joins Bryan to talk about what he has learned to help prevent the dreaded callback on the job. Callbacks are bad news for customer service, time, and profit. However, the highest cost is the inconvenience caused to the customer. To reduce callbacks, Bert recommends communicating your expectations to your customer clearly; explain what the expected performance should be and how a customer should use their system. We need to do better at having conversations with the customer where we listen to them; we should not explain everything through the paperwork and walk away. Customers become less of a callback risk when technicians stay with them until they are no longer a risk. The technician must run the equipment to ensure that it's working and set expectations before they leave. This tip can be a bit tricky, as many of us have to move from one emergency to the next, but the extra time and effort will almost surely help prevent a callback. The goal is to get a system to last as long as possible without having a problem. Overall, hard skills are less important than soft skills when it comes to callback prevention. Many techs have the technical knowledge; far fewer take the time to listen to the customer and get the whole picture of the problem. When it comes to hard skills, callback prevention requires more attentiveness and skill application than the technical skills themselves. With all that in mind, the ultimate key to preventing callbacks is to take responsibility for ALL of your work: testing, setup, communication, and fixes. Bert and Bryan also discuss: "White-shirt" techs "Callback risk" customers Reducing loads by adding insulation How rain and temperature affect performance Recognizing a customer's budget Checking for wire rub-outs and loose/poor connections Visual observation   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HER

This short podcast is for the newbies out there. For HVAC trade newbies, Bryan recommends applying 7 tips to help you win. When you start off in the trades, you'll want to check your mindset. Successful HVAC technicians are usually humble; recognize that you don't know everything. The truth is that nobody knows everything, and every other person has wisdom and knowledge to offer you. (However, don't mistake humility for a lack of confidence.) You'll also want to hang out with good people; you are the sum of the five people you spend the most time with, so you don't want your friends to drag you down intellectually or get you into trouble. (And make good use of your time!) Stay hydrated on the job! Water is the very best thing you can have on the job, especially during hot summers. To take care of your body, you will also want to wear safety glasses on the job and gloves when appropriate. Curiosity is also an incredibly important trait of successful techs. Push further to understand your work fully, and you will be much more successful in your career. If you are curious, you will bring more ideas to the table and have a better grasp on the work you do, which will hopefully help you get raises and promotions. Another extension of curiosity is to test what you know. Pursue a possibility and find all of its weaknesses; don't accept a solution as the truth without further investigation. Perhaps one of the most useful tips for newbies is to learn to be okay with failure. You sometimes won't have everything you need, whether that's a lack of tools or knowledge. Making difficult situations work is part of the job, and the fear of making mistakes should not hold you back.   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

Jim Bergmann returns to the podcast to talk about the power quality meter. He also discusses what it is good for and how to use one. A power quality meter accounts for the power factor in its measurements, and it measures true power in watts. We can notice failing capacitors and other issues that can cause a device to draw higher wattage. In inductive loads, the power factor will be less than 1. However, we can measure the power factor because the capacitor counteracts the inductive reactance and gets the power closer to unity; the current and voltage should be in phase with each other, so the circuit should be balanced. The main difference between watts and volt-amps (VA) is the power factor. Volt-amps represent the entire quantity of energy, watts represent power, and volt-amps reactive represent useless energy. So, the power factor is the difference between what makes watts useful and VA reactive unuseful. (Think about a pint of beer, which is VA: you can't drink the foam, which represents VA reactive, and the actual liquid beer is the watts. Unity would represent a pint of beer with no foam.) When looking at EER and SEER, the power quality meter helps you get a more accurate wattage reading, which allows technicians to determine efficiency more easily. You MUST know your power factor to measure wattage properly. Since consumers are billed on wattage, an accurate measurement is critical to make sure they're paying an appropriate price for energy. Jim and Bryan also discuss: Supco Redfish iDVM550 Matching capacitors to inductive loads Fan efficacy and PSC vs. ECM motors Back EMF Considerations for measuring frequency VFDs BTU capacity, amp draw, and efficiency Commissioning and benchmarking with power quality meters Single-phase vs. three-phase power factor tools   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this short podcast, Bryan talks through (once again) what REALLY causes capacitors to fail and what we can do about it. High temperatures and overvoltage (NOT undervoltage) are what cause capacitors to fail. (There are also some poor manufacturing practices out there. Remember: they should be just foil and oil.) Capacitors create a phase shift to assist split-phase induction motors. Normally, a three-phase motor can start and run just fine because the sine waves are all angled. That is not the case for split-phase motors. Start capacitors help startup, which is difficult for the motor. The capacitor stores and discharges each time there is a cycle change (usually 60 times per second). That rapid storing and discharging helps create a lag that gets the motor get moving. However, capacitors are limited by their design: their charge capacity (current) is dictated by size (microfarads), voltage, and frequency. If you measure amps on the start winding, you will notice that the amps are lower than on the run windings; the capacitor acts as a limiting factor. When the run capacitor fails, you have no current on the start winding. The motor does NOT cause the capacitor to fail; there is a slim-to-none chance that a motor's back EMF can cause capacitor failure. Excess temperature or voltage is what really causes capacitors to fail, and THAT can negatively affect the motor. The hotter a capacitor runs, the shorter its life will be. Locations with high temperatures year-round and lots of thunderstorms will have more capacitor failures than places with more temperate climates. Capacitor oil also plays a role in longevity. Oil exists for heat dissipation and should be mounted with the terminals up. Condenser cleanliness and temperature can also help or hinder the oil's efforts.   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

Eric Mele, Eric Kaiser, and John Oaks come on the podcast to talk about commercial PM best practices and what matters most. Drain cleaning is a critical part of the standard commercial PM. You must assess the drainage situation (pitch, length, location, etc.) to plan your cleaning strategy and arrive at the best result: the entire drain gets cleaned. If you use chemicals, you need to be very careful not to let them back up into other units. Condenser coil cleaning is another important PM procedure in both residential and commercial HVAC. However, you don't always need to clean the condenser coils. When you actually need to clean the coils, some best practices include splitting multi-row coils (on VERY dirty systems) and washing the coil against the airflow (usually from the inside out). Lots of commercial equipment use belts, so HVAC technicians should know how to work on them. Unfortunately, many HVAC technicians aren't great at aligning and tensioning belts. Bryan is of the school of thought that many belts that are adjusted should just be replaced. When working on gas equipment on rooftops, you can perform very accurate combustion analysis because the flue is in an ideal location for testing. Grilles are also very important in commercial HVAC, and the best practice is to check them for restrictions. As always, you cannot underestimate the importance of visual inspection, "do no harm," and making sure the equipment is running when you leave. The Erics, John, and Bryan also discuss: Drain pan cleaning tips Neutralizing algae in drains Clearing drains with nitrogen or shop vacs Transfer pumps Paperwork and documentation Environmental reasons NOT to clean coils needlessly Microchannel coils Quoting specific procedures Belt longevity Browning tools and literature Checking for phase imbalance Benchmarking equipment Maintenance people vs. technicians Communication   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.