HVAC School - For Techs, By Techs

In this short podcast, Bryan explains what it means to top off, drop in, and retrofit refrigerants. He describes the differences between those three things to dispel some of the confusion they may cause. Topping off a system means that you add refrigerant to a low existing charge to get it back up to a normal level. In some cases, people top off systems with dissimilar refrigerants (e.g., topping off R-22 systems with cheaper R-407C). Topping off a system with a dissimilar refrigerant is unacceptable, as it's against EPA guidelines and leaves you with an undefined refrigerant mixture. You're only supposed to top off a system with the same refrigerant that's already in it. High-glide refrigerant blends can be tricky to top off when there is a leak, as one refrigerant type may leak more quickly than the other and leave you with a different chemical profile. So, you're better off recovering and starting over when you have lost a significant amount of charge to a leak. If you want to recharge an entire system by recovering the existing charge, you would instead be using a "drop-in" refrigerant. There are no drop-in solutions for R-410A systems. However, some commercial equipment manufacturers can offer information about drop-in solutions, though they are relatively rare, especially as oil has changed over the years. When you drop in refrigerant, you don't have to change O-rings, Schrader cores, or other components. Drop-ins are NOT necessarily like-for-like when it comes to charging. "Retrofit" is a relatively broad term that refers to any type of refrigerant change. The retrofitting practices that may have worked for A1 CFC systems to A1 HCFC systems will NOT work for A1 to A2L refrigerants. We need new installations for flammable refrigerant systems. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Trevor Matthews, the founder of Refrigeration Mentor, is back on the podcast. This time, he and Bryan talk about the value of networking for HVAC techs as the conference season comes to a close. Many trade events are networking opportunities that allow you to build relationships with other tradespeople, educators, mentors, and even other companies. You can also learn many trade and business tools that help you as a technician. Many technical and business conversations occur at trade events, and there is a lot to learn from those, whether you're directly involved or just listening. It can also be useful to sit in on classes or presentations about topics that you don't directly deal with, such as building science. Networking also has value for technicians because it can provide several means of personal development. Making connections with potential mentors can open the doors to new career opportunities, even in places where you wouldn't have expected yourself to work. If you see someone you want to talk to at an event, feel free to go up and talk to them. Trade events are places where people expect to get to know one another, so many of the people who attend them genuinely want to talk to others in the trade. People like Trevor are happy to share their knowledge and help you develop yourself as a technician. You can also send people emails introducing yourself to them before the event if you're a bit introverted and uncomfortable putting yourself out there. Trevor and Bryan also discuss: Being isolated in a "bubble" Choosing to work or visit conferences Networking to avoid getting stuck Planning trips around trade conferences The 2023 HVACR Training Symposium Specialized conferences Refrigeration Mentor Learn more about Trevor's work at https://refrigerationmentor.com/. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

David Richardson of NCI joins the HVAC School podcast to talk about how we can implement educational growth effectively throughout the trade. NCI started as a premium training resource about airflow testing, but the organization eventually started teaching about combustion testing as well. When we improve the industry, we need to be able to have concrete ways to see what we've been doing wrong or what we can do better. Test instruments allow us to see the whats and whys behind what we do. Education needs to be focused on bringing those test instruments into training AND teaching others how to use them properly. Once we find a way to understand the invisible aspects of what we do, we can get into systems thinking and grasp the more abstract concepts much more easily. When people are introduced to concepts in a logical sequence, they can build their knowledge on what affects the system and why it does do. When we tie everything together, including using solid data, testing in and testing out, and using sources to help you interpret data, we can implement educational growth more effectively. Most of all, we can learn how to translate the technical into practical, which helps us communicate with the customers in ways that matter. However, the most important thing about test instrumentation and applying it to learning is understanding why you are doing those tests or why you want to do them. David and Bryan also discuss: The purpose of traverse tests The mechanics of NCI's teaching (PATH to performance) To charge or not to charge for combustion analysis What NCI does and how to get involved with NCI Learn more about NCI or get involved with their training at https://nationalcomfortinstitute.com/. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Corbett Lunsford of Home Diagnosis joins Kaleb to record a podcast about comfort investigation on TV. The two of them discuss how comfort investigation works on TV shows, what Home Diagnosis hopes to accomplish, and some building performance tips. Home Diagnosis is mostly aimed at homeowners, but HVAC technicians would also benefit from the show, as it dives into science and testing. The show promotes consumer education and contractor accountability. Diagnostics and testing are absolute MUSTS for providing the best possible solutions and transforming your business. You put yourself in another league when you take measurements and have the data to create tailored solutions. In other words, you can't manage what you can't measure, and if you're not testing, you're guessing. The current paradigm shift in the industry has to do with custom designs. Physics, chemistry, and microbiology are all important facets of applied science to consider when coming up with a custom solution. Many buildings have distinct microbiological profiles, including bakeries with yeast or cheese production or aging facilities. Natural events and human activity can change these buildings' microbiological profiles. Ventilation is part of the equation of home performance, and it's a pretty delicate one that HVAC techs can control. When it comes to ventilation, we would be wise to avoid selling products we don't understand. Ventilation solutions may also be appropriate for one structure but inappropriate for another, so we need to think about the applications of these solutions. Corbett and Kaleb also discuss: Comfort vs. efficiency vs. control ERVs vs. HRVs and humidity How the market influences custom solutions Preview of challenges in Season 3 of Home Diagnosis Microbiology of structures Learn more about Home Diagnosis at https://homediagnosis.tv/. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Blake Standen and Omar Tabba of BrainBox AI join the HVAC School podcast to talk about commercial HVAC predictive control. This conversation focuses on applying artificial intelligence to existing building systems, including the HVAC, to predict performance under certain weather and occupancy conditions. If you have controls that can predict performance and adapt, then you can maximize energy savings. A commercial HVAC system may include air handlers, chillers, boilers, RTUs, and all sorts of energy-consuming technologies. These systems also have controls that help direct the infrastructure, and artificial intelligence can help optimize the controls, make performance predictions based on forecast data, and make those controls communicate with foreign controls from other companies (such as via BACnet). BrainBox AI uses a cloud to collect and hold the data it needs to predict what a building will do and help control the infrastructure. Controls react to errors, and the goal of BrainBox AI is to predict errors before they happen. For example, AI can help solve short cycling under certain weather conditions. However, buildings that use pneumatics rather than digital controls and older systems may not be good candidates for AI solutions. One of AI's challenges is that it requires multiple layers of training: you're training the controls engineers, facilities staff, AND the AI itself. Another challenge of AI is that people don't fully understand that it's not the type of automation that takes people's jobs; we can minimize those perceptions with education. Blake, Omar, and Bryan also discuss: Machine learning vs. artificial intelligence Accuracy of prediction models Virtual testing environments Apathy as a challenge What happens when controls go offline or are adjusted? Tethered services Application programming interface (API) Controlling comfort and energy consumption vs. greenhouse gas emissions BrainBox's global partnership with ABB Learn more at https://www.brainboxai.com/. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Chris Micallef, the CEO of Falkonair, joins Nathan Orr at AHR to discuss energy savings for three-phase equipment. They also explore some of Falkonair's controls for compressors, especially on DC inverter equipment. Falkonair has software that allows users to control all types and brands of three-phase compressors with compatible variable frequency drives (VFDs). The software recommends the compatible VFD based on the amperage readings. Falkonair aims to bring this software to the refrigeration industry and then move on to HVAC contractors and data centers. The control unit adjusts the compressor speed to respond to changes in refrigerant charge levels (based on discharge temperature). These controls protect the compressor and maintain efficiency, even under less than ideal operating conditions. Energy efficiency can increase by 35% with Falkonair's control units in place. You can expect longer runtimes, a reduction in short cycles, and a reduction in humidity. If the refrigerant loss is too great, then the control can also shut down the compressor. However, it should take less time for a facility manager to notice that refrigerant loss is happening. The controls use temperature probes, so they don't cut into the refrigeration circuit. Although VFDs are good for reducing vibrational wear and tear, we have to be aware of potential issues with harmonics. Harmonics can damage the bearings, especially on pumps that don't have oil constantly lubricating the bearings. Chris and Nathan also discuss: VFD sizing considerations How Falkonair's AI works with hot gas bypass Software commissioning Oil return sequences on DC inverter systems Hertz ranges and limitations per compressor type How Falkonair's control units can exceed 35% efficiency gains Learn more about Falkonair at https://falkonair.com/. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Brynn Cooksey joined Eric Kaiser for a podcast about internal apprenticeship, its benefits, and how to make it work. Brynn is the general manager of Air Doctors Heating and Cooling LLC, a well-respected HVAC contracting company in Detroit, MI. Air Doctors Heating and Cooling LLC has its own in-house apprenticeship program based on Department of Labor guidelines. The apprenticeship program caters to new techs out of trade school and focuses on rigorous training. There is some administrative paperwork, but there are no additional administrative expenses. The only expenses of the apprenticeship program come from training and wages. Most of the administrative work comes from recordkeeping. Bumps in pay come with milestones, and RSES certification is available at the highest level of Brynn's program. Once techs receive their RSES CM, they become official journeymen and continue to learn more about the trade through incentivized training. The technicians at Air Doctors seem to like the training program. The program is very structured when it comes to training, hours, and pay, so the techs like predictability. Reduced callback rates are positive effects of the apprenticeship program; Brynn's current callback rate is less than 1% (was 3% before the program was put into place). The apprenticeship program is easy to set up with the government, and it makes companies eligible for national and local grants. Approved apprenticeship programs can also take advantage of other benefits, including labor scouting to grow the workforce. Everything about the apprenticeship program recognition process was free. Many businesses can take advantage of these programs to grow their workforce and train promising technicians who can transform the business. Email Brynn for more information at [email protected] If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Alex and Nicole of Faraday join Kaleb Saleeby and Ty Branaman to talk about new educational formats and options in the HVAC industry. Alex is the founder of Faraday, and Nicole is the head of operations. Ty is a notable HVAC educator who supports Faraday and its mission. Faraday is a free educational program that prepares apprenticeships for fieldwork, allows them to get EPA 608 certification, and helps place them in jobs with paid training. Although the program is free, there is a rigorous selection process to make sure only the most serious candidates join the program. The human aspect is very important to training, and Ty is one of the people who brings that to education programs. HVAC training is multifaceted, and the appliances are just the beginning. Training focuses on science and math as well as craftsmanship, which isn't what a lot of people think about when they think of HVAC. Faraday focuses on bringing the abstract and artistic concepts of the trade to training. However, Faraday also acknowledges just how important skills are to a person's career and life in general. Faraday also has live sessions with guest speakers, and these are available to current students and alumni. Lifelong learning and investment are important to Faraday, and the programs create a support system for students even after completion. Alex, Nicole, Ty, and Kaleb also discuss: Faraday's admissions process Ty's contributions to education and the industry Bringing the Masterclass format and delivery to HVAC The ambitions, interests, and fears of young people Costs of training Using Discord for communication and training Teaching life skills Faraday's vetting, coaching, and weed-out processes Producing coachable, well-rounded individuals If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Ashley (aka hvac_ash) joins the podcast to talk about how HVAC fits into social media, AHR 2022, and AmRad capacitors. Ashley works with Global the Source on the sales and distribution side of the business. Becoming an HVAC influencer is smart, especially when there is a dedicated audience in the industry. When you gain traction online, that can branch into marketing, which helps get the word out even more. It's also a great way to make connections organically once you have traction and learn from others' industry-related content. Ashley also has firsthand experience with the HVAC trade's obstacles for women. She believes that making groups like Women in HVACR more marketable and focusing on recruiting young women will help break those barriers down. There needs to be more effort to the recruiting process than just posting ads and job postings on social media. Global the Source is a distributor of AmRad products, including the well-known American-made capacitors and Turbo line of start capacitors (Turbolytic) and hard start kits (TES5). The quality of the AmRad capacitors' foil and the oil has been tested widely, even on the HVAC School YouTube channel; the conclusion is that AmRad capacitors are made of high-quality materials and last longer than many others. Ashley and Bryan also discuss: What it means to be a master distributor Being an HVAC influencer on Instagram Visiting AHR as an influencer and sales professional Strategic recruiting for underrepresented demographics AmRad's Turbo product family New AmRad products for failed run capacitors and stuck relays Follow Ashley on Instagram (hvac_ash) and DM her with questions or email her at [email protected]. Learn more about Global the Source and some of the AmRad products at https://globalthesource.com/. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Bill Spohn joins Eric Kaiser and Kaleb Saleeby at AHR 2022 to talk about his experiences designing and living in a home with NetZero HVAC. NetZero HVAC refers to system design with tight coordination with the house to make it as efficient as possible. Some of these systems are so tight and efficient that they approach passive house standards (0.6 ACH50). Bill lives in a modular home that also generates more energy than it consumes, and it doesn't rely on natural gas. The greatest expenses of Bill's NetZero home came from all the custom factors, as it didn't make sense to price many of the features on a square-foot basis. The heating and cooling system is also unique, as it is completely separate from the ventilation system, which is a Build Equinox CERV. On the IAQ side, the CERV monitors outdoor temperature and humidity, indoor CO2, and indoor VOCs. Bill also has a HAVEN central air monitor inside the CERV system as a backup. Bill's HVAC system is an air-source heat pump that provides two tons of heating and cooling and has low-temperature capabilities. The two-ton unit works for a 4400-square-foot home. Bill, Eric, and Kaleb also discuss: Energy independence Controlling radiant heat gains and window construction Construction and material fabrication Monitoring energy usage Energy recovery ventilation (ERVs) Thermal bridging at work in Bill's walls Knowledgeable customers Jim Bergmann's help with troubleshooting Radon issues Bill's podcast Solar inverters Measuring tool accuracy You can learn more by listening to Bill's podcast, Building HVAC Science. You can subscribe to the podcast on any podcast app of your choice or get an overview at https://buildinghvacscience.libsyn.com/. You can also check out Bill's blog at https://spohnhome.com/. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Collin Olson, the staff physicist of The Energy Conservatory (TEC), joins Eric Kaiser at AHR 2022 to talk a bit about data logging. Data logging refers to the act of using sensors to record data over time and then analyzing that data. TEC dipped its toes into data logging with the APT and then TECLOG. Data logging allows us to take and store multiple readings as well as extrapolate data into graphs, making it easier to analyze performance. The TECLOG4 software is the most up-to-date version. TECLOG is a simple software to use with basic training. The understanding of building science continues over a lifetime, but the actual software can be learned in approximately 30 minutes. TECLOG is free with TEC's hardware, such as the DG-1000. To get started, all you need is a precision manometer and a computer. However, it's worth nothing that the DG-1000 stores a lot of data, meaning that you can launch data logging sessions on the gauge without your computer. Some of the most important measurements are related to drafts and backdrafting. There are 250 Pascals in an inch of water column, and the DG-1000 can pick up very small changes in the Pascals and can indicate when depressurization happens and when it poses a risk. Improperly installed vents can also produce alarming drafting conditions due to air density; data logging can pick up that sort of information. Collin and Eric also discuss: The history of TEC's APT Wind and its effect on building pressures Event markers and hotkeys The link between depressurization, flue gases, and weather conditions Managing multiple blower doors at a time Check out TEC's software, including TECLOG4, at https://energyconservatory.com/downloads/. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Mark Tozzi from Carrier comes on the HVAC School podcast to talk about unique HVAC incentives in K-12 schools. When schools closed down during COVID-19 lockdowns, a new series of incentives came out for schools. Many of these incentives include access to technology, and improvements to HVACR equipment are covered under those programs. Schools can benefit from geography-tailored solutions, including air-cooled chillers in the Southeast and products meant to improve IAQ, including filtration upgrades and dehumidification strategies. To provide valuable solutions to schools, HVACR professionals and manufacturers need to get involved in local conversations, such as on school boards or at the district level. The incentive is quite broad, and it provides schools AND HVACR professionals with many opportunities. The funds need to be spent by 2023, so we can focus on doing business with schools this year. However, as we seize these opportunities to help our communities, we also need to make sure that we have the labor, training, and ambassadorship to make these initiatives successful. As an industry, we need to focus on recruitment and training to stimulate interest in the industry. Not to mention, as equipment advances, technicians need to be able to catch up with newer technology. The COVID-19 pandemic has put our industry into the spotlight, and people are paying more attention to their air quality and our work than ever before. Through community opportunities, recruitment, and education, we can hope to improve our industry. Mark and Bryan also discuss: OptiClean air scrubbers Buy boards How the HVAC industry might appeal to younger generations When are HVAC contractors seen as valuable to the general public? Learn more at carrier.com. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Chris Forth, the VP of regulatory codes and environmental affairs at Johnson Controls, joins Bryan for a live podcast at AHR 2022. This time, they discuss changing HVAC regulations and what that will mean for contractors, technicians, and installers. Johnson Controls focuses on institutional chillers, controls with digital platforms, air handlers, filtration, and alarm systems. Lately, Chris has gotten the industry ready to convert existing products and systems to high-efficiency equipment for low-GWP, A2L refrigerants. The transition to A2L refrigerants will be different from the transition from R-22 to R-410A. We needed to change the oil type (mineral oil to POE) and make equipment for different pressures when we went from R-22 to R-410A. However, the pressure and oil needs of A2L refrigerants are very similar to R-410A; the main obstacle is dealing with mild flammability. Every six years, the U.S. Department of Energy (DOE) sets minimum efficiency standards, and they determined that it's time for an upgrade. In other words, 14-SEER straight-cool A/C systems will no longer cut it in some places. In the Southeast, equipment that doesn't meet the new standards must be INSTALLED before 2023. (In other cases, the date of manufacturing is what matters.) Now, contractors need to be sure that they can install 14-SEER units before 2023 if they order them. Otherwise, contractors may be better off ordering 15-SEER units now to ensure that they can install the equipment. Chris and Bryan also discuss: North vs. south efficiency ratings AHRI match How manufacturers will be affected by these regulations American Innovation and Manufacturing Act (AIM Act) The self-extinguishing properties of A2L refrigerants Learn more about Johnson Controls at https://www.johnsoncontrols.com/. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Kevin Hart, the CEO of HAVEN, joins Kaleb Saleeby live from AHR 2022 to discuss how we can control IAQ with central air monitors and controllers. HAVEN, formerly TZOA, is an IAQ company that focuses on protecting building occupants' health by controlling air quality. HAVEN's approach to managing IAQ starts with collecting data about the air. Without that data, we can't come up with solutions tailored to individual buildings. We need sensors to gather that data, which would traditionally mean that we'd need a decentralized system with sensors everywhere. However, HAVEN takes a centralized approach to measuring and controlling indoor air quality. HAVEN's central air monitoring system is not an ordinary box product. Monitors constantly provide data that help HVAC professionals find points of improvement in a home and form a solid professional relationship with homeowners. The goal is to use data as a bridge to connect the homeowner and contractor as well as build trust. One of HAVEN's new projects is to expand into remote HVAC diagnostics. The search for deviations in heating, cooling, and comfort will allow HAVEN to get more involved in the HVAC industry and communicate diagnostic help and solutions more effectively. Kevin and Kaleb also discuss: HAVEN's name and vision Avoiding false positives for harmful substances with centralized monitoring Equipment longevity Stagnancy of air in homes in moderate climates The issue with constant 50% relative humidity Outdoor air quality and comparative analysis IAQ as a luxury rather than a necessity Predictions for the HVAC industry Learn more at https://haveniaq.com/ or become a HAVEN Pro today at https://pro.haveniaq.com/. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Jacques Beaudry-Losique, the CEO of Enginuity Power Systems, joins Nathan Orr live at AHR 2022. Enginuity manufactures energy-efficient engines that produce more power than traditional engines and recover waste heat to act as water heaters. Enginuity engines can run on propane and natural gas to help you run almost entirely off the grid and participate in electricity buyback programs. These units operate independently of the electrical grid and can act as generators during power outages and have a small footprint. However, a backup battery system is recommended for these units to maximize efficiency. Enginuity has a residential and commercial line. The E | ONE is best suited for residential applications, and the E | TWO is better for heavier commercial applications. The U.S. Army has been one of the most prominent supporters of Enginuity, which also manufactures its units exclusively in America. Distribution is done through a third party, including business owners and technicians; Enginuity doesn't deal directly with homeowners or building staff. As a result, A/C service technicians, installers, plumbers, and refrigeration technicians may end up being the people in the middle who do maintenance on Enginuity generators. After this conversation with Jacques, we are very interested in seeing what the future holds for Enginuity and combined appliances. Jacques and Nathan also discuss: The electrical grid's stability Enginuity's revolutionary piston design Ease of startup and commissioning Pricing questions Enginuity's target market and training resources for that target market Engine life expectancy Enginuity's projected rollout timeline and expansion plans Decentralizing power dependence Solar vs. fossil fuel energy The problem with power plants Learn more about Enginuity at https://enginuitypowersystems.com/. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Rick Nadeau, Director of Training and Technical Services at Samsung, talks with Kaleb Saleeby live from AHR. He explains some of the exciting ductless solutions that Samsung has to offer. Samsung's WindFree mini-split systems work with VRF systems or as normal ductless units. The WindFree product line is best known for preventing drafts due to microholes. These systems come in one-way and four-way cassettes and work very well for sensitive environments like nursing homes and bedrooms. These units also have humidity sensors that let the units know when it would and wouldn't be acceptable to go into WindFree mode. Samsung's systems may also have occupancy sensors, which determine when they can turn on to provide comfort and flexibility. The systems also have the capability to determine when the system is losing refrigerant to prevent major environmental and performance issues. Samsung has MaxHeat technology, which allows a system to have 100% heating capacity in low-ambient temperatures as low as -30 degrees Fahrenheit. So, the lack of reliance on auxiliary heat can reduce energy consumption and costs under most conditions. In general, much of Samsung's innovative technology is introduced across entire product lines. In the commercial sphere, Samsung's DVM S is an influential modular chiller and water heating system. Its flexible design (thanks to VRF technology) has made it a popular choice for product storage in vineyards. The DVM S Eco also has heat recovery capabilities. Rick and Kaleb also discuss: Stratification prevention and high-ceiling configurations Air velocity and unit cleanliness Refrigerant loss detection Learn more about Samsung's ductless systems and online training programs at https://www.samsunghvac.com/. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Steve Rogers from The Energy Conservatory (TEC) joins Eric Kaiser to talk about airflow measurement at AHR 2022. Steve is an expert in fluid dynamics and flow measurement, and he is a trainer in addition to being the president and CEO of TEC. Airflow is one of the most critical elements of an HVAC system; it allows us to move the correct amount of BTUs to condition the air properly. We have various ways of measuring system airflow and airflow to a space. We can use the TrueFlow grid for the former and flow hoods for the latter. When it comes to measuring airflow, calibrating the instrumentation is crucial. TEC uses a laboratory-grade orifice plate to calibrate the tools. So, the calibration process manages to yield high accuracy while using a low-maintenance device. To begin measuring airflow properly, start taking the total external static pressure (TESP) and looking at fan charts. TESP doesn't actually measure airflow, but it provides an idea of what the airflow might be like, and it's a practical, useful measurement in the field. The TEC TrueFlow grid has recently been upgraded, and it's a good step up from taking the TESP and referencing fan charts. It goes into the filter slot and measures the CFM per ton as well as the static pressure. Steve and Eric also discuss: Airflow's effect on latent and sensible cooling Blower door setups and chambers References for accuracy Relationship between static pressure and airflow Is the hand-ometer an acceptable form of airflow measurement? Challenges of pitot tubes and hot-wire anemometers Learn more about The Energy Conservatory at https://energyconservatory.com/. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Brett Wetzel and Kevin Compass from the Advanced Refrigeration Podcast join us to discuss commercial rack refrigeration and identify components. In supermarket racks, we typically have anywhere from 2-5 compressors on a single rack (with multiple evaporators, metering devices, and sometimes even condensers). These compressors may come in several varieties (including screw and scroll) and be digital or have VFDs. They also have common suction and discharge headers. The compressors all share oil from a single system. Oil separators can come in three varieties: centrifugal, impingement, and coalescing (most efficient). The separator would feed into the reservoir, which stores oil. Many rack systems use several different valves. Check valves to direct the refrigerant flow, especially on heat reclaim systems and split condensers. In some cases, there is a three-way valve or a solenoid valve that controls or stops the refrigerant flow. LDR (liquid differential regulating) valves maintain the required differentials during defrost. Ball valves can be found all over a rack (liquid line, suction line, discharge line, etc.) and can isolate a line. Standard and balanced-port TXVs or EEVs may also appear on racks. There is also an EPR, which controls evaporator temperature and pressure. Grocery systems have a drop leg before the receiver, which stores liquid refrigerant. We want a full column of liquid leaving the receiver, which we can confirm with a sight glass rather than subcooling. Brett, Kevin, and Bryan also discuss: Reheat and excess heat Split condensers Drain leg/drop leg vs. liquid line Mechanical subcooling and heat exchangers Counterflow piping Hot gas vs. Kool gas defrost Standard vs. balanced-port TXVs Distributors Evaporator fin spacing Cleaning components Check out the Advanced Refrigeration Podcast on any podcast app of your choosing. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Jim Fultz from Emerson joins Eric Kaiser at AHR to share his knowledge of universal boards and controls. Jim's work focuses on electronic controls within the White-Rodgers brand. Common White-Rodgers universal controls include the SureSwitch and universal defrost controls. The SureSwitch also has sealed contacts, which prevents insects and debris from shorting out the contacts. This past year, White-Rodgers debuted the All-Spark, which doesn't need electricity to be powered up and can be programmed right out of the box. The All-Spark works on all sorts of appliances, not just boilers and furnaces. Universal controls are generally safe to put in combustion units, even gas furnaces. New controls go through rigorous testing before they hit the market. The controls MUST stay within the OEM's guidelines; otherwise, they won't make it to the market. Sometimes, when boards need to be replaced, we also need to upgrade the igniter to match the voltage of the new board. The goal of universal controls is to save time and hassle for the technicians and the customers, which makes it easier to make sales. It's also easier for the distributor to get fast and accurate solutions to the technicians, especially when OEM parts may not be immediately available due to supply chain issues and normal shipping expectations. Jim and Eric also discuss: All-Spark benefits and features Manufacturer-specific vs. general universal controls White-Rodgers nomenclature Controls instructions Distributors and sales reps Evolution of controls for direct-spark and hot-surface ignition Training techs to install controls on equipment Learn more about White-Rodgers controls at https://climate.emerson.com/en-us/brands/white-rodgers. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

In this short podcast from AHR 2022, Leilani Orr and Eric Kaiser talk with the president and CEO of Malco Tools, Rich Benninghoff. Rich discusses some of the exciting new tools that Malco is bringing to the market and some plans for the future, especially when it comes to education. Malco has developed the Eagle-Grip, which is a set of locking-handle pliers made in the USA with American steel. The tool is currently in a soft launch; it is currently receiving a lot of interest, so Malco has been building up inventory, forming partnerships across industries, and collecting market feedback. One of Malco's most exciting products is the C-RHEX line of cleanable, reversible magnetic hex drivers. These hex drivers come in many sizes and are easy to clean; the cleanable and magnetic features are especially important, as the buildup of metal resin and clippings can decrease tool longevity and effectiveness without proper cleaning. Malco has also been focusing on trade schools and education through "Look Good, Feel Good, Do Good." The initiative gives back to the community and provides career and education-enhancing opportunities to young people who are serious about the trade. Over the next decade, expect to see Malco continue investing in product innovation. Rich is excited to grow the brand and help the HVAC, automotive, and other industries along the way. Rich also covers: Malco's history with sheet metal fabrication Relying on customers for feedback and ideas "Head of the Class" program Providing tools for shop classes in local school districts Learn more about Malco Tools at https://www.malcoproducts.com/. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Jason Obrzut joins Nathan Orr with the HVAC School podcast live from AHR. In this episode, they discuss A2L refrigerants and upcoming regulations. They explain what a "flammable" refrigerant really is and why the industry may be making a bigger deal of the new regulations than is really necessary. Whenever regulations are passed, we need to understand that there is a notable transition period. This period will mostly be about training, and the only people who should be working on the new equipment should be the most experienced technicians. A2L refrigerants are mildly flammable, non-toxic refrigerants, including R-32. Flame propagation is possible but quite rare for A2L refrigerants under normal operating conditions. However, even A1 refrigerants can propagate flame under the right conditions (just not ones we'd normally see). Many countries all over the world have been using A2L refrigerants for much longer than we have, so we can make those refrigerants work safely. All trades will evolve, and we need to be prepared and trained to adapt to changes over time. When we learn all the new practices that come with these new regulations, we become better technicians. The only place where we can make a difference is in our work, so it pays to focus on learning new things instead of resisting change. Jason and Nathan also discuss: A2L vs. A1 vs. A2 vs. A3 refrigerants What does "flammable" really mean? Recordkeeping regulations for A2L refrigerants Getting over the fear of the unknown Why the HFC phasedown is NOT driven by refrigerant manufacturer profits Learn more about ESCO's HVAC Excellence conference HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

David Holt with NCI returns to the podcast to discuss the evolution of HVAC training; we cover the past, present, and the possible future of training in the industry. In the past, we had a lot of hands-on training, whether it was one-on-one or in a traditional classroom setting. These learning practices remain beneficial today, especially since many uninformed practices are still prevalent in the industry today (charging to beer-can cold, condemning TXVs without a second thought, etc.). However, the pandemic has forced us to consider online and remote training in the present. The content has also changed from the past; we are a lot more aware of combustion and airflow nowadays, which are very important topics for safety and efficiency. Those training topics allow us to understand what we're doing when we take the "vital signs" of the equipment. Being better versed in basic and advanced diagnostics will also give us a more holistic understanding of the HVAC equipment as a system, which can help us truly optimize the systems instead of changing parts and making band-aid fixes. Moving forward, we can expect HVAC training to use virtual reality to help bring traditional hands-on training to the online sphere. We can't expect a perfect replacement, but we can expect improvements in technology to close the learning gaps that result from online training. David and Bryan also discuss: NCI training during the pandemic Components vs. systems ASHRAE Standard 221-2020 Older educational resources and standards Occupational safety Pricing Online classes, podcasts, and other modern training media Learn more about the National Comfort Institute (NCI)'s training and sign up HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE. Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

Jim Bergmann returns to the HVAC School podcast live from AHR 2022 to discuss a bit about proper system commissioning. He explains the commissioning mindset and some helpful procedures. Successful system commissioning starts with the mindset. A good commissioning organization broadens its vision; instead of focusing on the appliance, techs and installers focus on the system. Commissioning early on saves time later; you can focus on installs and maintenance instead of callbacks, and your organization can make more money as a result. When installing and testing new piping, make sure you insulate the tubing properly and keep the lines CLOSED OFF to the atmosphere. Measuring the line set is also critical for weighing the charge properly, as long lines have special considerations. When doing the decay test, use a quality vacuum rig and try to keep the micron gauge as far away from the pump as possible. Cleaning line sets also helps your vacuum results by getting rid of oil and moisture within the lines. Flowing nitrogen while brazing and sweeping with nitrogen are two other important installation/commissioning practices. They may seem idealistic, but it's easy to adopt these practices widely and reduce problematic scale buildup. Methods for setting airflow have changed over time. Nowadays, the best practice is to take a volumetric flow measurement (such as with a TrueFlow grid). Jim and Bryan also discuss: Preventing callbacks and warranty returns Evacuation and dehydration Factory practices One-hose evacuation with large hoses Flushing the line sets with pigs Nitrogen flow regulators "Airflow before charging" and metering devices Special considerations for MicroChannel coils If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE. Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

Russ King joins us for a short podcast episode about using 3D load and energy calculations with duct design. Russ has developed the Kwik Model 3D software program with the help of his son, Connor. Kwik Model 3D uses a video game platform to build a house out of boxes instead of a sketch. The software has evolved and been integrated into EnergyGauge to do load and energy calculations based on a house's geometry. Kwik Model makes it easy and fun to create that geometry profile for a home, which makes building design and load calculation attractive to technicians. Software like Kwik Model may especially become popular as Generation Z steps into the workforce; we can expect the learning curve to be quite shallow for the digital generation. The Manual J calculation uses the home's characteristics in Kwik Model and does all of the mathematical calculations in EnergyGauge for an advanced load calculation. KwikModel then receives those calculations for each room. Then, you can draw the ductwork and use an auto-size function to get the proper duct size based on the calculations. Energy simulations use several load calculations with advanced data to figure out what the energy usage will look like in a home with a certain set of load conditions. Russ and Bryan also discuss: Modeling quickly with Field Draw How building materials impact load calculations and energy simulations Energy simulations vs. load calculations Upcoming events with Russ King Kwik Model's tech support Using the Unity platform to develop software for many different industries Learn more about the software and get your 30-day free trial at kwikmodel.com. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE. Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

In this live podcast from AHR Expo 2022, John and Mike Pastorello of Refrigeration Technologies give us a history lesson in HVAC chemical chemistry. They also explain what it takes to make a truly beneficial product for the industry. From the beginning, Refrigeration Technologies has focused on solving problems instead of jumping on product trends. Before Big Blu was introduced, technicians had to rely on less-than-reliable electronic leak detectors and poor-quality soap bubbles. So, John Pastorello learned about the fundamentals of foaming and bubbles to create a leak reactant that works, even creating microbubbles for tiny leaks. Nylog has a similar origin story, and it has evolved to work for both mineral oil (red) and POE (blue) systems. As with Big Blu, John ran several tests to make sure the Nylog was compatible with HVAC equipment and did not cause contamination. The Viper Pan & Drain Treatment was developed to replace pan tabs, which failed to remove the dead biological material in drains. The spray coats the whole pan and dissolves sludge with enzymes. The Venom Packs are highly concentrated cleaners that arose from a move to consolidate the chemical line into something lighter, smaller, and faster. (Think about laundry detergent pods.) So, Venom Packs were inspired by laundry detergent and developed into a concentrated product line with recommended dilution ratios. Mike, John, Jessica, and Bryan also discuss: All the considerations that go into creating a leak reactant "Controversial" uses for Nylog Nylog white pipe dope for gas, water, air, and glycol Overcoming drain/pan odors Enzyme-based cleaning Safety considerations with HVAC chemicals Durability of Venom Pack packaging Family businesses Women in the business Learn more about Refrigeration Technologies at refrigtech.com. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE. Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

Michael Housh returns to the podcast to discuss upgrades and proposals that are worth considering. These upgrades and proposals can actually benefit the customer AND lead to clarity and profit without turning you into a white-shirt tech. When assessing a system for replacement, it's a good idea to look at the airflow side by measuring static pressure AND using a flow grid; these practices set you apart from others and supply you with good data about system sizing. Filtration is another area where you can consider upgrades and proposals; customers generally want to keep their air clean and may be happy to pay for better filtration, fresh air, and de/humidification. Surge protection is a high-value upgrade that many customers may benefit from, especially if the electrical company allows overvoltage or the customer has a voltage-sensitive ECM or inverter system. Some upgrades are useful and can be offered automatically (the customer can decline it); depending on the climate, a humidifier or dehumidifier may fit into that category. Proposals are a chance to put all of the offers on the table and allow the customer to select and decline whatever they want. When we adopt this business method, we would be wise to remove our egos from the process. Some processes that add clarity to proposals include creating checklists and taking lots of pictures for the customer. You'll also create trust between you and the customer when you establish that clarity. Michael and Bryan also discuss: HVAC industry game-changers Profit margins Free quoting Fresh air considerations Consistent overvoltage Metal oxide varistors (MOVs) and the ICM493 IAQ monitors Attic infiltration and can lights Proposal verbiage and templates Callbacks and consultations If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE. Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

In this short podcast episode, Clifton Beck joins us to talk about Bluon's free tech support and resources available to technicians and installers. Clifton has been very in touch with the HVAC technician community since he got his start in the trades, and he has taken that into tech support. He has noticed that the inefficiency in our industry tends to come from poorly learned practices, and working in tech support is a way for him to do his part to spread better practices while helping others. Lately, Bluon has become more of a tech support business. The new shift to focus on innovation has prompted Bluon to shift from making equipment more efficient to making technicians more efficient. The whole HVAC industry relies on that progression from developing on equipment to people. Tech support consists of answering calls but also creating training videos and creating layers of technician education and development. Manuals are just part of the picture; tech support helps with part identification AND the sequence of operations. Tech support reduces the amount of time it takes to learn about a part or locate components, which makes technicians more efficient and strengthens our industry. Overall, tech support calls are opportunities to train technicians to do better; they don't just have to give away simple answers that don't really help anyone. Clifton and Bryan also discuss: Bluon's growth Trends in tech support calls Tech support and community involvement Feeling accomplished as a tech support representative Learn more about Bluon's free tech support on the Bluon app, or you can check out bluon.com. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE. Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

Genry Garcia returns to the podcast to talk about blower doors and why ACH50 may needlessly complicate efforts to tighten a building envelope. A large element of indoor comfort comes down to controlling the load, especially the latent load. Even though we can control indoor humidity sources, we may also deal with infiltration, which contributes to a high latent load and decreases comfort. The blower door test comes in when we can no longer control the load and need to determine how much infiltration is happening. When using blower doors, we would typically use an ACH50 test, which takes the CFM50 (cubic feet per minute that the blower door moves to get the house up or down to 50 Pascals) and translates it to air changes per hour at 50 Pa. To do that, you would need to find the volume of the space, which adds hurdles that the HVAC technician needs to deal with. However, Genry prefers using the CFM50 and factoring in the square footage and LAIR (leakage area infiltration ratio) to determine how tight a house is; he doesn't focus on the building's volume. To decrease the leakage, it's best to stay focused on the CFM50 the entire time; worrying about the ACH50 just adds an extra step that we don't necessarily use. Genry and Bryan also discuss: Connecting design and execution Attic encapsulation How to use LAIR Ceiling height and stack effect Blower door testing for code compliance vs. comfort consultation/diagnostics Common duct problems in new constructions Balancing supply ducts Automation of communicating controls IAQ products and dehumidification If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE. Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

Eugene Silberstein, a co-author of Refrigeration and Air Conditioning Technology (RACT manual), joins the podcast to give us an introduction to psychrometrics. Psychrometrics focuses on the properties of air and its contents, especially as they relate to human comfort. To understand psychrometrics, we need to be able to quantify air: its weight, humidity, pressure, etc. We can do a better job as technicians if we figure out the air's content and see how it relates to the CFM and overall unit performance. That way, we can have a more holistic view of HVAC performance instead of just focusing on adding or recovering refrigerant to improve performance. The psychrometrics chart helps us understand the conditions of the air based on quantities like water vapor, dew point, and more. The chart may intimidate techs, but it contains a wealth of information that can help technicians understand the air and the customer's comfort better. Basic psychrometrics can also help us grasp why furnaces don't actually dry out air; they pull the moisture out of the air and pull it back in, so the absolute humidity stays close to the same. However, we commonly add humidifiers because the relative humidity drops with the temperature rise. Eugene and Bryan also discuss: How air filters and blower motors interact with the air Things that affect the weight of air per cubic foot Humidifying air and its effect on the density of air High-pressure air moving to an area of lower pressure How latent heat works Pressure and the atmosphere Absolute vs. relative humidity Learn about ESCO's e-learning network at hvacr.elearn.network/ and Psychrometrics Without Tears HERE. ESCO also holds the HVAC Excellence Conference; learn more about that HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE. Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

Brandon Marshall, Chemours's North American marketing manager for thermal and specialized solutions, joins the podcast to discuss refrigerant changes that are coming and how we can prepare for those. Brandon started in the industry by going to a technical school when he was 14 and has been hard at work ever since, studying light commercial design and going to college in between. Local and global regulations have changed a lot over the years and continue to change as we continue maximizing our equipment's efficiency. California will soon start switching to low-GWP refrigerant on new equipment in 2025; even R-410A can't be used in new equipment. We will begin seeing the rise of A2L refrigerants and moving away from the A1 refrigerants that are more detrimental to the environment; we'll have to focus on safety as we begin working with more flammable refrigerants. As new refrigerants get off the ground, we can expect increased communication between manufacturers and dealers to prepare for the sale of equipment built for the new refrigerants. Although we can't confirm anything, Brandon has speculated that the EPA will soon follow in California's regulatory footsteps when it comes to new equipment and R-410A. It's a good idea to stay educated, subscribe to A2L newsletters, and follow HVAC trends in Europe to predict what might come next in North America. Brandon and Bryan also discuss: Educational resources about refrigerants What "mildly flammable" actually means European HVAC equipment Chemours at the AHR Expo Learn more about Chemours A2L training at opteon.com or Opteon's YouTube channel. Check out what Chemours has in store at the AHR Expo at https://www.opteon.com/en/ahrexpo. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE. Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

Chuck Allgood with Chemours joins the podcast to cover the history of refrigerants and discuss what the future might hold. In the late 1800s, before Freon, the only refrigerants that were used were industrial chemicals like ammonia, CO2, and sulfur dioxide. DuPont stepped in to provide a better refrigerant for industrial refrigeration (which then spurred the rise of domestic refrigeration), so they created a non-toxic, non-flammable chemical called Freon-12 (CFC R-12) in 1928. However, in the 1970s-1980s, it was discovered that R-12 and other CFCs depleted the ozone layer due to the chlorine content. R-12 production was banned in the 1990s per the Montreal Protocol. HCFCs like R-22 also have chlorine but in smaller concentrations; those phaseouts have been much more recent. Following news of the HCFC phaseout, HFCs and refrigerant blends became more popular because their ozone depletion potentials were 0. Although HFCs don't deplete the ozone layer, some of them have high global warming potential (GWP). Regulations stemming from the Kigali Amendment, such as the American Innovation and Manufacturing (AIM) Act, have been introduced to phase down the production of HFCs to slow global warming due to refrigerants. HFOs have recently been developed to replace HFCs; these have olefins, which are double-carbon bonds with short atmospheric lifespans. So, they don't contribute to global warming as significantly as HFCs and have GWPs of less than 1. Chuck and Bryan also discuss: What Willis Carrier really invented Chlorine and ozone depletion Development of refrigerant blends Freon vs. Opteon branding Refrigerants and the greenhouse effect Oil lubricants Best practices for mildly flammable refrigerants Timeline of Opteon line refrigerant releases Learn more about Chemours A2L training at opteon.com or Opteon's YouTube channel. Check out what Chemours has in store at the AHR Expo at https://www.opteon.com/en/ahrexpo. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE. Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

Andy Holt joins the podcast to discuss the ever-relevant topic of overcoming conflict at work. Some people end up in conflicts often, so Andy recommends paying attention to how others react to the conflict you have perceived; if you are much more stressed than everyone else, then you need to look internally, not externally. The first step to overcoming conflict is to slow down and think about your reactions to perceived conflicts. Partaking in bickering and gossip with coworkers creates a negative environment for the entire team; the best way to avoid or resolve conflicts is to handle them directly and sincerely ask the other party to start over. Overall, it's best to take the high road and take initiative to make things right. When dealing with conflict with bosses, it's best to separate emotion from the facts and keep discussions simply factual. It's good to be open, honest, and understand that you can't control your boss's response. As a boss dealing with employee conflict, it's a good idea to avoid firing on the spot and give employees a chance to think about the conflict at hand, such as by giving them a paid "cool-off period." Customer conflicts may arise from pricing issues. The technician can ease tensions by quoting jobs up front and bundling services to show the customer where the value is. To resolve conflicts with customers, the best thing to do is be attentive to their concerns. Andy and Bryan also discuss: "Designing" a reaction Dealing with big egos Letting people go Working towards agreements vs. forcing bargains Dealing with hot tempers Taking ownership of comfort problems MeasureQuick and fact-based conversations If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE. Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

Matthew and Nick Wavra join the podcast to discuss everything that goes into job estimation in commercial HVAC. Nick has a lot of fieldwork and project management experience, and Matthew has marketing, software, and sales experience, which helps bring in and retain clients. Commercial estimation begins when a mechanical contractor asks for a bid on a job. The estimators go through the spec books, bidding documents, and any addendums to come up with takeoffs and a price. The estimator seeks approval from manufacturers to build the materials, and they use software to come up with an estimate. The pricing updates weekly to stay current and accurate in an economy that's currently facing inflation. Estimators develop takeoffs for materials and labor; each material has some sort of labor attached to it, though the labor estimates may need to be adjusted as conditions change. Commercial contractors may make mistakes when they miss equipment or elevation considerations (when estimating labor). On-screen takeoff options significantly reduce the risk of creating mistakes, so it may be unwise for contractors to do takeoffs by hand instead of using software to help. Matthew, Nick, and Bryan also discuss: Sheet metal price increases Software vs. man-made takeoffs DX piping vs. chilled water boilers Estimation in HVAC vs. refrigeration CRM (customer relationship management) Developing a commercial HVAC estimation training course Finding a niche in the HVAC estimation business Look for Nick and Matthew at the AHR Expo 2022 in Las Vegas! They will be at booth N9142 in North Hall. Learn more about Matthew and Nick's business by visiting hvacestimation.com/ or by calling Nick directly at (238)-900-6330. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE. Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

In this short podcast episode, Bryan goes over the basic gas furnace sequence of operations. There are a few variations, but the sequence of operations tends to stay consistent across most furnace types. First, a W call from the thermostat calls for heat. The circuit board will then assess the safeties to see if it can bring on the heat without causing flame rollout or other dangerous conditions. If the safety switches are all closed, then the furnace can bring on the heat. However, in some cases, the induced draft motor may come on first in some 80% furnaces. There needs to be a small negative pressure in the induced draft motor housing. To confirm that we have that pressure, a pressure switch will close under the right conditions. Then, ignition begins. In most cases, we use intermittent-spark ignition (ISI) or hot-surface ignition (HSI). It takes some time for these methods to light the pilot, which then lights the main burner. After that, the gas valve opens to fuel the burner. On an ISI system, that's about it until the blower comes on. However, once the main burner opens on an HSI system, a flame sensing rod can verify if you have a flame on that burner. There is a blower delay that prevents the blower from coming on and blowing a bunch of air that hasn't yet been heated. After that, the blower delay ends, and the blower comes on. Then, the furnace shuts off when the W call ends. Then the blower continues running for a little bit before turning off. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE. Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

Trevor Matthews, the founder of Refrigeration Mentor, returns to the podcast to talk about starting up an internal training program for an HVAC/R company. In some cases, the best lead technicians don't want to be head trainers if the responsibility is forced upon them. However, when there is a solid training plan in place, those senior technicians might actually find the task enjoyable. The first step to starting a training program is to ask the apprentices and technicians where their skills are at and how they want to develop their skills. That way, you can map out a program that works for the technician and figure out how to make time for thorough training. When you grow people within your company, you'll likely see more success than when you outsource training. It takes longer to develop the relevant skills in outsourced people; so, when you develop a solid internal training program, you can sustain it with the people who pioneered it. We also need to focus on evaluation in training. When we assess our techs' skills, we add accountability to our training programs. However, it takes time for techs to grow from a training program, and we need to make sure we're rewarding progress. Training also works best as a team approach. When we look at the techs' strengths, we can diversify the training program and make sure that several skill bases are covered. Trevor and Bryan also discuss: Common excuses to avoid training Motivated trainers and technicians Labor shortage and skills gap Visual, auditory, and kinesthetic learning preferences Prevention-based training Managerial involvement in training Learn more about Refrigeration Mentor at https://refrigerationmentor.com/. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE. Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

In this short podcast, Bryan explains the basics of flame sensing, also known as flame rectification. Flame sensing/rectification is a form of proving flame. When you can't prove flame, your furnace might be dumping unspent gas into the heat exchanger, which can cause an explosion. Flame sensing rods are common in hot-surface (HSI) and intermittent-spark (ISI) ignition. These rods stick out into the flame and connect to the furnace board. The flame creates a path between the rod and ground, which allows a very small current to flow to the board. Without a flame, there is voltage but no path, so the board can't sense a current and will shut the gas valve off to try again. Sensing rods can fail when they short out due to a cracked insulator, are physically broken, aren't placed in the flame, or get covered in silica or carbon. If the furnace or burner assembly isn't properly grounded, then the flame sensor also won't work. Flame sensing rods are often confused with thermopiles or thermocouples; the latter devices generate voltage and have a coating that can rub off with improper cleaning. Flame sensing rods don't have either of these features, so you can clean these by any means necessary (without breaking them or creating grooves or pits). To test a flame sensing rod, begin by making sure the furnace is properly grounded. Then, make sure the rod is in the right spot and that the burner assembly is in good order. Get a microamp meter (with a resolution that reads tenths of microamps). Then, connect your leads in series with the flame rod. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE. Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

This podcast episode is a throwback to one of Bryan's first small business podcasts. In this old episode, Australian electrician and businessman Joshua Nicholls explains how he built a business by focusing on customer experience and branding. Bryan grew Kalos similarly, so they talk about the journey of going from "man-in-a-van" businesses to larger businesses with several employees. Joshua wanted to bring old-school manners and integrity to the business world, and that's how he branded his business. The focus on customer service over marketing earned the customers' respect, and customers were happy to remain loyal to the business and recommend it to friends. The repeat business and referrals allow you to maintain a client base AND grow it without spending too much money on advertising. Eventually, the business grew big enough to require Joshua to change some of his internal processes. He needed to understand when to bring external help into the business, whether those helpers were financial advisors or mentors. Joshua reached a point where he got bored with his business, so he went to a conference in New Zealand and decided to start franchising the business. The business worked without him, and he decided to give a chance for young entrepreneurs to share in his business's success and spread his business all over the country. Joshua and Bryan also discuss: Joshua's origin story Authenticity in business What to do after the growth boom Profitability vs. work-life balance Turning customers into raving fans Scheduling appointments in a service business Knowing your numbers in business finance The "One Van, One Child" initiative If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE. Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

In this short podcast episode, Bryan covers the differences between defrost termination and failsafe. He also covers the basics of defrost in refrigeration applications. In medium-temp applications (also called coolers), the box stays above freezing temperatures, but the coil may drop below freezing. When the air is above freezing, we can use off-cycle defrost. The coil defrosts when the system naturally cycles off. We may also use timed defrost, which pumps down or cycles the compressor off at set times to force a defrost cycle. In low-temperature applications, the box will typically be below freezing. We may use electric heat to melt ice off the evaporator coil, and the fan stays off; this method is usually accompanied by a pump-down to remove refrigerant from the coil. We may also use hot gas defrost, which pumps discharge gas through the coil to melt the ice off it. (Kool gas may use a warm fluid instead of hot gas.) We want to stop the defrost as soon as the coil is ice-free; we don't want to keep adding heat when we don't need to melt anything. A defrost thermostat detects when the coil is free of ice and terminates the defrost when the temperature reaches around 55 degrees Fahrenheit; this is called defrost termination. We rely on a failsafe to terminate the defrost in case the defrost termination fails; the failsafe is the maximum amount of time a system is allowed to remain in defrost. Demand defrost uses time and temperature to tell the controls when to put the system into defrost; this method uses trend analysis and sensors to force the system into defrost at set times and intervals. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE. Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

This podcast episode is a throwback to one of Bryan's first podcasts about small businesses. Cesar Abeid, former VP of construction camera company Remontech, joined this podcast to discuss the basics of project management and a book that can help you step into that side of the business. Project management is a framework or set of tools to turn an idea into reality. Projects have a beginning and end to create something new, and project management is how we get from the beginning to the end while factoring in schedules and a budget. In essence, project management is a system. Effective project management requires a business to create processes and procedures for its services. For example, Remontech needs to plan the actual camera installation, but the company also has a bunch of internal processes to set up servers for recording. The key to project management is to remember what must be done and assign tasks to people as needed. One of the issues Cesar saw with project management books was the dryness and corporate nature of their language. As a project manager, Cesar used stories from his life to make his book more relatable and accessible to small business owners. Cesar and Bryan also discuss: Contractor-client communication External vs. internal processes Cesar's book: Project Management for You Cesar's preferred leisure activities Wasting time or learning? Purchase Cesar's book or learn more at https://pmforthemasses.com/product/project-management-for-you-bundle-1/. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE. Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

Bryan discusses impostor syndrome, what it is, and how it may actually be useful for us. When we feel that we're frauds and that others wouldn't like to be led by us if they knew how much we don't know, we're experiencing impostor syndrome. Contrary to what others might believe, impostor syndrome isn't all that bad and may even be necessary for a healthy self-image. On the other side, we have the Dunning-Kruger effect, which is when people are confident in the things they have very little actual knowledge of. They think they're experts and close themselves off to other sources of knowledge. On the other side of the Dunning-Kruger effect spectrum, true experts are acutely aware of what they still don't know. We would be wise to know what the edges of our knowledge are and give others a chance to share their expertise when we reach those limits. When people learn more about a subject, they become much more aware of what they don't know. Wisdom comes from knowing what you don't know. However, if you feel that feeling of inferiority, you can still share the knowledge you have while seeking feedback and deferring to others who know more than you. (That's especially true of Bryan, who has a summary knowledge of industrial refrigeration and defers to others who know more about it.) In the end, we're seeking authenticity and self-awareness. Rather than avoiding impostor syndrome, we can embrace it and understand how it can lead to self-awareness, wisdom, and especially self-improvement. "Fake it till you make it" can only help you up to a certain point. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE. Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

Amrit Robbins of Axiom comes on the podcast to discuss how we can use data science to transform grocery and cold storage. Axiom Cloud uses cloud analytics and AI to map data and analyze trends on refrigeration racks. It can be particularly useful to keep track of readings all the time because it's impractical to rely on a human to take and record readings 24/7. Grocery stores are unique because they have so much product at stake and are relatively inflexible in their usage of energy. If something goes wrong on a rack, thousands of dollars worth of products may be lost. If we could collect and review data at our fingertips, we could spot potential problems before the store loses money. These systems may also have alarms for case temperature problems, floodback conditions, and even some less immediate issues, such as a lack of floating suction. Axiom Cloud also monitors when systems go into defrost, so you can assess the cycles of case groups and figure out if they correspond to any issues. When you have data collection, you're not relying on a "virtual technician" to automate HVAC work. Instead, data science can empower HVAC technicians and help them do their jobs more efficiently so that they can respond to issues before they become emergencies and serve customers better. After all, computer-based systems can't repair or clean units! Amrit and Bryan also discuss: Generating value on behalf of the customer Compressor failures Technician labor shortage Creating sustainable working hours Developing more flexible energy usage Monitoring temperature rise across cases Thermal banking Preparing for data analytics to come to the industry Learn more at axiomcloud.ai. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE. Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

In this short podcast, Bryan goes over the basics of superheat and explains why it matters to us. Superheat is the temperature increase above a substance's saturation temperature or boiling point. When a substance is superheated, that means it is 100% vapor; there is no liquid at all. We can look at our superheat to determine how much refrigerant is feeding our evaporator coil. A lower superheat indicates that our evaporator is more full of refrigerant than a high superheat, meaning that the refrigerant is feeding the evaporator coil well. Generally, a lower superheat value will be more efficient, but if the superheat gets too low, we can get liquid in the suction line and compressor. An evaporator can maintain roughly the same temperature throughout the bulk of the coil because the temperature stays the same during a phase change. As the refrigerant boils off from its liquid state, it remains at the boiling point. You generally want to see no less than 6 degrees of superheat, especially at the compressor. Zero superheat indicates that you have some liquid refrigerant (or that the system is off). Superheat can get tricky when we use refrigerant blends with glide. The different refrigerants in a blend have different boiling points, so the evaporator temperature can drift up. When determining the superheat of blends, we use the dew point to calculate the superheat (and bubble point for subcooling). We get superheat in the evaporator (suction line at the evaporator outlet) and the compressor (suction line at the compressor inlet). The latter will be higher because some sensible heat will be absorbed in the suction line. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE. Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

In this podcast episode, Bryan and Eric Mele talk about sight glasses, the significance of subcooling in refrigeration, and liquid quality. While we measure subcooling quite often in HVAC work, we rely on sight glasses and liquid line receivers far more often in refrigeration. You need a sight glass to determine the liquid quality in a refrigeration system. Subcooling is one way to assure liquid quality without a sight glass or a receiver. Subcooling refers to the temperature drop below liquid saturation. Head pressure can dictate subcooling, and several other factors can dictate the condensing temperature, including stacking. We use sight glasses because a clear sight glass can tell us that we have a full column of liquid (therefore subcooling) without hooking up gauges. In HVAC, we care about having a certain level of subcooling because we want to make sure the refrigerant is fully liquid when it reaches the metering device; no bubbles should be present by the time it reaches the metering device. Like the suction line, the liquid line is a place where heat can be absorbed into the refrigerant. So, some manufacturers recommend insulating the liquid line to prevent heat from transferring to the refrigerant in the liquid line. Unit orientation also affects subcooling. For example, you can shorten the liquid line sizing if your liquid line goes downhill to the air handler. Conversely, longer lines and uphill liquid lines require special considerations when it comes to subcooling. Eric and Bryan also discuss: Liquid line receiver fill standards Subcooling and efficiency Sight glass placement Stacking liquid in the condenser Pump down strategies Mechanical subcooling Flash gas "Free" subcooling Ambient temperatures If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE. Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

In this short podcast, Bryan explains the basics of repairing aluminum, such as on coils or tubing. Repairing aluminum can save lots of time on mission-critical calls and can help stop refrigerant leaks that lead to ozone layer depletion or global warming. Soldering makes almost all of the aluminum repair work we will do. (Brazing is possible, as aluminum has a melting point of 1200 degrees, but that's still a bit too close to the brazing threshold.) When working with aluminum, we need to recognize that it melts at a lower temperature than brass, steel, and copper, and it doesn't change color. Aluminum is also thinner and almost fades away under excess heat. First, you'll want to figure out how to get the base temperature to the right temperature, usually with a flux. (Some fluxes require cleaning, some don't; either way, we recommend cleaning.) The powder flux should go clear, and then you'll be ready to apply the rod. In many cases, indirect heating can be difficult if not impossible. After you choose your alloy, you need to choose your torch. We recommend using a swirl-tip air-acetylene torch. (It's good to use a 3 tip for microchannel.) When working with an air-acetylene torch, you will run lower temperatures than oxyacetylene torches, but you will experience more convective heat. (Heat control is the key!) When doing a repair, you want products that will make a solid bond to the outside of the joint. Make sure your products are for repairs, not for joining aluminum tubing. If you do aluminum repairs on an evaporator or condenser coil, cut the fins out of the way. Make sure your work area is exposed and clean. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE. Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

In this short podcast, Bryan goes over energy transfer and heat, specifically specific heat. BTUs per ton is a common measurement; a BTU (British thermal unit) is the amount of heat it takes to raise the temperature of one pound of water by one degree Fahrenheit. 12,000 BTUs per hour is equal to one ton in heating or cooling technology. It takes one "ton" of heat to melt a ton of ice, but we kept the measurement and terminology as we moved away from using ice in industrial refrigeration. When it comes to specific heat, we have to remember that one BTU has a different heating or cooling impact on different substances. Most fluids have a specific heat lower than water, meaning that one BTU of heat will result in more heat transfer in that substance than water. Air is one such fluid that has a lower specific heat than water (0.24 vs. 1); it's easier to heat air than water. However, the specific heat of vapors can change with temperature and pressure. When we change a refrigerant from a liquid to a vapor in the evaporator coil, it will reach saturation before boiling. As the refrigerant boils, the temperature will stay the same because the absorbed heat will all contribute to the phase change as latent heat. Even though most refrigerants have low specific heat, direct expansion systems can still move a lot of heat because it takes a lot of latent heat to complete a phase change. In other systems that don't use direct expansion (using glycol or water instead), specific heat is more integral to the effectiveness of heat transfer because latent heat isn't a factor in heat capacity. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE. Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

In this podcast, Steve Rogers from The Energy Conservatory explains some pro tips for pressure measurement. There are three common types of pressure measurements: absolute, gauge, and differential. Absolute pressure is the pressure in a particular space in reference to a complete vacuum. (All absolute measurements use the zero point as a reference.) Gauge pressure uses atmospheric pressure as a reference point (which varies with altitude and location). Differential pressure relies on two connections (one of them is a reference point to the other). The Energy Conservatory recently designed a manometer (DG-8) that differs from the standard manometers. The purpose of that manometer is to make pressure measurements in a more cost-effective way. Most manometers have similar sensors (diaphragms move with pressure, and the measurement read is the resulting difference in resistance). However, the DG-8's methodology can help it yield much more accurate measurements. When dealing with small pressure measurements (like Pascals), the DG-8 is one of the most accurate manometers you will find on the market. When you look at room pressure, keep in mind that pressurizing one room will depressurize another. Temperature differences also impact the pressure, and the HVAC unit can cause differences in pressure to arise as a result of temperature differences. When you run the kitchen or bathroom exhaust and expel a lot of air in your home, you can also bring the home under negative pressure; that can even cause your water heater to backdraft. Steve and Bryan also discuss: Blower door manometers vs. DG-8 manometers Pascal scale Room pressures and air paths Infiltration and its effect on load calculations Dominant duct leakage Combustion appliance zone (CAZ) testing Mechanical ventilation and pressure Orphaned water heaters DG-8 and the TrueFlow grid Learn more about the DG-8 HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE. Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

Trevor Matthews from Refrigeration Mentor comes on the podcast to talk about Copeland reciprocating CS compressors. He and Bryan cover Bulletin AE4-1433 (found HERE) as they look at the operating envelopes for the CS compressor. The CS compressors are hermetic reciprocating compressors that can work with some of the newer refrigerants. You will likely see these compressors in applications with smaller tonnages. You'll usually want to charge these compressors with liquid refrigerant. If you have more than 6 pounds of charge in the system, using an accumulator is recommended. Under those charge conditions, the system also needs a check valve between the receiver and the condenser. Suction line pressure drop is one of the most important things to pay attention to in the system. Make sure the suction line is of an appropriate size, that filter-driers don't have restrictions, and that accumulators aren't clogged. Overall, many manufacturers recommend removing the duction driers to keep the pressure drop minimal. The recommended runtime for these compressors is also very short, only 5 minutes. CS compressors should cycle no more than 12 times per hour, and the off-time between cycles should be a minimum of 10 seconds. Before returning or replacing a compressor, make sure you check all of the electrical components, including the capacitor. If the compressor hums but has power, you could simply have a capacitor or potential relay issue. Trevor and Bryan also discuss: Return gas temperatures Discharge line temperature Compressor superheat and flooded conditions with refrigerant blends Crankcase heaters Pump-down recommendations to stop short cycling Initial charge vs. recharge Metering devices Line sizing Electrical shorts Sticking relays Single-phase vs. three-phase power Megohm testing Purging with and flowing nitrogen Burnout cleanup procedures Locking/tagging out equipment Hard start kits, potential relays, and start capacitors If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE. Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

In this short podcast episode, Bryan explains the science behind adiabatic cooling. Adiabatic cooling occurs in specific HVAC/R applications and in our environment as air temperatures and pressures change. When we think of cooling, we refer to the loss of heat; we are either referring to the change in the total BTU content of the air mass or the temperature change. Adiabatic cooling takes sensible heat and transforms it into latent heat. The most simple forms of adiabatic cooling can be seen in cooling towers and swamp coolers. In evaporative or swamp coolers, you have a pad saturated with water, and air moves over it. When air moves over the media, some of the energy helps evaporate the moisture on the pads, so the air loses sensible heat and becomes cooler. The thermal enthalpy (total heat content) stays the same, but some of the sensible heat has transferred to latent heat. Air that goes through a swamp cooler goes in with higher temperature and lower humidity, and it leaves with a lower temperature and higher humidity. The BTU content stays the same; the energy merely transforms. As a result, we usually only use swamp coolers in arid environments where higher humidity is desirable. You also can't compare these to compression-refrigeration systems because compression refrigeration aims to change the BTU content and is NOT adiabatic. When we run air over an evaporator coil, some of the water vapor in the air condenses to liquid water in the drain pan. Some of the energy in the refrigerant changes the state of the water vapor to liquid water instead of changing the temperature. You'll see a lower delta T when your return relative humidity (RH) is higher. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE. Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

In this short podcast episode, Bryan shares his top tips for fighting boredom at work. You can use these tips to help you get out of a rut if you don't feel productive or get bored easily. The first tip for fighting boredom is to see the art or creativity in your work. Even in the HVAC industry, there are plenty of opportunities for artisan skills and craftsmanship. When you see your work as an art that you need to refine, it's easier to get engaged in your work and feel proud of it. That's especially true of tasks like duct strapping and brazing. Another way to stop from getting bored is to do more things that challenge you. Being constantly challenged and being out of your comfort zone keeps you interested and can even spark a new passion. Pursuing mastery allows you to focus on one particular skill or subject to become an expert. When you master a skill, you also become a marketable job candidate and can carve out a niche within your organization. Mastery is about going deep rather than wide, and more people will feel enriched by working towards mastery than others. If you're a social person, finding a community can keep you from getting bored. When you have a community, you will be around people who have the same interests and experience the same challenges as you. So, you won't get bored from feeling alone. Mentorship is another way to rekindle your passion. When you choose to invest in and guide less experienced people in the trade, you can feel a renewed sense of purpose in your work. And if you're REALLY bored, you can change everything up entirely and try something new. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE. Check out information on the 2022 HVACR Training Symposium at hvacrschool.com/symposium/.

In this podcast episode, Bryan goes through the addendum to the book Review of Vacuum for Service Engineers. He and Jim Bergmann had the honor of revising the latest edition in 2020. You can get the latest edition of Review of Vacuum for Service Engineers from TruTech Tools HERE. Pulling a Schrader core before evacuation makes a big difference in the speed of the evacuation. You can use a core remover tool to pull the cores when the system is NOT pressurized. There are three common types of ports to access the system: the Schrader core, high-flow core (CoreMax), and the multi-position service valve. You can mid-seat the multi-position service valve for high flow, but you need to remove or depress cores on the other two port types. (You must use a special CoreMax CRT to remove high-flow cores.) Three factors limit the speed of evacuation: the conductance speed of the pump, of the connecting hoses, and of the system. The hoses and manifold can severely impact evacuation. TXV and piston metering devices have short orifices and have very little impact on the evacuation time; on TXVs and EXVs, the valve should be fully open. When pulling a vacuum, make sure the vacuum pump works properly and has clean oil. Once you know that the pump is working, only pull on a tight system (no leaks) and make sure the seals are in good shape. Bryan also discusses: Micron gauge and hose placement Core depressors and CRTs Refrigerant holding charge When core restrictions are helpful Single-hose vs. two-hose evacuation speed Moisture removal One-hose evacuation of a split air conditioner Decay testing Hard shut-off valves How to solve micron gauge issues Nitrogen sweeps for wet systems If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE. Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.