HVAC School - For Techs, By Techs

This podcast is a class that Bryan taught for BTrained in Birmingham, AL. He covers troubleshooting, installation, and commissioning best practices with a focus on the fundamentals. To be a good troubleshooter, you must be able to find the problem, identify the source of the problem, fix the problem, and optimize performance based on your data, the customer’s comments, and your observations. The Five Pillars of diagnosis aren’t comprehensive diagnostic or charging criteria, but they can help you charge or diagnose a system. Isolation diagnosis works best for electrical components; you isolate the problem area from the system and see how the system works without the suspected issue. If the system operates normally without the component in question, then we can conclude that our hypothesis about the “problem” part was correct. Wide-narrow-wide troubleshooting is an approach that allows you to inspect the entire system, zero in on the problem, and optimize the entire system. By starting wide, going narrow, and going wide again, you can troubleshoot holistically. Installations take place in several phases: pre-planning, planning, demo, installation, and commissioning. Many people place a lot of emphasis on the demo and installation and neglect the conversations and procedures associated with pre-planning, planning, and commissioning. Bryan also covers: Heuristics and mental shortcuts Evaporation vs. boiling Rules of thumb Head pressure, suction pressure, and compression ratio Energy transfer fundamentals What superheat and subcooling really indicate Restrictions and temperature drop Delta T “Redneck” compressor test Testing circuits Useful measurements and test instrumentation Causes of compressor failure Measuring airflow Low vs. high static pressure Bringing tribal knowledge to building design Ductless systems, ventilating dehumidification, and sensible heat ratio Manual J, attics, and combustion air Radiant barriers and heat transfer Supply relative humidity Dehumidifier configuration and system design Bad envelopes Vented attics Duct upgrades Total effective length and turning vanes Evacuation   Learn more about BTrained at https://btrained.net/ or on the BTrained YouTube channel at https://www.youtube.com/channel/UCnlDsWHT68gVwPrYYO5vhrw.  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.

Bryan has a bit of an industry nerd out with Ross Trethewey from “This Old House” and TE2 Engineering at IBS 2022 (the International Builders’ Show). Ross’s education and career have focused on mechanical engineering, especially with sustainable solutions. In building science, the key mindset is to think of the building as a system. Using that school of thought, Ross has developed building science and HVAC solutions that also consider indoor air quality and ventilation, such as hybrid VRF systems.  Many of Ross’s solutions take the best aspects of air-source and ground-source heat pumps and apply those to hydronics. Some exciting applications for those types of systems could include simultaneous heating and cooling as well as the integration of domestic hot water. Demand control ventilation has been used for a long time in the commercial world, but its possible use in residential applications is another exciting thing to consider. With proper control devices, DCV would give us the opportunity to control temperature, humidity, VOCs, carbon monoxide, carbon dioxide, and radon. In residential applications, DCV has to be a delicate balancing act, as bringing in too much outdoor air would require us to condition that air. High latent loads also present challenges to some of the ventilation solutions in development. Serviceability is another challenge to DCV usage in residential applications; whenever an innovative system is brought to the market, very few people will know how to fix and maintain those systems. One of the possible solutions is to create instruction manuals and give education similar to what already exists for package units. 3D models and animations also help make complicated systems easier to understand. Ross’s presence on “This Old House” marks the third generation of Tretheweys on the show. Ross is excited to talk about building science and HVAC innovations and concepts while on the show. Heat pumps are also getting better, especially due to inverter-driven compressors, enhanced vapor injection, advanced control systems, and ECMs. Heat pumps are safer than gas-fired equipment, and we have made them work well in subzero temperatures (because we’re nowhere near absolute zero). 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 podcast, Bryan goes through the entire process of replacing a compressor step-by-step. This process is what the Kalos team uses to replace a failed compressor and make sure it doesn’t fail again. Before replacing a compressor, you must figure out how the compressor failed; grounded conditions often lead to acid, so it’s a good idea to test for acid and see if you need to address a burnout. In any case, make sure you have the correct tools for the job (including a compatible replacement compressor). When you arrive at the job site, be sure to confirm the diagnosis and check to see if the unit has a hard start kit. That’s also the time to do a visual inspection, checking airflow as well as the filter, blower, and coil cleanliness. Recover and weigh out the refrigerant charge. Unscrew the foot bolts and lift the old compressor out. Then, seal the compressor once it’s out. If you’re dealing with burnout, clean out or replace the accumulator (you will install/reinstall it shortly). Cut out and replace the existing liquid line drier and install a suction drier in a place where it can be easily removed.   When piping in the new compressor, make sure you protect heat-sensitive parts and do a quality brazing job. Install the new capacitor and hard start kit, too, keeping wiring away from places where it may chafe. Test for leaks, evacuate the system, charge the system, and check your five pillars as well as voltage. Finish by cleaning the drain and double-checking airflow. Bryan also covers: Misdiagnosed compressor failure Parts needed for replacing a compressor What makes a compatible replacement compressor? Billing and pricing Alloys and fluxes Replacing TXVs, capacitors, contactors, and reversing valves Cutting vs. unsweating  Suction driers and pressure drop Charging considerations   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, 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 brynn.cooksey@airdoctorshvacservice.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.