HVAC School - For Techs, By Techs

In today's short podcast, Bryan discusses electric heat, how we use it in our work, and what it does. Also called heat strips or heat elements, electric heat is a supplemental heat source that we usually see on heat pumps. We generally see them in fan coils within a cartridge or a kit at the top of an air handler. However, not all systems have backup heat. We want to avoid running electric heat as much as possible because it is inefficient. There is almost nothing we can do to make heat strips more efficient; they will usually yield around 3.41 BTUs per watt. We usually only run heat elements when a heating system can't keep up with the heat loss. However, the electric heat often runs more often than it should, which can cause inefficient conditions. You can avoid inefficient conditions by programming the thermostat properly. If you reduce the voltage on the heat strips, the less heat they will produce. Current ratings also differ between 208v or 240v applications. When you have more voltage, you'll have more current as well. In some municipalities, you may have to use a thermostat that keeps heat strips OFF unless the temperature is below a certain value, often 40 degrees. Your electric heat should also be the last resort for a system. Heat strips also help with heating when a heat pump is in defrost. The defrost board backfeeds the electric heat. These heat strips are also often designed with an interlock that forces the blower on whenever the electric heat is on (but not the other way around). Bryan also discusses: Kilowatts and electrical ratings Wiring and relays Wire sizing Furnace-to-heat-pump conversions Possible hazards 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 comes on the podcast to discuss his newest project, Refrigeration Mentor. Refrigeration Mentor uses Trevor's experience as a trainer and field technician to guide others in their careers. Trevor's goal is to help commercial refrigeration technicians grow and become more confident in their skills. He wants them to become the best technician they can be, and he believes that mentorship is one of the things that make our industry great. Mentorship can help people advance their careers, sharpen their skills, and ease their anxiety about work. When we share knowledge, we bring value to the technicians. That value extends to the customer when technicians are more confident in their work and do better jobs. A good mentor has a commitment to doing quality work within the trade but will make their mentees feel comfortable to admit what they don't know. Mentors can also help their mentees develop a solid work-life balance that helps mentees be present to their jobs and their families. The mentor's job is to help their mentees reach their goals, whether that's learning a new skill, entering a leadership role, or even starting a business. Trevor also wants to help business owners or managers strengthen their teams. He believes that a dynamic culture and a strong emphasis on training will help a business (and the industry as a whole) grow. His mentorship approach comes from strengthening technicians, businesses, and the industry from the heart. Trevor and Bryan also discuss: Holistic training Hesitancy to admit what we don't know Passionate teachers Mental health Starting and managing a business from the inside Investing in training and mentorship Check out Trevor's website 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/sympos

In this podcast, Ben from HAVEN IAQ, Kaleb, and Bryan discuss how to control indoor air quality and take effective, meaningful, accurate measurements. HAVEN is a platform that offers hardware and software delivered to a homeowner through an HVAC professional. HAVEN's goal is to give its customers a healthier, more comfortable home using IAQ solutions. The hardware (controls, etc.) works with the HAVEN software to give customers and contractors data about IAQ and the performance of the HVAC equipment. Right now, you may install up to two HAVEN controllers and one monitor per zone to help control equipment and monitor the air content. Air sampling occurs every hour, whether the HVAC system is running or not. Customers can learn to control their ventilation habits to address acute events (e.g., a spike in humidity from cooking), which only result in short-term IAQ problems. However, contractors can use the air sampling data to develop solutions for chronic events (e.g., constant high humidity). Solutions, even simple filtration ones, are best left to the contractors to figure out. The integration of most IAQ products requires some degree of design and planning. HAVEN products do NOT provide plug-and-play solutions. While "demand" solutions can introduce outdoor air to prevent a viral problem, you could introduce a moisture problem without proper planning. Ben, Kaleb, and Bryan also discuss: HAVEN central air controller Building relationships with customers Software integrations with other platforms Filtration caveats HAVEN Pro Portal and Personal Use Program Ease of connecting HAVEN controllers to equipment "Demand" ventilation, dehumidification, etc. Importance of airflow Making IAQ product sales and educating homeowners IAQ placebos In-duct monitoring Introducing HAVEN products to your market Please visit pro.haveniaq.com to access HAVEN's Pro Portal. 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/.

Ryan Gorman comes on the podcast to discuss the differences between a college education and early career opportunities in the skilled trades. Many parents feel pressured to send their children to college and encourage them to get a four-year degree. Despite what society may lead us to believe, there is no shame in thinking that college may not be suitable for you or your child; the skilled trades have many opportunities for people to learn throughout their lives and make a good living. In many cases, parents may see college as a ticket to the starting line. Unfortunately, college tuition has skyrocketed over the years, and a good ROI is not guaranteed. Instead, a career in the skilled trades can allow a person to develop hard skills and land a well-paying job at a young age. As the skills gap widens, young people who learn skills make themselves attractive to employers and increase their earning potential. Children and teenagers who want to become engineers may actually prefer a trades career where they get to work with their hands. The path to the trades is less expensive than getting a four-year degree and may prove more fulfilling in the long run. Internships, small businesses, and trades careers are viable paths for young people; we don't present these possibilities at a young age, but they are worth considering for people who may not benefit from college. Ryan and Bryan also discuss: The arbitrary structure of college programs Parents wanting better for their children Overvaluing the 4-year degree Networking The skills gap Craftsperson vs. technician Feeling "stuck" Attending college at an older age Lifelong learning Universal skills vs. specialization Suggested resources for people who feel "stuck" 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/.

Jason Obrzut comes on the podcast to discuss A2L refrigerant facts. Jason is a member of AHRI's Safe Refrigerant Transition Task Force and author of the RACT manual. ASHRAE designates refrigerants into categories based on toxicity (A or B) and flammability (traditionally 1, 2, and 3). So, the new A2L designation indicates that a refrigerant is relatively non-toxic but has a flammability value between 1 (low) and 2 (moderate). While propane (R-290) is a good refrigerant because it is natural and has low toxicity, it is very flammable (A3). Future refrigerants will likely fall under the A2L designation; the mild flammability will probably be the tradeoff for efficient, low-toxicity refrigerant with a low environmental impact. However, A2L refrigerants cannot be vented, even despite their low GWP. We also cannot use these refrigerants in retrofits. A2L refrigerants will likely become much more prevalent around 2023 as HFC refrigerants phase down. The phase-down period will be specified shortly, and it will begin with a 10% reduction; the specific parameters of the phase-down have yet to be set. When working with A2L refrigerants like R-32, you can expect little to no change in how you work on equipment if you're already employing the best practices. Sizing and capacity will hardly change in the residential market. In the commercial sphere, these systems still look and operate quite similarly to current units. Jason and Bryan also discuss: Refrigerant detection systems (RDS) Flowing nitrogen and other best practices Non-A2L HFC alternatives Left-handed threads Non-standard safety practices R-32 properties Refrigerant glide To learn more about A2L refrigerants, check out the AHRI Safe Refrigerant Transition Task Force's webinars, newsletters, and fact sheets CLICK HERE. Check out information on the 2022 HVACR Training Symposium HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In today's podcast, Bryan and some Kalos employees discuss how to deal with difficult bosses and coworkers in HVAC/R work. Whether your coworkers have anger issues, are careless, or are miserable people, you don't want that negativity to affect your job satisfaction. Addressing the behavior may likely help, but you don't want to attack the other person. The key to dealing with difficult coworkers is to communicate boundaries respectfully with the goal of improving the work environment. Boundaries are also important when dealing with sarcastic people or those who make inappropriate remarks. Any work environment with lots of people is bound to have cliques and tribes. You're best off not getting involved in any of that drama; the best thing you can do is be kind whenever you have the opportunity. Nepotism may also fall under tribal behaviors, and it may cause you to rethink your future with a company. On the leadership side, micromanagers can be frustrating—doubly so if your boss also happens to be condescending. If you have micromanager tendencies, try setting clear objectives and give your technicians room to develop. (If you're on the receiving end, talk to your boss about bigger-picture objectives to cut down on micromanagement.) Learning is all part of working in the HVAC/R field, but you may encounter friction with bosses who won't invest in learning or coworkers who refuse to learn new things. Try to have productive conversations with these people. If you're talking to a boss who doesn't invest in training, try to communicate your professional and educational needs. If you have a stubborn coworker or helper who doesn't want to learn, try to help them understand the new material by using similes and metaphors. We also discuss: Distractions Sarcasm and rudeness Egomaniacs Inappropriate exaggeration Dishonesty Overreaction Check out information on the 2022 HVACR Training Symposium HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In today's podcast, Ed Janowiak comes onto the podcast to talk about the Air Conditioning Contractors of America manuals. Ed started off in the field and has recently become the new Manager of Design Education at ACCA. You can follow him on Snapchat (skinnyed). ACCA (Air Conditioning Contractors of America) is responsible for publishing and setting the standards in all of the books we use for residential and light commercial HVAC work. (Residential work typically encompasses Manuals J, S, D, and T). The manuals can be very math-heavy. Many software programs have come on the scene to help automate the math to some degree, but the manuals will still remain relevant for years to come. The ACCA manuals offer guidelines for predictable results, and much of a technician's success will come down to how well they understand the order of operations. In our trade, we have developed rules of thumb that help us with sizing and load calculations. However, those won't work all the time, and the predictability element is lost. The ACCA manuals exist so that you can complete your calculations, sizing, and equipment selections with some degree of rhyme and reason. ACCA updates the manuals on 5-year cycles; the manuals require periodic updates to keep up with new climate trends and new equipment as it hits the market. The information in the manuals is not 100% accurate and is variable, but that is just a product of our ever-evolving industry and world. Ed and Bryan also discuss: Leadership responsibilities in ACCA Why HVAC business owners should be aware of the ACCA manuals 400 CFM per ton Mediocre designs Moisture problems and design conditions Basements, elevation, and insulation Constructive criticism ACCA training Sign up for ACCA training classes. Check out information on the 2022 HVACR Training Symposium HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In today's podcast, Bryan and Jesse talk about how technicians can have conversations about finances and money in the HVAC business. The first step for any successful business is to provide customers/clients with a product or service of value. However, there must be a balance between providing something of value to customers and providing excellent customer service. When starting an HVAC business, one of the biggest mistakes is making money the top priority. Money can only become a factor after a business establishes the value of its services and communicates its value to its customers. There is no hard line for fair pricing, so the contractor and customer must have productive conversations to establish a price tag and the expectations for the work performed. That same mistake applies to employees who want raises or promotions. Employees may feel as though they are owed more for their work, but they must establish their value before they get a raise. Again, the goal is to avoid unmet expectations. Profitability and value are not just important to the managers and bookkeepers of an HVAC business. Technicians are the ones who bring those things to their organization. Labor is expensive, but it must be valuable if you want to turn a profit (either for the business or in the form of increased wages). Technicians can increase their value and profitability by mastering skills and learning niche practices. When a business becomes more profitable, it can invest in better training for its techs. It can also have more control over the customers it chooses to serve. Jesse and Bryan also discuss: Maintenance agreements Service repairs Misunderstandings about tax write-offs Bundling and flat-rate pricing Establishing value with commercial customers Technician skillsets Warranty challenges How to communicate price ranges Treating difficult clients with respect Check out information on the 2022 HVACR Training Symposium HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In today's short podcast, Bryan explains the differences between sleeve and ball bearings. Techs often make some avoidable mistakes because they either don't know the difference between the two or don't notice the bearing type on their equipment. On a basic sensory level, ball bearings tend to be louder than sleeve bearings. So, if you replace a sleeve bearing motor with a ball bearing motor, then excess noise may not indicate any problems after all. Lubrication is usually more consistent with ball bearings; those bearings have a far smaller contact area than sleeve bearings. Sleeve bearings don't usually have the best longevity; they have a larger contact area and can burn out quickly, so they are more common on smaller equipment where they will experience less intense axial forces. Those sleeve bearings also aren't as effective as ball bearings in variable-speed equipment. When techs put in a motor speed control and don't pay attention to the bearing type, they may end up burning up the motor if it has sleeve bearings. To determine which type of bearings your equipment should use, you can take note of a few different things. Ask yourself if there are motor speed controls or any sort of motor speed variability. When the answer is yes, you'll be better off using ball bearings. If longevity is a concern, then ball bearings are almost always the ideal choice. If nuisance noise and inexpensiveness are greater issues than longevity, then you'll be better off replacing a sleeve bearing motor with another sleeve bearing motor than a ball bearing motor. Check out information on the 2022 HVACR Training Symposium HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. You can also check out our handy calculators HERE.

In today's podcast, Trevor Matthews from Emerson talks about horizontal scroll compressors. Throughout the podcast, we refer to Bulletin AE4-1338 (R3). You can find that bulletin HERE. Horizontal scroll compressors are common in mobile applications, like buses and trains. They're shorter in height than other compressors, so they fit into tighter spaces and are ideal for transport refrigeration. Scroll compressors are particularly susceptible to overheating, and you need some controls to protect your compressor from damage. To prevent overheating, scroll compressors require pressure relief controls. You can typically use an OEM high-pressure control to protect the system. A low-pressure cutout installed in the suction line can help prevent TXV failure and a wide range of restrictions. Accumulators are especially important for horizontal scrolls in heat-pump applications. However, accumulators have a fine mesh screen that can become clogged easily. So, we highly recommend replacing your accumulator in the case of burnout, not reusing it. Refrigerant migration prevention is a little more complicated than in refrigeration systems with other compressors. You can use a crankcase heater, but you may also need a check valve in the discharge line and a liquid line solenoid valve. We don't use pump down cycles for refrigerant migration; we use them to prevent the gas from moving backward and reversing the scroll. When commissioning a three-phase compressor, you need to put your gauges on before starting the system up. You may also consider using a phase rotation monitor to make sure the scroll compressor is rotating in the correct direction (usually clockwise but not always). Trevor and Bryan also discuss: Variable-speed horizontal scrolls (ZRH vs. ZBH models) Superheat requirements Floodback and slugging Starting and running Extreme discharge line temperatures Arcing fusite under vacuum Functional checks Pressure drop in the suction line Operation envelopes Pressure control set points Check out Emerson for more information. 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 today's short podcast, Bryan discusses buck-boost (auto) transformers and what they do. Autotransformers are not automatic; the "auto" prefix comes from the fact that autotransformers only have one inductive winding. That winding is shared by the primary and the secondary, so it is not an isolation-type transformer. These transformers run current through the same winding used for induction. Buck-boost transformers rise or decrease voltage. When the transformer "bucks," it decreases voltage from primary to secondary, and a "boost" increases the voltage from primary to secondary. In other words, a "boost" is a step up, and a "buck" is a step down on a small scale. You can only wire these transformers if you use the manufacturer literature. There are many types of autotransformers, and you need to know the exact setup for your transformer's specific design. Generic diagrams will usually not suffice. When sizing a buck-boost transformer, you must keep your start load in mind as well. As technicians, we might not be able to handle the specifics of sizing based on the start load, but it's still something to keep in mind. The "buck" configuration of the buck-boost transformer is especially helpful in markets where the utility company tends to produce overvoltage. Our specific setup uses the Micron J750A1EB1A02, which you can learn more about on YouTube HERE. The "boost" configuration helps when a motor doesn't get enough voltage from the utility source. Before you buck or boost the voltage, remember to account for both sides of the equation; if the utility changes the voltage, you still want to be within range. Bryan also covers: Ratings Current and capacity changes based on voltage Inverter-driven technology Voltage monitors (ICM493) You can learn more about the 2022 HVACR Training Symposium HERE. If you have an iPhone, subscribe to our podcast HERE, and if you have an Android phone, subscribe HERE.

In today's podcast, John Ellis joins Bryan to talk about indoor air quality (IAQ). He also explains the ideal process for providing IAQ solutions. John has a lot of experience working as a consultant for people who have respiratory issues, so he has valuable perspectives. The HVAC and IAQ fields intersect in the areas of thermal comfort, humidity, building pressures, ventilation, filtration, and source control (which pollutants are present, where they come from, and how we can remove them). John does not believe in throwing IAQ products at a problem. He believes in a thorough analysis of the structure to present the customer with solutions tailored to their home and needs. Ideally, John would like to see technicians take a process-oriented approach to indoor air quality: investigate, analyze, and quote. He believes in the power of slow, complete diagnosis, including listening to customers' complaints. Remember, they've been living in the structure and can tell you about the issues they've noticed in their home and their health concerns. When you analyze a system, you may have to do additional testing beyond a visual inspection. Sometimes, you can't always find fungal growth or must call an expert to test for asbestos. The key to practicing IAQ is to be open-minded and seek help from experts beyond your field. While IAQ solutions can be expensive, they can be well worth it for many customers. Try not to pass your own judgment on the prices; after all, you are performing quality work and could save your customer money on medical bills. John also explains: How to start training for IAQ sales Customer questionnaires Maintenance agreements Becoming comfortable with IAQ diagnostics How to present high costs and financing options to customers Being a truly caring, attentive consultant IAQ marketing Making money as an IAQ consultant If you want to talk to John about IAQ, you can contact him at (505)-652-8119 or [email protected]. If you have an iPhone, subscribe to our podcast HERE, and if you have an Android phone, subscribe HERE. You can learn more about the 2022 HVACR Training Symposium HERE.

In today's podcast, Scott Krasman from TZOA, Andrew Greaves, and Kaleb Saleeby join Bryan for a conversation about mental health in the trades. We have a greater awareness of mental health than we ever did before, and although some of us may make fun of the topic, it is something we should focus on as HVAC technicians and business owners. "Toxic" is a common buzzword these days, but it's relevant here. A work environment with toxic traits will wear you down over time as you are exposed to disillusioned or selfish journeymen or senior techs at work who disregard your wellbeing and development. Sadly, these behaviors often come from low morale and projection. HVAC industry leaders can take strides by promoting a culture of inclusiveness and encouraging conversations about mental health. There is also an element of personal responsibility within techs to acknowledge if something is wrong and to have honest conversations with their leaders. As techs, we need to know when to ask for help if we need it. Leaders must also look at themselves and address their own mental health issues so that they don't project their issues onto others. As techs, we need self-awareness and intentionality to address our mental health. We need to understand what's going on with ourselves (even if we need to talk to mental health professionals) so that we can take steps to get the support we need. We also cover: Helping younger techs grow Growth and discomfort vs. abuse and suffering Training, communication culture, and workload What it means to be in a dark place and how to get out of it Opening up to others about our struggles Active recovery Relationship issues and addiction Self-diagnosis and misdiagnosis Executive functioning Technology for mental health Caring for your body You can learn more about the 2022 HVACR Training Symposium HERE. If you have an iPhone, subscribe to our podcast HERE, and if you have an Android phone, subscribe HERE.

In today's podcast, Jim Bergmann talks about troubleshooting the entire system. He takes a holistic approach to the art of troubleshooting, NOT just an equipment-centered one. According to NIST, the most common HVAC system problems are duct leakage, refrigerant undercharge, and oversized equipment (often for undersized ducts). Duct leakage heavily affects the envelope; the equipment only plays a part in conditioning a space. As such, you will want to seal up holes that lead to unconditioned spaces, such as behind the thermostat, to avoid creating negative pressure. When there is that negative pressure, especially close to the thermostat, the home could be at risk of over-cooling. We check that the filter is clean, but we rarely ever question if the filter is good enough for the home. If the filter does not do a good job of improving air quality, you may consider changing the filter type or reducing the air velocity. Even though we take temperature and pressure readings from the outdoor units, we sometimes fail to look for obvious non-equipment issues. Some yard cleanliness issues, such as vines or pet urine on the condenser, simply get overlooked. These issues may result in high head pressure and are usually more likely than refrigerant overcharge. Overall, many systems have issues that can be solved with solid visual inspections and corrective measures beyond the equipment, such as addressing duct leakiness. When you troubleshoot better, you bring in more revenue for the company and increase your likelihood of getting a raise while keeping your customers satisfied. Jim also covers: Energy penalties in most HVAC systems MeasureQuick and its limitations Impacts of duct leakage on a home What to check when cleaning condensate drains Cleaning evaporators and condensers Filter grilles HEPA filters and pressure drop Bad flex duct practices and sensible heat gain 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 today's podcast, Steven Rogers joins Bryan to talk about measuring total system airflow. Fluid measurement is NOT restricted to liquids; a fluid is anything that flows, including liquids and gases. In HVAC, we deal with both of them, but airflow is strictly limited to the flow of gas. The airflow we experience in HVAC is exclusively turbulent flow, NOT truly laminar flow. Total system airflow is difficult to measure directly; we can use flow hoods, but they have their limitations, especially on systems that have multiple returns. So, we measure pressures that give us clues about the airflow tendencies. One of the most recognizable measurements is static pressure. Many factors can contribute to poor static pressure, including dirty filters and poorly designed supply and return plenums. All measurements that you use to calculate static pressure will require an average. You take readings at multiple points of the duct, so you need to calculate an average value, whether you're using static pressure tips, a hot wire anemometer, or a vane anemometer. Measurements are also particularly difficult to take in the supply registers, as there are almost no runs of straight duct. Recently, the TrueFlow grid has come on the scene to make airflow measurement easier. The grid relies on torque and RPM data to determine the total system airflow. The TrueFlow grid slides in where the filter goes and measures the total system airflow. The grid works with an app that considers the system tonnage to let you know how good or bad the airflow is. Bryan and Steven also discuss: Bernoulli's principle "Moving" CFM targets Flow hood limitations Laminar vs. turbulent flow Static pressure probes vs. pitot tubes TESP and fan charts Precision vs. typical manometer TrueFlow grid vs. filter restriction Water heater backdraft Depressurization and combustion air zone Check out The Energy Conservatory's Website HERE. You can also check out the TrueFlow grid on that site or at HERE. Check out our handy calculators HERE.

In today's short podcast, Bryan explains how growth happens in an HVAC/R career. He also gives tips to get "unstuck" if you feel like you aren't moving forward. You won't move forward if you haven't set a goal to move forward. Making a "vision board" helps you determine what matters in your life, and it helps you clarify what you'll need to do in order to achieve your life goals. That way, you can use your career to help achieve those goals and see whose support you need. Having a growth mindset and a lifelong learning mindset is essential for success. The growth mindset will help you deal with the "growing pains" of advancement (such as occasional failures). People with positive attitudes also tend to see more possibilities for their future careers. On the other hand, negative people are likely to idle in their careers. You also want to surround yourself with people who will bring out your best. It's great to be around people who challenge you, have positive outlooks, and are happy for you when you make progress. Moreover, you want to be the person who is authentically excited when other people succeed and do good work. Also, try not to burn bridges with others. To advance in your HVAC career specifically, develop your hands-on skills. Think about it this way: are you merely doing your job's requirements, or are you working on yourself? Read through manuals and check out technical materials to become more literate with systems and do better work on them. Also, try to find a mentor who will help you grow. People skills are underrated in our industry but are critical for career advancement. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In today's podcast, Bryan and a team of Mitsubishi Electric Trane HVAC US (METUS) managers (Mike Schaefer, Charles Miltiades, and Sly Grimm) discuss mini-split controls strategies. Some contractors misunderstand what mini-splits are. Mini-splits CAN be ductless, but not all of them are ductless. Mini-split systems also have handheld controls, but those are not the only control options for mini-splits. Mini-split controls also come in wi-fi, wall-mounted, and wired varieties. Another common misconception about mini-splits is that they do not work in the cold. While that used to be accurate, modern mini-splits can function well as heat pumps that integrate backup heat. That is especially when it is also tied into a ducted system. A lot of thought goes into sensor placement, and contractors have many options as to where they can be placed. You can put wireless sensors in discreet locations, such as under the air return in the basement. Lately, there has been a market shift towards a preference for multizone equipment, so the wireless controls help manage several units instead of just one; you can manage 30+ indoor units. In general, homeowners are becoming more tech-savvy and are beginning to prefer tying all of their HVAC systems together and managing them all via one platform. As such, Mitsubishi controls can connect to smart home assistants, such as Alexa or Google. Mitsubishi mini-split controls also work with a cloud service that remembers data. However, a strong wi-fi system is necessary for these controls. The Mitsubishi Electric team also covers: Third-party controls and backup heat Integrating with boilers for primary heat Control placement Multizone controls Smart devices and signal strength Innovative solutions Learn more at mylinkdrive.com and METUS's YouTube channel. Check out our handy calculators HERE.

In today's short podcast, Bryan discusses the key factors for system performance WITHOUT doing a deep dive into system commissioning. "Performance" refers to system efficiency, capacity, air filtration/cleanliness, longevity, and the ability to match the latent and sensible loads of a space. System airflow is the main performance factor to consider. To determine proper airflow (CFM), consult Manuals S, J, and D to perform calculations. In general, the absolute lowest limit is around 275 CFM (in extreme dehumidification mode), and the highest limit should be around 525 CFM (in arid climates or at altitude). You can determine your CFM target after you set up your ECM motor in the design. Then, you can also check airflow indicators: total external static pressure and pressure drop across the filter. The best way to improve airflow is to reduce pressure drop across the filter and build a better return plenum. For improving overall system performance, make sure the ducts are appropriately sized. System charge is another important performance factor. There is a lot more to evaluating charge than checking the superheat and subcooling. If possible, it is a good idea to weigh the charge with a scale and see how it matches up with the line length. In terms of long-term performance, the condenser's location and cleanliness are also vital. Overall, a condenser works best if you put it in a slightly shaded area or on the north/east side of a building. The outdoor unit should also have some clearance from bushes and walls. Make sure the condenser is positioned away from pool equipment, water softener discharge, and dryer vent discharge. The goal is to keep the outdoor unit corrosion-free and able to "breathe." 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 today's podcast, Trevor and Bryan discuss Copeland Scroll Compressor Multiples for Air Conditioning. "Multiples" refer to equipment setups with multiple compressors that have connected suction and discharge lines, so they resemble parallel rack refrigeration setups. Multiples typically come in tandem (2) or trio (3) sets. Compared to having a single giant compressor, multiples are more efficient, more reliable, and have the ability to keep running in case if there's a compressor failure. As a result, we often use multiples in rooftop units, makeup air units, and chillers. When you're working on multiples or troubleshooting multiples, it's okay to have sight glasses that indicate different oil levels. If you shut the compressors down and restart them, they should equalize. If you have a single compressor failure on a set of multiples, then you may have to replace both compressors in a tandem set; the manufacturer does not make single replacements for some tandem models. So, you can check the Application Engineering (AE) bulletin to determine your replacement needs. Multiples may contain compressors of different sizes. Compressors of different sizes have different mass flow rates. In these cases, you would use a flow restrictor to balance the mass flow across the compressors. On the refrigerant management end, the Copeland Scroll multiples will generally benefit from a crankcase heater. Correct location and installation of the crankcase heater are critical for proper functioning in multiples, and you can find that information in the manufacturer literature. Sometimes, you may also need an accumulator if there is a risk of refrigerant migration. Bryan and Trevor also discuss: Individual vs. multiple compressor manuals Oil equalization lines Compressor clamping Variable speed motors and compressor variability Sweating and flow restrictors Maximum tilt Adding oil Torque values Check out the AE-1430 bulletin HERE. Check out Emerson's HVACR training HERE. Then, navigate to "Contractor Tool Box Talks with Emerson." 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 today's short podcast, Bryan clears up the differences between markup and profit margins in HVAC businesses. The number one mistake that people make in business is confusing markup and gross margin. For example, you can double the price of a $50-part and sell it for $100. That would be a 100% markup. However, your gross margin is NOT 100%; your gross margin is only 50%; you only made a 50% profit on the total sale. In the same case you have above, you have a 50% cost of goods sold (COGS). COGS is the direct cost of the expenses you paid to sell your service or product. The opposite of COGS is overhead. Overhead includes anything that doesn't directly bring money to your business (rent, utility bills, etc.). Let's say that your overhead costs total $30. You only end up with $20 of net profit. Typically, 10-20% net profit is a good (if slightly idealistic) goal. Net profit can contribute to business growth if you put it into your business. For example, you can use that money for advertising, buying vans, and buying better tools. If you want to determine a 10-20% goal, DO NOT USE MARKUP. Instead, you need to divide by your COGS expenses. In the case of the $50-scenario, let's say that our cost of goods sold is 60%, so that seems like a 40% markup. You would divide 50 by 0.6, and you would get $83.33. If you multiplied by markup (140% or 1.4), you would have gotten $70. You wouldn't come close to your gross margin number using the markup method. Learn more about Refrigeration Technologies HERE. Check out NAVAC HERE. Check out SpeedClean 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.

In today's podcast, Eric Mele and Bryan explain the planning, layout, and execution of HVAC projects. They mostly cover commercial ductwork but also touch on piping and some residential projects. Planning The first step is to review the construction plan WITH a site visit. It is best to see how a plan works within the space; plans may be feasible on paper but may not work out as planned in the actual space. During the site visit, you also want to establish solid communication with everyone else on the project. As such, it is best practice to have a coordination meeting with the general contractor and other trades (such as drywallers) to communicate potential areas of conflict. (When building ducts in commercial structures, you will want to watch out for conflicts with trusses, joists, fire sprinklers, and plumbing/drains. In residential structures, you will have to watch out for ventilation paths, such as dryer vents and kitchen exhaust vents.) Before deciding to alter the design, be sure to communicate any possible alterations to the GC and other trades. Layout If possible, the next step is to lay out your construction plans on the floor. Constantly referring back to paper or digital plans is not productive. You can usually chalk up or spray paint the concrete at a construction site to draw your layout and plan the construction accurately within the space. The floor is also likely to be your best reference. You can also use string to plot the locations where the hangers would go, especially if you have long runs of ductwork. Execution The first step of executing a project is preparing for hanging. When preparing for hanging, it is best to perform as much of the work on the floor as possible. The duct board can be stapled, taped, or masticed on the floor. Then, the hangers go up. If you have multiple people working on a project, one person can assemble the ducts on the floor and wait for the mastic to dry while another person puts up hangers. You can usually wrap the ducts on the floor, and it is usually easier to do so. However, it is best to check with your GC before you do it. You may need the ductwork to pass an inspection. When it comes to fasteners, you can use screws, flat strapping, or even aircraft cable. If using screws as fasteners, try to make sure that all of the screws have the same heads. Having to switch out drillbits for all the different screws is very inefficient. (As always, make sure your tools are easy to reach and in locations that won't hurt your back. It is a good idea to have a toolbelt or workstation.) When working with flex duct, make the takeoffs as easy for yourself as possible. You can use mastic as a seal for the collar instead of tape, as it may be easier to seal. (Either way, watch out for leaks.) No matter what you do, make sure you're taking care of your body, doing as much work on the floor as possible, and adhering to all applicable building codes. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In today's short podcast, Bryan explores the differences between startup and commissioning. Startups typically involve going in during the construction phase after the drywall has been sealed up. (Vents, ducts, and copper piping typically go in before the drywall.) A technician can then perform a startup. The startup includes testing the drain line, checking the charge, checking for leaks, and seeing if the equipment performs its most basic function. (Does the gas furnace make flame? Does the A/C unit blow cold air?) The startup's goal is to get the equipment working. A startup does NOT focus on peak performance. A good startup will typically suffice for a cookie-cutter residential construction. Conversely, the goal of commissioning is to optimize the equipment and test the advanced functions. Combustion analysis, airflow tests, and dehumidification tests all fall under the "commissioning" umbrella. Commissioning is where we use Manual S and Manual J to see if the equipment is appropriate for the home. Data collection, especially on sensible and latent capacities, is the core element of commissioning. Commissioning also involves checking up on secondary functions, such as checking if heat strips activate during defrost. A custom construction plan will require commissioning to ensure that the equipment runs optimally in the uniquely designed space. So, in short, equipment startup is about making sure the equipment works as it should on a basic level. On the other hand, commissioning uses data and specific instrumentation to make sure the equipment is running to its design and full potential. Bryan also covers: Stages of residential construction Startup in new construction projects Capping and filling drains Who can perform a startup? (Junior techs, installers, senior techs, etc.) Instrumentation for commissioning If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In today's podcast, Eric Kaiser and Bryan talk about mentorship in the HVAC industry. They discuss what it means to be a good mentor, how to find a good mentor, and what it means to be mentored. Mentorship is an organic process. Most mentees don't go up to someone they respect and formally ask that person to be their mentor. Respect is the foundation of the mentor-mentee relationship; formal mentorship often resembles friendship in many ways. However, mentorship can take more forms than the traditional mentor-mentee relationship. In the digital age, podcasts and YouTube channels that readily share information about a skill are resources that can fulfill the same role as a traditional mentor. A good mentor has a willingness to explain the how and why behind a question or process; they don't give simple answers. Good mentors must also be able to provide resources for their mentees; they know the limits of their knowledge and are willing to find those answers with their mentees. Often, the better mentors are humble and don't flaunt their experience. Good mentors want to see their mentees do well and grow; they don't want their mentees to follow and copy them. The support in the relationship goes both ways. The mentee must want to support their mentor, not compete with them. Mentees must be willing to start conversations and ask for clarification; an ineffective mentee waits for answers to be spoonfed to them. Good mentees are also willing to challenge their mentors at times [respectfully]; they don't excessively flatter their mentors. Bryan and Eric also cover: Personal growth Online mentorship resources Cultish mentors Outgrowing and leaving mentors "Stealing" in mentor relationships Unproductive mentorship Honoring mentorship If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In today's podcast, Bryan explores the upsides of choosing a career in the skilled trades instead of going to college. He also covers ways to prepare your child for a trades education and career while they are still deciding what to do with their lives. When we think about what we want for our kids, the following goals come up quite often: purpose, financial upside and reward, freedom from debt, and joy. The trades can offer a lifestyle that covers all of these bases. However, the opinions of our friends and the fear of failing as a parent may prevent us from encouraging our children to enter the trades. Going to college has plenty of downsides, such as saddling students with debt and not guaranteeing opportunities to move forward in a career. Alternative career paths include the HVAC/R trades, electricians, off-grid solar technicians, and so on. Your child will learn hard skills on these career paths that are easily transferable. These trades also generally have plenty of apprenticeship opportunities. In the case of HVAC/R, technicians may also have the opportunity to earn a lot more money in only a few years. At that rate, they will have ideally saved some money to go to college later on if they believe that college is truly the right choice for them. Bryan also covers: The desire for purpose and impact in a career Doing good work vs. being seen doing good work Advantages and disadvantages of college The societal obsession with certificates of completion How to avoid feeling "stuck" as a young adult What it means to have a high opportunity/learning ceiling Interesting and meaningful problem-solving in a career Acquiring hard skills Diversity of challenges in a career Strong lateral problem-solving skills Advantages and disadvantages of home education Autodidactism Alternative career paths with financial and personal upside If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In today's short podcast, Bryan explores triple evacuation. Many people believe that we don't like triple evac, but that's simply NOT true. We're here to set the record straight. If the manufacturer tells you to follow triple evacuation processes, then it's a good idea to do what they say. We won't argue with that. However, our argument is that the procedure can be more time-consuming than it's worth when it's NOT necessary. Deep vacuum technically counts as a vacuum pulled below 500 microns (in residential, that target is usually 200-300 microns). Most modern micron gauges and tools make it easy to achieve a deep vacuum. In a triple evacuation, you pull the vacuum three times (instead of once). Between pulling vacuums, you break with nitrogen before pulling the vacuum back down. Triple evacuation originated in a time when micron gauges and vacuum pumps were less reliable. We did not take deep vacuum very seriously, especially since mineral oil (MO) typically did not break down inside the system. (Modern oils like polyolester/POE break down rather easily, so pulling a deep vacuum is much more vital nowadays.) Instead of merely breaking with nitrogen, Bryan recommends flowing it. It's best to flow the nitrogen with force to move the oil around more effectively. In turn, your vacuum will pull down more quickly and efficiently. So, triple evacuation isn't bad, but it can be time-consuming. Just be sure to follow all best practices if you perform a triple evacuation. Join us as we cover: Deep vacuum targets Micron targets Breaking with nitrogen Flowing nitrogen POE vs. mineral oil Old manufacturer literature about deep vacuum Microns 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 today's podcast, Bryan explains how he teaches physics. He believes that teaching physics is about continuously building a mental model, and he covers the methods and mindsets that facilitate that learning style. The basic Wikipedia definition of physics states that it is a science that deals with matter, energy, and their interactions. Even then, we can simplify "matter" to "stuff." Simplifications like these help students feel more familiar with the subject and NOT feel intimidated by the material. Students learn best when they feel like they can grasp the topics out of the gate. That is why the math-based approaches of traditional education might turn students away from physics. Some students who don't like math might feel out of their depth when teachers approach topics with a mathematical approach. Instead, effective teaching is about attaching experiences to a concept. Teachers can take stock of what students already know and build on that. They can also attach experiences to a concept, such as by allowing students to have hands-on experiences with physics examples in the real world. Once students have relevant experiences, they have the tools to learn through similes and analogies. Bryan covers: Socratic learning Comparing levers to seesaws for educational purposes Experimentation and experience Similes, metaphors, and analogies Shortcomings of math-based learning methods Creating "cartoons" in your head to learn topics Teaching superheat and subcool with mental "cartoons" States of matter Humidity and the weight of water vapor Electron movement Steam and why it's complicated Teaching electricity with comparisons (water, drawbridges, jump ropes) How children (and babies) learn about physics as they navigate the world Mythbusting Remember, when it comes to education, the goal is to learn, NOT to impress people. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In today's short podcast, Bryan explores the dangers of cold tanks during refrigerant recovery. Whenever you have a recovery tank, you only want to fill it to 80% capacity in the liquid state. The same goes for all sorts of vessels (coils, etc.). However, capacity isn't the only factor to consider for safety. We need to know what our maximum temperature will be. You will be in greater danger of overfilling a tank when it is cold because higher temperatures increase the pressure. High pressure in a closed space may lead to explosions. When you fill a tank to 80% under cold conditions, normal temperature conditions could put you in the danger zone (let alone temperatures above 100°F). So, it's better to determine your tank fill based on densities at the MAXIMUM temperatures you will encounter, NOT for the measurements at artificial cooling conditions (such as when you put the tank in ice water during recovery). In the end, just be careful when you're recovering into a cold tank or using tanks when it's cold outside. That will help you avoid hydrostatic pressure buildup and explosions. Bryan covers: The 80% capacity rule for filling vessels with liquid Why the 80% capacity rule varies by temperature Temperature, pressure, and density Hydrostatic pressure AHRI's 77°F guideline Ice buckets for recovery What to do if a tank vents its refrigerant on you while driving If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In today's podcast, Nikki and Bryan discuss dehumidification. They cover the relationship between cooling and dehumidification, humidity control, and dehumidifier installation practices. If the A/C unit is the king, the dehumidifier is the queen. The A/C unit controls cooling and humidity, but it can only do so much. A dehumidifier helps the A/C manage comfort under more demanding conditions. Many factors contribute to comfort, including sensible heat ratio (SHR), relative humidity (RH), and ventilation. Dehumidification reaches all of those factors. Humidity control requires a holistic approach. Band-aid fixes DO NOT work. Dehumidifiers should work with the A/C system and building design to keep RH in the 50-55% range. Proper installation is vital. For example, tying into the HVAC supply is a recommended practice. Returns are the opposite; dedicated returns are preferred. Other factors to consider are proper sizing, Manual J, and customer expectations. Join Nikki and Bryan as they cover: Relative humidity targets Sensible heat ratio (SHR) Latent removal capacity Ventilation Building design and tightness Manual J Challenges with ductless systems Ducting into the supply with dedicated returns Installation practices Dehumidifier sales and customer service And much more… To learn more about Santa Fe Ultra series, go to www.santa-fe-products.com. You can scroll through the products to find the Ultra series free-standing ventilating dehumidifiers. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In today's podcast, Trevor and Bryan discuss how to troubleshoot thermostatic expansion valves (TXVs/TEVs). They also dive into the various types, applications, and components of TXVs. TXVs are metering devices that control evaporator superheat to protect compressors from harm. Controlling heat also regulates pressure, which improves efficiency and prevents issues like floodback and overheating. TXVs contain several components that manage the forces that open and close the valve. These components include powerheads, diaphragms, springs, and more. The components all contribute to a delicate balance that can be broken when they fail or are installed improperly. TXV failures lead to high or low superheat and eventually compressor failure. When you diagnose a TXV, you may encounter hunting, broken powerheads, filthy screens, and improperly sized valves. Once you verify the cause of the issue, you'll likely have to adjust the TXV, replace a component, or replace the whole TXV. That can be a tricky decision that will largely depend on the type of failure, the type of TXV (conventional vs. balanced port), and the TXV's application (residential HVAC, refrigeration, etc.). Join Bryan and Trevor as they cover: Opening and closing forces Internal and external equalization Non-bleed/hard shutoff TXVs and design limitations Conventional valves vs. balanced port valves Brazing in TXVs Strapping the TXV bulb to the suction line TXVs in refrigeration vs. HVAC Liquid quality, sight glasses, and subcooling TXV sizing Suction pressure/superheat hunting High and low superheat causes Adjusting vs. replacing valves And much more... Check out Emerson's HVACR training HERE. Then, navigate to "Contractor Tool Box Talks with Emerson." If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this short podcast episode, Bryan discusses push-pull recovery, how it works, and what we need to know about it. Push-pull recovery is a somewhat counterintuitive method of recovering liquid rapidly. We simply do that by pulling refrigerant out of the system and pushing it into the tank. However, when we pack refrigerant into a tank, the tank pressure and temperature increase. So, it can be more difficult to get refrigerant into the tank as the job goes on. When we recover liquid refrigerant on large systems (20+ pounds of charge), you connect a line from the liquid line or receiver and attach it to one side of the tank. Then, you pull from the system the other side of the tank should lead into the recovery machine. Attaching to the recovery machine helps depressurize the tank. When pulling out of the tank, you'll want to make sure the refrigerant is a vapor. The recovery machine should be pulling only vapor refrigerant out of the tank. While you're depressurizing your tank, you will be pressurizing your system to push the liquid refrigerant out of the system and into the recovery tank. (Short hoses with a large diameter are usually best for quick recovery.) 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 episode, Bryan goes over one of his most valuable tips for pulling a vacuum on a small system. It can be very difficult to pull a vacuum on a small system, especially when you're dealing with a low-temperature application like a freezer. When you pull a vacuum, you're creating a low-pressure area that affects molecule behavior. So, you're creating a situation where the molecules push their way out of the system and into your vacuum pump. The low temperature and small tubing, especially capillary tubes, make this process exceptionally difficult. A very good vacuum pump can still have a hard time achieving a deep vacuum. To make this process a little easier, Bryan likes to add heat. When you add a heat blanket around components with oil, you negate the low-temperature obstacle and make it easier to separate refrigerant from oil. You may also use a heat gun on areas where using a heat blanket is impractical. If the area is cold or has refrigerant and oil together, then you'll benefit from applying heat. Don't go crazy and use open flames, but a heat blanket or heat gun will usually be safe. 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 episode, Bryan and Eric Mele explain how HVACR technicians can END callbacks with a few best practices. Rushing through calls will often lead to callbacks. One of the most common mistakes techs make is failing to check the condensate drain before walking away from a job. To end callbacks, technicians would be wise to check the entire system and note any possible problem areas; in commercial HVAC and refrigeration, pay attention to variation across evaporators, condensers, and drainage systems. Customer service is a huge component of residential HVAC; you can prevent callbacks by listening to the customer's concerns, addressing their comfort issues (even if it lies beyond the obvious problem), checking your "five pillars," and thoroughly explaining what you've done. Even if a problem seems to drag out, take all the steps necessary to alleviate your customers' fears. Electrical problems also cause callbacks, especially dual-run capacitors. So, it's a good idea to check for wiring rubouts and make sure the wires look clean and organized. If you can offer an electrical solution to the customer at a cost, do it, even if they might decline it; that way, the callback is on them, not you. Overall, being thorough, communicating with the customer, and offering solutions is the key. If possible, it's best to explain everything at once and have one money conversation. If you can't get a full diagnosis until the customer approves a repair, be transparent about that. Eric and Bryan also discuss: Multi-equipment setups in commercial settings Dealing with difficult customers Managing customers' expectations HVAC in new homes Determining if a unit has been set up correctly Smart thermostats Cleaning drains and equipment Preventing flooded starts OEM vs. aftermarket parts Commonly replaced parts (reversing valves, TXVs, etc.) Establishing a process that works Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this podcast episode, Bryan and Eric Mele discuss the diagnosis and prevention of compressor overheating in HVAC and refrigeration. The main causes of compressor overheating are inadequate cooling back to the compressor, low charge, restrictions, and sometimes even poor suction line insulation. We want to keep the suction temperature low while maintaining appropriate superheat. If the suction line temperature is too high, the compressor can't cool down well enough. Dirty condenser coils, low voltage, weak capacitors, or an inadequate condenser fan can also lead to compressor overheating. Electrical problems, including too little capacitance, will make a compressor go out on thermal overload. When you have refrigerant problems, the thermal mass will just keep growing; it takes a long time to heat the compressor up, and it will take a long time to cool it down. In a thermal overload, a bimetallic disk in the compressor will open and break all three legs of power. When a compressor goes out on thermal overload, it will make an open circuit, and you will read infinite ohms. Knowing that the compressor has gone out on thermal overload is just the beginning of compressor overheating diagnosis. So, to begin diagnosis, you'll want to make sure there's refrigerant in the system. Inspect the unit visually and note anything that seems odd. Then, you'd check your capacitor for electrical problems. You can also feel the compressor to get an idea of the extent of the overheating (try not to burn yourself). You'll also want to monitor the amp draw, condensing temperature, suction pressure, and superheat. Eric and Bryan also discuss: Axial fans Condenser fan intermittent failures Resetting the compressor Cooling down the compressor Setting up your meter Being out on high pressure Wrapping wire to increase ammeter resolution High return gas temperature Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this short podcast episode, Bryan and Eric Mele talk about re-tapping transformers for single-phase equipment in 208v applications. Most single-phase equipment can work for 230v or 208v, meaning that they can operate with low voltage. However, we typically see 208v in commercial buildings. The sine waves of 208v equipment are 120 degrees out of phase, not 180 degrees (as in split-phase applications). We get lower voltage from leg to leg (208v, though the voltage can be a little higher or lower). Power companies generally put out slightly higher voltage to reduce line losses. Most systems can work on multiple voltages, but they come with a transformer that's set to the 230v or 240v setting. However, under those settings, you can experience issues in 208v applications. If you put equipment tapped to 230v or 240v in a commercial setting, you may have issues, especially if you're farther away from the air handler. You may not get full 208v and may see contactors that don't pull in intermittently, and you may get intermittent cooling calls. Intermittent problems become worse when you have long thermostat wiring. In those cases, re-tapping the transformer is your only option. When the original voltage is incorrect, you'll need to re-tap the primary (high-voltage power going in). If you fail to tap the primary correctly, the voltage going out of the secondary won't be correct. When it's time to test the equipment, you'll always want to be sure to test the equipment under load. Make sure you cap extra wires and cap them independently of each other; those wires do have voltage, and we need to be cognizant of that. Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

In this podcast episode, Ben Reed from TZOA, a disruptive air technology brand, joins us to discuss the indoor air quality map and compass. We spend a majority of our lives indoors, so TZOA tries to improve IAQ in homes to keep us healthier. HVAC manages airborne chemicals, so indoor air quality ties right into our industry; HVAC technicians will become more valuable when they become well-versed in IAQ technologies. In residential HVAC, we are already used to listening to customer complaints and observing the home. Technicians (and even IAQ products) can "map" out the customer concerns and home features to develop a comfort and home-health solution. TZOA is working on putting together that "map and compass" model to optimize home health and comfort by noting problem areas and pointing us to the tools to solve the problem. HAVEN uses a central air monitor (CAM), which is an in-duct, whole-home IAQ monitor that measures particulates, temperature, and humidity. The monitor pairs with software to fulfill the "map and compass" model and assist with diagnosis. The air monitor and software help dispel uncertainty around IAQ products while providing accurate readings that point to solutions. It's also worth noting that HAVEN's tools can only be purchased and installed by HVAC professionals. So, they're helping bridge the communication gap between technicians and customers. TZOA is also attempting to build trust and confidence in IAQ products through education, collaboration with industry experts, and allowing HVAC technicians to use and experiment with their products. Ben and Bryan also discuss: HAVEN and TZOA's beginnings IAQ uncertainty and reputation Multiple chemical sensitivity Ventilation and dilution The future of TZOA products TZOA's personal use program Working with reputable companies and people Integrating IAQ into maintenance plans Learn more about TZOA and HAVEN at haveniaq.com. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this podcast episode, Bryan and Trevor Matthews of Emerson Canada discuss the Copeland 2-stage ZPS scroll compressors. Please join us by following along in bulletins AE4-1428 and AE4-1365. The ZP91KCE to ZP143KC Copeland compressors don't have internal pressure reliefs (IPRs). Those higher-pressure compressors make very loud noises when they go off, and it'll blow hot discharge gas on the internal overload to shut down the compressor. Some scroll compressors have temperature operating disks (TODs), which are bimetal disks that open upon a temperature increase and reroute the gas. Other compressors have advanced scroll temperature protection (ASTP), which is a snap-back disk near the floating seal. You don't just want to shut the suction service valve to pump the scroll down. Instead, common service procedures include checking voltage to the compressor, the internal motor, the blower/fan operation, the suction pressure, and the compressor wiring. If you install crankcase heaters for oil management, be sure to install them correctly to avoid overheating the compressor. You'll also want to verify that crankcase heater voltage and ensure that it is properly grounded. Two-stage modulating Copeland scrolls work with a 24v DC solenoid in the scroll set. That solenoid energizes and de-energizes, which either fully or partially loads the compressor. Load matching is ideal for efficiency and comfort, meaning that the two-stage Copeland scrolls perform well in those areas. Unsurprisingly, the fully-loaded option draws more current than the partially-loaded option. These two-stage compressors don't have IPRs, so you will need a high-pressure control set to 650 PSI. Trevor and Bryan also discuss: TOD vs. ASTP Operating envelopes Hipot testing Single-phase compressors Using Copeland compressors in pool heaters Oil and refrigerant dilution Wiring up CoreSense Reversing valve sizing issues Visit climate.emerson.com for more resources. Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this podcast episode, Bryan, Trevor Matthews, and Jim Dick of Emerson talk about the screw compressor and how it works. This time, they focus on the Vilter single-screw compressors. Vilter is an industrial compressor division of Emerson (compare to Copeland). Vilter also makes reciprocating compressors, but the screw compressor is its claim to fame; you may want to consider using a screw compressor when you want greater capacity and control than a reciprocating compressor. Screw compressors also work well for applications with constant loads; they do, however, have microprocessors that can monitor system performance to maximize efficiency. Vilter uses a compressor with a single screw, whereas most compressors have twin screws. Twin screws have a motor that continuously turns the rotor, which causes the screws to mesh together; the compression happens as gas fits between the screws, and the gas volume decreases as the space between the screws closes. In a single-screw compressor, the gas compresses on the outside of the screw. In any case, we must seal the gas in the flutes, and oil helps us with that. Liquid should not get into either type of screw compressor, as liquid is not compressible and will damage the compressor. When you service a screw, the oil temperature and discharge pressure will likely be the most important values to watch out for. During maintenance inspections, you'll also want to pay special attention to the bearings, the four pressure transducers, and oil filtration system. Jim, Trevor, and Bryan also discuss: Microprocessors Star rotors Oil uses, management, and components Motor RPM Multiple compressors and added capacity Calibrating pressure transducers Zeroing vs. calibrating Suction screens Jim's interesting findings Injecting oil Value engineering and consistency 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 episode, Bryan talks about condensation and how HVAC technicians can solve condensation-related problems. He also discusses humidity control and how that can affect sweating. We may have heard the phrase, "Condensation is where hot meets cold." That's not necessarily true; while it may seem that sweating happens where hot meets cold, the dew point is the main cause. We won't see condensation unless we have air that reaches the dew point. When air flows across surfaces that have a temperature below the dew point, you'll start to see sweating on the surface. Clouds and fog indicate liquid water in the air; if you see fog, then you will know that the ambient temperature is below the dew point. We also can't see steam; steam is water vapor, but the "steam" we see is actually liquid water. Water vapor is also lighter than air, so it rises in the vapor form. When we see condensation or sweating, we must ask ourselves if the surface is colder than it's supposed to be. Ducts can sweat when the airflow is too low, and the air handler can sweat when the evaporator freezes. If we were to heat the air as a solution, we can decrease the relative humidity, but heating the air doesn't change the dew point or total moisture content. The next step is to make sure we don't have infiltration at boots or can lights. Infiltration can cause sweating, especially in unconditioned spaces. You'll also want to make sure that the duct insulation is straight and that the ducts have been properly strapped. The house itself can also cause infiltration, especially through fireplaces and chases; a blower door test can help you determine the leakiness of the home. Ventilating dehumidification may also work as a solution. Check out Richard Sims's presentation on our YouTube channel HERE. Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this podcast episode, Bryan and Chris Mohalley of Regal Beloit discuss the different types of ECM. They also cover applications where you can expect to find ECMs. In the HVAC industry, we typically use three types of motors: constant-torque, constant-airflow, and constant-speed. Every ECM works on electronic commutation, so constant-torque motors use that to maintain torque output (X13). The constant-airflow motor is also known as the variable-speed motor, and it is one of the first ECM types. We typically only use constant-speed motors in outdoor fan motor applications. Likewise, we generally use the first two motor types for indoor fan motors inside air handlers. ECMs were NOT designed to address the static pressure problems of PSC motors and duct issues; variable-speed motors may attempt to compensate for duct problems, but that's not its purpose. (Variable-speed motors work like cruise control in a car.) However, when motors compensate for poor duct systems, they could run higher RPM than desirable in order to hit the system targets and can generate excess heat. Constant-torque motors maintain a certain torque value, which can get tricky when the loads begin to vary. When static pressure goes up, there's less air in the system, which means that there's less air for the wheel to move (a smaller load). Current and RPM can increase when static pressure goes up, but the torque would stay the same. Chris and Bryan also discuss: What is a variable-speed motor? Permanent split capacitor (PSC) motors Duct sizing and design Static pressure and motor life expectancy Reactive power and power factor Torque vs. speed taps Blower performance curves Different series of motors PWM (pulse-width modulation) and inputs Setting DIP switches Evergreen VS Why should you read the manual? Check out some more ECM resources at regalmmu.com. Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this podcast episode, Bryan and Eric Kaiser discuss the right and wrong way to do HVAC/R jobs and approach HVAC/R work. Breaking things down into "right" and "wrong" categories is a rather simple way to approach a problem; we throw nuance and alternatives out the window, which can be worse than doing something "wrong." Instead of viewing things as right and wrong, we would be better off if we looked at our objectives and focused on solving problems instead of being right. Although there are surely correct ways to pull a vacuum, it's more useful to set standards than argue about what's right. Set standards that are appropriate for the situation (the equipment, your tools, your skill level, etc.). Of course, it would also be best if we could try to set our egos aside. We need to have humility and acknowledge that we're all trying to improve for the sake of our customers. That said, we could all benefit from focusing on achieving successful outcomes instead of being "right." Ultimately, many of our struggles to determine right from wrong can be solved by listening to the customer. Our goal is to tailor our practices to our customers' needs, even in commercial work where customer service isn't as important. Being overly dogmatic doesn't do much to help a customer, and it fails to account for the unique details of each situation we encounter in the field. Eric and Bryan also discuss: The right vs. wrong way binary Maturity Situational awareness Evacuation best practices Customer discretion and expectations Do aesthetics matter? Commercial vs. residential HVAC Evaluating suppliers and manufacturers reasonably How oil and parts have evolved Flowing nitrogen Setting goals Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this podcast episode, Bryan and Chris Mohalley from Regal Beloit discuss EC motors. They also describe ECM applications and how those motors work. EC motors (ECMs or "ECM motors") are electronically commutated motors. These motors are generally three-phase AC motors operated by a drive; that drive is a combination of an AC-to-DC converter, microprocessor, and frequency drive. So, the frequency delivered to the motor is generated electronically. When it comes to inputs, the ECM works like a printer. One input provides power (from the wall to the printer). The other cable tells the printer what to do and when to do it (from the computer to the printer). An ECM will have a line voltage connection and a constant 24v communication input. Constant-torque ECMs work like PSC motors in the way they use control taps; other ECMs may use DIP switches. ECMs are direct-drive motors that differ from PSCs because they don't have a capacitor. EC motors also have a permanent magnet, which can affect diagnosis if you rarely come across indexing. AC motors use magnetism; when you pass energy through the stator coil, the coil creates an invisible magnetic field, which then induces a magnetic field into the rotor. When the rotor picks up a magnetic effect, it starts to spin. EC motors have that magnetic effect in their magnets. Chris and Bryan also discuss: Regal Beloit's history and brands Effectiveness of metaphors and acronyms in our industry Constant-torque ECM vs. variable-speed motor Motor modules Changes to the ECM design over time ECM manufacturers Three-phase power and controls Reading ohms Glued-on vs. slotted magnets RPM and the effects of poles and frequency of power delivered For more resources for EC motors, check out regalmmu.com. Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this short podcast episode, Bryan compares strategies for increasing the subcooling, including stacking liquid and mechanical subcooling. Subcooling is a consequence of condensing; when we change the refrigerant from a vapor to a liquid, it will drop below saturation temperature after it becomes completely liquid. There are three phases in the condenser: desuperheating, condensing, and subcooling. The first few rows of the coil reduce the superheat of the vapor entering the condenser. Once there is no more superheat, heat rejection helps the saturated refrigerant transform into a liquid entirely. Near the end of the coil, liquid refrigerant can keep losing heat, and it becomes subcooled. We can only achieve subcooling by stacking liquid in the condenser. When you stack liquid in the condenser, it can give off its heat to the outdoor air. However, too much subcooling isn't necessarily a good thing. Your condensing temperature should be above the outdoor temperature; we call this value the condensing temperature over ambient (CTOA). When your condensing temperature is too close to the ambient temperature, you won't get much heat rejection. If your subcooling goes up because you're stacking too much liquid, you'll drive up your CTOA and head pressure. If you increase your head pressure, you'll increase your compression ratio. Your efficiency will suffer. So, when stacking liquid, you'll want to find a happy medium. However, in systems with liquid receivers, you may not see much liquid stacking at all. Getting some extra subcooling can boost your system capacity. We have some mechanical subcooling devices that use heat exchangers to drop the temperature of the refrigerant in the liquid line. That way, the refrigerant can absorb more heat when it's in the evaporator coil. Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this podcast episode, Bryan, Chad, John, and Allison discuss proper design for ductless and ducted HVAC systems, especially mini-splits. They also discuss potential future improvements to equipment and duct designs. Mini-splits are smaller than traditional HVAC units, so they make zoning a bit easier. However, load calculation plays a huge role in equipment selection and zoning because you must get the right number of zones to match the equipment capacity and meet your load requirements. Proper design is difficult, and a common mistake includes using one piece of equipment to serve the whole house, especially on new constructions. Some designers also don't offer multiple options to the customer, which can be a mistake. Most of the time, we end up downsizing systems, not making them larger. Failing to smooth out turns in the ducts and use proper fittings can also negatively affect airflow and pressure. If you're working on new construction, you'd be best to get an idea of the building design ahead of time and clearly communicate what you need to create a proper duct design. Going from traditional to mini-split duct design has a bit of a learning curve. It's easy to make mistakes when you aren't prepared to deal with the function of variable capacity in mini-splits. You can avoid making mistakes by learning about the equipment (and duct materials) during the selection process, not after the selection. Chad, John, Allison, and Bryan also cover: Adjusting the structure Replacing old equipment with higher-SEER equipment Selecting filters and filter grilles Static pressure options Total length vs. total equivalent length Register sizing Flex ductwork Drop ceilings Texas's energy grid and how it relates to potential setbacks Replacing furnaces with heat pump systems Future micro-split heat pumps Check out energyvanguard.com and think-little.com. Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this short podcast episode, Bryan explains what atmospheric pressure really is, pressure units and conversions, and why those are matter. Atmospheric pressure is the weight of the air around us pushing down on us. We normally see that value expressed as 14.7 PSI (or 0 PSIG). Before we dive too deep into atmospheric pressure, we should understand some basic pressure units. We may see pressure expressed in microns when we're pulling a vacuum; we are trying to pull the atmosphere out of the system, so our goal is to get as close to 0 as possible. Whenever we pull a vacuum, we get liquid water to boil off and remove molecules inside the system. The industry standard is 500 microns. 14.7 PSI(A) is equivalent to about 760,000 microns, so the micron is an extremely small pressure measurement. You may also see the bar scale, which is equivalent to 1 atmosphere (atm). One bar equals just over 14.5 PSIA. You may also encounter the Pascal unit, which is common on the building science side of our industry. One PSI is equal to 6,894.76 Pascals. When we look at small pressures, such as static pressure or gas pressure, we may use the inch of water column ("wc). One inch of water column is equal to 248.84 Pascals. We also have inches of mercury ("Hg) and the torr (mmHg), which are related to the micron. All units are interrelated, but they have their appropriate applications. Atmospheric pressure matters when altitude enters the equation. When the pressure changes at a higher altitude, the air density also changes. The air is less dense, so you have less oxygen in the air. When you have less oxygen in the air, combustion is more likely to be incomplete. So, we may need to derate furnaces. We also need to take altitude into account when we calibrate gauges at significant altitudes compared to sea level. Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this podcast episode, Bryan and Trevor Matthews discuss compressor short cycling. They discuss how to diagnose and prevent that issue. Trevor and Bryan primarily refer to the Bulletin AE17-1262 throughout this episode, which you can find HERE. Compressor misdiagnosis is very common, but we generally encounter two types of compressor failures: electrical failures and lubrication failures. Short cycling causes a loss of oil in the compressor, which may lead to lubrication-related failure. Each time a compressor starts, there is a reduction in suction pressure; the pressure drop then causes the saturation pressure to drop. That can then cause the oil to flash and shoot out of the compressor. Short cycling has many potential causes, including protectors, thermostats, low and high-pressure controls, oversized condensers, and oversized compressors. In some cases, the controls can also cause operational short cycling to meet customer demands (or failure to match the load). Each manufacturer may have a different acceptable range of starts per hour, but some customers may request more or fewer starts than recommended. Cycle length and frequency are keys to system longevity. So, we can prevent compressor short cycling by keeping the system operating within the manufacturer's specs. There are also several components that can help manage the factors that cause short cycling, including bleed resistors on capacitors, which manage relay operation. Troubleshooting is also one of the main preventative measures; if you replace the compressor without troubleshooting, your new compressor may short cycle and fail prematurely just like the first one. Trevor and Bryan also discuss: Oil behavior and losses Customer demands Manufacturer specs and communication Oversized compressor issues Internal low-leak discharge check valves Digital scroll compressors in a tandem set Short cycling's effects on the whole system Airflow and pressure Load matching Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this podcast episode, Bryan and Craig Migliaccio (AC Service Tech) discuss some HVACR recovery tips and best practices. When you select a recovery tank, you need to know which refrigerant is in the tank. So, it's a good idea to make sure you label each recovery cylinder. You don't want to contaminate refrigerant in the recovery tank, use a recovery tank with contaminated refrigerant, or have too much air inside the cylinder. If the tank is empty, you'll have to pull a vacuum on it before you use it for the first time. Tank fill can be a tricky business. You have the tare weight and water capacity, which you can use to determine the maximum refrigerant fill (factoring in the refrigerant's specific gravity at 130 degrees and the 80% capacity). Weighing in the charge is important so that you stay within an appropriate range as not to build up hydrostatic pressure and risk injury. Recovery machines will give you the quickest recoveries. (When using one of those, you can extend your machine's life by using a filter drier during recovery.) However, you can also keep the pressure of the tank low during recovery; one of our best tips is to put the cylinder in an ice bucket during recovery. Regardless of what you use for recovery, you ALWAYS want to use a scale to weigh the tank as you recover refrigerant. Craig and Bryan also discuss: Hydrostatic pressure Figuring out the refrigerant type in an unmarked tank Contamination Core removal Waterproof scales Leaks and low refrigerant charge conditions Pulling from the liquid and suction lines De minimis venting Check out Craig's website at acservicetech.com. Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this episode, Bryan and Craig Migliaccio (AC Service Tech) talk about some best practices you can use while swaging and flaring copper. There are a few different ways you can flare copper. Craig likes using a round deburring tool before flaring the copper. After the burr has been cleanly removed, Craig likes using an eccentric flaring tool for the actual flaring. Bryan's favorite flaring tool is the NAVAC battery-powered flaring tool for quick, accurate flares. Both Craig and Bryan agree that it's better not to deburr if you're likely to drop the burr or copper shavings into the tubing. You can also use a tiny bit of Refrigeration Technologies Nylog on the flare face to make sure that the contact is sufficient and secure. Along with flaring, we also have tube expansion or swaging. There are several tools you can use, including drill, hammer, and block swages. Craig likes to avoid swaging tools that leave large gaps; adding heat to make the swaging process smoother may result in oxidation. He prefers using a drill swage on downward-facing tubes; the drill swage can provide friction and heat while keeping the copper tube clean. Overall, Craig doesn't have a favorite swaging tool; he acknowledges that each swaging tool has an appropriate application. It's NOT a good idea to use a tube expander near the compressor. Craig and Bryan also discuss: Deburring in difficult situations Over-reaming with blade deburring tools Flares on higher-pressure systems Comparing the flare size to the flare adapter size Old flaring tools, new flares Ductless or mini-split systems Cleaning the lines if you drop anything inside of them When to use a fitting Check out Craig's website at acservicetech.com. Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this podcast episode, Bryan and Jim Fultz discuss the White-Rodgers SureSwitch and determine whether contactors are obsolete or not. Contactors are electrical controls; they started off very expensive and usually outlasted equipment, so they are currently smaller, cheaper, and less durable than they used to be. Modern contactors have open contacts and are susceptible to insect damage. Sometimes, an electrical arc can cause contactor pitting, which can weld the points together and render the contacts useless. The SureSwitch is more than a contactor; it is also a brownout monitor, short cycle timer, and a random start timer that helps with brownout recovery. The installation instructions are also thorough and include helpful information like torque specs. It also has a high-visibility LED. The SureSwitch has sealed contacts, so insects can't get to the contact points and cause pitting or failure to close. There is also a latching relay feature, which prevents chattering at lower voltages; the points stay fully closed. The SureSwitch also has a microprocessor that monitors the electrical current going inside the relay. If that microprocessor detects arcing, it knows that the contact points had closed somewhere close to the peak of the arc, and it will adjust itself accordingly. The SureSwitch now has a multi-volt coil, so it can work in residential AND commercial HVAC. Instead of being limited to single-phase 240v applications, we can now apply that contactor to three-phase and 208v applications. Jim and Bryan also discuss: Shunts Contactor chattering Opening or closing at the zero point of the sine wave Mounting points Why insects like to get into contactors Contact configuration Time delays Maintenance contracts and customer loyalty incentives Short cycling for testing purposes Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this episode, Bryan and Craig Migliaccio (AC Service Tech) discuss all the ways that nitrogen can make your job easier. Nitrogen is an inert gas that we can use for purging refrigerant lines and completing scale-free brazing jobs. As techs, we should have at least one inert gas in our trucks to help us do the best job possible. We can use inert gases for purging refrigerant from tubing, flowing and preventing oxidation while brazing, and pressurizing a system for leak detection or a pressure test. You'll also find nitrogen useful for getting oil out of the way before pulling a vacuum. You can also use nitrogen to help clean out a drain line. However, you'll want to be careful; if the PVC pipe isn't secure, you could create leaks (or a total blowout). You can cause severe structural damage if you flow a compressed gas under too much pressure. In some cases, we also use nitrogen to pressurize a gas line (including propane or natural gas lines). We can pressurize that to about 6 PSI to get the pressure up to a more desirable level. (Not to mention, we can reinflate tires with nitrogen, though that's not a strictly HVAC-related application.) Outdoor units may be installed near a dryer vent, which increases the risk of the unit getting dirty. When that's the case, you can use nitrogen to blow off any of the lint and debris. Overall, you can use nitrogen for applications where you'd usually use compressed air. Anytime you work with any kind of inert gas, you need a flow meter and regulator; a normal gauge manifold just won't cut it. Make sure you flow the gases at appropriate pressures, too. Check out Craig's website at acservicetech.com. Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.