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HVAC School - For Techs, By Techs

HVAC School - For Techs, By Techs

936 episodes — Page 8 of 19

Troubleshooting The Modern ECM

Chris Mohalley returns to the podcast to talk about troubleshooting the modern ECM (or EC motor) and give diagnostic tips. ECMs are electronically commutated motors; they are mechanical motors with an electronic control module that dictates everything the motor does. As with all motors, ECMs have inputs and outputs. If the motor is not running, the first step is to check the line voltage and make sure that it is correct and connected continuously, as that's one of the main inputs on all ECMs; there is no relay or switch on the line side. The motor itself is the output, so you will know if the output is correct if the motor is rotating and generating airflow as intended. Constant-speed and constant-torque motors can all be diagnosed with a basic voltmeter. One of the most difficult parts of troubleshooting constant-torque ECMs is knowing how the taps are programmed by the manufacturer; reading the manual and schematic is advantageous during diagnosis, especially as these motors have evolved to use pulse-width modulation (PWM) and have nine speeds instead of five (energizing pin 1 at the same time as another pin, diagnosed with 24v AC). Constant-airflow motors tend to have inputs that are less complicated than the five or nine-speed taps. Chris and Bryan also discuss: Inputs: line voltage and signals TechMate Pro, multimeters, and Genteq TECINspect diagnostic tools Constant-speed vs. constant-torque vs. constant-airflow motors Diagnosing PWM signals with DC voltage Adjusting airflow with DIP switches Are board and motor failures common? Why we don't diagnose the motor separately from the control Learn more about Regal Rexnord's FREE training at https://regal.mmu.com. Learn more about the HVACR Training Symposium or buy a virtual ticket today at https://hvacrschool.com/symposium. 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.

Feb 16, 202331 min

Training for the Future w/ Clifton & ESCO

Clifton Beck of ESCO Group returns to the podcast to talk about training for the future. He also talks about how he became an educator, what it's like to be a trades educator with ESCO Group, and how educators can handle the recent HFC phasedown and the rise of A2L refrigerants. Especially with the COVID-19 pandemic, mass media has changed the way the industry thinks about training. Organizations like ESCO have evolved, and that is evident in their curricula; changes are being made to keep up with field tools and equipment to make sure technicians are up to date. A large network of industry experts makes these training curricula possible. Virtual and media education have changed the way we think of educators. Many of the most knowledgeable people in the industry, including people like Craig Migliaccio, work in the field and aren't traditional educators but have a large positive influence on the industry due to social media. Refrigerant regulation changes, including the HFC phasedown, present opportunities for training to focus on combating misinformation and adapting to field conditions. Training should aim to eliminate confusion and anger in these situations. Proper installation and service procedures will make the A2L transition much easier. Clifton and Bryan also discuss: Clifton's professional history HVAC experts and relationship building ESCO Institute and HVAC Excellence The evolution of educators and expectations for them HFC phasedown facts Recovery, recycling, and reclaiming refrigerant appropriately Commercial vs. residential HVAC/R and refrigerant regulations Educators as social media personalities HVAC Excellence Conference Learn more about ESCO Group's resources at https://www.escogroup.org/. You can also check out the ESCO Group YouTube channel at https://www.youtube.com/@escogroup. Learn more about the HVACR Training Symposium or buy a virtual ticket today at https://hvacrschool.com/symposium. 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.

Feb 9, 202340 min

MERV vs. Motors

ECM expert Chris Mohalley joins the podcast to talk about the balance between selecting air filtration and motor performance, also known as "MERV vs. Motors." As the industry realizes that filtration is more important, we're starting to see an interest in filters with MERV ratings of 13 or higher. However, there are some design challenges associated with static pressure drops across filters, motor responses to static pressure, and airflow. If the airflow isn't set properly, that could affect the refrigerant charge and temperature rise. PSC motors' performance directly follows the load; as static pressure increases, the airflow rate produced by the motor decreases. They may also make loud noises when the static pressure is high but satisfactory airflow. However, they are robust and don't typically fail quickly due to high static pressure. Electrically commutated motors (ECMs) are operated by electronic controls and come in constant torque or constant airflow varieties. The former has a performance curve (like a PSC motor) but doesn't appear to suffer from longevity issues when the static pressure is high; the latter can adjust airflow based on static pressure, but it is likely to have issues maintaining airflow during high static pressure conditions. Regardless, there is still an operational envelope; going outside of that envelope will likely result in a capacity and/or efficiency hit if there is high static pressure. Chris and Bryan also discuss: COVID-19 pandemic and the evolution of filtration Face velocity across filters Amps in constant torque vs constant airflow motors Swings in airflow/performance Educating the customer about "upgrading" filters Using performance manuals Learn more about Regal Rexnord's training at https://regal.mmu.com. Learn more about the 4th Annual HVACR Training Symposium or buy a virtual ticket today at https://hvacrschool.com/symposium. 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.

Feb 7, 202339 min

Effective Filtration & More w/ John Ellis

John Ellis, a business consultant who specializes in IAQ training, joins the podcast to talk about effective filtration, product development, and more. John has recently worked with an OEM to bring field practicality and application to the engineers who design products. Filtration design is a relatively poorly understood concept in the industry; we tend to overlook a filter's ability to remove particulates from the air when we prioritize static pressure drop. We have to understand how the duct design can make higher-MERV filters work and how the face velocity plays into design and comfort. John also talks about bypass HEPA filtration and its appropriate uses and potential for misapplication. Bypass HEPA may be integrated with the HVAC system (but run independently of the system) or installed independently of the HVAC; its effectiveness will be dictated by its runtime, and it doesn't filter everything. IAQ products and strategies need to produce quantifiable results, and our industry needs people to be trained to measure and produce those results, not push products. Education, integrity, and competence are the keys to starting conversations about IAQ methodologies that actually benefit the customer. When we're ready to have those conversations with the customer, we can show the customer that we prioritize their health, safety, and comfort; it's good to use maintenance procedures as times to follow up with the customer and make sure their IAQ needs are being met. Communication is critical here. John and Bryan also discuss: Design, production, and distribution MERV ratings Oversized filter-back returns with media filters Blow-by Charcoal carbon pellets vs. activated carbon Oxidizers and microbiology disruption Sales resistance & being pushed to make more sales Problems with circuit boards Learn more about John's work at https://thenewflatrate.com/ or contact him directly at (505)-652-8119. Learn more about the 4th Annual HVACR Training Symposium or buy a virtual ticket today at https://hvacrschool.com/symposium. 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.

Feb 2, 202350 min

Do Houses Need to Breathe? w/ Allison Bailes

Dr. Allison Bailes from Energy Vanguard joins the podcast to answer the age-old question: do houses need to breathe? He also talks about his new book, A House Needs to Breathe... Or Does It? You can purchase that book directly through the Energy Vanguard site at https://energyvanguardstore.com/ or on Amazon. HVAC professionals can benefit from learning about building science because there is a lot of overlap between the two, and an HVAC technician who knows about building science can set themselves apart in the market. In short, Dr. Bailes doesn't think a house needs to "breathe," especially if a house brings in low-quality air, especially humid air, through gaps and cracks. Some people also use the term "breathe" differently; some may be referring to leakiness, and others may refer to drying out a house. It is necessary for a house to be dry, but we want to make sure that fresh air is controlled. If you build a home tightly, you have to ventilate it correctly. We have to control air, liquid water, water vapor, and heat. Heat is especially complicated, as it has three different ways of moving and can come in sensitive and latent varieties. One way of controlling those is through control layers like vapor barriers, though these aren't always needed; we must understand the vapor flow to determine if a vapor barrier is necessary. Dr. Bailes and Bryan also discuss: Energy Vanguard's resources The chapters of "A House Needs to Breathe... Or Does It?" IAQ - filtration, humidity control, ventilation, and source control Challenges with attic air Dr. Bailes's book-writing process The HVACR Training Symposium and other events w/ Dr. Bailes Keep up with Energy Vanguard, read the blog, and subscribe to the weekly newsletter at https://www.energyvanguard.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.

Jan 26, 202331 min

What the Heck is High Performance HVAC w/ David Holt

David Holt with the National Comfort Institute (NCI) returns to the podcast to talk about high-performance HVAC and what the heck it even is. High-performance HVAC is all about delivering the highest possible equipment performance out of the box. High-performance HVAC is a key element of NCI's work; equipment should be able to deliver the health, comfort, safety, reliability, and efficiency expected by the occupants, and equipment that can't do that often has root issues we need to troubleshoot and fix. In many cases, the root cause has something to do with airflow issues. As contractors, we can focus more heavily on testing fan airflow to get to the bottom of poor HVAC performance, even when there may not be an apparent airflow problem. We need the proper test instrumentation to measure CFM, a key indicator of performance. We can't expect to maximize system performance until the airflow is correct across the heat exchange surfaces. Many factors that contribute to poor equipment performance actually have to do with building science, including issues like air leakage. Although HVAC contractors can't control that, we can be successful if we have a culture and mindset that makes us put our customers first and work with the circumstances we're given to deliver the best possible solution. David and Bryan also discuss: David's role at NCI Manufacturer, distributor, contractor, technician, and customer relationships How to measure CFM effectively Effects of improperly Issues that arise during building construction Parts vs. equipment vs. systems What makes a good service technician The high-performance mindset Having a classroom vs. a commitment to training If you want to get more involved in HVAC training, you can text David at (706)-332-2212 or visit https://nationalcomfortinstitute.com/pro/. Learn more about NCI's High-Performance HVAC Summit at https://www.gotosummit.com/. Check out the HVACR Training Symposium and order your virtual tickets before, during, or after the symposium (Jan 19-21, 2023) at https://hvacrschool.com/symposium. 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.

Jan 19, 202346 min

Setting Realistic Customer Expectations w/ Ed Janowiak

Ed Janowiak returns to the podcast to talk about setting realistic customer expectations when designing residential HVAC systems across climates, seasons, and load conditions. Being honest and aggressive is one of the best ways to set realistic expectations, and our load calculations and equipment selection need to reflect that. Manual J calculations must consider non-design days, not just the design conditions, including partial load conditions. Partial load conditions that aren't accounted for may make it more difficult for the HVAC system to control latent heat, potentially leading to moisture problems indoors. We have to set expectations in the summer a bit differently than we set expectations in the winter, and we must account for the equipment type when we create expectations. Heat pumps perform differently than furnaces, and oversized furnaces typically present fewer problems than oversized heat pumps in areas with high latent loads. Clients must also be willing to acknowledge that systems won't perform exactly as designed during partial load conditions. You can put the information in writing and make clients sign the paperwork to ensure that they understand the expectations you've set. Laying out expectations and making clients read them is a good way to prevent conflict or identify clients that may not accept the expectations. Ed and Bryan also discuss: Ed's three "Hate Me" reasons Oversizing furnaces vs. straight-cool A/C units vs. heat pumps Electrification Heat pumps in cold climates Humid vs. arid climates Designing systems with ancillary dehumidification Not being responsible for clients' lifestyle choices ACCA collaboration and industry support Learn more about the training ACCA has to offer at https://www.acca.org. Check out the HVACR Training Symposium and order your virtual tickets before, during, or after the symposium (Jan 19-21, 2023) at https://hvacrschool.com/symposium. 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.

Jan 12, 202345 min

Mini Split Install and Service Tips

Craig Migliaccio, aka AC Service Tech, returns to the podcast to share his knowledge about mini-split install & service. He also talks a bit about his upcoming book, "Inverter Mini-Split Operation and Service Procedures." Mini-splits are unique because they are compartmentalized in ways that traditional central-air ducted systems are not. Mini-splits come in many varieties, including ducted and ductless types, as well as multi-zone types. Many are inverter-driven and have more electrical efficiency as a result and can vary their capacities based on load variation. Mini-splits have metering devices at their outdoor units, and these devices may be electric expansion valves (EEVs) or capillary tubes. Inverter mini-splits also don't have filter driers because their PVE oil doesn't have the same acid concerns as POE oil, and they don't have traditional liquid lines. Flare connections are also critical when installing ductless systems, especially because you want systems to be tight to prevent leaking and contamination. Craig likes eccentric flaring tools with offset cones, and he recommends using flare nuts from the equipment manufacturer, not the line set manufacturer. He covers other flaring best practices as well. The charge is quite small in mini-splits, so weighing the charge and being careful and deliberate during charging is critical. Refrigerant leaks can also be highly problematic; corrosion and poor flare connections are common causes of leaks. Craig and Bryan also discuss: Hyper-heat systems Coefficient of performance (COP) and BTU output Moving between PSC and ECM or inverter technologies Mini-splits vs. VRF/VRV technologies Pressure testing and leak detection Compressor diagnosis Thermistors and electrical resistance Heat sinks and mounting circuit boards Selecting a location to install a mini-split Things to consider when checking the charge Why measure superheat and subcooling? Cleaning and maintenance best practices Check out Craig's YouTube channel at https://www.youtube.com/@acservicetech. Starting January 1st, 2023, you can buy Craig's book on his website, which has a bunch of other good resources. Visit that site at https://www.acservicetech.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.

Jan 3, 202350 min

CO Doesn't Leak w/ David Richardson

David Richardson from NCI returns to the podcast to talk about why CO (carbon monoxide) doesn't leak and what it does instead. CO is a highly dangerous gas that is colorless and odorless, and we can keep ourselves safe by staying aware of it with personal low-level CO monitors. However, CO doesn't leak; it spills, especially via backdrafting, a blocked flue, or updrafting. Whenever the flue gas comes back inside the structure unintentionally, there is room for a potential CO problem. With proper testing, we can determine the cause of that spillage and make the best choice to stop it from happening. When there is an excessive draft, there's often turbulence in the draft hoods, which leads to spillage. Spillage commonly happens at the draft hood, but it can also happen near the burner compartment of a gas appliance. Smoke tests won't detect that, but CO testing will. However, we need to look for rising CO levels over the run cycle of the equipment. If you test CO levels in the ducts, you're only seeing how the fans are distributing the CO; you're not checking the likely source of CO. Water heaters often give visual clues of improper venting, especially if there's soot, rust near the venting, or discoloration near the burner compartment. David and Bryan also cover: CO poisoning symptoms CO monitors vs. alarms The roles of stack effect and airflow in CO spillage Air taking the path of least resistance CO testing best practices CO and changes in sinus pressure Combustible gas leak detectors Low-level CO monitors Wind and its effects on pressurization or depressurization Electric appliances, generators, and CO poisoning Learn more about NCI's training courses at http://nationalcomfortinstitute.com/. You can also contact David directly at [email protected]. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Dec 29, 202238 min

One HSI Furnace Control to Rule Them All w/ Jim Fultz

Jim Fultz with Emerson White-Rodgers returns to the podcast to talk about one HSI furnace control to rule them all, the 50M56X-843 Universal Single Stage Integrated Furnace Control. The 50M56X does not come with wiring harnesses; the control comes with the plugs that the majority of manufacturers use, making it a versatile and user-friendly universal part. It also works with the White-Rodgers Connect app to help you configure the part with the burners. You can also do some basic configuration when it comes to the blower motor. With the 50M56X and Emerson White-Rodgers Connect app combination, you can quickly and accurately configure the control without wi-fi or a password. An igniter is included in the box with the 50M56X; the igniter must match the control. The control also comes with a three-digit display that communicates the microamp current from the flame sensor, meaning you don't need to use a meter on the flame sensor. So, you can carry less truck stock and complete more calls with this universal part. The device also has some potentially useful extra features. For example, the 50M56X stores error codes for 14 days, not permanently, to prevent causing confusion for future technicians. It also has a bus connector for the thermostat and a dehumidification terminal for thermostats with dehumidification capabilities. Jim and Bryan also cover: White-Rodgers universal vs. aftermarket vs. OEM parts Blower speed and X13, ECM, and PSC motors Near-field communication (NFC) capabilities Cross-referencing Technology and ethical business 50M56X warranty information Integration with Sensi thermostats WR Mobile App (available on Google Play and the App Store) Learn about Emerson White-Rodgers and their featured products on our partner page HERE. Check out the wide array of products and resources Emerson White-Rodgers has to offer at https://emerson.com/universalcontrols. 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.

Dec 27, 202239 min

Using Ice to Balance Energy Consumption

Yaron Ben Nun from Nostromo Energy joins the podcast to talk about ice banking, a way of using ice to balance energy consumption. Nostromo Energy is an Israel-based company that has recently started working in California. Water has a very high latent heat of fusion, meaning it can absorb and store a lot of energy between its solid and liquid states of matter. By storing ice, Nostromo Energy can support commercial and industrial structures that utilize chiller-type applications by offering a clean and sustainable battery thanks to water and its physical properties. Load balancing or management will be critical as the electrification of heating sources continues. Lithium-ion batteries aren't sustainable solutions in many of these cases, and that's where ice banking can support the grid by providing a thermal battery. Water offers many advantages as a medium for storing energy, especially since it is natural and doesn't have the numerous economic and labor concerns that come with the production of many other batteries. However, there have been some challenges with the widespread adoption of ice banking, especially when it comes to retrofitting and the ability to match the demand for new power stations. Water is also heavy, meaning that it can be difficult to manage in rooftop applications. Nostromo Energy keeps working to solve those problems and increase the coefficient of performance (COP), especially by maintaining a relatively high freezing temperature. Yaron and Bryan also discuss: Yaron's career and Nostromo Energy HVAC equipment and the electrical grid Economic and labor factors of lithium-ion battery production Discharge rates and glycol cycles COP and compression ratio Heat recovery chiller technology Carbon counting, kilowatt-hours, and carbon emission Thermal energy storage and tax rebate eligibility Learn more at nostromo.energy. 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.

Dec 22, 202232 min

We need to Pay Better! - An Audio Manifesto

Eric Kaiser and Ty Branaman return to the podcast to talk about why we need to pay technicians and field workers better in the HVAC industry and how small and medium businesses can help current employees. When the pay for entry-level HVAC positions can't compete with fast-food, retail, or warehousing jobs, we can't expect people to flock to the industry, especially since so much skill is required. Overtime is also almost unavoidable in many places, and it's a problem that requires a more nuanced solution than getting more trucks on the road. The tricky part about paying more for overtime is that it's challenging to implement pricing structures that charge the end user proportionally. As prices for equipment, fuel, and living essentials go up, the company often has to eat those extra costs if they want to pay their technicians fairly. In some cases, HVAC businesses feel bad for the customer when the cost of everything increases, which could be doing a disservice to the techs who deserve higher wages for their work. HVAC companies can increase their value by setting themselves apart in their markets, such as by performing unique services that benefit customers; effort and skill are required, which can justify higher prices. We have to be realistic about what our competitors are selling and work towards selling comfort, not just parts or systems. Eric, Ty, and Bryan also discuss: Challenges with reducing overtime HVAC sales and higher pay rates Customers' willingness to pay Base pay and incentives How managers can take care of their employees Understanding employee motivation Using profits for personal luxury items vs. reinvesting in a business Knowing our numbers Understanding employee discussions about pay 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.

Dec 20, 202247 min

Refrigerant Myth Busting w/ Dr. Chuck

Dr. Chuck Allgood from Chemours returns to the podcast to do some refrigerant myth-busting. Many people don't understand why high-GWP HFCs can impact the atmosphere if the refrigerant is heavier than air. High-GWP HFCs exist for a long time, and they last long enough for natural mixing and the wind to distribute their molecules throughout the atmosphere. HFOs, by comparison, are more reactive in the atmosphere and have relatively short lifespans, meaning they have less of an effect on the environment. Even though refrigerants with lower GWPs are entering the market, it's always been our job to keep refrigerants inside the system where they can't harm the environment. However, when leaks occur, these lower-GWP refrigerants break down quickly outside the system but not inside it. Contractors and manufacturers should still work together to reduce leak rates as much as possible, even as we keep innovating. Another common myth is around "natural refrigerants," which are common in some forms of refrigeration, but "natural refrigerants" may be a misleading term; although you find them in nature, they undergo heavy manufacturing and processing before being used in HVAC/R systems. Even "non-toxic" and "non-flammable" labels for A1 refrigerants may be misleading, as they don't capture the full picture of their risks. There are also some myths around oil miscibility; oil still needs the help of refrigerant velocity and volume to move it through a system. POE and PVE oil are great in terms of miscibility and also get entrained in the refrigerant to ensure good oil return to the compressor. Dr. Chuck and Bryan also discuss: Dr. Chuck's recent work and research "Heat rises" and buoyancy Pseudoscience HFO stability and reactivity Trifluoroacetate (TFA), toxicity, "forever chemicals" Education and change in the industry "Future-proof" vs. innovation Phosgene Learn more about Chemours and their A2L training at opteon.com. You can also check out the Chemours/Opteon YouTube channel at https://www.youtube.com/@OpteonProducts/videos. 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.

Dec 15, 202238 min

The Good, Bad and Ugly of Trade Schools

Ty Branaman and Eric Kaiser return to the podcast to discuss the good, the bad, and the ugly of trade schools. They cover the opportunities and challenges they've observed in trade schools. As with for-profit colleges, for-profit trade schools market programs aggressively and can take people who are at a crossroads in their life and saddle them with debt. In some cases, trade schools are hesitant to fail people and end up passing people who don't have the technical proficiency to be effective tradespeople. Sometimes, trade schools don't emphasize practical skills and contractors' experiences as much as they could, either. The tricky part about trade schools is their allocation of resources, which instructors typically can't control. Sometimes, too much money is spent on equipment, and not enough is spent on the instructors. There needs to be an appropriate balance of both in an effective program. Administrative distractions can also make programs less likely to produce effective technicians. The admission process also doesn't always sort people into appropriate classes; many people with low proficiency are put into classes that are too advanced for them. People are going into trade schools with less mechanical aptitude than in previous generations, and trade schools often skip over the basics of tool use. Students need to know how to use tools before they learn how to fix systems, and that tool proficiency needs to be reinforced. Continuing education is also more focused on paperwork than application and isn't as thorough as it probably could be. Ty, Eric, and Bryan also discuss: First-generation trade school graduates Administrative challenges with trades instructors Motivating students Instructor qualifications "PowerPoint teaching" Automated systems Bringing work experience to the classroom Where does podcasting fit into trades education? 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.

Dec 13, 202245 min

Selecting Proper Cleaners w/ John Pastorello

John Pastorello from Refrigeration Technologies returns to the podcast to talk about selecting proper cleaners for various HVAC/R jobs. From the beginning, the goal of Refrigeration Technologies has been to make cleaners that are safe but have the same effectiveness as the strong, hazardous varieties in the industry. The more hazardous cleaners are not food safe and may be corrosive, dangerous to inhale, or irritating to the skin or eyes. Some cleaners can also damage components; brighteners aren't recommended for use on aluminum coils for that reason. John is a fan of foaming cleaners because the foam gives the cleaner more contact area and holds the detergent in place for a longer time. Foaming cleaners tend to be good for degreasing. However, if used improperly, the foam can overflow in the drain pan and get messy. Many residential and light commercial HVAC contractors may benefit from keeping Viper EVAP+ for evaporator coils, Heavy Duty for condenser coils, and Brite only when there is an extremely dirty condenser coil. The Viper aerosol coil cleaner can also work well for small systems. The Pan & Drain Treatment also keeps drain sludge and odors at bay inside condensate lines and pans. Instead of relying on harsh chemicals to dissolve microbial growth, Refrigeration Technologies cleaners help use enzymes to dissolve odor-causing biological material in HVAC systems. John and Bryan also discuss: PPE to use when working with cleaners Acid-based cleaners and "non-acid" cleaners Dwell time and contact Dilution ratios NSF registration and what it means to be "food-safe" Viper Venom Packs Watch our 3D video showing how to use several Refrigeration Technologies products HERE. Learn more about Refrigeration Technologies products and resources at refrigtech.com. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Dec 8, 202239 min

Good Tech, Good Service Manager?

Eric Kaiser and Ty Branaman return to the podcast to talk about the progression from technician to service manager and if a good tech always makes a good service manager. They discuss career paths, differing skills between technicians and service managers, and how HVAC/R companies can support techs who wish to remain techs. In many cases, top technicians are pulled into service manager positions to keep them with the company. Sometimes, older technicians who have lost some mobility and strength over the years end up going to managerial positions to stay in the industry. Some people genuinely want to acquire managerial positions. Not everybody is motivated by promotions, and HVAC business managers would benefit from knowing what their employees value and want for their professional lives. Just as we have to teach technicians hard skills to be good at their jobs, we have to teach soft skills to service managers. We can't expect skilled technicians to enjoy or feel comfortable in leadership positions without knowledge of the expectations and required skills. When people genuinely want to go into service manager positions, they can benefit from having a clear path supported by goals and frequent performance reviews to keep them on the right track. However, some people may want to stay technicians; we can do right by them to keep their bodies in good shape so that they can get the most out of their careers and be able to enjoy all types of activities after they retire. Ty, Eric, and Bryan also discuss: Leadership training Setting expectations for positions Keeping technicians happy Residential vs. Commercial HVAC soft skills Taking care of employees over customers Making room for different personalities and providing opportunities for them 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.

Dec 6, 202234 min

Why Aren't the Trades More Respected? w/ Kimberly Llewellyn

Kimberly Llewellyn from METUS joins the podcast to talk about the value system around the trades and why the trades aren't more respected. In many cases, the people who are involved in engineering and design miss the practical details that the tradespeople would be able to pick up on. In many cases, tradespeople aren't consulted early enough in the design process, and their input deserves to be brought to the table. Often, not everyone on a project team is on board with the project's goal, and the trades need to be on board from the beginning to work towards the same goal as the architects and engineers. However, the trades aren't as respected because of the current American dream's emphasis on 4-year college, even despite the student loan debt problem many college graduates have. Despite that, building and troubleshooting systems that are necessary for survival is a fundamental skill for society. The trades can be especially hard on people and leave them feeling beaten down. To reengage the tradespeople and affirm their value, we need to give them credit for their contributions and expertise. It would also benefit younger generations if we could map out a trades career path and make the career progression opportunities clearer. Kimberly and Bryan also discuss: Kimberly's experiences with the trades Theory vs. practice 4-year college, the trades, and our current value system in education Professionalism and being treated as professionals Revising contracts and liability concerns (for contractors/subcontractors) Having mutual respect Consultation and what it means in the trades Working for manufacturers and other career opportunities Contracting as a "race to the bottom" Funding training programs vs. investing in people Mentorship in the trades Underpriced bids and pricing methods 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.

Dec 1, 20221h 31m

Getting More People Into The Trade

Eric Kaiser and Ty Branaman return to the podcast to talk about getting more people into the trade. They focus on how the HVAC/R industry could be better at attracting and training skilled workers, not just getting more bodies to fill HVAC/R tech and installer positions. People are starting to see more value in skilled trades careers, but it's difficult to find people who share your company's values and want to grow as HVAC/R professionals. Skilled tradespeople need time, education, and money invested in them, so it can be difficult for HVAC/R business owners to make those investments when other jobs pay close to the same without the same degree of investment from the company and the employee. To attract more people to the trade, HVAC/R business owners ought to focus on how to give their employees a means of giving a good life. That means making incremental changes to employee pay, benefits, and training to make the trades a competitive option for people who want to improve their skills and grow. We could consider increasing entry-level pay to attract skilled people, allowing us to be more selective in our hiring. Performance reviews can also be more goal-focused to help HVAC/R talent grow within a company. Companies also ought to focus on training their tradespeople to use the many tools at their disposal nowadays; providing these tools and acknowledging the needs of employees will make the industry much more appealing and competitive. Eric, Ty, and Bryan also discuss: Labor organizations Making gradual changes to the industry Competing with other similar industries Changing landscape of job ads and applications "Back in my day..." Ways of providing tools 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.

Nov 29, 202224 min

Becoming a Complete Tech

Genry Garcia returns to the HVAC School podcast to talk about what becoming a complete tech really means and entails. He talks about his professional journey and what we must do to address our deficiencies. Career progression looks a bit different for everyone, with some technicians going to trade school and others starting as helpers and working their way up. We get used to taking readings and start noticing patterns. Then, we start understanding why we see certain pressures. Our experiences are our most valuable tools for becoming better technicians, but they can be reinforced with other learning materials, including books and podcasts. There comes a point when we acknowledge that we are solid technician but may want to specialize in a certain aspect of the trade. For Genry, that was building performance and humidity control; along the way, he listened to people who knew more than him and took on many jobs that he'd learn from and would keep him humble. Everything goes back to the basics; we have to be able to solve all the basic problems and understand the fundamentals. Then and only then can we start thinking about building performance and focus on becoming experts at it. However, we also have to assess our ecosystem and see if it would allow us to grow or if it's more suited for stability. We also have to be willing to be wrong and grow from those mistakes. Genry and Bryan also discuss: The pros and cons of trade school Egos and admitting wrongdoing Mental models Humidity control Looking back on previous work with shame Building envelopes, pressures, and leakage Where and how to learn more about building science and performance Self-auditing and the Dunning-Kruger effect Get in touch with Genry on Facebook by joining his Facebook Group 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.

Nov 24, 202240 min

Inductive Current Myths - Short #158

In this short podcast in our electrical myths series, Bryan talks about some inductive current myths. There is a common myth surrounding voltage drop in inductive loads. When you decrease the voltage in a circuit with a resistive load, you'll see a relatively proportional drop in resistance (ohms) and current in accordance with Ohm's law. So, we'll see a decrease in current, but we have to keep in mind that load temperatures also affect the resistance (and the current, by extension). Some people will claim that reducing the voltage in an inductive load (like a motor or compressor) will increase the current. That is actually generally a myth; many people believe this myth because the current drop is NOT proportional, unlike in resistive loads. The resistance that shows up in a motor is called inductive reactance, which is an opposing magnetic field that creates back electromotive force (back EMF) and impedes the circuit. Back EMF and inductive reactance contribute to the impedance or total resistance of the circuit. Decreasing the voltage may cause the resistance to increase, as some of the work will start contributing to heat instead of mechanical motion; the motor derates, becomes less efficient, and draws more current than it needs, but it doesn't actually draw more total current. However, some variable-speed motors on VFDs may draw more current because the motor module speeds up the motor to make up for the voltage deficiency, static pressure, etc. ECMs also fall into this category and may draw more current if the motor module or VFD calls for it. However, in terms of simple electrical math without VFD logic, the current won't typically increase if the voltage drops, even in inductive loads. 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.

Nov 22, 20229 min

Why it REALLY gets hot upstairs w/ Alex Meaney

Alex Meaney returns to the podcast to explain why it REALLY gets hot upstairs and what we can do about it. He also talks a bit about his new business. Heat technically doesn't rise; warm air is less dense than cooler air, so cooler air sinks as warmer air rises. In many cases, people blame stratification and the stack effect for warm upstairs areas, but there may actually be other issues at play, especially if the issue only seems to happen in the summer. Many apparent convective problems are actually due to building science errors, especially poor insulation when walls are exposed to attic space. When air moves via convection, it brings the heat it contains with it, which can contribute to comfort problems. To help figure out what is going on, try to see what the floor temperature is; a cold floor usually indicates a building design mistake, particularly a joist bag problem. Some of the solutions that may sound good aren't actually that effective, including placing return ducts higher. In many cases, we have to think about fixing the actual building, not the HVAC system. Some attics that are poorly ventilated and insulated will need to be reinforced. Alex and Bryan also discuss: Mean HVAC Consulting & Design Wind washing and exposure within the insulation R-value Pressurization and how it relates to hot air "rising" Manual J and its shortcomings with significant heat gains/losses Duct design and using a Ductulator Soffit vents, ridge vents, blown-in insulation, and infiltration Why building science skills are important for HVAC technicians Poorly conceived home designs Diagnostic tips and tricks Vapor-permeable air barriers Sizing, capacity, and power consumption Learn more about what Alex is doing at meanhvac.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.

Nov 17, 202249 min

Electrical Myths - Single phase is Really 2-Phase - Short #157

In this short podcast, Bryan busts the common electrical myth that single-phase 240v power is really two-phase power. When power goes into a structure that runs 240v appliances, we may understand that two 120v sine waves are 180 degrees out of phase with each other, but that isn't 100% accurate. If we were to use an oscilloscope to watch the electrical sine waves, we would see two sine waves 180 degrees out of phase because the transformers are center-tapped. Center-tapping creates a neutral center point that becomes our reference. The transformer has two sides: a primary and a secondary. The number of wraps on each side is proportional to the other, and the number of wraps also dictates whether a transformer steps the voltage up or down. However, when you use the center tap as a reference, that also makes the voltage appear to be halved. In many residential structures, a single phase of power goes into the transformer from the power company. If you were to use the center tap as your reference on each side of that transformer, you would read 120v; the two 120v readings add up to 240v. However, if you were to use the other side as the reference (as in a corner-tapped transformer), you would read 240v. On an oscilloscope, you would see the same thing; using the center tap as the reference, you would see two 120v sine waves completely opposite each other. If you were to measure completely across the transformer, however, you would see a single 240v wave, which is larger. Remember: only one phase comes from the power company. We only appear to get two separate waves because of our available point of reference. 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.

Nov 15, 20229 min

Pumping Away, Hydronics Changes And Electrification

Moe Hirsch joins the podcast to discuss the hydronics side of the industry, particularly focusing on Dan Holohan's Pumping Away and exciting developments in the hydronics market, especially regarding electrification. Pumping Away is many people's entry point to hydronics. It contains some good basic information about boilers, especially when it comes to learning about the pressures involved in pumping and how the components manipulate pressure throughout the system. Boilers use many of the same fundamentals as compression-refrigeration HVAC systems; pressure drops are similar, as are phase changes in steam boilers. Boilers also employ pumps instead of compressors, but the processes are similar. The pump or circulator makes a pressure differential within the boiler, which adds pressure to the circulator outlet and results in negative pressure on the suction side. However, problems like air bubbles and magnetite buildup can negatively impact performance. The electrification side of the boiler industry is exciting, especially because of the relative safety of electricity compared to combustible fossil fuels. However, electrification comes with its own set of concerns, especially when natural gas prices are low. In some markets, electrical grids also haven't caught up with the demand for electricity yet. Moe and Bryan also discuss: Moe's recent work in the industry Changes in boiler infrastructure over the years Pumping away from the boiler vs. pumping at the boiler Pressure's role in boiler systems Similarities between parallel racks and boilers Challenges with ECM circulators Evolution of boiler motors and controls Magnetic and hydraulic circulation Low-temperature heat pumps with radiant heated systems Moe's ideal HVAC system Natural gas health and safety risks (carbon monoxide) To learn more about what Moe is doing, check out turnupthecomfort.com or contact Moe directly at [email protected]. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Nov 10, 202251 min

Electrical Myths - Hard Starts Reduce Start Current - Short #156

In this short podcast, Bryan busts the myth that hard starts reduce the start current on the run winding of a compressor. A single-phase motor's main winding is the run winding; it has a lower resistance and a higher current than the auxiliary winding, also known as the start winding. Hard start kits are often used on HVAC systems with single-phase compressors (which usually have PSC motors). These kits usually consist of a start capacitor and a potential relay, which takes the start capacitor out of the circuit. We don't typically use hard starts on three-phase motors or ECMs. Single-phase compressors often have to start under a big load, especially in long-line applications (at the manufacturer's recommendation) or if the compressor simply has a hard time starting. In cases where you have a voltage drop or low voltage, particularly due to long branch circuits, you may also use a hard start kit. However, they do NOT reduce the starting current or "save" compressors. Hard starts reduce the time-averaged starting current because they get the compressor to start up more quickly (therefore, the starting current is higher for a shorter time). However, hard starts do NOT reduce the spike of current upon startup. Like run capacitors, hard start kits allow current to flow on the start winding, but the run winding current stays the same. Hard start kits boost the start winding current faster, not at a lower current, reducing how long the system is in locked rotor. If they stay in the circuit too long, they could overheat the start winding and need to be taken out. Therefore, we don't want to use hard start kits without careful consideration. Soft starts are different entirely; they CAN reduce starting current. 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.

Nov 8, 202215 min

The 24-Hour Technician w/ Andy Holt

Andy Holt joins the podcast to talk about what it means to be a 24-Hour Technician. We talk about what it means to be HVAC/R technicians AND deal with the human aspects of our lives at the same time. Service technicians differ from installers in that they do much of their work solitarily. They spend a lot of time by themselves. They're also on their feet very often and may do emotionally exhausting work, but they can earn a respectable living and accumulate savings for the future. To make our work and the emotional burdens that come with it more manageable, we can try to control how we react—take out head trash. Most people—but especially technicians—experience anxiety, and worrying about things takes a major toll on us. We also may need to apologize to people who we simply can't access. Andy goes over some of his best tips for dealing with those sources of worry. The goal is to eliminate negativity—clearing up negative aspects of your life and not being weighed down by individuals who negatively affect your life. As technicians, we do a lot of work to help other people, and the opportunities are endless for us. Customers may not always understand the value of the work we do, but we can bring positive experiences to them. We can find a lot of fulfillment in our work that way and bring positivity to our own lives. Andy and Bryan also discuss: Replacing negative thoughts with more positive ones The power of handshakes and eye contact Carrying burdens and being kind Apologies and forgiveness How to apologize to inaccessible people Being a "24-Hour person" Using overtime to avoid our lives outside of work How to manage anxiety Casting a future Andy Holt's Outdoor University To get in touch with Andy, visit https://toprate.com/ or call (706)-888-2332. You can also email Andy at [email protected]. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE.

Nov 3, 202240 min

Furnace Commissioning w/ MeasureQuick 2.0

Jim Bergmann returns to the podcast to talk about furnace commissioning procedures and the development of measureQuick 2.0. MeasureQuick 2.0 has been a collaborative effort between Jim Bergmann and Joe Medosch, and it comes with an upgraded user interface that allows for faster operation and easier system data access and storage, and it works with more tool manufacturers' tools. Gas furnaces need to be commissioned to reach their maximum potential (and lifespan). MeasureQuick 2.0 provides commissioning instructions and recommends starting with a visual inspection, including the flame rectification system (rod, circuit board, and grounding). Electricity is conducted during the flame rectification process—only in the microamp scale—so a dedicated circuit is crucial to keep it working as it should. When commissioning a high-efficiency furnace, we should make sure the condensate drain cannot become clogged. The filter should block the airstream completely and not allow for any bypass, which could make the secondary heat exchanger, condensate drain, or circuit board dirty. The combustion air zone (CAZ) is also important; we don't want contaminants in there, as those could create acids that rot out your furnace components. Jim has also recently worked with the folks at TEC to make MeasureQuick 2.0 compatible with the TrueFlow grid and DG8. This integration allows you to identify airflow issues much more quickly and easily than before. MeasureQuick 2.0 also stores a lot more historical data, especially as it relates to the built-in visual inspection checklist. Jim and Bryan also discuss: The history and methodology of measureQuick 2.0 What technicians tend to miss the most Furnace circuit boards Electrical signals and flame rectification Filtration best practices IAQ accessories and pressure drop Combustion air zone (CAZ) Evolution of airflow measurement with measureQuick Venting termination considerations Clocking the meter and setting the fuel pressure CO and CO air-free PPM Low-level CO protection Checking manifold and inlet pressure Is the industry ready for universal heat pumps? 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.

Oct 27, 20221h 24m

Light Commercial PM Process

Mike Klokus and Jeff Crable walk us through Kalos Services' light commercial PM process. First, we verify that everyone is clear on the agreement. Then, we start the PM with a thorough visual inspection, taking copious notes about things that look concerning. Once we've done a visual inspection, we clean the condensers. We try to use only water when possible, though safe cleaners may be necessary in some cases. When checking the electrical components, we make sure the wires are neat and have tight connections. We take our electrical readings and check the capacitor. Then, we check the system's refrigerant temperatures and pressures. We measure the superheat, subcooling, and pressures throughout the system and record those. Once we move indoors, we check and replace the filter in accordance with the agreement. We do another visual inspection at the air handler, paying special attention to blower wheel cleanliness, panel insulation, and wire routing and connections. When cleaning the evaporator, we want to try to stick with water or self-rinse cleaners. We want to make sure that we use very mild chemicals, and any foaming cleaners should be diluted appropriately and rinsed entirely. Drain cleaning is one of the most critical parts of a PM. We check for double traps and to make sure that the drain lines are properly pitched, trapped, and vented; vents should be uncapped, but cleanouts must be capped. We finish with a final inspection, making sure all disconnects are back in, cleaning up all trash and tools, and sharing any notes with the customer. Mike and Jeff also cover: Cleaning microchannel and multi-row coils Critical electrical readings How to replace panels carefully Filter replacement Modifying ductwork and return boxes for accessibility Cleaning drain pans thoroughly Pulling and cleaning blower wheels Common drains and condensate pumps Traps, cleanouts, and vents Testing heat strips Finishing up calls 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.

Oct 20, 20221h 25m

Electrical Myth - Wire Length Code - Short #155

In this short podcast, Bryan covers a common electrical myth about wire length and its relationship with the National Electrical Code. The NEC is concerned with safety—protecting buildings and people—but less so with making sure things work. Wire sizing is a common topic, and length is important because it can contribute to the voltage drop in a circuit. In many cases, we refer to the MCA (minimum circuit ampacity) to select an appropriate wire size. If you run more current through an undersized conductor, it gets hotter and will experience a voltage drop—though not proportionally. It's worth noting that nothing in the circuit is fixed; voltage, amperage, and resistance all follow Ohm's law but are variable as different things start happening in a circuit. In many cases, the NEC generally doesn't require us to size conductors to accommodate for voltage drop. Conductors have some degree of resistance, so longer wires will result in a greater voltage drop than you would see in a shorter wire. It makes sense for the wire to overheat, but that won't happen because the greater resistance in the circuit will reduce the current. There is less work being done. Longer wires and circuits that are sized correctly shouldn't overheat or present a safety issue. The NEC recommends but does not require voltage drop to stay below 5% across a conductor. That is a performance recommendation, not a safety concern. We need equipment to perform correctly, but NEC won't prevent electricians from setting up branch circuits that are longer than the ideal length. Excessively long branch circuits are common in commercial structures, and it's up to HVAC technicians to notice that and measure the voltage drop to make sure it's not negatively affecting the equipment. 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.

Oct 18, 202212 min

Why CO2 Matters w/ Trevor Matthews

Trevor Matthews, the founder of Refrigeration Mentor, returns to the podcast to talk about why CO2 matters in commercial refrigeration and even HVAC applications. CO2 (R-744) has entered the residential HVAC sphere in some places around the world, though it hasn't come to the North American markets yet. CO2 is one of the most eco-friendly refrigerants on the market, with a GWP of 1, and it's very good at moving heat. However, CO2 has some challenges, including its low critical point and higher pressures. CO2 comes with some safety concerns, and its systems have a complicated infrastructure. Since CO2 can exist as a liquid, vapor, or solid under operating conditions, you could end up with dry ice in the system. These issues require skilled, attentive technicians. As the industry moves to natural refrigerants like CO2 and hydrocarbons, we need to stop the race to the bottom. Technicians need to learn how to take their time and do the job right when they work on CO2 equipment so that they can be safe and save energy. The future of troubleshooting will eventually lie in electronic controls that take measurements constantly. Technicians won't lose their necessity with these changes, but it will be easier for them to respond to those measurements directly without connecting gauges. Technicians will also be able to access performance logs, which can help diagnose long-term problems. Trevor and Bryan also discuss: Trevor's history working with CO2 Refrigerant regulations Transcritical CO2 and climate The skills and proficiency of young technicians Dry ice in CO2 systems Pressure transducers and pressure release valves Manufacturer support and quality control Data logging and electronic controls in commercial refrigeration Trevor's recommended resources for CO2 education and training Check out Trevor's mentorship and training initiative at 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.

Oct 13, 202239 min

Electrical Basics

This podcast is Bryan's full-length electrical basics class for the Kalos technicians. He covers electrical theory and circuit basics. Volts, resistance, and amps all affect the behavior of electricity in circuits. These are also critical factors in electrical safety. Watts and kilowatts come from the multiplication of the volts and amps, though not every volt-amp does work; the power factor indicates how much work the volt-amps are actually doing. Some of the volt-amps are reactive (kVAR) and don't do the real power of watts. Electrons move by interacting with other atoms. Substances can be conductors or insulators, and conductors have very few valence electrons, which move in and out of other atoms easily. Insulators have many valence electrons and are more stable. Insulators have high resistance, and conductors tend to have low resistance. Circuits consist of loads, switches, and power supplies. Loads actually do things and consist of light bulbs and motors. Switches pass power and don't do work. Power supplies can be finite, like batteries, but also include transformers that take power from the utility company. Open circuits don't move electricity, but closed circuits create a complete path that allows electrons to move. Electricity takes all available paths, not just the path of least resistance. Bryan also covers: Electricity and the body GFCIs and AFCIs Shock and arc flash protection Lockout/tagout Electricity and fall hazards Energy transfer Resistive vs. inductive loads Magnetism and flux Direct current (DC) vs. alternating current (AC) How power companies and generators work Open vs. short circuits "Path of least resistance" Tripping breakers Electrical units of measurement Step-up and step-down transformers Electrical frequency (hertz) Variable frequency drives (VFDs) Microfarads and capacitors Parallel and series circuits Becoming more proficient at reading diagrams 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.

Oct 6, 20221h 27m

Myth: Path of Least Resistance - Short #154

In this short podcast, Bryan debunks the myth that electricity only takes the path of least resistance. It is true that more current will typically take paths of lower resistance; it's much easier for more electrons to flow through a path with lower resistance, which is consistent with Ohm's law. Ohm's law states that a circuit will have higher current with you have lower resistance so long as the voltage stays the same. In most cases, the voltage stays relatively constant; transformers don't often need to limit their currents, so there usually isn't a voltage drop. When power supplies are regulated, the voltage is usually fixed, not the amperage. As a result, dropping the resistance in a circuit will increase the current. Ohm's law holds true for both resistive and inductive loads. Inductive loads, however, are a bit tricky because the resistance isn't constant. As motors spin faster, they create back EMF or impedance, which is magnetic resistance. The resistance only shows up once a motor, solenoid, or another electromagnetic component is energized; the resistance is much more dynamic. An electrical current takes ALL parallel paths, not just the path of least resistance. The current also stays proportional to the resistance, even when it takes paths of many different resistance values. Our bodies are also parallel paths, so there's a risk of electric shock even though our bodies usually have much higher resistance than loads. Wet skin has less resistance than dry skin, so that's why electricity and water are so dangerous to us; lower resistance means that more current can flow through our bodies. If electricity ONLY took the path of least resistance, we wouldn't be able to operate all the appliances and electrical components in our homes. The only prerequisite is an electrical potential (voltage). 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.

Oct 4, 202210 min

Dehumidification in Shoulder Seasons w/ Nikki

Nikki Krueger from Santa Fe Dehumidifiers returns to the podcast to talk about dehumidification equipment and strategies in the shoulder seasons (spring and fall). The shoulder seasons (and the weeks leading up to them) are when many homeowners begin to notice moisture problems in their homes. HVAC units and dehumidifiers should have a king-queen relationship. The HVAC unit is the king and controls the bulk of temperature and humidity during the day, but the dehumidifier can take care of the humidity when the king needs help. To remove moisture optimally, an HVAC unit needs longer runtimes and a cold evaporator coil. However, there will still likely be gaps in performance, and that's when the dehumidifier can step in. Proper equipment sizing can help us achieve better runtimes; we want to avoid oversizing the HVAC equipment, but oversizing is a bit less critical when it comes to installing dehumidifiers. The actual install configuration is more important when it comes to dehumidifiers (i.e., whether it takes supply or return air and ties into the supply or return). Dehumidification can be coupled with ventilation and filtration; ventilating dehumidifiers bring in outdoor air and should filter it before dehumidifying. The air mixing tends to occur in the dehumidifier, and the mixed, dehumidified air then moves into the supply airstream. Nikki and Bryan also discuss: Condensating vents, walls, and equipment Modern homes, energy efficiency, and HVAC Infiltration and the building envelope's effect on humidity Effects of equipment sizing and wall/duct insulation Fan speed, air mixing, condensation, and humidity Andy Ask and Ken Gehring's contributions and legacies Humidity from household habits and behaviors Santa Fe Oasis 105 features and operation 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.

Sep 29, 202258 min

Time Management - Short #153

In this short podcast episode, Bryan gives some quick tips for time management. You can save a lot of time by prioritizing what really matters and delegating tasks. One of the simplest but most effective ways to manage your time is to use a calendar. You can even apply the calendar to your personal life; you can get into a habit of scheduling important appointments, deadlines, and tasks. Google Calendar also allows other people to see and interact with your schedule, so it's a great tool for scheduling performance reviews, interviews, and meetings. When you prioritize things, think about the negative and positive impacts of each thing. The ones with the highest positive and negative impacts should take priority over things with less significant positive or negative impacts. Many of the major business initiatives take place in the slow season, and many of our urgent client issues take priority during the busy seasons. Delegating is also a critical task. Just because you can do something, that doesn't mean you should do it. So, it often makes more sense to give someone a task if they're uniquely qualified for it. If someone is uniquely qualified to do a task, then you can delegate that task to them. Delegating is NOT the same as passing work to someone else because you don't want to do it. To delegate effectively, you need to assess qualifications and prioritize. On the management side, you can put processes in place that allow you to spend less time managing and more time doing meaningful things at work that you actually enjoy. Making videos and audio tutorials can make it easy to demonstrate processes and procedures within your company. Then, you can focus on leading by example, creating, and making everybody better overall. 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.

Sep 27, 202215 min

Become a Better Mentor w/ Eric Kaiser

Eric Kaiser returns to the podcast to talk about how to become a better mentor. He explains the topic from the perspective of a mentor and a mentee. The goal of mentorship is to pass your knowledge on to someone else. When you give someone the knowledge to succeed in the HVAC/R trade, you move the trade forward and allow yourself to try new career opportunities when someone can replace you. Some of the most effective mentorship strategies establish the mentor as a guide rather than someone who spoon-feeds the mentee. Mentorship is about supporting discovery, which also builds the relationship between the mentor and mentee. Mentors can also learn from their mentees when they allow their mentees to discover the answers to their questions. Mentors can also benefit their mentees by talking about health, especially mental health. Those who have been in the trade a long time may know how to draw boundaries between their work and their personal lives; mentees can benefit from open discussions about those things, and it helps to know that their mentor cares for them. Good mentors help mentees prioritize their health and wellness and break mental health stigmas. Mentors can also share references to other possible teachers with their mentees. Those relationships are especially important for mentors who don't have all the answers. Mentorship provides the context for training, and those connections provide as much context as possible. Mentors can also be mentees themselves, and those relationships are what really advance the trade. Eric and Bryan also discuss: Online education vs. in-person mentorship The role of the apprentice or mentee The Socratic method Mentoring people about health and safety practices Bryan and Eric's mentors Recognizing who mentors are and treating them appropriately 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.

Sep 22, 202243 min

HVAC Measurement Types and Benefits

Eric Kaiser joins the HVAC School podcast to talk about HVAC measurement types and the benefits of taking each one. He also talks about point measurements and data trends. Point measurements include static pressure, voltage readings, and readings provided by gauges. We only take those measurements once. However, when you track those on several occasions over time, you can build data trends. Single-point measurements give us information about what is happening at the moment, but they don't give us a long-term view of the system's health. Absolute and differential measurements also have different purposes entirely. Absolute measurements require us to compare a reading to a specific, unchanging reference point, but differentials compare one measurement to another. When we turn point measurements into trend measurements, we can see some degree of causation. Changes in data trends indicate that a problem occurred at a certain point in time and could be due to changes that coincided with the deviation from the norm. However, that's intermittent trending that relies on us to take point measurements at spaced-out points in time. Continuous trending allows us to use sensors and test instruments that map changes constantly. At the end of the day, point measurements are like snapshots, and continuous data trends are like videos; the former only shows part of the picture, and the latter can help us solve more difficult problems by giving us a more complete idea of what's happening. Eric and Bryan also discuss: Qualitative vs. quantitative measurements Filter restrictions and static pressure Gauge vs. atmospheric pressure Combined trend measurements How tool usage and calibration impact measurements Non-invasive testing Recorded data and sample frequency Comparative troubleshooting in spaces with similar equipment Resolution vs. accuracy vs. precision 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.

Sep 15, 202243 min

Ventilation and 62.2 Intro & Rant w/ Genry Garcia

Genry Garcia joins the podcast to give an intro to ASHRAE Standard 62.2. He and Bryan also share a nice rant about accountability in HVAC design. Standard 62.2 is the ventilation standard for low-rise residential buildings, which dilutes airborne contaminants like VOCs and CO2. Before coming up with a ventilation strategy, we need to assess the leakage rate of the building, such as via a blower door test. However, we also need to consider how bringing in outdoor air might negatively affect efficiency and comfort if we don't do it right. Exhaust ventilation removes air from the structure and relies on infiltration to bring air back in. Instead, we can use controlled intake air, which is brought in from the outdoors instead of unconditioned spaces in the home. Ventilating dehumidification is a strategy we can use to comply with 62.2; we can bring in filtered outdoor air and dehumidify it before injecting it into the supply ductwork. When we introduce ventilation in a Florida installation, bringing it in through the return is typically not ideal, especially if it's unfiltered. People can go wrong with 62.2 if they remain shortsighted; when designing ventilation systems, we need to think about a lot more than the load calculations and CFM of fresh air needed. We need to focus on accessibility, ventilation strategies, and location-specific installation practices. Consulting tradespeople during the design process would likely make ventilation systems much more accessible, sensible, and effective. Genry and Bryan also discuss: Ventilation as an IAQ strategy Infiltration credits Pressurization Continuous vs. spot measurement Holding the right people accountable during the design phase Intermittent vs. continuous ventilation Automating ventilation with sensors Controlling ventilation on a timer Genry's ideal methods of controlling ventilation 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.

Sep 8, 202255 min

Pressure Enthalpy without Tears

RACT manual co-author Eugene Silberstein joins the podcast to talk about the titular topic of his book, Pressure Enthalpy Without Tears. Pressure Enthalpy Without Tears is a book that introduces engineering concepts to HVAC technicians in a way they can understand and apply in the field. Enthalpy is a fancy way of saying "heat," and we use it to refer to the total heat content (BTUs). The pressure-enthalpy chart shows the relationship between the refrigerant pressure and enthalpy in a system; it's like a P-T chart that shows the relationship between heat content instead of temperature. Each refrigerant has its own pressure-enthalpy chart, but the points and lines on the chart usually form a right trapezoid. Dirty air filters and other less-than-ideal conditions can distort the trapezoid or shift it on the chart. Each side of the trapezoid represents the refrigerant inside a major component of the HVAC system: evaporator, compressor, condenser, and metering device. The pressure-enthalpy diagram allows you to get a look at individual components while keeping the entire system in mind. To plot points on a pressure-enthalpy chart, you need the high side pressure, low side pressure, condenser outlet temperature, evaporator outlet temperature, and compressor inlet temperature. Pressure is usually measured in absolute units (rather than gauge units), but ballpark estimates are typically sufficient. Entropy is another concept we need to consider. Compression theoretically leaves no additional entropy and is reversible. Crossing a line of entropy means that a process is no longer reversible. Eugene and Bryan also discuss: Technicians vs. engineers Temperature vs. heat content Psychrometric and pressure-enthalpy charts Using the pressure-enthalpy diagram to assess operation costs Electrical measurements Predicting compressor failure Putting passion into learning and trades education You can visit https://www.escogroup.org/ to purchase Pressure Enthalpy Without Tears and access all of ESCO Group's resources. You can also use the code HVACSchool22 for a discount on ESCO Group's eLearning services. 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.

Sep 1, 202247 min

Total Heat of Rejection - Short #152

In this short podcast, Bryan talks about THOR, total heat of rejection. He explains what it is and why we should care about it when working on HVAC/R systems. THOR is another aspect of pressure-enthalpy calculations, along with net refrigeration effect (NRE) and total heat of compression. When we talk about system capacity, we're often referring to heat absorbed in the evaporator coil (NRE). Heating is on the opposite side of the coin; when we bring heat into a home, we care more about how much heat is rejected than absorbed. That's where THOR comes in. More heat is rejected at the condenser than absorbed in the evaporator. The total heat content increases due to additional heat being absorbed in the suction line. Compressors also have motors that aren't 100% efficient, so a bit of inefficiency also adds a small amount of heat to the refrigerant (in a system operating normally). All of that heat adds up to the total heat of rejection (THOR). Even though a higher total heat of rejection is desirable when we want heat pumps to bring heat into the home, we don't want our compression ratios and discharge temperatures to get too high. We have to avoid oil breakdown and other negative effects. So, modern heat pumps use variable frequency drive technologies or liquid or vapor injection to get a lot of capacity out of the compressor without overheating it. The effective THOR only happens in the condenser. Some heat rejection may occur in the discharge line, but none of that is of use to us when we need to bring heat indoors. Check out Eugene Silberstein's book, Pressure Enthalpy Without Tears, at https://escogroup.org/shop/itemdetail.aspx?ID=1445. 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.

Aug 30, 202210 min

Hard Start vs. Easy Start

Matteo Giovanetti from Micro-Air joins the HVAC School podcast to talk about the differences between a hard start and an EasyStart. Micro-Air's "EasyStart" provides a soft start rather than a hard start. A hard start abruptly ramps up the voltage and current to the motor start; a soft start is a much gentler start that results from a gradual voltage and current increase on the start AND run windings. The EasyStart marks a paradigm shift in how we think about "saving" compressors. It attempts to avoid drawing unnecessary inrush current, which is very common with hard starts. Hard starts may even lead to premature failure if the potential relay fails and can't take the start capacitor out of the circuit. EasyStart has a different wiring configuration compared to hard start kits. A hard start kit consists of a start capacitor wired in series with a potential relay, which increases the torque on the compressor and removes the start capacitor from the circuit. The EasyStart has four wires; the black and white wires (L1 and L2) connect directly to the contactor, a brown wire that splices directly to the run winding, and an orange wire to the HERM terminal of the run capacitor. EasyStart also records information about the compressor during the first few startups to optimize its performance. It also monitors overcurrent and fault conditions with phase detection; when it detects a stall, it shuts off the compressor and doesn't attempt to restart it until a few minutes have passed. Matteo and Bryan also discuss: EasyStart models Solar, generator, and RV use Impedance Positive temperature coefficient resistors (PTCRs) Compressors running backward EasyStart's Bluetooth capabilities Tech support and product education Offering useful upgrades to customers Running and starting watt specifications for generators Learn more about EasyStart or purchase it directly from https://www.microair.net/. You can also contact the manufacturer by email at [email protected]. You can view the EasyStart home installation video at https://www.youtube.com/watch?v=bp4U-husy1o&ab_channel=MicroAir. 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.

Aug 25, 20221h 18m

Heat of Compression - Short #151

In this short podcast, Bryan explains what the heat of compression is and why we should care about it as HVAC/R professionals. More heat is rejected in the condenser than absorbed in the evaporator coil, and that's because the compressor adds heat. That added heat is called "heat of compression." That heat does NOT contribute to the net refrigeration effect (NRE), as it doesn't contribute to cooling. When we compress something, we increase the system entropy during that process. Entropy is the waste and disorder associated with work. There is some inefficiency, which we see in the form of additional heat. So, the HVAC system needs to reject that additional heat of compression, and we can plot and track reversible changes by following lines of constant entropy. As the temperature increases, the molecules begin moving more quickly. However, the refrigerant doesn't absorb many more BTUs in the compressor (in a properly operating system). The temperature spikes, but the compressor doesn't typically add a significant number of BTUs to the refrigerant. Heat also enters the system via the suction line, which also doesn't contribute to the NRE. Long, uninsulated suction lines can absorb a lot of heat without cooling the space at all. That heat also has to be rejected in the condenser. So, short, well-insulated suction lines tend to absorb less heat. When plotting the heat of compression, we're looking at BTUs added into the system in the compressor, discharge line, and suction line. BTUs that don't contribute to the NRE may fall under the "heat of compression" label, though the actual definition may vary by organization. Check out Eugene Silberstein's book, Pressure Enthalpy Without Tears, at https://escogroup.org/shop/itemdetail.aspx?ID=1445. 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.

Aug 23, 20228 min

Intro to ACCA Manual T

Ed Janowiak joins the podcast to introduce us to ACCA Manual T. Compared to other manuals, Manual T is one of the least-considered ACCA manuals. However, it's the manual that advises us on how not to blow high-velocity air on people and has maintained the same standards since the mid-1900s. Unlike Manuals J, S, and D, Manual T is not recognized in code compliance. Manual T deals with air distribution; it helps us find out the throw and spread, which informs our ductwork design in Manual D. We need to know the customer's expectations and the air velocity we'll need to manage at the registers before designing the ductwork. Register placement is also a critical element of Manual T. Throw and spreqd can vary wildly, and register selection and placement are going to have a significant effect on comfort as a result. Register placement on the ceiling may achieve the Coanda effect to assist with air distribution, and that can be especially useful in low-load or passive homes. Low-load homes are an interesting case, as they use less hardware than other homes, meaning that we need to make the most of calculations and equipment selection. Manual T ultimately focuses on using the diffusers and registers, rather than the equipment, to spread air throughout a space. Knowledge of the principles in Manual T also allows us to communicate, establish, and manage expectations with the customer. Ed and Bryan also discuss: Registers, diffusers, grilles, and vents Filter restrictions ACCA Manual LLH Air movement in the occupied vs. unoccupied zone Manual T as an extension of Manual D What it means to lend credibility in this industry Floor vs. ceiling registers based on climate 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.

Aug 18, 202240 min

Net Refrigeration Effect - Short #150

In this short podcast, Bryan explains what the net refrigeration effect (NRE) is and how it affects HVAC systems. The net refrigeration effect (NRE) is what happens in the evaporator coil. The evaporator is the heat absorber; as air passes over the coil, the cooler refrigerant within the evaporator absorbs that heat and boils. The NRE is the net energy change that occurs during that process. You can plot the NRE on a pressure-enthalpy chart. When air moves over the evaporator coil, there is a change in enthalpy or BTUs per pound in the refrigerant (usually called delta h). There should be more BTUs per pound in refrigerant exiting the coil than when it went in. We have to know how many pounds of refrigerant we're circulating (mass flow rate) and how many BTUs are in those pounds. Many of those BTUs come from latent heat transfer, which happens when the refrigerant boils. When refrigerant undergoes a phase change, it remains at a constant temperature (sensible heat), but it continues absorbing heat. The heat absorbed contributes to the phase change, and that's latent heat. Most of the NRE deals with those latent BTUs. (Note: this does NOT refer to latent heat loads.) In addition to the boiling or saturation phase, we also have to consider BTU changes when refrigerant flashes off at the beginning of the evaporator coil and heat obtained during the superheating phase at the top of the coil. We can maximize our NRE by running a cold evaporator coil (without freezing) and ensuring the evaporator is full of boiling refrigerant. BTUs absorbed in the suction line do NOT count towards the NRE, as they don't contribute to cooling spaces or refrigerated boxes. Check out Eugene Silberstein's book, Pressure Enthalpy Without Tears, at https://escogroup.org/shop/itemdetail.aspx?ID=1445. 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.

Aug 16, 202212 min

Systems Thinking - Gas and Combustion

Eric Kaiser returns to the podcast to talk about how we can use systems thinking to approach gas appliances and combustion in HVAC installation and service. Gas lines can be made of a few different materials, including black iron, copper, and CSST. These all have benefits, setbacks, and appropriate applications. For example, copper is common in propane (LP) systems but not natural gas. In coastal environments, galvanized pipe tends to be most common due to the increased likelihood of corrosion. Gas lines may also need sleeves to prevent them from interacting with moisture. The piping also needs to be routed in accordance with code; in many cases, joints need to be exposed so that a technician can check for leaks. Keeping joints inside walls is risky, especially when light switches cause sparks and could potentially ignite leaking natural gas. In any case, leak detection can be tricky unless you have a combustible gas leak detector and bubbles that work well for gas lines. Safety has to be the top priority when it comes to venting, especially on water heaters. A personal low-level CO monitor can also keep you and your customers safe by detecting small yet harmful amounts of carbon monoxide. Makeup air and combustion air are also important in gas appliances; unbalanced pressures may result in undesigned return paths. Traps and improper pitch may also lead to improper venting, as condensate may get trapped in the pipe and may lead to freezing or other complications. Eric and Bryan also discuss: Pipe material and flow rate Pipe sizing and connectors Regulator issues on gas water heaters and pool heaters Thread sealant products and best practices Bubble solution recommendations Signs and risks of backdrafting Exhaust pipe insulation Drain installation 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.

Aug 11, 202254 min

HVAC School Admin Discussion - Moderating a Successful Community

Some admins from the HVAC School Facebook group join the podcast to discuss the art of moderating a successful community. Bryan is joined by Eric Kaiser, Ty Branaman, Michael Housh, and Neil Comparetto. A community based on a skilled trade gives people an inviting space to share information and ask questions. It's also a space that allows people to practice how they present information. Groups also connect people across geographical locations, and we can get regional perspectives that change the way we think about things. However, community standards are necessary to keep groups professional and on-topic. Swearing is a slippery slope that may lead to personal attacks, which make the community hostile and unhelpful. The main goal is to keep a respectful atmosphere, and moderators have to draw the line somewhere, but there's a difference between cultivating a productive atmosphere and being dogmatic. People who interact in those communities need to do it for altruistic reasons, not to satisfy their egos. Giving detailed, accurate answers (ideally with a source to back up the information) is the best way to contribute meaningfully. Engaging in rigorous debates with an open mind is also a great way to see many different viewpoints. Debates in HVAC communities are great, but they require boundaries and mutual respect between debaters. Namecalling, blaming others, or dragging politics into the discussion is unproductive. Overall, it's best to stay positive and try to keep things helpful, and admins try to maintain an atmosphere that can be both serious and lighthearted but is always helpful and respectful. HVAC communities and groups are not places to share other groups, content, or job postings. These groups are not marketing centers; they are forums for learning and discussing the work we do every day. Ty, Neil, Michael, Eric, and Bryan also talk about: How they got started in online HVAC communities Unproductive arguments about codes Banning and muting members Receiving feedback Avoiding logical fallacies in debates How egos hold people back Trite and unproductive catchphrases, slogans, and jokes Responding to disagreements productively Communicating with people appropriately Admitting fault and refraining from judging others who are incorrect Moderating posts for quality and shareability 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.

Aug 4, 202259 min

Systems Thinking - HV / LV / Condensate

Eric Kaiser returns to the podcast to discuss high-voltage wiring, low-voltage wiring, and condensate assemblies as they relate to systems thinking. On the high-voltage side, the disconnect should be in a secure location, and it should be able to keep water out. The wires should be appropriately sized, have an appropriate level of tension, and should not be vulnerable to chafing or abrasion. Overall, best practices include using proper grommets and ensuring that you have a solid connection. Do not run high voltage wiring in parallel with low-voltage or control wiring. It's also worth noting that double-lugging is a poor practice that is against code. On the low-voltage side, you also need to be careful of where you route your wires to avoid induction, contact with hot surfaces, or abrasion. The insulation ratings also need to be appropriate. We can think of the condensate assembly as its own system. Condensate drains have uphills and downhills, and they may have traps, vents, and cleanouts throughout. Cleanouts and vents may be confused for each other, but cleanouts allow the technician to access and clean the drain. Cleanouts are also capped when in use, but vents are not. The location of a vent can help equalize the siphoning effects of pressurization. Condensate systems also consist of pans and switches. In those cases, redundancy is desirable to prevent overflowing. Secondary drain pans should be large enough to overlap with the primary pan, especially in horizontal air handlers. Eric and Bryan also discuss: Conductor length best practices Connecting stranded to solid wire Lug torquing Variation in wire sizing Testing low-voltage wires Cleanout tees Single vs. multiple drains with other appliances Drain pitch and if there could be "too much fall" 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.

Jul 28, 202246 min

Systems Thinking - Copper & Line sets

Eric Kaiser returns to the podcast to talk about how copper, piping, and line sets play into systems thinking. Nowadays, we have to think about POE and PVE oil, and we need to design line sets in a way that assists with oil carry while preventing liquid refrigerant migration. The height of the evaporator relative to the condenser is a major factor to consider during the design phase. Especially when chases are run underground, we need to watch for possible threats to the copper. Water softener discharge and excess pool water may damage the copper over time, and systems should be designed to keep line sets away from those. In many cases, Florida chases are sealed with mastic, which doesn't prevent water from getting in (but does prevent rodents and insects from entering the home. Flowing nitrogen is one of the best practices you can do while brazing. Nitrogen displaces oxygen, which contributes to oxidation and produces scale. When cutting copper, you will also want to make sure that you don't get copper shavings inside the tube. The pressure test is also an important step for leak detection. Following the manufacturer's instructions, pressurize the system and apply a liquid leak reactant (bubbles) to joints and other common leak points. It's a good idea to have at least one line drier in the system, and it should be able to work both ways in a heat pump system. Ideally, the line drier should be in a serviceable location, as it will be easier to detect restrictions when it's on the line set. Eric and Bryan also discuss: Air and vapor barriers Long line guidelines Underground chase depth Derate values Controversial reaming/deburring practices Line drier best practices 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.

Jul 21, 202233 min

Systems Thinking In HVAC w/ Eric K

Eric Kaiser joins the podcast to talk about systems thinking in HVAC. Systems thinking allows us to solve problems and address customers' comfort holistically instead of focusing on just the equipment. The key to systems thinking is to think outside the appliance. System design plays a major role in performance. Duct design, drain placement, and equipment placement all matter, and we can only do so much to mitigate factors of poor design. We need to assess the building envelope and consider how the HVAC system interacts with it. Building envelope and duct leakage will significantly affect HVAC performance and occupant comfort. Ventilation also matters, especially since many homes rely on exhaust-only ventilation. However, the air that leaves the building must be replaced, and we often don't control where that air comes from. When you control the source of your fresh air ventilation to meet ASHRAE 62.2, filtration may further help control the quality of the air that comes in. Installation and commissioning are other things we need to consider when thinking of the HVAC equipment systemically. The wiring needs to be correct, and we need to verify that the system is achieving the proper airflow in the first place. Static pressure is another factor that we must consider during commissioning, as an abnormal static pressure could indicate a filter that doesn't fit or is too restrictive. It's best to start by looking at the appliance and widening your scope from there until you know about the system as a whole. Eric and Bryan also discuss: Is the house a duct system? Oversizing equipment Stack effect Loose vs. tight houses Filtration best practices Radiant heat transfer Ductwork best practices Data trends of cause and effect 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.

Jul 14, 202253 min

Logical Fallacies - False Cause & Strawman

Nathan Orr joins Bryan to talk about some logical fallacies, namely the false cause and strawman. They explain how those fallacies show up in the trade. It's difficult to present arguments without using fallacies, but people tend to rely on fallacies to uphold extreme religious or ideological viewpoints or conspiracy theories. Fallacies are also often easier to communicate than nuanced science and data. "False cause" relates to the phrase "correlation does not equal causation." It can be tempting to link coincidences and say that one thing causes the other, but that could very well not be true. For example, more compressors fail during lightning storms. It's reasonable to assume that lightning causes the failures, but lightning is not simply striking all of the compressors; other power outages and other conditions that happen during storms are more likely plausible causes. Confirmation bias also makes it easy to cling to a false cause. People are likely to disregard data that doesn't align with what they already believe. A strawman misrepresents (or deliberately misstates) another argument to make it easier to attack. People often apply the strawman fallacy to conversations about forming ice in a system during vacuum and duct sizing. Strawman arguments happen more often in business matters, especially if people impugn the intentions of the other party. In many cases, being open to new information will prevent you from falling prey to logical fallacies. Nathan and Bryan also discuss: Flat-earthers Inverter board failures at night Evaporator coil corrosion Simultaneous capacitor and fan motor failures Logical fallacies in chance and gambling The pitfalls of anecdotal evidence and small samples Appeal to emotion Defining "better" Mounting TXV bulbs Heuristics and mental shortcuts 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.

Jul 7, 202242 min

Tips for Learning in HVAC/R w/ Trevor Matthews

Refrigeration Mentor founder Trevor Matthews returns to the HVAC School podcast to talk about personal development and training, including tips for learning in HVAC/R. When you're looking at a problem in the field or in training, it pays to take a step back, cool down, and reevaluate your mindset. Trevor recommends thinking about the worst-case scenario and seeing how you can either prevent it or grow from it. It's good to walk away for a little bit anytime you feel like you're overanalyzing anything so that you don't make blunders. Trevor has found that reading books is one of the best ways to learn about HVAC/R. HVAC/R professionals can greatly benefit from investing in themselves and setting up their own self-directed training programs. Trainers and mentors can't be the only ones motivating HVAC/R professionals, holding them accountable, and stimulating their growth. Many times, our own limiting beliefs of ourselves hold us back, and we need to convince ourselves that we can learn difficult things, even if it isn't easy. We can also limit our ratio of entertainment to education; focusing more on the latter can greatly benefit your personal development. Setting educational goals is also difficult when we work long hours and simply don't have the time or energy to invest in ourselves. The industry needs reform, and reform that raises base rates and prevents an over-reliance on overtime might also attract some new professionals to the field. Trevor and Bryan also discuss: Trevor's new podcast Clearing your head Books about doing the hard things first Autodidactism and "learning how to learn" Subconscious cost-benefit analysis The industry's addiction to overtime Helpful books and podcasts for personal development Getting rid of "tunnel vision" Recommended book/podcast list: Eat That Frog!: 21 Great Ways to Stop Procrastinating and Get More Done in Less Time by Brian Tracy How to Win Friends & Influence People by Dale Carnegie QBQ! The Question Behind the Question: Practicing Personal Accountability at Work and in Life by John G. Miller Mindset: The New Psychology of Success by Carol S. Dweck Grit: The Power of Passion and Perseverance by Angela Duckworth Mastery by Robert Greene Good to Great: Why Some Companies Make the Leap and Others Don't by Jim Collins Built to Last: Successful Habits of Visionary Companies by Jim Collins Entreleadership: 20 Years of Practical Business Wisdom from the Trenches by Dave Ramsey Culture Code: The Secrets of Highly Successful Groups by Daniel Coyle Discipline Without Punishment: The Proven Strategy That Turns Problem Employees Into Superior Performers by Dick Grote Atomic Habits: An Easy & Proven Way to Build Good Habits & Break Bad Ones by James Clear Rich Dad Poor Dad: What the Rich Teach Their Kids About Money That the Poor and Middle Class Do Not! by Robert T. Kiyosaki The Richest Man in Babylon by George S. Clason The Big Short: Inside the Doomsday Machine by Michael Lewis Antifragile: Things That Gain from Disorder by Nassim Nicholas Taleb Think and Grow Rich by Napoleon Hill The 5 AM Miracle Podcast The Mindvalley Podcast Hidden Brain Podcast 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.

Jun 30, 202233 min

Threaded Connection Tips - Short #149

In this short podcast episode, Bryan shares some of his top threaded connection tips. He also clears up some confusion about connection types. Threaded connections include flare and compression-type fittings (like chatleff or Aeroquip fittings). The threads don't actually make the seal; the pressure pushing the surfaces together is what makes a seal. Bryan doesn't recommend putting traditional thread locks on flares, but refrigerant oil or mild assembly lubricants can help the flare come together more smoothly without imperfections. However, you need to be careful when using a torque wrench and use the lowest acceptable specification to avoid over-torquing. Leaks are common problems with flare fittings, but those often happen in cases where flares are poorly made. Scored faces, loose flares, and over-torqued flares are common causes of leaks. However, many modern flaring tools can make perfect flares quite easily. You must also remember to deburr the copper for the best results. Compression-type fittings often have O-rings, which are the parts that actually do the sealing. (Leaks WILL happen without the O-ring in place.) You can use an assembly lubricant with these fittings, but you still have to be mindful of torque spec adjustments. Pipe-thread connections actually rely on the threads, not pressure or an O-ring, to create a seal. Pipe dopes (or thread sealants) tend to be best on these connections, but you want to leave the last couple of threads bare so that pipe dope doesn't get into the system. As with brazed and soldered joints, the copper used for threaded connections needs to be cleaned, cut squarely, and deburred for best results. Bryan also covers: Assembly lubricants Brazing vs. soldering Zoomlock IMC 1107.5.4 Protecting seals during brazing and soldering 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.

Jun 28, 202214 min