HVAC School - For Techs, By Techs

Demand Cooling in Low Temp R22 w/ Jeremy Smith

In this podcast, Jeremy Smith joins us to discuss demand cooling in low-temperature applications that use R-22 refrigerant. R-22 is NOT an ideal low-temperature refrigerant because it leads to high compression ratios. The discharge gas also gets really hot and can burn up the oil in the system. (The head of the compressor is even hotter than the discharge line, so if the temperature is high enough to cause oil breakdown in the discharge line, it's almost surely worse inside the compressor)...

Low Voltage Electrical Basics

Bryan and Kaleb cover the basics of low-voltage electrical applications. They focus on the practical stuff, not just the theory that confuses techs. Many techs have a hard time with low-voltage electrical concepts and components because it's not easy to visualize what happens; we only see wiring diagrams, not metaphors that help us understand what's going on. The low-voltage control circuit starts with the transformer. The transformer has a primary side (where the high voltage comes in) ...

Impacts of Compression Changes - Short #94

In this short podcast, Bryan talks about the impacts of compression and airflow changes. He also discusses some of the ramifications of those changes. In order for us to energize the second stage of a compressor, we need to energize both Y1 AND Y2. On stage 2, we're running that compressor at full speed (350-450 CFM per ton). The compressor will also perform at rated capacity. When you stage down to stage 1, your blower should ramp down, and the compressor should produce less capacity (m...

Superheat and Subcooling Basics

In this podcast episode, we ONCE AGAIN talk about superheat and subcooling. This episode is a recap to help people who struggle with the concept. You get superheat when you have 100% vapor, and you have subcooling when you have 100% liquid; any liquid-vapor mixtures are in a saturated state. We usually measure superheat outside at the suction or vapor line. It's best to take the superheat reading as close to the port as possible. Anything in the saturated state is boiling; you can only...

Psychrometric Basics

In this psychrometric basics podcast, Bryan and Kaleb talk about the properties of air. They also discuss dry-bulb, wet-bulb, dew point, and relative humidity. Psychrometrics is the study of the relationship between air and its properties. The psychrometric chart can be a bit intimidating, but you can use it in a variety of ways. A technician should care about this chart because it helps with whole-home diagnosis. You can't see the whole picture of someone's comfort unless you know the p...

A Huge Pricing Mistake - Short #93

Many contractors make a huge pricing mistake: confusing markup with margin. The distinction between those two things can be the difference between being profitable and losing it all. If you want to mark up something that costs $10 by 50%, you multiply it by 1.5 to get $15. So, did we make a 50% gross margin? No; we only made $5 on a $10 transaction; if we take 10/15, we get o.66. So, we really only made a 33% gross margin. When we factor overhead in, 33% is normally nowhere near enough. ...

A Frank UV discussion w/ Ron Saunders from Fresh-Aire UV

In this podcast, Ron Saunders from Fresh-Aire UV comes on and answers questions about UVC. He clears up misconceptions and pulls no punches. Fresh-Aire UV (Triatomic Environmental) used to manufacture and sell ozone solutions, but the business evolved to sell UV and carbon-based IAQ solutions. UV lights exist on a spectrum of varying wavelengths. Some UV lights at the higher end of the spectrum produce ozone, but UVC light does not. UVC's frequency (~250 nanometers) is outside the range ...

Q&A with Richard, Ross and Evan Trethewey

In this free-flowing conversation, Trethewey talk about growing up with This Old House, what the show is like behind the scenes, what Rich misses about the past, what the future holds for the trade and some nerdy specifics between Bryan and Ross.    Thanks to Richard, Ross & Evan for making this happen. Check out the This old House Podcast “ClearStory” on your favorite podcast player    TE2 Engineering    RST Thermal

Q&A with Richard, Ross, and Evan Trethewey

In this free-flowing conversation, the Trethewey family talks about growing up with This Old House, what the show is like behind the scenes, what Rich misses about the past, what the future holds for the trade, and some nerdy specifics between Bryan and Ross. The show business is a collaborative effort between the producers and talent (even though they're real people, not actors), and the Trethewey boys find the end result almost cathartic. This Old House was never scripted; there were bea...

Blower Doors ACH50 vs. Natural Infiltration

Two of the great air and infiltration expert minds of our time, Gary Nelson and Steve Rogers from TEC (The Energy Conservatory), come on the podcast to talk about blower doors. They also discuss blower door testing and how it compares to real-life infiltration. A blower door has a fan to measure the air flowing through it, and you generally install it in a doorframe. Blower doors hook up to manometers to measure the pressure differential between the inside of a building and the outside. ...

Keeping your Scruples when Selling IAQ - Short #92

In this short podcast episode, Bryan explains how to keep your humanity and make moral decisions when selling IAQ products. As the COVID-19 pandemic has started to grab hold of the world, we've seen an uptick in IAQ interest. When you have greater consumer interest, there are opportunities to hoodwink customers. While some IAQ products are indeed not very effective against viruses, there are some good products that you can sell to customers to benefit their health. Pretty much every prod...

Real Indoor Air Quality w/ Nikki from UltraAire

Nikki Krueger joins us to talk about how humidity impacts indoor health and some ways to make our indoor air quality better (for real). Indoor air quality is all about manipulating the air in our homes to reduce pollutants and keep our air quality high. From air dilution to running bath fans to air purifiers, there is a lot more we can do to make our homes healthier. We can't entirely isolate ourselves from viruses, bacteria, and fungi. However, there are many other things inside our hom...

Manometers - Short #91

In this short podcast episode, Sal Hamidi of ProductsByPros joins Bryan to discuss what manometers are and how they measure pressure. Manometers measure pressure at a much higher scale than a micron gauge but lower than that of a pressure gauge; they measure pressure differentials by comparing static pressure to another source of pressure as a reference. Across all segments of the industry, we use manometers to measure static pressure. Static pressure is the pressure of air against the duc...

Is The Future of Air Conditioning Self-Contained Propane Chillers?

Michael Housh and Jim Bergmann join Bryan to look into the crystal ball to see the future of air conditioning and design the PERFECT residential system. Self-contained propane heat recovery chillers are futuristic devices that do simultaneous heating and cooling. While they may not be suitable for all climates, they can switch between heating and cooling modes, like heat pumps. They may also be able to service domestic hot water centrally as well. Although propane heat recovery chillers ar...

Is The Future of Air Conditioning Self Contained Propane Chillers?

Michael Housh and Jim Bergmann join Bryan to look into the crystal ball and design the PERFECT residential system

Filter + Fan = IAQ Revolution

Thomas Talhelm, the founder of Smart Air, joins Bryan on the podcast to talk about how a filter and a fan in China sparked an IAQ revolution. The simple device changed his thinking about air purification. As a graduate student in China, Thomas witnessed the Beijing "Air-pocalypse" firsthand. That was when he became aware of the issue of air pollution and the potential health issues it can cause. So, he dove into the world of air purification. The most popular air purifier on the market w...

The Inverter Voltage Problem - Short #90

In this short podcast episode, Bryan talks about the steady-state voltage problem that can take out inverter boards and what to do about it. Inverter-driven equipment refers to a variable-frequency drive with ECM compressors and fans. We're talking about modern split-phase equipment rated for 208v or 230v power. However, the split-phase power will yield 240v. Most motors and components for 240v equipment have ratings for 230v AC power. L1 and L2 power can also be significantly higher tha...

Testing A/C Vitals w/ Jim Bergmann

Jim Bergmann and Michael Housh join Bryan to talk about testing A/C vitals. They discuss the new vitals mode in MeasureQuick and how it works. As with many of MeasureQuick's other functions, vitals mode is an invaluable tool for green and experienced HVAC techs alike. The new vitals mode helps us with charging, airflow, and other staples of A/C testing and commissioning. Vitals mode allows the user to give MeasureQuick some information about the system; when they provide that information, ...

Short #89 - Liquid Line Temperature

In this short podcast episode, Bryan explains how to use liquid line temperature as a quick diagnostic indicator on split A/C systems. Liquid line temperature is one of the first things to check when you approach a system. Checking that temperature is also a great way to get into non-invasive testing. The temperature should be between 4 and 15 degrees warmer than the outdoor temperature (unless it is wet). If the liquid line is cooler than the environment, then there could be a restricti...

Viruses, Bacteria, and Fungus #LIVE

In this live podcast episode, we discuss viruses, bacteria, and fungi. We also explain how they interact with HVAC equipment, their effects on indoor air quality, and how businesses can protect their customers and employees. Since we work with the public, we can minimize the risk of viral transmission by keeping our distance between others and avoid handshakes and other forms of contact. However, we also have to respect the feelings of the customers we're serving. Many people confuse vir...

Viruses, Bacteria and Fungus #LIVE

Short #88 - Science vs. What Works

In this short podcast episode, Bryan talks about science and how to balance practice and experience with the “why” behind what we do. He also explains how either one can cause an error if you aren’t careful. Science is not just about reading nerdy theories in books; it's all about understanding why the processes in our world. In that sense, many of us field technicians are scientists. When we use problem-solving skills in the field, we try to understand what is going on and why our propose...

New Business Processes #LIVE

We discuss some of the new, possibly strange-sounding business processes we've decided to implement at Kalos in 2020. First of all, we are going to add terms and conditions that our customers must agree to. These terms and conditions include a "hold harmless" disclaimer regarding viruses, fungi, and bacteria. Florida forbids us from discussing mold, so a "hold harmless" disclaimer protects us from liability for something we aren't even allowed to discuss. We also have to reinforce auto...

A Groundbreaking Motor Technology

Ben with Infinitum Electric comes on to tell us more about his super-innovative, groundbreaking PCB (printed circuit board) motor technology that we saw at AHR 2020. The Infinitum motor is a relatively simple permanent magnet motor that can also work as a generator. Infinitum got its start with generators, and the groundbreaking new motor technology works quite similarly to generators. These motors can also work with variable frequency drive technology. In this groundbreaking motor, th...

Refrigerant Management Strategies w/ Rick Roland

Rick from Certified Refrigerant Services joins us to talk about recovery and refrigerant management. He also explains what to look for and do to get the most from your program. A refrigerant management program offers recovery services, reclamation, and other options for processing refrigerants. Rick's company also buys and sells refrigerants. With his line of work, there are also plenty of opportunities to educate contractors. The goal is to reduce refrigerant mixing and keep high-qualit...

New Refrigerants from Honeywell

Chris LaPietra, vice president and general manager of Honeywell Stationary Refrigerants, joins us to talk about some new releases from Honeywell. He also covers refrigerants in general. As our industry reduces its reliance on R-22 (and eventually R-410A), we have turned to more flammable solutions. There is a tradeoff in safety for the lower GWP, though. However, along with some slightly less flammable A2L refrigerants, Honeywell is releasing two new A1 refrigerants: R-466A and R-515B (N...

EPA Myths and recovery Best Practices #LIVE

Eric Kaiser comes on the live podcast to talk through some commonly repeated EPA myths. We also discuss how to get the most from your recovery machine and tanks. The EPA exists to interpret broad laws into specific standards, such as by translating climate initiatives into venting guidelines. One of the most common EPA myths is that you cannot charge a leaking system. If you can repair the leak and get the leak rate below the specified percentage, then you can recharge the system. Not ev...

News from NATE w/ Gurminder

Gurminder Sidhu joins us from NATE to talk about what NATE is all about and bring us some news about the new changes and improvements. NATE was created for the industry by the industry; the organization arose from a need to promote education and standardize HVAC qualifications. Today, NATE continues to address the industry's needs by offering education and certification for technicians. NATE also understands the need of explaining the "why" behind our daily work. The people at NATE also ...

HVAC Design Mythbusting #LIVE

Alex Meaney from MiTek/Wrightsoft joins us at AHR 2020 to talk about some HVAC design myths and how to bust them in your mind. It was a really fun talk with a great guy. One common HVAC design myth worth busting is that we can use a set friction rate with a Ductulator to make duct systems work. The friction rate only applies per 100 feet, and it has different degrees of impact based on duct sizing and fan speeds. We CANNOT guarantee that a system will work if we subtract losses to filter...

Mentors and Role Models w/ Andrew Greaves

Andrew Greaves joins us again from AHR 2020. This time, he discusses what mentors and role models do in our trade and why they're important. Mentors are not just the grouchy senior techs who throw hammers at apprentices. Mentors have an active role in others' professional development; they spend a lot of time with their mentees and actively aid their growth. Not everyone is cut out to be a mentor, as the role comes with a lot of responsibility (and possibly stress). Role models indirectly ...

AHR 2020 Roundup from the Floor

In this podcast, HVAC School team members Kaleb and Leilani walk the floor and talk to various people about their products and companies at AHR 2020. Bryan also has a quick conversation with Frank from HVAC Outlawz. The newest RectorSeal surge protection (RSH-50 with the 60A disconnect) uses MOVs and gas discharge tubes, which work together to fight off power surges. The effectiveness of the product has allowed RectorSeal to give customers a lifetime warranty on their product. RectorSeal...

Building Performance Round Table

In this live recording from the AHR Expo, Kaleb Saleeby, Nate Adams, Michael Housh, and Steve Rogers discuss building performance. The building science world is an exciting place; we're all excited about improvements to reheat dehumidification, which is when we use waste heat to take care of humidity without cooling. As equipment becomes more efficient, we also look forward to tackling new challenges that make us think more broadly. New people are also stepping up, using new tools, accessi...

Live w/ Mike from Refrigeration Technologies

Mike from Refrigeration Technologies talks to us about his journey in business, some new and old products, and how well the business is growing. Refrigeration Technologies tries to make products that do the job correctly the first time and are safe for techs to use. The products are odorless, don't burn skin, and are safe around food. John and Mike Pastorello are passionate about using chemistry to make quality products that make techs' lives easier. Mike joined his father's business ful...

Richard w/ This Old House Shares His Story

Richard Trethewey from This Old House joins Bryan on the podcast and tells his incredible story and shares some encouragement and laughs. Richard works with his sons, Ross and Evan. He has always worked in a family business and then left it to start his own with his sons. Family businesses truly are the backbone of this industry, as our business attracts lots of family-oriented business owners. Richard's sons volunteered to join the business early on. This Old House started off with a ...

Micron Gauges - Products by Pros

This podcast is by Sal at Products by Pros, featuring Bryan Orr of HVAC School. In this episode, Sal asks Bryan all about micron gauges.   Products by Pros Guest: Bryan Orr   What should technicians look at when deciding on a micron gauge? You should look for superior accuracy and resolution, especially if you'll be doing decay testing. You need to see what the trends are in clear detail. (The Bluvac app makes that easy.) Why should a tech even use a micron gauge? You use a m...

Connecting STEM and HVAC w/ Rachel Kaiser

Rachel and Eric Kaiser join us to talk about connecting STEM concepts to the trades. They also explain how to teach STEM in a way that sticks. STEM refers to science, technology, engineering, and math. In traditional classroom settings, teachers usually tout these subjects as the ones that lead to the most promising careers. However, STEM concepts are not limited to their respective subjects; we use many of those scientific and mathematic concepts in the trades as well. Rachel believes t...

Connecting Stem and HVAC w/ Rachel Kaiser

Rachel and Eric Kaiser join us to talk about making STEM concepts more common in the trades and how to teach STEM in a way that sticks

Short #87 - Our Install Reminders

This short episode is a review of a list of installation reminders made by Kalos manager Jeff Crable. Kalos is doing a bunch of these installs for a commercial customer. Hopefully, the business leaders can take a few things from our checklist and help out their installers. Whenever we do an install for our large commercial customers, we give our installers a long checklist of reminders; that way, they can do the best install possible. Some of those install reminders include: Don't rus...

Reversing Valve Diagnosis & Replacement w/ Kaleb

In this face-to-face discussion, Bryan and Kaleb share some tips for diagnosing and replacing the reversing valve on a heat pump. These valves may also be known as four-way valves. Kaleb and a trainee recently had to diagnose a heat pump with a scroll compressor. The motor was also over-amping due to a failed capacitor, and the compressor was making a metallic grinding noise. Because reversing valves are pilot-activated, they need a pressure differential to shift, so the scroll plate can...

Short #86 - Hoodwinked

In this short podcast episode, Bryan talks about the times he has been hoodwinked in his career. It's time to name and shame. One time at a trade show, Bryan came across a product called KVAR. KVAR is already an electrical term for kilovolt-amps reactive; those are volt-amps that show up and generate heat but don't do anything useful, just like foam in a beer mug. So, the product supposedly balanced out the power factor to save energy. However, power companies don't charge based on VA; the...

Pool Heater Talk #LIVE

This live podcast episode is all about pool heater talk. We cover gas pool heaters and pool heat pumps, explaining how they work and common issues. Pool heat pumps work a lot like air conditioners, but they have heat exchangers that help transfer their heat to the water. Instead of having a typical condenser, a pool heater has a unit that works like a heat pump's outdoor coil in heat mode. There is usually an option to cool the water, but there are almost no cases where someone would wan...

R290 Facts and Service w/ True Refrigeration

Alejandro Rios from True Refrigeration comes on to talk about self-contained R290. He explains what it is, why to love it, and how to service the sealed system. R290 is pure propane, and it has recently made a name for itself as an emerging refrigerant. It is an A3 refrigerant, meaning that it is non-toxic and highly flammable. As we move away from HFCs and other refrigerants with high global warming potential (GWP), we will encounter more flammable refrigerants, usually A2L and A3 refri...

HVAC SchoolR290 Facts and Service w/ True Refrigeration

Alejandro Rios from True comes on to talk about self contained R290, what it is, why to love it and how to service the sealed system

Short #85 - Low Voltage, Low Voltage

In this short podcast episode, Bryan explains what happens when your low-voltage circuit puts out a lower voltage than it should. Bryan recently received an email asking about the low voltage on a 20-ton split system with a long control wire; the voltage coming back to the condenser is only 19 volts, so there was some contactor chattering. First, in a case like that, you'll want to figure out why the voltage isn't as high as it should be. The control wire and line sets could be longer than...

Codes and Failed Inspections #LIVE

In this live podcast from the Castbox app, we talk about codes and common causes for failed inspections. We talk about these topics both broadly and with some specifics. Many of the places where we fail to meet codes are on the electrical side. Electrical components have fire and electrical shock hazards, and codes are stringent for arc and ground fault protection. Leaking current to ground can shock someone, and arcs can cause damage to property and human life. We commonly see failed in...

FURNACE TALK #LIVE

In this live podcast episode from the Castbox app, we have four techs join us to talk about common furnace issues and best practices. Those of us in heat-pump-dominant markets rarely have to worry about common furnace issues related to gas pressure and flow. In that same vein, we also don't have to worry about clocking the gas meter, which is a common practice on gas furnaces. Checking input and performing combustion analysis is critical to the diagnostic process AND can give you an idea o...

Mixed Air Temperature w/ David Richardson

David Richardson with NCI, author of Duct Dynasty, joins us on the podcast to talk about mixed air temperature and more topics of interest. When you bring outside air into the home, you introduce positive pressure into the home. That way, you can offset air lost via mechanical ventilation or through cracks, improving air quality. We often assume that the building will "breathe," but tighter constructions make it difficult for the home to bring in enough fresh air to offset harmful chemica...

Short #84 - Power Passing vs. Consuming

In this short podcast, Bryan briefly explains why we use a voltmeter to measure “voltage drop” across loads and switches. He also covers some of the differences between passing and consuming power. Many of us are naturals at using voltmeters already. Voltmeters have two leads, and those exist to measure the difference or potential between them. Voltage is a reference to what is going on between the leads; whenever resistance exists, we have a voltage drop. Resistance can sometimes be des...

Impactful HVAC/R Instruction

Ty Branaman from NTI comes on the podcast to share his passion for teaching. He also discusses his approach to impactful HVAC/R instruction. It can be difficult for instructors to create an appropriate balance between teaching theory and practical knowledge. Students and trainees need to have technical skills in the field, but they also need a solid foundation. Impactful HVAC/R instruction requires a balance of the nerdy stuff and physical skills; good instructors put the theoretical parts...

Short #83 - Practical Safety Improvements

In this short podcast, we take a quick look at Bryan’s take on practical safety improvements. He also discusses the safety year in review at Kalos. Kalos had a great year in terms of safety. As the managers look back on the year, they attribute their success to having a practical approach to safety. To make practical safety improvements, we must be safety-conscious without obsessing over the risks of our job. Our jobs always have an element of danger, and our goal should be to minimize tho...