Hvac School - For Techs, By Techs

Jason Obrzut joins Nathan Orr with the HVAC School podcast live from AHR. In this episode, they discuss A2L refrigerants and upcoming regulations. They explain what a “flammable” refrigerant really is and why the industry may be making a bigger deal of the new regulations than is really necessary. Whenever regulations are passed, we need to understand that there is a notable transition period. This period will mostly be about training, and the only people who should be working on the new equipment should be the most experienced technicians. A2L refrigerants are mildly flammable, non-toxic refrigerants, including R-32. Flame propagation is possible but quite rare for A2L refrigerants under normal operating conditions. However, even A1 refrigerants can propagate flame under the right conditions (just not ones we’d normally see). Many countries all over the world have been using A2L refrigerants for much longer than we have, so we can make those refrigerants work safely. All trades will evolve, and we need to be

David Holt with NCI returns to the podcast to discuss the evolution of HVAC training; we cover the past, present, and the possible future of training in the industry. In the past, we had a lot of hands-on training, whether it was one-on-one or in a traditional classroom setting. These learning practices remain beneficial today, especially since many uninformed practices are still prevalent in the industry today (charging to beer-can cold, condemning TXVs without a second thought, etc.). However, the pandemic has forced us to consider online and remote training in the present. The content has also changed from the past; we are a lot more aware of combustion and airflow nowadays, which are very important topics for safety and efficiency. Those training topics allow us to understand what we’re doing when we take the “vital signs” of the equipment.  Being better versed in basic and advanced diagnostics will also give us a more holistic understanding of the HVAC equipment as a system, which can help us truly optim

Jim Bergmann returns to the HVAC School podcast live from AHR 2022 to discuss a bit about proper system commissioning. He explains the commissioning mindset and some helpful procedures. Successful system commissioning starts with the mindset. A good commissioning organization broadens its vision; instead of focusing on the appliance, techs and installers focus on the system. Commissioning early on saves time later; you can focus on installs and maintenance instead of callbacks, and your organization can make more money as a result. When installing and testing new piping, make sure you insulate the tubing properly and keep the lines CLOSED OFF to the atmosphere. Measuring the line set is also critical for weighing the charge properly, as long lines have special considerations. When doing the decay test, use a quality vacuum rig and try to keep the micron gauge as far away from the pump as possible. Cleaning line sets also helps your vacuum results by getting rid of oil and moisture within the lines. Flowing ni

Russ King joins us for a short podcast episode about using 3D load and energy calculations with duct design. Russ has developed the Kwik Model 3D software program with the help of his son, Connor. Kwik Model 3D uses a video game platform to build a house out of boxes instead of a sketch. The software has evolved and been integrated into EnergyGauge to do load and energy calculations based on a house’s geometry. Kwik Model makes it easy and fun to create that geometry profile for a home, which makes building design and load calculation attractive to technicians. Software like Kwik Model may especially become popular as Generation Z steps into the workforce; we can expect the learning curve to be quite shallow for the digital generation. The Manual J calculation uses the home’s characteristics in Kwik Model and does all of the mathematical calculations in EnergyGauge for an advanced load calculation. KwikModel then receives those calculations for each room. Then, you can draw the ductwork and use an auto-size f

In this live podcast from AHR Expo 2022, John and Mike Pastorello of Refrigeration Technologies give us a history lesson in HVAC chemical chemistry. They also explain what it takes to make a truly beneficial product for the industry. From the beginning, Refrigeration Technologies has focused on solving problems instead of jumping on product trends. Before Big Blu was introduced, technicians had to rely on less-than-reliable electronic leak detectors and poor-quality soap bubbles. So, John Pastorello learned about the fundamentals of foaming and bubbles to create a leak reactant that works, even creating microbubbles for tiny leaks. Nylog has a similar origin story, and it has evolved to work for both mineral oil (red) and POE (blue) systems. As with Big Blu, John ran several tests to make sure the Nylog was compatible with HVAC equipment and did not cause contamination. The Viper Pan & Drain Treatment was developed to replace pan tabs, which failed to remove the dead biological material in drains. The spr

Michael Housh returns to the podcast to discuss upgrades and proposals that are worth considering. These upgrades and proposals can actually benefit the customer AND lead to clarity and profit without turning you into a white-shirt tech. When assessing a system for replacement, it’s a good idea to look at the airflow side by measuring static pressure AND using a flow grid; these practices set you apart from others and supply you with good data about system sizing. Filtration is another area where you can consider upgrades and proposals; customers generally want to keep their air clean and may be happy to pay for better filtration, fresh air, and de/humidification.  Surge protection is a high-value upgrade that many customers may benefit from, especially if the electrical company allows overvoltage or the customer has a voltage-sensitive ECM or inverter system. Some upgrades are useful and can be offered automatically (the customer can decline it); depending on the climate, a humidifier or dehumidifier may fit

In this short podcast episode, Clifton Beck joins us to talk about Bluon’s free tech support and resources available to technicians and installers. Clifton has been very in touch with the HVAC technician community since he got his start in the trades, and he has taken that into tech support. He has noticed that the inefficiency in our industry tends to come from poorly learned practices, and working in tech support is a way for him to do his part to spread better practices while helping others. Lately, Bluon has become more of a tech support business. The new shift to focus on innovation has prompted Bluon to shift from making equipment more efficient to making technicians more efficient. The whole HVAC industry relies on that progression from developing on equipment to people. Tech support consists of answering calls but also creating training videos and creating layers of technician education and development. Manuals are just part of the picture; tech support helps with part identification AND the sequence

Genry Garcia returns to the podcast to talk about blower doors and why ACH50 may needlessly complicate efforts to tighten a building envelope. A large element of indoor comfort comes down to controlling the load, especially the latent load. Even though we can control indoor humidity sources, we may also deal with infiltration, which contributes to a high latent load and decreases comfort. The blower door test comes in when we can no longer control the load and need to determine how much infiltration is happening. When using blower doors, we would typically use an ACH50 test, which takes the CFM50 (cubic feet per minute that the blower door moves to get the house up or down to 50 Pascals) and translates it to air changes per hour at 50 Pa. To do that, you would need to find the volume of the space, which adds hurdles that the HVAC technician needs to deal with. However, Genry prefers using the CFM50 and factoring in the square footage and LAIR (leakage area infiltration ratio) to determine how tight a house is

Eugene Silberstein, a co-author of Refrigeration and Air Conditioning Technology (RACT manual), joins the podcast to give us an introduction to psychrometrics. Psychrometrics focuses on the properties of air and its contents, especially as they relate to human comfort. To understand psychrometrics, we need to be able to quantify air: its weight, humidity, pressure, etc. We can do a better job as technicians if we figure out the air’s content and see how it relates to the CFM and overall unit performance. That way, we can have a more holistic view of HVAC performance instead of just focusing on adding or recovering refrigerant to improve performance. The psychrometrics chart helps us understand the conditions of the air based on quantities like water vapor, dew point, and more. The chart may intimidate techs, but it contains a wealth of information that can help technicians understand the air and the customer’s comfort better. Basic psychrometrics can also help us grasp why furnaces don’t actually dry out air;

Brandon Marshall, Chemours’s North American marketing manager for thermal and specialized solutions, joins the podcast to discuss refrigerant changes that are coming and how we can prepare for those. Brandon started in the industry by going to a technical school when he was 14 and has been hard at work ever since, studying light commercial design and going to college in between. Local and global regulations have changed a lot over the years and continue to change as we continue maximizing our equipment’s efficiency. California will soon start switching to low-GWP refrigerant on new equipment in 2025; even R-410A can’t be used in new equipment. We will begin seeing the rise of A2L refrigerants and moving away from the A1 refrigerants that are more detrimental to the environment; we’ll have to focus on safety as we begin working with more flammable refrigerants. As new refrigerants get off the ground, we can expect increased communication between manufacturers and dealers to prepare for the sale of equipment bu

Chuck Allgood with Chemours joins the podcast to cover the history of refrigerants and discuss what the future might hold. In the late 1800s, before Freon, the only refrigerants that were used were industrial chemicals like ammonia, CO2, and sulfur dioxide. DuPont stepped in to provide a better refrigerant for industrial refrigeration (which then spurred the rise of domestic refrigeration), so they created a non-toxic, non-flammable chemical called Freon-12 (CFC R-12) in 1928. However, in the 1970s-1980s, it was discovered that R-12 and other CFCs depleted the ozone layer due to the chlorine content. R-12 production was banned in the 1990s per the Montreal Protocol. HCFCs like R-22 also have chlorine but in smaller concentrations; those phaseouts have been much more recent. Following news of the HCFC phaseout, HFCs and refrigerant blends became more popular because their ozone depletion potentials were 0. Although HFCs don’t deplete the ozone layer, some of them have high global warming potential (GWP). Regul

Andy Holt joins the podcast to discuss the ever-relevant topic of overcoming conflict at work. Some people end up in conflicts often, so Andy recommends paying attention to how others react to the conflict you have perceived; if you are much more stressed than everyone else, then you need to look internally, not externally. The first step to overcoming conflict is to slow down and think about your reactions to perceived conflicts. Partaking in bickering and gossip with coworkers creates a negative environment for the entire team; the best way to avoid or resolve conflicts is to handle them directly and sincerely ask the other party to start over. Overall, it’s best to take the high road and take initiative to make things right. When dealing with conflict with bosses, it’s best to separate emotion from the facts and keep discussions simply factual. It’s good to be open, honest, and understand that you can’t control your boss’s response. As a boss dealing with employee conflict, it’s a good idea to avoid firing

Matthew and Nick Wavra join the podcast to discuss everything that goes into job estimation in commercial HVAC. Nick has a lot of fieldwork and project management experience, and Matthew has marketing, software, and sales experience, which helps bring in and retain clients. Commercial estimation begins when a mechanical contractor asks for a bid on a job. The estimators go through the spec books, bidding documents, and any addendums to come up with takeoffs and a price. The estimator seeks approval from manufacturers to build the materials, and they use software to come up with an estimate. The pricing updates weekly to stay current and accurate in an economy that’s currently facing inflation. Estimators develop takeoffs for materials and labor; each material has some sort of labor attached to it, though the labor estimates may need to be adjusted as conditions change.  Commercial contractors may make mistakes when they miss equipment or elevation considerations (when estimating labor). On-screen takeoff opti

In this short podcast episode, Bryan goes over the basic gas furnace sequence of operations. There are a few variations, but the sequence of operations tends to stay consistent across most furnace types. First, a W call from the thermostat calls for heat. The circuit board will then assess the safeties to see if it can bring on the heat without causing flame rollout or other dangerous conditions. If the safety switches are all closed, then the furnace can bring on the heat. However, in some cases, the induced draft motor may come on first in some 80% furnaces. There needs to be a small negative pressure in the induced draft motor housing. To confirm that we have that pressure, a pressure switch will close under the right conditions. Then, ignition begins. In most cases, we use intermittent-spark ignition (ISI) or hot-surface ignition (HSI). It takes some time for these methods to light the pilot, which then lights the main burner. After that, the gas valve opens to fuel the burner. On an ISI system, that’s ab

Trevor Matthews, the founder of Refrigeration Mentor, returns to the podcast to talk about starting up an internal training program for an HVAC/R company. In some cases, the best lead technicians don’t want to be head trainers if the responsibility is forced upon them. However, when there is a solid training plan in place, those senior technicians might actually find the task enjoyable. The first step to starting a training program is to ask the apprentices and technicians where their skills are at and how they want to develop their skills. That way, you can map out a program that works for the technician and figure out how to make time for thorough training.  When you grow people within your company, you’ll likely see more success than when you outsource training. It takes longer to develop the relevant skills in outsourced people; so, when you develop a solid internal training program, you can sustain it with the people who pioneered it.  We also need to focus on evaluation in training. When we assess our t

In this short podcast, Bryan explains the basics of flame sensing, also known as flame rectification. Flame sensing/rectification is a form of proving flame. When you can’t prove flame, your furnace might be dumping unspent gas into the heat exchanger, which can cause an explosion. Flame sensing rods are common in hot-surface (HSI) and intermittent-spark (ISI) ignition. These rods stick out into the flame and connect to the furnace board. The flame creates a path between the rod and ground, which allows a very small current to flow to the board. Without a flame, there is voltage but no path, so the board can’t sense a current and will shut the gas valve off to try again.  Sensing rods can fail when they short out due to a cracked insulator, are physically broken, aren’t placed in the flame, or get covered in silica or carbon. If the furnace or burner assembly isn’t properly grounded, then the flame sensor also won’t work. Flame sensing rods are often confused with thermopiles or thermocouples; the latter devi

This podcast episode is a throwback to one of Bryan’s first small business podcasts. In this old episode, Australian electrician and businessman Joshua Nicholls explains how he built a business by focusing on customer experience and branding. Bryan grew Kalos similarly, so they talk about the journey of going from “man-in-a-van” businesses to larger businesses with several employees.   Joshua wanted to bring old-school manners and integrity to the business world, and that’s how he branded his business. The focus on customer service over marketing earned the customers’ respect, and customers were happy to remain loyal to the business and recommend it to friends. The repeat business and referrals allow you to maintain a client base AND grow it without spending too much money on advertising.   Eventually, the business grew big enough to require Joshua to change some of his internal processes. He needed to understand when to bring external help into the business, whether those helpers were financial advisors or m

In this short podcast episode, Bryan covers the differences between defrost termination and failsafe. He also covers the basics of defrost in refrigeration applications.   In medium-temp applications (also called coolers), the box stays above freezing temperatures, but the coil may drop below freezing. When the air is above freezing, we can use off-cycle defrost. The coil defrosts when the system naturally cycles off. We may also use timed defrost, which pumps down or cycles the compressor off at set times to force a defrost cycle.   In low-temperature applications, the box will typically be below freezing. We may use electric heat to melt ice off the evaporator coil, and the fan stays off; this method is usually accompanied by a pump-down to remove refrigerant from the coil. We may also use hot gas defrost, which pumps discharge gas through the coil to melt the ice off it. (Kool gas may use a warm fluid instead of hot gas.)   We want to stop the defrost as soon as the coil is ice-free; we don’t want to keep

This podcast episode is a throwback to one of Bryan’s first podcasts about small businesses. Cesar Abeid, former VP of construction camera company Remontech, joined this podcast to discuss the basics of project management and a book that can help you step into that side of the business. Project management is a framework or set of tools to turn an idea into reality. Projects have a beginning and end to create something new, and project management is how we get from the beginning to the end while factoring in schedules and a budget. In essence, project management is a system. Effective project management requires a business to create processes and procedures for its services. For example, Remontech needs to plan the actual camera installation, but the company also has a bunch of internal processes to set up servers for recording. The key to project management is to remember what must be done and assign tasks to people as needed. One of the issues Cesar saw with project management books was the dryness and corpo

Bryan discusses impostor syndrome, what it is, and how it may actually be useful for us. When we feel that we’re frauds and that others wouldn’t like to be led by us if they knew how much we don’t know, we’re experiencing impostor syndrome. Contrary to what others might believe, impostor syndrome isn’t all that bad and may even be necessary for a healthy self-image. On the other side, we have the Dunning-Kruger effect, which is when people are confident in the things they have very little actual knowledge of. They think they’re experts and close themselves off to other sources of knowledge. On the other side of the Dunning-Kruger effect spectrum, true experts are acutely aware of what they still don’t know. We would be wise to know what the edges of our knowledge are and give others a chance to share their expertise when we reach those limits. When people learn more about a subject, they become much more aware of what they don’t know. Wisdom comes from knowing what you don’t know. However, if you feel that fe