HVAC School - For Techs, By Techs

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; he doesn’t focus on the building’s volume. To decrease the leakage, it’s best to stay focused on the CFM50 the entire time; worrying about the ACH50 just adds an extra step that we don’t necessarily use. Genry and Bryan also discuss: Connecting design and execution Attic encapsulation How to use LAIR Ceiling height and stack effect Blower door testing for code compliance vs. comfort consultation/diagnostics Common duct problems in new constructions Balancing supply ducts Automation of communicating controls IAQ products and dehumidification   If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE. Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

Eugene Silberstein, co-author of Refrigeration and Air Conditioning Technology, introduces us to psychrometrics, focusing on air properties and human comfort. Understanding air's content helps us have a holistic view of HVAC performance. The psychrometrics chart contains valuable information to understand air conditions. Furnaces don't dry out air; they pull moisture out and back in. Air filters, blower motors, weight of air, humidification, and high-pressure air movement are also discussed.

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 built for the new refrigerants. Although we can’t confirm anything, Brandon has speculated that the EPA will soon follow in California’s regulatory footsteps when it comes to new equipment and R-410A.  It’s a good idea to stay educated, subscribe to A2L newsletters, and follow HVAC trends in Europe to predict what might come next in North America.  Brandon and Bryan also discuss: Educational resources about refrigerants What “mildly flammable” actually means European HVAC equipment Chemours at the AHR Expo   Learn more about Chemours A2L training at opteon.com or Opteon’s YouTube channel. Check out what Chemours has in store at the AHR Expo at https://www.opteon.com/en/ahrexpo.  If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE. Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

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). Regulations stemming from the Kigali Amendment, such as the American Innovation and Manufacturing (AIM) Act, have been introduced to phase down the production of HFCs to slow global warming due to refrigerants. HFOs have recently been developed to replace HFCs; these have olefins, which are double-carbon bonds with short atmospheric lifespans. So, they don’t contribute to global warming as significantly as HFCs and have GWPs of less than 1. Chuck and Bryan also discuss: What Willis Carrier really invented Chlorine and ozone depletion Development of refrigerant blends Freon vs. Opteon branding Refrigerants and the greenhouse effect Oil lubricants Best practices for mildly flammable refrigerants Timeline of Opteon line refrigerant releases   Learn more about Chemours A2L training at opteon.com or Opteon’s YouTube channel. Check out what Chemours has in store at the AHR Expo at https://www.opteon.com/en/ahrexpo.  If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE. Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

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 on the spot and give employees a chance to think about the conflict at hand, such as by giving them a paid “cool-off period.” Customer conflicts may arise from pricing issues. The technician can ease tensions by quoting jobs up front and bundling services to show the customer where the value is. To resolve conflicts with customers, the best thing to do is be attentive to their concerns. Andy and Bryan also discuss: “Designing” a reaction Dealing with big egos Letting people go Working towards agreements vs. forcing bargains Dealing with hot tempers Taking ownership of comfort problems MeasureQuick and fact-based conversations   If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE. Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

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 options significantly reduce the risk of creating mistakes, so it may be unwise for contractors to do takeoffs by hand instead of using software to help. Matthew, Nick, and Bryan also discuss: Sheet metal price increases Software vs. man-made takeoffs DX piping vs. chilled water boilers Estimation in HVAC vs. refrigeration CRM (customer relationship management) Developing a commercial HVAC estimation training course Finding a niche in the HVAC estimation business Look for Nick and Matthew at the AHR Expo 2022 in Las Vegas! They will be at booth N9142 in North Hall.   Learn more about Matthew and Nick’s business by visiting hvacestimation.com/ or by calling Nick directly at (238)-900-6330.  If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE. Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

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 about it until the blower comes on. However, once the main burner opens on an HSI system, a flame sensing rod can verify if you have a flame on that burner. There is a blower delay that prevents the blower from coming on and blowing a bunch of air that hasn’t yet been heated. After that, the blower delay ends, and the blower comes on. Then, the furnace shuts off when the W call ends. Then the blower continues running for a little bit before turning off.   If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE. Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

Trevor Matthews, 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 techs’ skills, we add accountability to our training programs. However, it takes time for techs to grow from a training program, and we need to make sure we’re rewarding progress. Training also works best as a team approach. When we look at the techs’ strengths, we can diversify the training program and make sure that several skill bases are covered. Trevor and Bryan also discuss: Common excuses to avoid training Motivated trainers and technicians Labor shortage and skills gap Visual, auditory, and kinesthetic learning preferences Prevention-based training Managerial involvement in training   Learn more about Refrigeration Mentor at https://refrigerationmentor.com/.  If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE. Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

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 devices generate voltage and have a coating that can rub off with improper cleaning. Flame sensing rods don’t have either of these features, so you can clean these by any means necessary (without breaking them or creating grooves or pits). To test a flame sensing rod, begin by making sure the furnace is properly grounded. Then, make sure the rod is in the right spot and that the burner assembly is in good order. Get a microamp meter (with a resolution that reads tenths of microamps). Then, connect your leads in series with the flame rod.    If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE. Check out our handy calculators HERE. Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

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 mentors.   Joshua reached a point where he got bored with his business, so he went to a conference in New Zealand and decided to start franchising the business. The business worked without him, and he decided to give a chance for young entrepreneurs to share in his business’s success and spread his business all over the country.   Joshua and Bryan also discuss: Joshua’s origin story Authenticity in business What to do after the growth boom Profitability vs. work-life balance Turning customers into raving fans Scheduling appointments in a service business Knowing your numbers in business finance The “One Van, One Child” initiative   If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.   Check out our handy calculators HERE. Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.