HVAC School - For Techs, By Techs

In this podcast episode, Ty Newell from Build Equinox comes on to discuss the CERV2 and how it embodies "advanced fresh air." The CERV2 is the second-generation version of the CERV. A basic ERV allows for discharge air leaving the home to pass the intake air. When the airstreams cross through a core, there is an exchange of sensible and latent energy. The ERV may promote dehumidification and cooli...

Our main man, Bill Spohn, joins us again to talk specifically about combustion. He also explains how to select and properly utilize a combustion analyzer. It's critical to do combustion analysis when you service equipment for the first time or just after installation. We need benchmarks, so that's when our combustion analyzers can come in handy. (Of course, you also want to use your senses to insp...

In this short podcast, Bryan shares some of his advice for people looking to get into the trades by starting an HVAC/R career. When you step into the HVAC/R trade, you must remember that you'll acquire a mix of skills and talents that all work together. You must reflect on yourself and see if you'll be a good fit for the trade. Do you enjoy working with your mind and your hands? Do you enjoy worki...

Jaden Lane joins us to discuss some best practices when using an air flow hood. She also explains how the Dwyer Smart is innovating in the hood space. An air flow hood is an excellent tool, but we can't just assume that it'll work correctly in any system. Various vents and diffusers can cause different flow patterns to reach the hood, so you can get an incorrect reading if the flow hood is not awa...

Russ King joins us to discuss simplifying duct design for residential contractors. We focus on using 3D software for duct modeling. While computers are great tools for duct design, you must be careful with them. Computer technology doesn't correct your mistakes; it allows you to make mistakes more quickly. Russ made 3D software specifically for duct modeling, and its goal is to help technicians/co...

Bill Spohn with TruTech Tools joins us to talk about why being "approximately correct" is better than being "exactly wrong" when it comes to test instruments. When you see a number, that doesn't necessarily mean that you're dealing with a number you're supposed to see. For example, nitric oxide can present as "false CO" to a carbon monoxide sensor. Test instruments that mistake nitric oxide as car...

Bernadette Shahin of Aeroqual joins Bryan and Kaleb as they all dig very deep into indoor air quality (IAQ) sensors and instruments. They also cover the certainty and uncertainty of measurements. Reference method instruments generally have to operate within a set of parameters, notably a temperature range. Gas laws make the gases act differently, so you want the temperatures and pressures to stay...

Jordan Cummings is back to discuss some of the most important points in the proper installation of VRF and VRV systems. We especially cover piping best practices. When it comes to piping, the biggest concerns on VRF and VRV systems are making sure the piping can handle the refrigerant velocity and ensuring proper oil return. Most VRF systems use PVE oil, but you still want to be cognizant of oil t...

Bryan and Eric Mele have a relaxed conversation on time management on the job. They also explain how to manage time in life as a whole. Some people are naturally fast because they cut corners in the name of time management. Instead, something Eric has learned to do is optimize his processes. He gets his work done a lot more quickly because he knows how to get the most out of the trips to his truck...

In this short podcast episode, Bryan explains what suction line traps and inverted traps are. He also covers the purposes they serve. It's a bit hard to find literature on suction line traps, so it's always best to read the manual and follow the manufacturer's guidelines. We traditionally use P-traps on suction lines to hold oil and let it go up the walls of the refrigerant piping. You need enough...

In this short podcast episode, Bryan explains how you can prevent and overcome price objections in your HVAC business. You can prevent price objections by avoiding the "budget" reputation. If your company establishes itself as a "budget" or "cheap" company, you will attract coupon-clipper customers. Coupon-clippers can be difficult to work with because of how cost-conscious they are. Customers who...

In this short podcast, Bryan explains why latent capacity is prone to disappearing. He also explains what actually happens when the latent capacity drops. When you measure enthalpy split across the coil, you'll learn that the equipment design makes it perform to AHRI design conditions. Those design conditions are 95-degree outdoor temperature and 80-degree indoor temperature at 50% indoor relative...

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...

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...

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...

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...

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 whol...

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 onl...

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 pr...

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 Trethew...

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 manome...

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...

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 ours...

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...

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 ab...