Roman Baugh, Matthew Condron, and Luke Peterson discuss the importance of proper condensate drain installation and maintenance, particularly in commercial applications. The conversation begins with the hosts examining the typical drain configurations seen in different regional markets, highlighting the significant variations in practices across the country. Sizing and configuration of condensate drains can have a significant impact on system performance, especially in high-static pressure systems. He emphasizes that the "one-size-fits-all" approach of using a 2-inch trap is often insufficient ..read more

In this short podcast episode, Bryan explains electronic expansion valve (EEV) types. EEVs perform the same function as TXVs, but they operate electronically, not mechanically. The EEV makes sure that the evaporator is full of the right amount of refrigerant at saturation; it doesn't just affect evaporator pressure. We don't want high superheat (due to inefficiency), and we don't want zero superheat (due to the risk of compressor failure). EEVs commonly have a stepper motor with a set of discrete settings depending on how many rotations the motor has made. It can be fully open or fully closed ..read more

This episode of the HVAC School Live Stream covers the key concepts around heat pump efficiency and understanding the coefficient of performance (COP). Eric Kaiser from TruTech Tools and Jim Fultz from White-Rodgers provide valuable insights into how heat pumps operate and how to optimize their performance, especially in colder weather conditions. The discussion begins by exploring the COP of heat pumps and how it compares to the efficiency of electric resistance heat. A COP above 1 means the heat pump is delivering more heat for the same amount of energy input compared to electric resistance ..read more

In this short podcast episode, Bryan talks about motor protection types, including overloads. The most common overload we see in residential HVAC is a built-in thermal overload, which is usually a bimetallic disk that flexes in response to heat (such as from a locked condition, electrical problem, or simply running hot) and opens the circuit. The two metals have different expansion and contraction rates, which causes the flexing; they will return to their original position once the motor cools down. In some cases, these can fail when they open and close too often; they are not designed for swi ..read more

This podcast features a lively discussion on expansion valves, particularly thermostatic expansion valves (TXVs or TEVs), with a panel of expert guests - Corey Cruz (a market refrigeration tech), Matthew Taylor (head of refrigeration service at Kalos), and Joe Shearer (with Precision Air Conditioning). The conversation kicks off by busting some common myths surrounding expansion valves. The guests agree that minutiae like the precise clocking (rotational orientation) of the sensing bulb or whether it's mounted horizontally or vertically tend to be overemphasized. The key is ensuring good therm ..read more

In this short podcast episode, Bryan answers an audience member's question and explains how to learn superheat & subcooling, two fundamental aspects of the HVAC/R trade. You can submit questions of your own at https://www.speakpipe.com/hvacschool.  Saturation is when a substance is in the liquid and vapor state in the same place. Eugene Silberstein likes to help us envision it by encouraging us to think of a horizon line on the ocean; anything below it is fully liquid (subcooled, what a submarine would travel through), and anything above it is a vapor (superheated, which a flying ..read more

In this episode of the HVAC School Podcast, Bryan Orr and Trevor Matthews delve into the importance of setting goals, focusing on them, and taking actionable steps to achieve them. They emphasize that goal-setting is crucial for personal and professional growth and that it requires introspection, prioritization, and sacrifice. Trevor shares his experience of setting a goal to buy his first house and how writing down the specifics, such as the number of bedrooms and bathrooms, helped him achieve that goal within a few years. He stresses the need to start small, with easily achievable goals, and ..read more

In this short podcast episode, Bryan talks about when to switch to emergency heat. He talks about coefficient of performance (COP) and how it's a deciding factor when to run emergency heat, which is when a system ONLY runs the backup heat; it doesn't use it as supplementary heat. When we have a heat pump with backup electric heat, we shouldn't ever rely just on emergency heat; we want the heat pump to run. Electric heat is just designed to supplement the heat pump's heating because it's inefficient. Hybrid or dual-fuel systems can use gas or hydronic fuel-based heat, and they work well on thei ..read more

Shelby Breger, co-founder of Conduit Tech, joins Bryan Orr on the HVAC School Podcast to discuss her company's innovative lidar-enabled design and sales software tool for HVAC contractors. Conduit Tech's software utilizes lidar sensors in iPads and iPhones to scan homes and create 3D models and 2D floor plans. It overlays load calculations factoring in property data, orientation, cooling/heating degree days, and building materials. This allows contractors to perform detailed load calculations on-site in just 15 minutes or less while engaging homeowners visually. Breger explains that the core g ..read more

In this short podcast episode, Bryan talks about the four different combustion venting categories for gas appliances as set by ASHRAE and where you'll see them. He also shares some notes about pressurization. These categories deal with the pressurization and temperature ranges of the vents. Category 1 venting is used for old-school open-combustion gas furnaces; they have high flue gas temperatures and are considered low or mid-efficiency furnaces. This venting category is not positively pressurized, and it has a single-wall flue and operates more like chimneys, as the appliance is usually unde ..read more