In today’s podcast, Bryan explores the upsides of choosing a career in the skilled trades instead of going to college. He also covers ways to prepare your child for a trades education and career while they are still deciding what to do with their lives. When we think about what we want for our kids, the following goals come up quite often: purpose, financial upside and reward, freedom from debt, and joy. The trades can offer a lifestyle that covers all of these bases. However, the opinions of our friends and the fear of failing as a parent may prevent us from encouraging our children to enter the trades.  Going to college has plenty of downsides, such as saddling students with debt and not guaranteeing opportunities to move forward in a career. Alternative career paths include the HVAC/R trades, electricians, off-grid solar technicians, and so on. Your child will learn hard skills on these career paths that are easily transferable. These trades also generally have plenty of apprenticeship opportunities. In the case of HVAC/R, technicians may also have the opportunity to earn a lot more money in only a few years. At that rate, they will have ideally saved some money to go to college later on if they believe that college is truly the right choice for them. Bryan also covers: The desire for purpose and impact in a career Doing good work vs. being seen doing good work Advantages and disadvantages of college The societal obsession with certificates of completion How to avoid feeling “stuck” as a young adult What it means to have a high opportunity/learning ceiling Interesting and meaningful problem-solving in a career Acquiring hard skills Diversity of challenges in a career Strong lateral problem-solving skills Advantages and disadvantages of home education Autodidactism Alternative career paths with financial and personal upside If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In today’s short podcast, Bryan explores triple evacuation. Many people believe that we don’t like triple evac, but that’s simply NOT true. We’re here to set the record straight. If the manufacturer tells you to follow triple evacuation processes, then it’s a good idea to do what they say. We won’t argue with that. However, our argument is that the procedure can be more time-consuming than it’s worth when it’s NOT necessary. Deep vacuum technically counts as a vacuum pulled below 500 microns (in residential, that target is usually 200-300 microns). Most modern micron gauges and tools make it easy to achieve a deep vacuum. In a triple evacuation, you pull the vacuum three times (instead of once). Between pulling vacuums, you break with nitrogen before pulling the vacuum back down. Triple evacuation originated in a time when micron gauges and vacuum pumps were less reliable. We did not take deep vacuum very seriously, especially since mineral oil (MO) typically did not break down inside the system. (Modern oils like polyolester/POE break down rather easily, so pulling a deep vacuum is much more vital nowadays.) Instead of merely breaking with nitrogen, Bryan recommends flowing it. It’s best to flow the nitrogen with force to move the oil around more effectively. In turn, your vacuum will pull down more quickly and efficiently. So, triple evacuation isn’t bad, but it can be time-consuming. Just be sure to follow all best practices if you perform a triple evacuation. Join us as we cover: Deep vacuum targets Micron targets Breaking with nitrogen Flowing nitrogen POE vs. mineral oil Old manufacturer literature about deep vacuum Microns   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.

In today’s podcast, Bryan explains how he teaches physics. He believes that teaching physics is about continuously building a mental model, and he covers the methods and mindsets that facilitate that learning style.  The basic Wikipedia definition of physics states that it is a science that deals with matter, energy, and their interactions. Even then, we can simplify “matter” to “stuff.” Simplifications like these help students feel more familiar with the subject and NOT feel intimidated by the material. Students learn best when they feel like they can grasp the topics out of the gate. That is why the math-based approaches of traditional education might turn students away from physics. Some students who don’t like math might feel out of their depth when teachers approach topics with a mathematical approach.  Instead, effective teaching is about attaching experiences to a concept. Teachers can take stock of what students already know and build on that. They can also attach experiences to a concept, such as by allowing students to have hands-on experiences with physics examples in the real world. Once students have relevant experiences, they have the tools to learn through similes and analogies. Bryan covers: Socratic learning Comparing levers to seesaws for educational purposes Experimentation and experience Similes, metaphors, and analogies Shortcomings of math-based learning methods Creating “cartoons” in your head to learn topics Teaching superheat and subcool with mental “cartoons” States of matter Humidity and the weight of water vapor Electron movement Steam and why it’s complicated Teaching electricity with comparisons (water, drawbridges, jump ropes) How children (and babies) learn about physics as they navigate the world Mythbusting Remember, when it comes to education, the goal is to learn, NOT to impress people. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In today’s short podcast, Bryan explores the dangers of cold tanks during refrigerant recovery. Whenever you have a recovery tank, you only want to fill it to 80% capacity in the liquid state. The same goes for all sorts of vessels (coils, etc.).  However, capacity isn’t the only factor to consider for safety. We need to know what our maximum temperature will be. You will be in greater danger of overfilling a tank when it is cold because higher temperatures increase the pressure. High pressure in a closed space may lead to explosions. When you fill a tank to 80% under cold conditions, normal temperature conditions could put you in the danger zone (let alone temperatures above 100°F). So, it’s better to determine your tank fill based on densities at the MAXIMUM temperatures you will encounter, NOT for the measurements at artificial cooling conditions (such as when you put the tank in ice water during recovery). In the end, just be careful when you’re recovering into a cold tank or using tanks when it’s cold outside. That will help you avoid hydrostatic pressure buildup and explosions. Bryan covers: The 80% capacity rule for filling vessels with liquid Why the 80% capacity rule varies by temperature Temperature, pressure, and density Hydrostatic pressure AHRI’s 77°F guideline Ice buckets for recovery What to do if a tank vents its refrigerant on you while driving If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In today’s podcast, Nikki and Bryan discuss dehumidification. They cover the relationship between cooling and dehumidification, humidity control, and dehumidifier installation practices. If the A/C unit is the king, the dehumidifier is the queen. The A/C unit controls cooling and humidity, but it can only do so much. A dehumidifier helps the A/C manage comfort under more demanding conditions. Many factors contribute to comfort, including sensible heat ratio (SHR), relative humidity (RH), and ventilation. Dehumidification reaches all of those factors. Humidity control requires a holistic approach. Band-aid fixes DO NOT work. Dehumidifiers should work with the A/C system and building design to keep RH in the 50-55% range. Proper installation is vital. For example, tying into the HVAC supply is a recommended practice. Returns are the opposite; dedicated returns are preferred. Other factors to consider are proper sizing, Manual J, and customer expectations. Join Nikki and Bryan as they cover: Relative humidity targets Sensible heat ratio (SHR) Latent removal capacity Ventilation Building design and tightness Manual J Challenges with ductless systems Ducting into the supply with dedicated returns Installation practices Dehumidifier sales and customer service And much more… To learn more about Santa Fe Ultra series, go to www.santa-fe-products.com. You can scroll through the products to find the Ultra series free-standing ventilating dehumidifiers.   If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In today’s podcast, Trevor and Bryan discuss how to troubleshoot thermostatic expansion valves (TXVs/TEVs). They also dive into the various types, applications, and components of TXVs. TXVs are metering devices that control evaporator superheat to protect compressors from harm. Controlling heat also regulates pressure, which improves efficiency and prevents issues like floodback and overheating. TXVs contain several components that manage the forces that open and close the valve. These components include powerheads, diaphragms, springs, and more. The components all contribute to a delicate balance that can be broken when they fail or are installed improperly. TXV failures lead to high or low superheat and eventually compressor failure.  When you diagnose a TXV, you may encounter hunting, broken powerheads, filthy screens, and improperly sized valves. Once you verify the cause of the issue, you’ll likely have to adjust the TXV, replace a component, or replace the whole TXV. That can be a tricky decision that will largely depend on the type of failure, the type of TXV (conventional vs. balanced port), and the TXV’s application (residential HVAC, refrigeration, etc.). Join Bryan and Trevor as they cover: Opening and closing forces Internal and external equalization Non-bleed/hard shutoff TXVs and design limitations Conventional valves vs. balanced port valves Brazing in TXVs Strapping the TXV bulb to the suction line TXVs in refrigeration vs. HVAC Liquid quality, sight glasses, and subcooling TXV sizing Suction pressure/superheat hunting High and low superheat causes Adjusting vs. replacing valves And much more...   Check out Emerson’s HVACR training HERE. Then, navigate to “Contractor Tool Box Talks with Emerson.” If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this short podcast episode, Bryan discusses push-pull recovery, how it works, and what we need to know about it. Push-pull recovery is a somewhat counterintuitive method of recovering liquid rapidly. We simply do that by pulling refrigerant out of the system and pushing it into the tank. However, when we pack refrigerant into a tank, the tank pressure and temperature increase. So, it can be more difficult to get refrigerant into the tank as the job goes on. When we recover liquid refrigerant on large systems (20+ pounds of charge), you connect a line from the liquid line or receiver and attach it to one side of the tank. Then, you pull from the system the other side of the tank should lead into the recovery machine. Attaching to the recovery machine helps depressurize the tank. When pulling out of the tank, you'll want to make sure the refrigerant is a vapor. The recovery machine should be pulling only vapor refrigerant out of the tank. While you're depressurizing your tank, you will be pressurizing your system to push the liquid refrigerant out of the system and into the recovery tank. (Short hoses with a large diameter are usually best for quick recovery.)   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.

In this short podcast episode, Bryan goes over one of his most valuable tips for pulling a vacuum on a small system. It can be very difficult to pull a vacuum on a small system, especially when you're dealing with a low-temperature application like a freezer. When you pull a vacuum, you're creating a low-pressure area that affects molecule behavior. So, you're creating a situation where the molecules push their way out of the system and into your vacuum pump. The low temperature and small tubing, especially capillary tubes, make this process exceptionally difficult. A very good vacuum pump can still have a hard time achieving a deep vacuum. To make this process a little easier, Bryan likes to add heat. When you add a heat blanket around components with oil, you negate the low-temperature obstacle and make it easier to separate refrigerant from oil. You may also use a heat gun on areas where using a heat blanket is impractical. If the area is cold or has refrigerant and oil together, then you'll benefit from applying heat. Don't go crazy and use open flames, but a heat blanket or heat gun will usually be safe.   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.

In this podcast episode, Bryan and Eric Mele explain how HVACR technicians can END callbacks with a few best practices. Rushing through calls will often lead to callbacks. One of the most common mistakes techs make is failing to check the condensate drain before walking away from a job. To end callbacks, technicians would be wise to check the entire system and note any possible problem areas; in commercial HVAC and refrigeration, pay attention to variation across evaporators, condensers, and drainage systems. Customer service is a huge component of residential HVAC; you can prevent callbacks by listening to the customer's concerns, addressing their comfort issues (even if it lies beyond the obvious problem), checking your "five pillars," and thoroughly explaining what you've done. Even if a problem seems to drag out, take all the steps necessary to alleviate your customers' fears. Electrical problems also cause callbacks, especially dual-run capacitors. So, it's a good idea to check for wiring rubouts and make sure the wires look clean and organized. If you can offer an electrical solution to the customer at a cost, do it, even if they might decline it; that way, the callback is on them, not you. Overall, being thorough, communicating with the customer, and offering solutions is the key. If possible, it's best to explain everything at once and have one money conversation. If you can't get a full diagnosis until the customer approves a repair, be transparent about that. Eric and Bryan also discuss: Multi-equipment setups in commercial settings Dealing with difficult customers Managing customers' expectations HVAC in new homes Determining if a unit has been set up correctly Smart thermostats Cleaning drains and equipment Preventing flooded starts OEM vs. aftermarket parts Commonly replaced parts (reversing valves, TXVs, etc.) Establishing a process that works   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this podcast episode, Bryan and Eric Mele discuss the diagnosis and prevention of compressor overheating in HVAC and refrigeration. The main causes of compressor overheating are inadequate cooling back to the compressor, low charge, restrictions, and sometimes even poor suction line insulation. We want to keep the suction temperature low while maintaining appropriate superheat. If the suction line temperature is too high, the compressor can't cool down well enough. Dirty condenser coils, low voltage, weak capacitors, or an inadequate condenser fan can also lead to compressor overheating. Electrical problems, including too little capacitance, will make a compressor go out on thermal overload. When you have refrigerant problems, the thermal mass will just keep growing; it takes a long time to heat the compressor up, and it will take a long time to cool it down. In a thermal overload, a bimetallic disk in the compressor will open and break all three legs of power. When a compressor goes out on thermal overload, it will make an open circuit, and you will read infinite ohms. Knowing that the compressor has gone out on thermal overload is just the beginning of compressor overheating diagnosis. So, to begin diagnosis, you'll want to make sure there's refrigerant in the system. Inspect the unit visually and note anything that seems odd. Then, you'd check your capacitor for electrical problems. You can also feel the compressor to get an idea of the extent of the overheating (try not to burn yourself). You'll also want to monitor the amp draw, condensing temperature, suction pressure, and superheat. Eric and Bryan also discuss: Axial fans Condenser fan intermittent failures Resetting the compressor Cooling down the compressor Setting up your meter Being out on high pressure Wrapping wire to increase ammeter resolution High return gas temperature   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this short podcast episode, Bryan and Eric Mele talk about re-tapping transformers for single-phase equipment in 208v applications. Most single-phase equipment can work for 230v or 208v, meaning that they can operate with low voltage. However, we typically see 208v in commercial buildings. The sine waves of 208v equipment are 120 degrees out of phase, not 180 degrees (as in split-phase applications). We get lower voltage from leg to leg (208v, though the voltage can be a little higher or lower). Power companies generally put out slightly higher voltage to reduce line losses. Most systems can work on multiple voltages, but they come with a transformer that's set to the 230v or 240v setting. However, under those settings, you can experience issues in 208v applications. If you put equipment tapped to 230v or 240v in a commercial setting, you may have issues, especially if you're farther away from the air handler. You may not get full 208v and may see contactors that don't pull in intermittently, and you may get intermittent cooling calls. Intermittent problems become worse when you have long thermostat wiring. In those cases, re-tapping the transformer is your only option. When the original voltage is incorrect, you'll need to re-tap the primary (high-voltage power going in). If you fail to tap the primary correctly, the voltage going out of the secondary won't be correct. When it's time to test the equipment, you'll always want to be sure to test the equipment under load. Make sure you cap extra wires and cap them independently of each other; those wires do have voltage, and we need to be cognizant of that.   Learn more about Refrigeration Technologies HERE. 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.

In this podcast episode, Ben Reed from TZOA, a disruptive air technology brand, joins us to discuss the indoor air quality map and compass. We spend a majority of our lives indoors, so TZOA tries to improve IAQ in homes to keep us healthier. HVAC manages airborne chemicals, so indoor air quality ties right into our industry; HVAC technicians will become more valuable when they become well-versed in IAQ technologies. In residential HVAC, we are already used to listening to customer complaints and observing the home. Technicians (and even IAQ products) can "map" out the customer concerns and home features to develop a comfort and home-health solution. TZOA is working on putting together that "map and compass" model to optimize home health and comfort by noting problem areas and pointing us to the tools to solve the problem. HAVEN uses a central air monitor (CAM), which is an in-duct, whole-home IAQ monitor that measures particulates, temperature, and humidity. The monitor pairs with software to fulfill the "map and compass" model and assist with diagnosis. The air monitor and software help dispel uncertainty around IAQ products while providing accurate readings that point to solutions. It's also worth noting that HAVEN's tools can only be purchased and installed by HVAC professionals. So, they're helping bridge the communication gap between technicians and customers. TZOA is also attempting to build trust and confidence in IAQ products through education, collaboration with industry experts, and allowing HVAC technicians to use and experiment with their products. Ben and Bryan also discuss: HAVEN and TZOA's beginnings IAQ uncertainty and reputation Multiple chemical sensitivity Ventilation and dilution The future of TZOA products TZOA's personal use program Working with reputable companies and people Integrating IAQ into maintenance plans   Learn more about TZOA and HAVEN at haveniaq.com. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this podcast episode, Bryan and Trevor Matthews of Emerson Canada discuss the Copeland 2-stage ZPS scroll compressors. Please join us by following along in bulletins AE4-1428 and AE4-1365. The ZP91KCE to ZP143KC Copeland compressors don't have internal pressure reliefs (IPRs). Those higher-pressure compressors make very loud noises when they go off, and it'll blow hot discharge gas on the internal overload to shut down the compressor. Some scroll compressors have temperature operating disks (TODs), which are bimetal disks that open upon a temperature increase and reroute the gas. Other compressors have advanced scroll temperature protection (ASTP), which is a snap-back disk near the floating seal. You don't just want to shut the suction service valve to pump the scroll down. Instead, common service procedures include checking voltage to the compressor, the internal motor, the blower/fan operation, the suction pressure, and the compressor wiring. If you install crankcase heaters for oil management, be sure to install them correctly to avoid overheating the compressor. You'll also want to verify that crankcase heater voltage and ensure that it is properly grounded. Two-stage modulating Copeland scrolls work with a 24v DC solenoid in the scroll set. That solenoid energizes and de-energizes, which either fully or partially loads the compressor. Load matching is ideal for efficiency and comfort, meaning that the two-stage Copeland scrolls perform well in those areas. Unsurprisingly, the fully-loaded option draws more current than the partially-loaded option. These two-stage compressors don't have IPRs, so you will need a high-pressure control set to 650 PSI. Trevor and Bryan also discuss: TOD vs. ASTP Operating envelopes Hipot testing Single-phase compressors Using Copeland compressors in pool heaters Oil and refrigerant dilution Wiring up CoreSense Reversing valve sizing issues   Visit climate.emerson.com for more resources. Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this podcast episode, Bryan, Trevor Matthews, and Jim Dick of Emerson talk about the screw compressor and how it works. This time, they focus on the Vilter single-screw compressors. Vilter is an industrial compressor division of Emerson (compare to Copeland). Vilter also makes reciprocating compressors, but the screw compressor is its claim to fame; you may want to consider using a screw compressor when you want greater capacity and control than a reciprocating compressor. Screw compressors also work well for applications with constant loads; they do, however, have microprocessors that can monitor system performance to maximize efficiency. Vilter uses a compressor with a single screw, whereas most compressors have twin screws. Twin screws have a motor that continuously turns the rotor, which causes the screws to mesh together; the compression happens as gas fits between the screws, and the gas volume decreases as the space between the screws closes. In a single-screw compressor, the gas compresses on the outside of the screw. In any case, we must seal the gas in the flutes, and oil helps us with that. Liquid should not get into either type of screw compressor, as liquid is not compressible and will damage the compressor. When you service a screw, the oil temperature and discharge pressure will likely be the most important values to watch out for. During maintenance inspections, you'll also want to pay special attention to the bearings, the four pressure transducers, and oil filtration system. Jim, Trevor, and Bryan also discuss: Microprocessors Star rotors Oil uses, management, and components Motor RPM Multiple compressors and added capacity Calibrating pressure transducers Zeroing vs. calibrating Suction screens Jim's interesting findings Injecting oil Value engineering and consistency   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.

In this short podcast episode, Bryan talks about condensation and how HVAC technicians can solve condensation-related problems. He also discusses humidity control and how that can affect sweating. We may have heard the phrase, "Condensation is where hot meets cold." That's not necessarily true; while it may seem that sweating happens where hot meets cold, the dew point is the main cause. We won't see condensation unless we have air that reaches the dew point. When air flows across surfaces that have a temperature below the dew point, you'll start to see sweating on the surface. Clouds and fog indicate liquid water in the air; if you see fog, then you will know that the ambient temperature is below the dew point. We also can't see steam; steam is water vapor, but the "steam" we see is actually liquid water. Water vapor is also lighter than air, so it rises in the vapor form. When we see condensation or sweating, we must ask ourselves if the surface is colder than it's supposed to be. Ducts can sweat when the airflow is too low, and the air handler can sweat when the evaporator freezes. If we were to heat the air as a solution, we can decrease the relative humidity, but heating the air doesn't change the dew point or total moisture content. The next step is to make sure we don't have infiltration at boots or can lights. Infiltration can cause sweating, especially in unconditioned spaces. You'll also want to make sure that the duct insulation is straight and that the ducts have been properly strapped. The house itself can also cause infiltration, especially through fireplaces and chases; a blower door test can help you determine the leakiness of the home. Ventilating dehumidification may also work as a solution.   Check out Richard Sims's presentation on our YouTube channel HERE. Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this podcast episode, Bryan and Chris Mohalley of Regal Beloit discuss the different types of ECM. They also cover applications where you can expect to find ECMs. In the HVAC industry, we typically use three types of motors: constant-torque, constant-airflow, and constant-speed. Every ECM works on electronic commutation, so constant-torque motors use that to maintain torque output (X13). The constant-airflow motor is also known as the variable-speed motor, and it is one of the first ECM types. We typically only use constant-speed motors in outdoor fan motor applications. Likewise, we generally use the first two motor types for indoor fan motors inside air handlers. ECMs were NOT designed to address the static pressure problems of PSC motors and duct issues; variable-speed motors may attempt to compensate for duct problems, but that's not its purpose. (Variable-speed motors work like cruise control in a car.) However, when motors compensate for poor duct systems, they could run higher RPM than desirable in order to hit the system targets and can generate excess heat. Constant-torque motors maintain a certain torque value, which can get tricky when the loads begin to vary. When static pressure goes up, there's less air in the system, which means that there's less air for the wheel to move (a smaller load). Current and RPM can increase when static pressure goes up, but the torque would stay the same. Chris and Bryan also discuss: What is a variable-speed motor? Permanent split capacitor (PSC) motors Duct sizing and design Static pressure and motor life expectancy Reactive power and power factor Torque vs. speed taps Blower performance curves Different series of motors PWM (pulse-width modulation) and inputs Setting DIP switches Evergreen VS Why should you read the manual?   Check out some more ECM resources at regalmmu.com. Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this podcast episode, Bryan and Eric Kaiser discuss the right and wrong way to do HVAC/R jobs and approach HVAC/R work. Breaking things down into "right" and "wrong" categories is a rather simple way to approach a problem; we throw nuance and alternatives out the window, which can be worse than doing something "wrong." Instead of viewing things as right and wrong, we would be better off if we looked at our objectives and focused on solving problems instead of being right. Although there are surely correct ways to pull a vacuum, it's more useful to set standards than argue about what's right. Set standards that are appropriate for the situation (the equipment, your tools, your skill level, etc.). Of course, it would also be best if we could try to set our egos aside. We need to have humility and acknowledge that we're all trying to improve for the sake of our customers. That said, we could all benefit from focusing on achieving successful outcomes instead of being "right." Ultimately, many of our struggles to determine right from wrong can be solved by listening to the customer. Our goal is to tailor our practices to our customers' needs, even in commercial work where customer service isn't as important. Being overly dogmatic doesn't do much to help a customer, and it fails to account for the unique details of each situation we encounter in the field. Eric and Bryan also discuss: The right vs. wrong way binary Maturity Situational awareness Evacuation best practices Customer discretion and expectations Do aesthetics matter? Commercial vs. residential HVAC Evaluating suppliers and manufacturers reasonably How oil and parts have evolved Flowing nitrogen Setting goals   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this podcast episode, Bryan and Chris Mohalley from Regal Beloit discuss EC motors. They also describe ECM applications and how those motors work. EC motors (ECMs or "ECM motors") are electronically commutated motors. These motors are generally three-phase AC motors operated by a drive; that drive is a combination of an AC-to-DC converter, microprocessor, and frequency drive. So, the frequency delivered to the motor is generated electronically. When it comes to inputs, the ECM works like a printer. One input provides power (from the wall to the printer). The other cable tells the printer what to do and when to do it (from the computer to the printer). An ECM will have a line voltage connection and a constant 24v communication input. Constant-torque ECMs work like PSC motors in the way they use control taps; other ECMs may use DIP switches. ECMs are direct-drive motors that differ from PSCs because they don't have a capacitor. EC motors also have a permanent magnet, which can affect diagnosis if you rarely come across indexing. AC motors use magnetism; when you pass energy through the stator coil, the coil creates an invisible magnetic field, which then induces a magnetic field into the rotor. When the rotor picks up a magnetic effect, it starts to spin. EC motors have that magnetic effect in their magnets. Chris and Bryan also discuss: Regal Beloit's history and brands Effectiveness of metaphors and acronyms in our industry Constant-torque ECM vs. variable-speed motor Motor modules Changes to the ECM design over time ECM manufacturers Three-phase power and controls Reading ohms Glued-on vs. slotted magnets RPM and the effects of poles and frequency of power delivered   For more resources for EC motors, check out regalmmu.com. Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this short podcast episode, Bryan compares strategies for increasing the subcooling, including stacking liquid and mechanical subcooling. Subcooling is a consequence of condensing; when we change the refrigerant from a vapor to a liquid, it will drop below saturation temperature after it becomes completely liquid. There are three phases in the condenser: desuperheating, condensing, and subcooling. The first few rows of the coil reduce the superheat of the vapor entering the condenser. Once there is no more superheat, heat rejection helps the saturated refrigerant transform into a liquid entirely. Near the end of the coil, liquid refrigerant can keep losing heat, and it becomes subcooled. We can only achieve subcooling by stacking liquid in the condenser. When you stack liquid in the condenser, it can give off its heat to the outdoor air. However, too much subcooling isn't necessarily a good thing. Your condensing temperature should be above the outdoor temperature; we call this value the condensing temperature over ambient (CTOA). When your condensing temperature is too close to the ambient temperature, you won't get much heat rejection. If your subcooling goes up because you're stacking too much liquid, you'll drive up your CTOA and head pressure. If you increase your head pressure, you'll increase your compression ratio. Your efficiency will suffer. So, when stacking liquid, you'll want to find a happy medium. However, in systems with liquid receivers, you may not see much liquid stacking at all. Getting some extra subcooling can boost your system capacity. We have some mechanical subcooling devices that use heat exchangers to drop the temperature of the refrigerant in the liquid line. That way, the refrigerant can absorb more heat when it's in the evaporator coil.   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this podcast episode, Bryan, Chad, John, and Allison discuss proper design for ductless and ducted HVAC systems, especially mini-splits. They also discuss potential future improvements to equipment and duct designs. Mini-splits are smaller than traditional HVAC units, so they make zoning a bit easier. However, load calculation plays a huge role in equipment selection and zoning because you must get the right number of zones to match the equipment capacity and meet your load requirements. Proper design is difficult, and a common mistake includes using one piece of equipment to serve the whole house, especially on new constructions. Some designers also don't offer multiple options to the customer, which can be a mistake. Most of the time, we end up downsizing systems, not making them larger. Failing to smooth out turns in the ducts and use proper fittings can also negatively affect airflow and pressure. If you're working on new construction, you'd be best to get an idea of the building design ahead of time and clearly communicate what you need to create a proper duct design. Going from traditional to mini-split duct design has a bit of a learning curve. It's easy to make mistakes when you aren't prepared to deal with the function of variable capacity in mini-splits. You can avoid making mistakes by learning about the equipment (and duct materials) during the selection process, not after the selection. Chad, John, Allison, and Bryan also cover: Adjusting the structure Replacing old equipment with higher-SEER equipment Selecting filters and filter grilles Static pressure options Total length vs. total equivalent length Register sizing Flex ductwork Drop ceilings Texas's energy grid and how it relates to potential setbacks Replacing furnaces with heat pump systems Future micro-split heat pumps   Check out energyvanguard.com and think-little.com. Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this short podcast episode, Bryan explains what atmospheric pressure really is, pressure units and conversions, and why those are matter. Atmospheric pressure is the weight of the air around us pushing down on us. We normally see that value expressed as 14.7 PSI (or 0 PSIG). Before we dive too deep into atmospheric pressure, we should understand some basic pressure units. We may see pressure expressed in microns when we're pulling a vacuum; we are trying to pull the atmosphere out of the system, so our goal is to get as close to 0 as possible. Whenever we pull a vacuum, we get liquid water to boil off and remove molecules inside the system. The industry standard is 500 microns. 14.7 PSI(A) is equivalent to about 760,000 microns, so the micron is an extremely small pressure measurement. You may also see the bar scale, which is equivalent to 1 atmosphere (atm). One bar equals just over 14.5 PSIA. You may also encounter the Pascal unit, which is common on the building science side of our industry. One PSI is equal to 6,894.76 Pascals. When we look at small pressures, such as static pressure or gas pressure, we may use the inch of water column ("wc). One inch of water column is equal to 248.84 Pascals. We also have inches of mercury ("Hg) and the torr (mmHg), which are related to the micron. All units are interrelated, but they have their appropriate applications. Atmospheric pressure matters when altitude enters the equation. When the pressure changes at a higher altitude, the air density also changes. The air is less dense, so you have less oxygen in the air. When you have less oxygen in the air, combustion is more likely to be incomplete. So, we may need to derate furnaces. We also need to take altitude into account when we calibrate gauges at significant altitudes compared to sea level.   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this podcast episode, Bryan and Trevor Matthews discuss compressor short cycling. They discuss how to diagnose and prevent that issue. Trevor and Bryan primarily refer to the Bulletin AE17-1262 throughout this episode, which you can find HERE. Compressor misdiagnosis is very common, but we generally encounter two types of compressor failures: electrical failures and lubrication failures. Short cycling causes a loss of oil in the compressor, which may lead to lubrication-related failure. Each time a compressor starts, there is a reduction in suction pressure; the pressure drop then causes the saturation pressure to drop. That can then cause the oil to flash and shoot out of the compressor. Short cycling has many potential causes, including protectors, thermostats, low and high-pressure controls, oversized condensers, and oversized compressors. In some cases, the controls can also cause operational short cycling to meet customer demands (or failure to match the load). Each manufacturer may have a different acceptable range of starts per hour, but some customers may request more or fewer starts than recommended. Cycle length and frequency are keys to system longevity. So, we can prevent compressor short cycling by keeping the system operating within the manufacturer's specs. There are also several components that can help manage the factors that cause short cycling, including bleed resistors on capacitors, which manage relay operation. Troubleshooting is also one of the main preventative measures; if you replace the compressor without troubleshooting, your new compressor may short cycle and fail prematurely just like the first one. Trevor and Bryan also discuss: Oil behavior and losses Customer demands Manufacturer specs and communication Oversized compressor issues Internal low-leak discharge check valves Digital scroll compressors in a tandem set Short cycling's effects on the whole system Airflow and pressure Load matching   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this podcast episode, Bryan and Craig Migliaccio (AC Service Tech) discuss some HVACR recovery tips and best practices. When you select a recovery tank, you need to know which refrigerant is in the tank. So, it's a good idea to make sure you label each recovery cylinder. You don't want to contaminate refrigerant in the recovery tank, use a recovery tank with contaminated refrigerant, or have too much air inside the cylinder. If the tank is empty, you'll have to pull a vacuum on it before you use it for the first time. Tank fill can be a tricky business. You have the tare weight and water capacity, which you can use to determine the maximum refrigerant fill (factoring in the refrigerant's specific gravity at 130 degrees and the 80% capacity). Weighing in the charge is important so that you stay within an appropriate range as not to build up hydrostatic pressure and risk injury. Recovery machines will give you the quickest recoveries. (When using one of those, you can extend your machine's life by using a filter drier during recovery.) However, you can also keep the pressure of the tank low during recovery; one of our best tips is to put the cylinder in an ice bucket during recovery. Regardless of what you use for recovery, you ALWAYS want to use a scale to weigh the tank as you recover refrigerant. Craig and Bryan also discuss: Hydrostatic pressure Figuring out the refrigerant type in an unmarked tank Contamination Core removal Waterproof scales Leaks and low refrigerant charge conditions Pulling from the liquid and suction lines De minimis venting   Check out Craig's website at acservicetech.com. Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this episode, Bryan and Craig Migliaccio (AC Service Tech) talk about some best practices you can use while swaging and flaring copper. There are a few different ways you can flare copper. Craig likes using a round deburring tool before flaring the copper. After the burr has been cleanly removed, Craig likes using an eccentric flaring tool for the actual flaring. Bryan's favorite flaring tool is the NAVAC battery-powered flaring tool for quick, accurate flares. Both Craig and Bryan agree that it's better not to deburr if you're likely to drop the burr or copper shavings into the tubing. You can also use a tiny bit of Refrigeration Technologies Nylog on the flare face to make sure that the contact is sufficient and secure. Along with flaring, we also have tube expansion or swaging. There are several tools you can use, including drill, hammer, and block swages. Craig likes to avoid swaging tools that leave large gaps; adding heat to make the swaging process smoother may result in oxidation. He prefers using a drill swage on downward-facing tubes; the drill swage can provide friction and heat while keeping the copper tube clean. Overall, Craig doesn't have a favorite swaging tool; he acknowledges that each swaging tool has an appropriate application. It's NOT a good idea to use a tube expander near the compressor. Craig and Bryan also discuss: Deburring in difficult situations Over-reaming with blade deburring tools Flares on higher-pressure systems Comparing the flare size to the flare adapter size Old flaring tools, new flares Ductless or mini-split systems Cleaning the lines if you drop anything inside of them When to use a fitting   Check out Craig's website at acservicetech.com. Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this podcast episode, Bryan and Jim Fultz discuss the White-Rodgers SureSwitch and determine whether contactors are obsolete or not. Contactors are electrical controls; they started off very expensive and usually outlasted equipment, so they are currently smaller, cheaper, and less durable than they used to be. Modern contactors have open contacts and are susceptible to insect damage. Sometimes, an electrical arc can cause contactor pitting, which can weld the points together and render the contacts useless. The SureSwitch is more than a contactor; it is also a brownout monitor, short cycle timer, and a random start timer that helps with brownout recovery. The installation instructions are also thorough and include helpful information like torque specs. It also has a high-visibility LED. The SureSwitch has sealed contacts, so insects can't get to the contact points and cause pitting or failure to close. There is also a latching relay feature, which prevents chattering at lower voltages; the points stay fully closed. The SureSwitch also has a microprocessor that monitors the electrical current going inside the relay. If that microprocessor detects arcing, it knows that the contact points had closed somewhere close to the peak of the arc, and it will adjust itself accordingly. The SureSwitch now has a multi-volt coil, so it can work in residential AND commercial HVAC. Instead of being limited to single-phase 240v applications, we can now apply that contactor to three-phase and 208v applications. Jim and Bryan also discuss: Shunts Contactor chattering Opening or closing at the zero point of the sine wave Mounting points Why insects like to get into contactors Contact configuration Time delays Maintenance contracts and customer loyalty incentives Short cycling for testing purposes   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this episode, Bryan and Craig Migliaccio (AC Service Tech) discuss all the ways that nitrogen can make your job easier. Nitrogen is an inert gas that we can use for purging refrigerant lines and completing scale-free brazing jobs. As techs, we should have at least one inert gas in our trucks to help us do the best job possible. We can use inert gases for purging refrigerant from tubing, flowing and preventing oxidation while brazing, and pressurizing a system for leak detection or a pressure test. You'll also find nitrogen useful for getting oil out of the way before pulling a vacuum. You can also use nitrogen to help clean out a drain line. However, you'll want to be careful; if the PVC pipe isn't secure, you could create leaks (or a total blowout). You can cause severe structural damage if you flow a compressed gas under too much pressure. In some cases, we also use nitrogen to pressurize a gas line (including propane or natural gas lines). We can pressurize that to about 6 PSI to get the pressure up to a more desirable level. (Not to mention, we can reinflate tires with nitrogen, though that's not a strictly HVAC-related application.) Outdoor units may be installed near a dryer vent, which increases the risk of the unit getting dirty. When that's the case, you can use nitrogen to blow off any of the lint and debris. Overall, you can use nitrogen for applications where you'd usually use compressed air. Anytime you work with any kind of inert gas, you need a flow meter and regulator; a normal gauge manifold just won't cut it. Make sure you flow the gases at appropriate pressures, too.   Check out Craig's website at acservicetech.com. Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this podcast episode, Bryan and Craig Migliaccio, AC Service Tech, talk about ultrasonic leak detection. They discuss its effectiveness and if it's worth the hype. Ultrasonic leak detection works best when there's oil on the inside of the tubing; it works best when the system is equalizing after shutoff. Oil or moisture can create a squealing noise, which is an indicator of a leak. Ultimately, lack of success with ultrasonic leak detection comes down to user discomfort and a lack of proficiency. Bubbles alone won't be enough, so it's good to use an ultrasonic detector, even if you need to use a heated-diode or infrared detector as a backup if you lack confidence. You can use nitrogen to assist with leak detection BEFORE refrigerant goes into the system; nitrogen is great because it is an inert gas. However, you must be careful with pressurization, as overpressurization may lead to leaks. You must also keep in mind that nitrogen is the dominant element in our atmosphere, so no leak detector would be able to sample nitrogen alone. If refrigerant is in the system, we can use heated-diode leak detection with relative ease. However, heated-diode leak detectors require a lot of maintenance. In any case, sensors must be matched to the refrigerant you're looking for. Infrared detectors generally work well, but they can be confusing and lead to errors. You must usually keep moving infrared thermometers to catch a leak accurately. Craig and Bryan also discuss: Various types of leak detectors Having confidence in your tools Pressure test vs. leak detection Using your senses first Sensor placement Stratus leak detector Reading the manual Servicing leak detectors Leak reactant (soap bubbles) limitations Relying on guesswork   Check out Craig's site at acservicetech.com. Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this podcast episode, Jim Fultz with White-Rodgers joins us to discuss universal defrost controls. He also explains when and why you might use universal controls. Bryan and Jim cover a universal defrost control for heat pumps (Model #: 47D01U-843). You can follow along by reading the manual HERE. Universal defrost controls can replace OEM defrost controls. Universal controls are sometimes more readily available than OEM parts, so they can be good repair options.  The White-Rodgers universal heat pump defrost control comes with the board, installation instructions, two wiring harnesses, two thermistor-style sensors, and a bag with screws, wire nuts, and other mounting materials. This particular control is compatible with 400 different product SKU numbers, so it's a versatile replacement. The display of the White-Rodgers universal heat pump defrost control gives a lot of feedback; it has orientation options and can communicate more information than mere flashing LEDs. You'll have to set the display orientation in an ideal position, but the controls will help you out with that. You'll also want to keep these defrost controls out of the sun, away from snow, and on the back of the unit. If you don't already have an outdoor coil temperature sensor set up, then you'll want to install the sensor at the bottom of the condensing unit coil. As far as the actual defrost options go, you can set seven different options that correspond to specific manufacturers' controls (OEM Quick Setup). The short cycle time, reversing valve, time delay, and maximum defrost times can be tailored to each manufacturer's equipment. Jim and Bryan also discuss: Spade connections Wiring diagrams for the universal defrost control Outdoor thermostat and electric heat Oil behavior Demand defrost Annual energy savings Table settings Reversing valve shift delay time Auxiliary heat Low-temperature compressor cutout Brownout protection Force-initiation   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this short podcast episode, Bryan and Craig Migliaccio discuss why you maybe don't want to buy new tools. Whenever you get new tools, you have to account for a learning curve and potential change to your practices. Changing your practices and procedures isn't necessarily a bad thing, but you have to practice with the tool and account for different setup and cleanup procedures. However, once you find a good process, you don't want to mess with it too much. You will also want to account for changes to your tool maintenance procedures. When you go from analog to digital tools, you want to make sure you understand exactly what you're measuring. So, Craig recommends spending time with compound gauge sets and to understand how to find superheat and subcooling before you start using digital gauges. It's best to have some good tactile experience troubleshooting a system with analog gauges. Probes have several advantages, including their Bluetooth compatibility, reduction in refrigerant losses, eliminated risk of contamination, and accuracy. However, without a solid foundation in troubleshooting, switching to probes may make you a bit inefficient. Calibration is another factor to consider with new tools. You must know how (and when) to calibrate your tools. Calibration is part of maintenance, and it's something you need to account for whenever you purchase a new tool and learn how to use and take care of it. Whenever you get a new tool, remember that you want consistency, efficiency, and positive outcomes for customers. Craig and Bryan also discuss: Pulling cores Evacuation and recovery Accuracy of sensor technologies Finding the tools that work for YOU Muscle memory with tools Ideal applications   Check out Craig's work at acservicetech.com. Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this podcast episode, we find out how Craig Migliaccio became "AC Service Tech." He makes educational materials and has even written a book. You can check out his website HERE and his YouTube channel, AC Service Tech, HERE. Craig got into the HVAC trade after coming from a construction background; he mostly worked on existing homes and had to handle some HVAC tasks. From there, he got into service and went headfirst into the HVAC industry by starting his own business: a carpentry and HVAC business. Craig also got into the teaching side of the trade, starting off by becoming a maintenance supervisor at a school. As a teacher, he emphasized the importance of basic mechanical skills when he taught high schoolers and young adults. He also noticed that a lot of people were interested in the HVAC industry, so that's what he focused on as a teacher. Craig started making his own videos to introduce students to a topic, and that's where his story as AC Service Tech began. In the classroom, Craig drew from many different resources. So, he decided to continue adding to his knowledge. He eventually compiled his knowledge and began making his own resources. As a content creator, Craig is more independent and less of a collaborator, but he still manages to have an impact on others. He has also published a book (Refrigerant Charging and Service Procedures for Air Conditioning) and a workbook, which are valuable teaching and learning tools. Bryan and Craig also discuss: Obtaining knowledge and building skills Figuring out what you don't know as an instructor Sequence of instruction Making an impact as a writer and instructor Community vs. substance in content creation Using your knowledge to help others Craig's available educational resources   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this short podcast episode, Bryan and Craig Migliaccio discuss the skills and knowledge you should have to start in the HVAC industry. Of course, basic mechanical skills and knowledge are important before you get into the HVAC trade. You'll greatly benefit from knowing where and how to hammer nails, tighten screws, and identify all sorts of tools. When getting into the HVAC industry, one of the low-hanging fruits that you need to consider is your sheet metal skills. Know how to cut sheet metal, use shears, use a duct knife, and make a decent sheet metal job. Take shop classes, work on cars, and get more experience to work on your mechanical skills and tool knowledge. A basic sense of maturity is also crucial for getting into the HVAC industry. You have to be able to work hard and feel some sort of satisfaction from working hard. The HVAC trade is also full of self-starters, so it's best that you're a self-starter when it comes to basic life skills. The location where you will work in HVAC is also relevant. Make sure you have regional knowledge of building design and HVAC infrastructure (duct design, system types, joist orientation, etc.). Take an interest in local homes; look for supply and return registers. Know the HVAC equipment you will be working on and where it will be located in many buildings. It's also good to research terminology and know what you're talking about before you begin applying for HVAC technician/installer jobs. Craig and Bryan also discuss: The problem of the word "should" Using saws and drills Solving everyday mechanical problems Sensing maturity Researching companies before you apply Watching videos and reading books Work ethic and desire to learn   Buy Craig's book HERE and his YouTube channel HERE. Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this podcast episode, Bryan and Trevor Matthews of Emerson Canada discuss strategies for controlling liquid refrigerant in A/C and refrigeration systems. They also read through the AE22-1182 bulletin, which you can find HERE. Liquid refrigerant is one of the most common causes of compressor damage and even failure. It can also cause a loss of oil, which leads to reduced lubrication and subsequent damage. Compressors are vapor pumps, and they are not designed to handle much liquid refrigerant at all. Off-cycle refrigerant migration is one of the main causes of liquid refrigerant reaching the compressor. Controlling liquid refrigerant in the off cycle is important because oil can also saturate that liquid refrigerant inside that compressor. That can cause a severe problem when the compressor starts up again. However, crankcase heaters can keep refrigerant migration at bay, as the refrigerant will be less likely to migrate and condense inside the compressor. Liquid line solenoid valves and pump down cycles prevent refrigerant from going into the evaporator during the off cycle. During a pump down cycle, the compressor pumps all the liquid refrigerant into the condenser and receiver. If anything leaks past the solenoid, the compressor keeps pumping the liquid out. It's also best practice to use a crankcase heater if you use a one-time pump down. Trevor and Bryan also discuss: How to navigate Copeland bulletins Oil miscibility with refrigerant vapor Oil viscosity and its effect on oil return Tripping oil pressure safeties Crankshafts and bearing wear Slugging vs. flood back Minimizing refrigerant charge Continuous vs. one-time pump down Compressor temperature and its effect on liquid refrigerant control Accumulators Overheating or carbonizing oil with crankcase heaters Oil separators   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this short podcast episode, Bryan talks about the TXV power element or power head. He explains what it does and why it's important. A TXV power element threads onto the top of the valve, and it's where the sensing bulb attaches to the valve. It is the component that applies the opening force to the TXV. When you lose the charge in the element, it stops exerting an opening force on the valve. So, the valve completely shuts and doesn't allow refrigerant to get to the evaporator coil. You'll get high superheat and a starved evaporator. Whenever you're checking one of those elements, it would be wise to check for a leak. The capillary tube that goes between the bulb and the element is usually easy to diagnose. You can usually see cracks, leaks, or rubouts quite easily. (If you're used to working with TXVs, you may even be able to hear or feel when the bulb is light on charge.) Because the element threads to the valve, it is usually quite easy to replace without condemning the entire TXV. If you're not sure that the TXV power element is the issue, you'll want to turn the superheat adjustment nut to the fully counterclockwise position (fully open). Once you do that, verify that the superheat is still too high. Then, remove the bulb from the suction line and warm it up in your hand for a little while. If the element still has charge, you'll notice more opening force on the valve. If the valve doesn't change at all, then the power element is the most likely problem. You should also not be able to depress the TXV's diaphragm with your thumb; if you can depress the diaphragm, then the element has lost its charge.   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this episode, Bryan and Alex Meaney talk about value engineering. They discuss what it means to value engineer better when it comes to construction projects. Value engineering is about finding ways to reduce the costs of a project. However, we don't want to do a bad job or use extremely cheap materials just to bring the price tag down. In many cases, builders will want to reduce the cost as much as possible, but we also want to make sure the construction project works in the end. In other words, 2+2 doesn't quite have to equal 4, but we don't want it to equal 3. We can't afford to lose work or do bad work. When we value engineer, we have to bring some sales experience to the table. We will have to negotiate with builders, and the process of value engineering is transactional. We also have to be honest about solutions that will work and ones that won't. It's best to show builders previous value engineering solutions that have failed. You don't have to sound robotic in your meetings with builders, but you want to be sincere and have a consultation process that works for you. It's a good idea to let previous results speak for themselves. However, you will want to mention options that you think the builder will reject. More often than you could imagine, the builders do indeed take those more expensive add-ons. Alex and Bryan also discuss: Speaking your customer's language Coming to the table with the most expensive option Selling vs. consulting Printing your failures Approaching a sales conversation with pros and cons Changing solutions and technologies Finding a consultation process that works Price objections about parts warranties New constructions vs. retrofits Where builders usually want to cut costs Flex duct   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this short podcast episode, Bryan talks about the placement of the TXV sensing bulb. He also explains how it affects the opening force on the TXV. The TXV sensing bulb (or sensor on an EEV) provides the opening force for the valve. The warmer the bulb gets, the more the valve opens; the colder the bulb gets, the more the valve closes. The TXV also has a closing force provided by the spring pressure and equalizer (usually the external equalizer). So, if you have a bulb that has been poorly mounted or insulated, you tend to have more opening force than the design. Your suction line will generally be colder than the airstream around the evaporator coil. If the sensing bulb has poor contact with the suction line, it will likely read warmer temperatures than it should. When the TXV opens more than it should, the valve loses control and could lead to flooded conditions. (If that liquid gets to the compressor, then you could get catastrophic damage.) Generally speaking, improper TXV bulb placement will result in low superheat and potential flooding. When you have a high superheat or a starved evaporator, the sensing bulb placement is rarely the actual problem. When mounting a sensing bulb, the suction line should be clean. Get rid of all Armaflex residue and ensure that the bulb is also clean. In some cases, you may need to insulate the bulb. You must also ensure that you mount the sensing bulb securely near the evaporator outlet, and you can be a few inches downstream of the external equalizer. Another common suggestion is to place the bulb on top of the line if the line is smaller than 7/8" (larger than 7/8", you can mount the bulb at 4 o'clock or 5 o'clock on the line).   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this podcast episode, Bryan, Erich Vinson, and Anthony Marino talk about dealing with difficult customers in the HVAC industry. When working with customers in general, it is best to make eye contact with the customer, listen to them, and put yourself in their shoes. When dealing with difficult customers, we must remember that there are several potential causes for their "difficulty." You can't control that; you just have to let the anger run its course and diffuse the situation as much as possible. Some customers also try to stir up drama; in those cases, it is best to focus on the mission and stick to fixing the problem at hand to avoid adding negativity to the situation. Instead, we want to focus on communicating the appropriate information while avoiding overcommunication. Being thoughtful is the key to good customer service. So, follow-up is especially important because it shows that we care about the customer show attention to detail, and have been deliberate in our service. Commercial managers and owners also care about their bottom line. So, we need to be attentive to their business-related concerns. Price objections are common among difficult customers. You'll want to put yourself in the customer's shoes and give them the choice to order a cheaper part. You can use that situation to explain the value of your labor. If you keep your body language under control, you can handle those difficult conversations well. Erich, Anthony, and Bryan also discuss: Residential vs. commercial HVAC customer experiences Managing our own emotions before we approach customers Being dragged into corporate or landlord drama Being deliberate Where price objections come from What makes residential and commercial customers upset Dealing with disrespect   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this short podcast episode, Bryan explains how hydrostatic pressure can build up in refrigerant cylinders and present a hazard to technicians. Your refrigerant cylinders have tare weight and water capacity values stamped on the tank. You'll want to use these when weighing the refrigerant you recover because you don't want to exceed 80% capacity. However, capacity changes when the liquid density changes; that density will change with pressure and temperature. Hydrostatic pressure builds up when you have overfilled refrigerant vessels. When those vessels get warm, the density will decrease, and the liquid refrigerant expands. At some point, the vessel will contain 100% liquid and can no longer expand, so hydrostatic pressure will build. When that happens, you have a dangerous situation on your hands; the vessel may even explode. AHRI recommends using 77 degrees as a guideline for figuring out the vessel capacity. However, we recommend using 130 degrees out of an abundance of caution; the back of your van probably won't get much hotter than that, so we use it as an operational maximum. We only get hydrostatic pressure when we recover refrigerant as a full liquid. When we recover refrigerants like R-410A in the liquid phase, we get a 45-PSI increase for each degree (Fahrenheit) of temperature increase. For R-22, that number is about 60 PSI; with R-134A, that number is about 40 PSI. When we get temperature swings from an ice bucket (~32 degrees) to the back of a hot van (~130 degrees), the pressure can build up within the vessel. We also need to think about hydrostatic pressure when pumping down systems with microchannel coils. Hydrostatic pressure can build up in the receiver, and liquid can fill your condenser.   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this podcast episode, Bryan, Trevor Matthews, and Jim Dick from Emerson give us all an introduction to industrial refrigeration. Jim works with contractors to provide tech support. He also does the startup and commissioning of refrigeration compressors and gas compression units. Industrial refrigeration refers to warehouses and distribution networks. Grocery refrigeration is commercial refrigeration for the end-user, but industrial refrigeration is commercial refrigeration for the distribution network before the product reaches the end-user. Many of these large systems use natural refrigerants (including ammonia) and are easier to work on because of their scale and easy-to-access valves. However, the ammonia charge is small and is almost never in the same space as people, and industrial equipment often uses a brine fluid for heat transfer. If techs want to move into industrial refrigeration, Jim recommends attending seminars on ammonia and natural refrigeration. Trevor believes that trade schools are currently lacking industrial refrigeration programs, and he hopes to see that change in the future. Most people who succeed in the industrial side of the business are good electrical troubleshooters. When working on large equipment, you will have many electrical sensors and controls. The piping side is usually easier to learn than the electrical side, so some electrical proficiency is desirable. Many techs struggle with electrical concepts, so we encourage going back to the basics; do whatever you need to do to get a solid foundation. There are also many electrical contractors who would love to teach people who struggle with electrical concepts. However, learning about electricity also requires commitment and honesty about when you're in over your head. Bryan, Trevor, and Jim also discuss: Emerson's Vilter brand Ammonia-CO2 cascade systems Propane refrigerant Gaps in industrial education Building electrical troubleshooting skills Manufacturer-contractor relationships and dealership networks   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this short podcast episode, Bryan talks about the strategies we can use to prevent refrigerant migration during the off cycle. We often see refrigerant migration when the compressor is lower than the evaporator, especially in low-ambient conditions when the refrigerant can condense in the crankcase. When the compressor starts up, you get a violent reaction as the refrigerant boils off and ejects oil. That can wear out the compressor and reduce the lubrication. Crankcase heaters are some of the most common devices we use when preventing refrigerant migration. These can be of the insertion or belly-band variety. As their name suggests, crankcase heaters keep the crankcase warm during the off cycle to prevent the refrigerant from condensing. However, that isn't a complete solution for stopping flooded starts and other issues. In the cases of flooded starts, we can use liquid line solenoid valves. These valves close off the liquid line when de-energized (in the off cycle). In many cases, we can use these WITH a crankcase heater for more protection. We also use pump down solenoids to prevent refrigerant migration. In these cases, the liquid line solenoids will de-energize while the compressor and condenser fan keep running. Then, the system cycles off on a low-pressure switch. If there is any leakage in the valves, the compressor can short-cycle. You can prevent short cycling if you have a pump-out control. However, it is usually a good idea to use a pump down solenoid with a crankcase heater. We also use hard shutoff (HSO) or non-bleed TXVs in residential HVAC. These function a bit like a liquid line solenoid valve, but you'll also want to use a crankcase heater for added protection.   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this podcast episode, Eric Mele joins Bryan for some weird transformer talk. They discuss corner-tapped transformers and some thought experiments. We hadn't been able to get our heads around corner-grounded transformers until recently. "Grounding" doesn't necessarily change the phase or lead that you ground. If you take the secondary of a 24-volt transformer and measure from your two colors, you'll measure 24v. However, if you connect a lead to ground, you'll still read 24v. (Don't ground both, or you'll get a short.) Ground is just a path back to the power source. Electrons don't suddenly "leak" from something connected to ground. Grounded and neutral conductors can potentially be dangerous. There can still be potential even though your leads wouldn't pick it up. In residential HVAC, we're used to seeing neutral and ground connected at the main distribution panel. However, it's not always okay to connect ground and neutral or use ground as a current-carrying conductor. If you've got split-phase power going into a regular home, you've got 120 volts 180 degrees out of phase with each other. If we don't have a center-tap neutral, it would function similarly to a 24v transformer. In that case, it's not necessarily unsafe to read 0v on neutral. We get tripped up because we think in terms of using a meter, not in terms of actual potential voltage. In a delta configuration, you will have a high leg connecting to neutral (B phase is usually high; A and C phases are usually normal). You can't really center-tap a delta, so you have to tap the center of one phase. Eric and Bryan also discuss: Working out of a truck vs. a van Shunting high-voltage spikes to ground Center-tapped transformers and "wild legs" Ground is NOT necessarily the earth Hot legs on the primary AND secondary   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this short podcast episode, Bryan compares internal and externally equalized valves. He also covers how forces act upon the TXV. Equalization does not happen on the off cycle. When we talk about equalization, we are merely talking about a force that balances against the bulb force. A TXV sets the superheat within an operating range at the evaporator outlet; the sensing bulb on the TXV detects temperature and pressure at the evaporator outlet. So, those readings apply an opening force to the bulb. (Think of this process as being quite similar to you measuring the superheat and suction pressure.) The equalizing force is a closing force. When the closing force is applied to the TXV, it balances against the opening force provided by the sensing bulb. So, we have two ways of providing the closing force: within the valve at the evaporator inlet (internal) or externally. In an internally equalized TXV, the closing force that equalizes the bulb's opening pressure is taken at the evaporator inlet. The measurement is internal to the valve at the evaporator inlet. However, in externally equalized valves, the closing force comes from the evaporator outlet, which is beyond the valve. Externally equalized valves work best on systems with significant pressure drops within the evaporator coil or on systems with distributors. If we were to use internally equalized TXVs in those cases, it would be like measuring superheat at the wrong location. If you don't have a significant pressure drop, then you can use an internally equalized valve. These systems will usually be small (less than one ton) and won't have distributors. Most of the time, we will see externally equalized TXVs; these will ideally take readings within six inches of the bulb.   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this podcast episode, Bryan talks with Bill Spohn about his most recent project, SpohnHome. SpohnHome explores Bill's journey in custom home performance. Projects are complicated because so many trades work together to accomplish a building. However, custom homes are particularly challenging, especially in Bill Spohn's case. His home is a "personalized performance home," so he's prioritizing energy efficiency, indoor air quality, and comfort as well as aesthetics. The home's design and purpose resemble that of a passive building. Although much of the construction went smoothly, there was a misunderstanding about the sewer conditions; unbeknownst to the township, a nearby property had a private sewer installed, so Bill could no longer tie the plumbing into the existing sewer system. That development put a monkey wrench in the plans, and Bill's team had to come up with new ideas for a septic system (and had to follow a bunch of rules). Even though a project may seem to have a perfect plan, setbacks can still occur due to miscommunication or unfortunate events (such as the death of someone integral to the project, as Bill experienced). Bill also used an air-source heat pump with zones for his HVAC system. He had to experiment with his home's ventilation to strike the ideal hybrid solution, as IAQ and efficiency were very important to him on this project. Custom constructions also have plenty of room for the team to do some unconventional things, including making 3D models of the home that gives accurate volume measurements. Bryan and Bill also discuss: Customer follow-up Modular building Plumbing conditions Divining and drilling wells Fresh air and filtration solutions Air sealing and blower door testing Dealing with snow Humidity considerations TruTech Tools news   You can find out the details of Bill's home construction at spohnhome.com. Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this short podcast episode, Bryan talks about some tips you can use when working with a multi-position service valve. A service valve will have a line connection, which connects the valve to your line set. You also have a gauge port that you can connect to, a valve stem, and a packing gland nut (directly beneath the valve stem). If your stem is completely back-seated, then your gauge port is completely closed from both the line and system connection. If you crack the stem off the back seat, then the gauge, line, and system can all communicate. Completely front-seating the valve will generally close off the line connection, but it may also close off to the system connection on some valves. Mid-seating puts the valve stem right in the center for maximum flow. If you're working with a service valve in a grocery refrigeration application or old A/C system, you may be tempted to use any old wrench on the valve and can damage the valve. So, whenever you work with one of these valves, make sure you use a refrigeration service wrench only. Also, be sure to exercise caution. The packing gland nut helps keep everything together and prevents leaks. However, you need to loosen it by a quarter to full turn before opening the valve. If you don't loosen the packing gland nut, you will have a hard time adjusting the valve, and you may even damage it. Whenever you do any brazing on or near a service valve, be sure to protect it from the heat (such as with Refrigeration Technologies WetRag). You'll also want to mid-seat the valve before you start flowing nitrogen.   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this podcast episode, Bryan and Trevor Matthews from Emerson talk through scroll compressors in commercial refrigeration equipment. Scroll compressors are not a monolith; although they all function similarly, they have different fine details and manufacturing protocols by application. Low-temp, medium-temp, high-temp, and A/C scroll compressors each have unique designs, operating conditions, and service considerations. Copeland has a medium-temp scroll compressor line (ZB and ZS) for medium and high-temp applications. They also have a low-temp line (ZF). Within those lines, there are also small displacement and large displacement compressors, advanced scroll temperature protection devices, and other unique features. Since scroll compressors are prone to thermal overload, some Copeland compressors have advanced scroll temperature protection devices. These devices help redirect the discharge gas to the suction gas, which gets the compressor to trip out on thermal overload more quickly. In cases when you're tempted to condemn the compressor, shut it off and let it cool down before you jump to conclusions. The compression ratio is the main difference between A/C and refrigeration scroll compressors. A/C scrolls can handle a compression ratio of 11:1. Conversely, refrigeration scrolls can handle 26:1 compression ratios. Copeland scroll compressors also have electronic controls. When setting up these controls, you need to keep the scroll compressor type and special features in mind, including temperature protection devices. In other words, you can't set up a low-temp compressor the same as a medium-temp and so on. Bryan and Trevor also discuss: Differences across Copeland scroll compressors Low-temp vs. medium-temp vs. high-temp refrigeration Copeland compressor nomenclature Compressor pump down Proper vacuum CoreSense diagnostics Vapor injection and compressor capacity PTC (positive temperature coefficient) thermistors Using AE bulletins as tools Crankcase heaters and other accessories   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this episode, Bryan and Bert talk about soft skills. They also discuss why soft skills are important in highly technical trades. Bert's class defined "soft skills" as communication skills; these can be verbal but may also include body language and how we respond to emotional situations. Bert thinks these skills are some of the most important skills you can develop in the HVAC industry and in life overall. You will only be able to make the most of your talents and career if you work on your communication and people skills. You can start improving your soft skills when you learn to see yourself accurately. Are you introverted or extroverted? Have a Type A or Type B personality? Once you can see your strengths and weaknesses, you can learn where you need to be more engaged with the customer or give them some space. You can analyze your relationships to see where your strengths and weaknesses are (or if you're the problem in your interactions with others). Listening skills are also crucial for interactions with customers. Being a good listener, keeping your emotions in check, and proposing solutions will give your customers a better experience. Having the discipline to be a good listener will also help your work and personal relationships. If you need some tips or have some questions about your general vibe, ask people who want to tell you the truth about their "experience" with you (and listen to them). Body language is also critical. Do your best to show that you're attentive, helpful, and friendly. Bert and Bryan also discuss: Residential vs. commercial interpersonal skills Skills vs. natural abilities Metacognition Customer experience Discipline Working well with your bosses or other employees Eye contact Complaining (just don't do it) Dos and don'ts of showing empathy   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this podcast episode, Bryan and Jim Bergmann talk about gas furnace diagnosis and inspection. They cover the ins and outs of furnace assessment. A gas furnace diagnosis requires a few important measurements, but a solid visual inspection is perhaps even more vital. You'll want to look at the venting and condensate disposal systems. You'll want to make sure the flue gas can escape properly and that the terminations are correct and safe; if you're not looking at the manual and checking the venting, you can put your customers at risk of serious CO poisoning and even death. On the condensate disposal system side, you risk trapping flue gases in the trap. Condensate can also build up into the secondary heat exchanger, which leads to a rise in CO. We also need to look out for issues on the electrical side. Reverse polarity and poor grounds are often the greatest culprits for electrical failures. Broken connections are also common problems as with other HVAC systems. Dust and dirt can also get behind the circuit board, which can cause flame rectification problems. Fixing an electronic circuit board can intimidate some techs, but soldering a circuit board is quite a bit like soldering a coil. When it comes to measurements, your pressures are going to be some of the most important readings you can take. It's also a wise idea to have your own combustion analyzer and make sure to take care of it over time. Bryan and Jim also discuss: New MeasureQuick developments Measurements to use in MeasureQuick CAZ testing CO sources 90+ furnace condensate drains Air filtration and MERV ratings AHRI CO testing steps Conduction through the flame rectification circuit Incoming gas pressure Incorporating MeasureQuick into diagnosis   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this short podcast episode, Bryan talks about the differences between pitot tubes and static pressure probes. He also explains how each one works. People often mix up static pressure probes and pitot tubes. A pitot tube is a tube within a tube, and a static pressure probe is just a tube with holes in the side but not at the end. When we measure static pressure, we're measuring the pressure against the duct. (Think of it as balloon pressure rather than air velocity.) We use static pressure probes to look for a differential between a probe and atmospheric pressure or between two probes. As the air travels around a static pressure probe pointing in the correct direction, its velocity force will not act on the probe. We do NOT want to measure velocity with a static pressure probe. Pitot tubes, however, come in twos. One tube comes off the side (attach a hose to this one), and one comes off the bottom. You can use the side port of the pitot tube to measure static pressure. You also have an end port to measure total pressure, which is static pressure plus velocity pressure. When using a pitot tube, you can get the velocity pressure by subtracting the static pressure from the total pressure.  You point the pitot tube into the airstream to get that measurement. However, pitot tubes will only give you accurate data if you have an accurate manometer and have ideal velocity conditions. Proper positioning and duct traverse techniques are also integral to getting accurate data.   Learn more about Refrigeration Technologies HERE. If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.