HVAC School - For Techs, By Techs

In this short podcast episode, Sal Hamidi of ProductsByPros joins Bryan to discuss what manometers are and how they measure pressure. Manometers measure pressure at a much higher scale than a micron gauge but lower than that of a pressure gauge; they measure pressure differentials by comparing static pressure to another source of pressure as a reference. Across all segments of the industry, we use manometers to measure static pressure. Static pressure is the pressure of air against the duct, not the actual air velocity. (Static pressure can give you an idea of the airflow, but you need pitot tubes or flow hoods to measure the actual airflow.) We can also use Magnehelics to measure static pressure, but it's just a specialized type of manometer. We can also use manometers in conjunction with blower doors to perform zonal pressure diagnostic tests. Blower door tests require the technician to pull the house pressure down to -50 Pascals. Then, the technician uses a very precise manometer to help determine the air changes per hour (ACH). Manometers are also invaluable tools in markets with lots of gas furnaces, as they measure gas pressure. You measure gas pressure on the inlet AND outlet side of the gas valve to make sure the pressures are correct. Every tech should have a regular manometer for everyday use to measure static or gas pressure. Techs on the building science side of the industry should have a precision manometer, which is an expensive but very precise instrument. Sal and Bryan also discuss: Pressure scales (in wc., PSI, Pascals, etc.) Absolute vs. relative scales Accuracy, precision, and resolution   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.

Michael Housh and Jim Bergmann join Bryan to look into the crystal ball to see the future of air conditioning and design the PERFECT residential system. Self-contained propane heat recovery chillers are futuristic devices that do simultaneous heating and cooling. While they may not be suitable for all climates, they can switch between heating and cooling modes, like heat pumps. They may also be able to service domestic hot water centrally as well. Although propane heat recovery chillers are impractical for residential use right now, they could hold the key to the future of air conditioning. Geothermal systems sound like a great energy source in theory, but the cost of installation may not be worth the investment for many homeowners. You only get payback on geothermal when it's time to replace the unit, so it takes a long time to recoup your initial expenses. While these systems may work well in northern climates, you won't see many geothermal systems in the South. Even though some customers have personal convictions about saving energy and efficiency, cost, effectiveness, and maintenance are going to be the most important factors to most homeowners. One of the challenges to adopting new technology is the lack of knowledge of new technologies. We expect a lot out of technicians when it comes to knowing how components work and what they do. When we introduce technology-heavy new systems, it can take a long time for technicians to become proficient with those technologies. Michael, Jim, and Bryan also discuss: Pool heating Equipment ROI Solving the flammability problem of R-290 Radiant heating and cooling Heat exchangers and piping resistance Pre-conditioning outdoor air Niches in the industry Ice banks New flammable refrigerants   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.

Thomas Talhelm, the founder of Smart Air, joins Bryan on the podcast to talk about how a filter and a fan in China sparked an IAQ revolution. The simple device changed his thinking about air purification. As a graduate student in China, Thomas witnessed the Beijing "Air-pocalypse" firsthand. That was when he became aware of the issue of air pollution and the potential health issues it can cause. So, he dove into the world of air purification. The most popular air purifier on the market was about $1,000, but Thomas felt that the price tag was way too high for protecting human health. Instead, Thomas decided to make his own air purifier with just a filter and a fan. He bought a laser particle counter to test his DIY air purifier and began publishing his data to make his health and safety data accessible and make cleaner air available to everyone. So, the goal of Smart Air is to lead an IAQ revolution by educating others about air pollution, sharing data about IAQ products, and improving health. The goal is NOT to earn lots of money. Thomas also uses his own experiments and data to answer tough but practical questions. For example, he has done studies to discover if indoor or outdoor air is cleaner. (Of course, the answer depends on location, but it's still a question that we've needed to ask for the sake of consumer health.) However, educating consumers and being transparent about the data requires a delicate balance of marketing and communication. Thomas and Bryan also discuss: Social enterprises vs. non-governmental organizations (NGOs) Smart Air in international markets COVID-19 and masks Being a researcher/professor Organizing data Sharing data in workshops The future for Smart Air   Check out Smart Air at smartairfilters.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 the steady-state voltage problem that can take out inverter boards and what to do about it. Inverter-driven equipment refers to a variable-frequency drive with ECM compressors and fans. We're talking about modern split-phase equipment rated for 208v or 230v power. However, the split-phase power will yield 240v. Most motors and components for 240v equipment have ratings for 230v AC power. L1 and L2 power can also be significantly higher than 240v, sometimes going as high as 250v. Inverter boards have a widespread failing problem in locations with high steady-state voltage. Surge protectors only work for spikes in voltage, such as lightning strikes; they don't protect equipment from steady-state high voltage. Inverter boards are rated for 10% voltage over 230v and 5% lower than 208v. The operating range is 197-253v, but consistent overvoltage that doesn't quite reach 253v can still lead to failure. We attempted to fix the problem by using the ICM493. These protectors have single-phase monitoring and have a NEMA 3R rating (suitable for outdoor usage). You can set the high and low voltage limits and get the benefits of thermally protected MOV surge protection. Although the inverters stopped failing, they started shutting off when they weren't supposed to. We discovered that the power companies were allowed to run up to 252v, which was right on the limit! Power companies may also run voltages 1-2v higher than 252v, so that explained the failures and shutoffs. If you decide to use the ICM493, you need to calibrate the voltage based on measured voltage (such as from a voltmeter). Then, you set it for 230v +/-10%. If you experience recurring problems with overvoltage, the power company probably won't be much help. In that case, you can use a buck-boost transformer.   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.

Jim Bergmann and Michael Housh join Bryan to talk about testing A/C vitals. They discuss the new vitals mode in MeasureQuick and how it works. As with many of MeasureQuick's other functions, vitals mode is an invaluable tool for green and experienced HVAC techs alike. The new vitals mode helps us with charging, airflow, and other staples of A/C testing and commissioning. Vitals mode allows the user to give MeasureQuick some information about the system; when they provide that information, MeasureQuick can instruct them to use the most appropriate charging method. When you add enough refrigerant to create a liquid seal, you will begin to see a temperature drop across the evaporator. At that point, MeasureQuick would inform the user to stop charging and raise the airflow. MeasureQuick's vitals mode guides the user through the commissioning process by focusing on the main drivers: airflow and charging. The app also focuses on secondary drivers, including low-pressure, high-pressure, superheat, and approach. You can get to vitals mode by hitting the "trending" button twice. At the bottom, you can start with the quick charge; you then choose your refrigerant and the charging method. Vitals mode can help several new techs during the cooling season. The weigh-in feature helps prevent overcharging, which is a problem that's all too common. MeasureQuick has been working to fill the gaps in training by helping technicians do jobs correctly and avoid the confusion of listening to many different senior techs or trainers. Jim, Michael, and Bryan also discuss: Subcooling and line length Approach Sensible capacity vs. latent capacity Target temperature split Superheat Trade school vs. field training for charging Increasing the quality of HVAC instruction   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 to use liquid line temperature as a quick diagnostic indicator on split A/C systems. Liquid line temperature is one of the first things to check when you approach a system. Checking that temperature is also a great way to get into non-invasive testing. The temperature should be between 4 and 15 degrees warmer than the outdoor temperature (unless it is wet). If the liquid line is cooler than the environment, then there could be a restriction. If there is a restriction, you could have a clogged liquid line drier or a partially closed service valve. When you have a larger condenser coil in relation to your capacity, your liquid line will be closer to the ambient temperature; the refrigerant must be at a higher temperature than the outdoor air to give off heat. You should also not see a pressure drop across the liquid line. An important value is the condensing temperature over ambient (CTOA). On a normally operating piece of equipment, the condensing temperature will be 15-30 degrees above the outdoor temperature. The CTOA is a design feature that sets the differential between the saturation temperature and the ambient temperature. So, before the refrigerant subcools, it will be 15-30 degrees above the outdoor ambient temperature. Subcooling goes below the CTOA. If we have a 30-degree CTOA and subtract 10 degrees of subcooling, then our liquid line will be about 20 degrees above the ambient temperature. If you add up all the numbers and find that the liquid line is warm, then you likely have an airflow restriction (dirty condenser, etc.). You shouldn't see a temperature differential across the liquid line; if you see one, then you likely have a restriction in the liquid line or lines that are too long.   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 live podcast episode, we discuss viruses, bacteria, and fungi. We also explain how they interact with HVAC equipment, their effects on indoor air quality, and how businesses can protect their customers and employees. Since we work with the public, we can minimize the risk of viral transmission by keeping our distance between others and avoid handshakes and other forms of contact. However, we also have to respect the feelings of the customers we're serving. Many people confuse viruses, bacteria, and fungi (mold). All particles are small and would typically pass right through a MERV-8 filter; you typically need MERV-11 or better to catch all three. While our equipment can harbor those particles, the equipment can't create them. While bacteria and fungi can propagate on their own, viruses need a host to propagate.  Viruses can go airborne, but they only grow and propagate inside our bodies. So, we don't need to worry about minimizing growth on surfaces or inside HVAC equipment. We make it harder for bacteria, fungi, and viruses to survive by keeping the relative humidity between 30% and 55%. That is part of the reason why certain viruses become prominent seasonally, though our own immune systems are also a factor. Probiotic cleaners also exist to attack biofilm on surfaces. To achieve that goal, probiotic cleaners promote good bacterial growth to fight the bad growth we want to eliminate. We may expect probiotic technologies to improve even more in the future. However, those won't affect viruses strongly because viruses don't GROW in equipment. We also discuss: Virus transmission Masks and gloves Mobile air scrubbers HVAC technicians as essential workers Microns Legionella COVID-19 vs. influenza HEPA and activated-carbon filtration Photocatalytic oxidation (PCO), bi-polar ionization, and UV lighting Is oxidization effective? Good vs. bad bacteria and probiotic cleaning   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 science and how to balance practice and experience with the “why” behind what we do. He also explains how either one can cause an error if you aren’t careful. Science is not just about reading nerdy theories in books; it's all about understanding why the processes in our world. In that sense, many of us field technicians are scientists. When we use problem-solving skills in the field, we try to understand what is going on and why our proposed solutions might fix the issue. We partake in experimentation all the time when we look for solutions, too; we formulate hypotheses about what will happen when we apply a fix, and we test our hypotheses by seeing what happens. However, there has also been a rise in pseudoscience, which uses observation to come to a conclusion WITHOUT the due diligence of experimentation. We see this quite often in brazing; some old-timer technicians use poor brazing practices but still manage to get leak-free joints. While those brazing practices may work on the low side of the system, you can't expect the results to be the same when brazing in a compressor. The methods may "work" in some cases, but they're not backed by scientific understanding, so they can't produce good results under higher-pressure conditions. Science is not perfect and can go wrong, though. When we don't understand the application and the "why" behind the work, we can't expect products and tools to work as they're meant to work. That's when errors pop up. To avoid those errors, investigate the "why" and test out your hypotheses. Bryan also discusses: Multiple ways to do things Thomas Edison vs. Nikola Tesla Poor brazing practices Not pulling a deep vacuum Ozone generators and deodorizers "Hack" work   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.

We discuss some of the new, possibly strange-sounding business processes we've decided to implement at Kalos in 2020. First of all, we are going to add terms and conditions that our customers must agree to. These terms and conditions include a "hold harmless" disclaimer regarding viruses, fungi, and bacteria. Florida forbids us from discussing mold, so a "hold harmless" disclaimer protects us from liability for something we aren't even allowed to discuss. We also have to reinforce automobile safety to protect ourselves and our employees. Small fender-benders can spiral into serious legal problems when we lack proper evidence, so we decided to use GPS technology and dashcams in company vehicles. That way, we can collect more data on incidents to see who is really at fault in an accident. We've also clarified safety practices in our employee handbook. New business processes also include changing how we pay people per diem. In our construction and refrigeration divisions, our employees eat and sleep out of town, so they need compensation. We've put new processes in place to reimburse employees for those expenses without taxing that money. We also set rules based on the time of year, zip code, and average food/lodging rates. Overall, most of our new business practices are going into place to make Kalos a safer workplace with more efficient administrative processes We also discuss: Warranties on certain products "Assumption of privacy" Company credit cards vs. gas cards Dispatch/service software IRS "proof of transactions" Nurse triage and dealing with injuries Worker's compensation rates OSHA training and SDS Document signage and subcontractor agreements SambaSafety Slack vs. ServiceTitan Keeping track of parts, inventory losses, and supply house plans "Kaizen"   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.

Ben with Infinitum Electric comes on to tell us more about his super-innovative, groundbreaking PCB (printed circuit board) motor technology that we saw at AHR 2020. The Infinitum motor is a relatively simple permanent magnet motor that can also work as a generator. Infinitum got its start with generators, and the groundbreaking new motor technology works quite similarly to generators. These motors can also work with variable frequency drive technology. In this groundbreaking motor, the traditional stator has all of the iron and copper taken out, and copper is etched into the circuit board. When you take the iron out of the equation, you eliminate core losses and get a much more efficient stator. Instead, electromagnetic waves travel through the air via flux transfer over the air gap, which rotates the motor. The machine has low inductance overall. Energy efficiency is the core of Infinitum's philosophy. The original idea for Infinitum's motor came from optimizing performance in specific applications; Infinitum increased the efficiency while keeping the motors small and quiet. After that, the motor outgrew its application and opened the doors to innovation. There is great promise for Infinitum motors in the aerospace industry because they are lightweight, quiet, and highly efficient. However, Infinitum is also interested in short-term applications, including fans, pumps, and compressors in the HVAC/R industry. Ben and Bryan also discuss: Generator vs. motor technology VFD system integration How to operate motors with low inductance Investors and why they choose to invest Development of major automotive and aerospace technology Serviceability of the motors Using printed circuit boards as stators Starting conversations with OEMs   Check out more about Infinitum and its new motor technologies at infinitumelectric.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.