HVAC School - For Techs, By Techs

This podcast is by Sal at Products by Pros, featuring Bryan Orr of HVAC School. In this episode, Sal asks Bryan all about micron gauges.   Products by Pros Guest: Bryan Orr   What should technicians look at when deciding on a micron gauge? You should look for superior accuracy and resolution, especially if you'll be doing decay testing. You need to see what the trends are in clear detail. (The Bluvac app makes that easy.) Why should a tech even use a micron gauge? You use a micron gauge to verify that you have pulled a proper vacuum. What role does fear or pain play in the use of micron gauges? People respond primarily to pain; most technicians in the field know what they can get away with to avoid the pain of punishment for bad practices. What type of technician doesn’t care about proper vacuum or micron gauges? They typically come from companies that don't care about having clear startup and commissioning practices. What is the cost of adoption for high-end tools? Technicians think in terms of the tyranny of the urgent. They have to take time to learn it, and many of them don't have that time. What are the pressures techs deal with? Scheduling pressures are already immense, and field techs are also under constant pressure to get work done and do their jobs even better. How can techs save time and relieve pressures? Learn how to do things right and become proficient with newer, better tools. How do you pull a proper vacuum? Don't use leaky manifold gauges during evacuation; just use good-quality vacuum-rated hoses. Use core remover tools and keep your micron gauge as far away from your pump as you can get it during evacuation. What are the incentives for techs to do things properly? A common thread among many techs is that they want to avoid blame; if we focus on reducing blame, then techs might feel more encouraged to learn and do things correctly. (There will always be sticks in the mud, though.) What role does integrity play when it comes to business owners doing things properly? Integrity comes in when we show techs how to do procedures right. When you teach techs how to do things right, the work will speak for itself, and your company will earn a positive reputation. What micron gauge from AccuTools would you suggest for technicians? I recommend the Pro for new techs or installers, the LTE for intermediate technicians, and the Micro for pros. Why do you consider AccuTools micron gauges reliable? I consider those products reliable because they work consistently with the typical wear-and-tear that's expected in the field. Except in cases of extreme abuse, they seem to maintain their sensing abilities very well.   Looking to learn more? Go check out hvacrschool.com/evac or the AccuTools YouTube channel HERE. Want to have your local suppliers carry AccuTools? Reach out to sal@productsbypros.com If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

Rachel and Eric Kaiser join us to talk about connecting STEM concepts to the trades. They also explain how to teach STEM in a way that sticks. STEM refers to science, technology, engineering, and math. In traditional classroom settings, teachers usually tout these subjects as the ones that lead to the most promising careers. However, STEM concepts are not limited to their respective subjects; we use many of those scientific and mathematic concepts in the trades as well. Rachel believes that undergraduate programs would be more effective if they focused more on teaching critical thinking and less on making students meet requirements for degrees. Eric believes that traditional education needs to be more holistic; right now, trades education fixates on details; that approach may help for teaching specific tasks, but it doesn't broaden the students' knowledge. We can start talking about STEM more broadly when we start eliminating stigmas around STEM topics. For example, many students dislike math, but many of those people still use math effectively in several real-world applications without knowing it. We can break down that stigma against math to start having productive discussions and connecting STEM to the trades and other careers. The next step is to spark interest in others so that they seek out new STEM knowledge. The HVAC trade has many scientific concepts in play, even though we focus on diagnostics and field techniques at work. Most of our diagnostic skills are informed by the principles of heat transfer and phase changes. Rachel, Eric, and Bryan also discuss: HVACR Training Symposium Undergraduate vs. graduate programs University research and funding Principles of algebra in real life Gas laws and galvanic corrosion as chemistry concepts in HVAC Theoretical vs. diagnostic vs. instructional applications Continued learning vs. degree programs Applications and limitations Hands-on BEFORE theoretical Choosing to learn Improving safety and productivity through education   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.

This short episode is a review of a list of installation reminders made by Kalos manager Jeff Crable. Kalos is doing a bunch of these installs for a commercial customer. Hopefully, the business leaders can take a few things from our checklist and help out their installers. Whenever we do an install for our large commercial customers, we give our installers a long checklist of reminders; that way, they can do the best install possible. Some of those install reminders include: Don't rush the details. Ensure the drain line is clean, pitched correctly, trapped, ventilated, and insulated. Install float switches in the unit and auxiliary pan. Wire in series and test. Replace the auxiliary drain pan or ensure that it's in good condition and has proper sizing. Hang the auxiliary drain pan WITH Unistrut; don't hang with wire. Install a new thermostat. Attach and hang the ductwork properly; silver-tape will NOT support duct board plenums. Replace incorrectly sized breakers (for licensed electrical contractors only). Replace old and faulty disconnects (for licensed electrical contractors only). Ensure that the outside conduit is watertight or replaced. Anchor condensers properly with isolators if the pad is attached to the building foundation. Mark the unit with the correct number using paint and stencils or vinyl stickers. Post pictures of the units and data tag in the appropriate location in our communication software; make detailed notes. Address vertical air handlers and take them as they come. If a unit is in a difficult area, try moving to a more accessible place if you can. Pour gallons of water into the drain pan and observe draining. Listen for noises of concern. All work will be checked by lead techs or managers. Get everything right the first time if you want a full bonus.   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 face-to-face discussion, Bryan and Kaleb share some tips for diagnosing and replacing the reversing valve on a heat pump. These valves may also be known as four-way valves. Kaleb and a trainee recently had to diagnose a heat pump with a scroll compressor. The motor was also over-amping due to a failed capacitor, and the compressor was making a metallic grinding noise. Because reversing valves are pilot-activated, they need a pressure differential to shift, so the scroll plate can sometimes pop up and make noise during bypass. Another possibility was that the compressor could have been running backward, but that wasn't the case. There are some cases when techs misdiagnose a compressor problem as a reversing valve failure; however, in Kaleb's case, there was a problem with the reversing valve that then caused compressor failure. To determine if a system has a reversing valve issue, you should look at the temperature difference across the valve (more than 3 degrees). Another thing to look for is an abnormally low compression ratio (high suction, low head pressure). You also want to watch the compressor amperage, as it will likely be lower than normal. When doing more advanced tests, such as delivered capacity tests, use Bluetooth tools to make your life a lot easier; that way, you can clamp your probes on. When Kaleb replaces a reversing valve, he cuts them out wherever possible. If he can't cut them out, he sweats them out and sweats the new one in. Sometimes, it's also easier to remove the entire condenser coil during replacement. Kaleb and Bryan also discuss: Common suction port Causes of compressor damage Unreasonably hot discharge lines Compressor amperage drop Common suction, common discharge lines Kaleb's compressor replacement Cutting out suction dryers Sweating out reversing valves in Trane units Purging with nitrogen before a pressure test Deburring properly   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 times he has been hoodwinked in his career. It's time to name and shame. One time at a trade show, Bryan came across a product called KVAR. KVAR is already an electrical term for kilovolt-amps reactive; those are volt-amps that show up and generate heat but don't do anything useful, just like foam in a beer mug. So, the product supposedly balanced out the power factor to save energy. However, power companies don't charge based on VA; they charge based on wattage, which already accounts for the power factor. So, the KVAR products made no actual difference; the KVAR motor was simple and very inefficient, which did little to improve energy savings. Bryan was hoodwinked because he didn't ask the right questions. He should have asked about the difference between volt-amps and watts, and he should have asked to see hard data about energy savings. Hoodwinking happens quite often in our industry; the only way we can prevent it from happening to us is to learn more and ask the right questions. So, how do we avoid hoodwinking? The best thing we can do is ask to see the data. Don't accept platitudes, graphs, or name-dropping; ask about the test methodology and specific details. Indoor air quality (IAQ) is an area that has a high potential for hoodwinking. Unfortunately, the IAQ products' data is often incomplete and only tests for a few contaminants. While the products have the potential to do a lot of good, there is potential for deceptive marketing and lazy science. Something to remember, however, is that not everybody who hoodwinks you has bad intentions. They sometimes don't understand what they're doing or are more familiar with marketing than science.   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.

This live podcast episode is all about pool heater talk. We cover gas pool heaters and pool heat pumps, explaining how they work and common issues. Pool heat pumps work a lot like air conditioners, but they have heat exchangers that help transfer their heat to the water. Instead of having a typical condenser, a pool heater has a unit that works like a heat pump's outdoor coil in heat mode. There is usually an option to cool the water, but there are almost no cases where someone would want to use that mode. The heat exchanger is the core component of a pool heater, and this part has evolved a lot to improve efficiency and reduce the effects of water chemistry. The old designs were cupronickel tube-in-tube heat exchangers where the refrigerant and water flow in opposite directions. Unfortunately, these corroded and failed easily. Titanium coaxial heat exchangers replaced those, though they can still fail. If heat exchangers fail, water can get into the refrigerant circuit; when that happens, the whole heat pump will fail prematurely. Actuators are also components that commonly cause issues. Gas pool heaters work similarly to gas furnaces, so they tend to work better than heat pumps in low-ambient conditions. However, they have their own set of challenges. They have very short lifespans in Florida and corrode easily because steel, heat, chlorine, and water all interact in the same area. Inducer fans especially tend to rust out easily. We also discuss: Manufacturer quality control Hooking up gauges Water level and flow Low ambient conditions BTUs Float switches Internal thermal overload Heat and water pressure losses Temperature sensor issues on pool heat pumps Pool vs. spa mode Special considerations for indoor pools Flame rollout Cleanliness issues Double-lugging Circuit breaker failure Piping configuration and valves   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.

Alejandro Rios from True Refrigeration comes on to talk about self-contained R290. He explains what it is, why to love it, and how to service the sealed system. R290 is pure propane, and it has recently made a name for itself as an emerging refrigerant. It is an A3 refrigerant, meaning that it is non-toxic and highly flammable. As we move away from HFCs and other refrigerants with high global warming potential (GWP), we will encounter more flammable refrigerants, usually A2L and A3 refrigerants. R290 is a natural refrigerant and has a GWP of only 3, making it more attractive than 400-series blends and some A2L refrigerants. You can also vent R290 because it has such a low GWP and an ozone-depleting potential (ODP) of 0. Self-contained systems that use R290 have a relatively small charge. However, they effectively run colder coils. Due to the colder coils, these systems have a net refrigeration effect (NRE) about 30% better than previous equipment models with other refrigerants. R290 is also versatile and can work in medium and low-temp refrigeration. Many of the service procedures are quite similar to other refrigeration systems. However, you have to be EXTRA diligent to check for flammable gas leaks; you must use a combustible gas meter for leak detection, NOT your typical electronic leak detector. Like most self-contained equipment, True's equipment is factory-sealed, and you must braze in your own service ports. However, as long as you vent the refrigerant in open areas and purge the line with nitrogen, you normally don't need to worry about anything catching fire. Alejandro and Bryan also discuss: Regulations for self-contained systems Terminal venting High-efficiency R410A systems Small charges Residual refrigerant and evacuation Adding service ports and sealing them Refrigerant recovery with SHORT hoses POE oil Energy savings   Check out True's 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 short podcast episode, Bryan explains what happens when your low-voltage circuit puts out a lower voltage than it should. Bryan recently received an email asking about the low voltage on a 20-ton split system with a long control wire; the voltage coming back to the condenser is only 19 volts, so there was some contactor chattering. First, in a case like that, you'll want to figure out why the voltage isn't as high as it should be. The control wire and line sets could be longer than the design specs, which may contribute to the problem. If the distance between components is the main issue, then you can use a relay to mitigate voltage drop and amp draw. You'll also want to check that you've tapped the transformer correctly. Since most transformers are single-phase, they'll probably start off tapped to 240v; when you're dealing with three-phase equipment, you must ensure that the transformer is tapped to 208v. One of the obvious issues to check is the voltage drop. If 26 volts are coming out of the transformer but you're only measuring 19, then you're clearly losing volts and have some resistance. Think about ALL of the conductors; is the drop the same across all of them? If so, then you've likely got a length and wire sizing problem. You can correct that issue with proper wire sizing; you can't always control the length, but if you can, then it's a good issue to address. If there's an issue with only one conductor, then the switch could have a problem, or there might be some wire splices. If the load is drawing higher current than it should, then something could be impeding the motion on the solenoid, contactor, or another electrical component.   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 from the Castbox app, we talk about codes and common causes for failed inspections. We talk about these topics both broadly and with some specifics. Many of the places where we fail to meet codes are on the electrical side. Electrical components have fire and electrical shock hazards, and codes are stringent for arc and ground fault protection. Leaking current to ground can shock someone, and arcs can cause damage to property and human life. We commonly see failed inspections due to improper marking on the air handler. In the HVAC industry, we have specific wire and breaker-sizing codes for our trade (440 in the NEC). Inspection failures are common in this area, as it's easy to leave the incorrect breaker in place. You also must have a disconnect or easily accessible circuit breaker that can function as a disconnect. In our market, we must also insulate drains and show proper attention to strapping, pitch, float switches, and cleanouts; otherwise, the drains may fail inspection (though it's rare). Clearances also come up quite often and are especially relevant to safety in our industry, as we don't want condensers blocking panels. Obstructed rooms or lack of egress are also common code violations related to safety. Anchorage is another safety-related code category, and there are special requirements in locations that are prone to high winds (like Florida) or earthquakes (California). You can't assume that units installed on rooftops have been anchored correctly, so be sure to check the anchorage. We also discuss: Pulling permits CO detectors PVC primer on condensate drains National Electrical Code (NEC) vs. AHJ Catwalks in attics Duct sealing and mastic vs. metal tape Florida Energy Conservation, Mechanical, and Building Codes Customer complaints Furnace venting and GAMA tables Smoke detectors Locking caps Wire protection Sealing boots   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 from the Castbox app, we have four techs join us to talk about common furnace issues and best practices. Those of us in heat-pump-dominant markets rarely have to worry about common furnace issues related to gas pressure and flow. In that same vein, we also don't have to worry about clocking the gas meter, which is a common practice on gas furnaces. Checking input and performing combustion analysis is critical to the diagnostic process AND can give you an idea of the unit's safety. There is no reason NOT to do combustion analysis when commissioning a furnace. Furnaces also have electrical components with flashing error codes. You must be careful when interpreting those codes, as multiple issues could show up under one code. (Compare it to going out on high pressure; that error doesn't necessarily indicate a pressure switch issue and could entail other problems.) Common codes deal with the flame sensor, but flame sensor failure is rare; the issue could come down to simple maintenance. When cleaning parts, the most important thing to do is make sure the carbon and debris come off; you don't have to overthink the cleaning material. Cracked heat exchangers are common issues that can present unsafe conditions, though they won't always have CO problems. If there is an issue with a cracked heat exchanger, the technician usually CANNOT turn off the system at the gas. (We usually CAN shut off the power at the switch, though.) Only the gas company can typically shut off the gas. We also discuss: Restrictions at ports Adjustments for altitude Carbon monoxide poisoning Proper drain line Clocking the gas meter in commercial settings Gas pool heater problems Parts that commonly need cleaning Steel wool vs. sand cloth High limit codes Clogged burner wings CO-monitoring Venting issues and negative pressurization Intake/exhaust pipe issues Power passing vs. consuming   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.