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Latest Episodes:

Why it REALLY gets hot upstairs w/ Alex Meaney Nov 17, 2022

Show notes

Alex Meaney returns to the podcast to explain why it REALLY gets hot upstairs and what we can do about it. He also talks a bit about his new business.

Heat technically doesn't rise; warm air is less dense than cooler air, so cooler air sinks as warmer air rises. In many cases, people blame stratification and the stack effect for warm upstairs areas, but there may actually be other issues at play, especially if the issue only seems to happen in the summer.

Many apparent convective problems are actually due to building science errors, especially poor insulation when walls are exposed to attic space. When air moves via convection, it brings the heat it contains with it, which can contribute to comfort problems. To help figure out what is going on, try to see what the floor temperature is; a cold floor usually indicates a building design mistake, particularly a joist bag problem.

Some of the solutions that may sound good aren't actually that effective, including placing return ducts higher. In many cases, we have to think about fixing the actual building, not the HVAC system. Some attics that are poorly ventilated and insulated will need to be reinforced.

Alex and Bryan also discuss:

Mean HVAC Consulting & Design
Wind washing and exposure within the insulation
R-value
Pressurization and how it relates to hot air "rising"
Manual J and its shortcomings with significant heat gains/losses
Duct design and using a Ductulator
Soffit vents, ridge vents, blown-in insulation, and infiltration
Why building science skills are important for HVAC technicians
Poorly conceived home designs
Diagnostic tips and tricks
Vapor-permeable air barriers
Sizing, capacity, and power consumption

Learn more about what Alex is doing at meanhvac.com.

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Electrical Myths - Single phase is Really 2-Phase - Short #157 Nov 15, 2022

Show notes

In this short podcast, Bryan busts the common electrical myth that single-phase 240v power is really two-phase power.

When power goes into a structure that runs 240v appliances, we may understand that two 120v sine waves are 180 degrees out of phase with each other, but that isn't 100% accurate. If we were to use an oscilloscope to watch the electrical sine waves, we would see two sine waves 180 degrees out of phase because the transformers are center-tapped. Center-tapping creates a neutral center point that becomes our reference.

The transformer has two sides: a primary and a secondary. The number of wraps on each side is proportional to the other, and the number of wraps also dictates whether a transformer steps the voltage up or down. However, when you use the center tap as a reference, that also makes the voltage appear to be halved.

In many residential structures, a single phase of power goes into the transformer from the power company. If you were to use the center tap as your reference on each side of that transformer, you would read 120v; the two 120v readings add up to 240v. However, if you were to use the other side as the reference (as in a corner-tapped transformer), you would read 240v.

On an oscilloscope, you would see the same thing; using the center tap as the reference, you would see two 120v sine waves completely opposite each other. If you were to measure completely across the transformer, however, you would see a single 240v wave, which is larger.

Remember: only one phase comes from the power company. We only appear to get two separate waves because of our available point of reference.

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Pumping Away, Hydronics Changes And Electrification Nov 10, 2022

Show notes

Moe Hirsch joins the podcast to discuss the hydronics side of the industry, particularly focusing on Dan Holohan's Pumping Away and exciting developments in the hydronics market, especially regarding electrification.

Pumping Away is many people's entry point to hydronics. It contains some good basic information about boilers, especially when it comes to learning about the pressures involved in pumping and how the components manipulate pressure throughout the system.

Boilers use many of the same fundamentals as compression-refrigeration HVAC systems; pressure drops are similar, as are phase changes in steam boilers. Boilers also employ pumps instead of compressors, but the processes are similar.

The pump or circulator makes a pressure differential within the boiler, which adds pressure to the circulator outlet and results in negative pressure on the suction side. However, problems like air bubbles and magnetite buildup can negatively impact performance.

The electrification side of the boiler industry is exciting, especially because of the relative safety of electricity compared to combustible fossil fuels. However, electrification comes with its own set of concerns, especially when natural gas prices are low. In some markets, electrical grids also haven't caught up with the demand for electricity yet.

Moe and Bryan also discuss:

Moe's recent work in the industry
Changes in boiler infrastructure over the years
Pumping away from the boiler vs. pumping at the boiler
Pressure's role in boiler systems
Similarities between parallel racks and boilers
Challenges with ECM circulators
Evolution of boiler motors and controls
Magnetic and hydraulic circulation
Low-temperature heat pumps with radiant heated systems
Moe's ideal HVAC system
Natural gas health and safety risks (carbon monoxide)

To learn more about what Moe is doing, check out turnupthecomfort.com or contact Moe directly at info@turnupthecomfort.com.

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Electrical Myths - Hard Starts Reduce Start Current - Short #156 Nov 08, 2022

Show notes

In this short podcast, Bryan busts the myth that hard starts reduce the start current on the run winding of a compressor.

A single-phase motor's main winding is the run winding; it has a lower resistance and a higher current than the auxiliary winding, also known as the start winding.

Hard start kits are often used on HVAC systems with single-phase compressors (which usually have PSC motors). These kits usually consist of a start capacitor and a potential relay, which takes the start capacitor out of the circuit. We don't typically use hard starts on three-phase motors or ECMs.

Single-phase compressors often have to start under a big load, especially in long-line applications (at the manufacturer's recommendation) or if the compressor simply has a hard time starting. In cases where you have a voltage drop or low voltage, particularly due to long branch circuits, you may also use a hard start kit. However, they do NOT reduce the starting current or "save" compressors.

Hard starts reduce the time-averaged starting current because they get the compressor to start up more quickly (therefore, the starting current is higher for a shorter time). However, hard starts do NOT reduce the spike of current upon startup. Like run capacitors, hard start kits allow current to flow on the start winding, but the run winding current stays the same.

Hard start kits boost the start winding current faster, not at a lower current, reducing how long the system is in locked rotor. If they stay in the circuit too long, they could overheat the start winding and need to be taken out. Therefore, we don't want to use hard start kits without careful consideration.

Soft starts are different entirely; they CAN reduce starting current.

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The 24-Hour Technician w/ Andy Holt Nov 03, 2022

Show notes

Andy Holt joins the podcast to talk about what it means to be a 24-Hour Technician. We talk about what it means to be HVAC/R technicians AND deal with the human aspects of our lives at the same time.

Service technicians differ from installers in that they do much of their work solitarily. They spend a lot of time by themselves. They're also on their feet very often and may do emotionally exhausting work, but they can earn a respectable living and accumulate savings for the future. To make our work and the emotional burdens that come with it more manageable, we can try to control how we react—take out head trash.

Most people—but especially technicians—experience anxiety, and worrying about things takes a major toll on us. We also may need to apologize to people who we simply can't access. Andy goes over some of his best tips for dealing with those sources of worry. The goal is to eliminate negativity—clearing up negative aspects of your life and not being weighed down by individuals who negatively affect your life.

As technicians, we do a lot of work to help other people, and the opportunities are endless for us. Customers may not always understand the value of the work we do, but we can bring positive experiences to them. We can find a lot of fulfillment in our work that way and bring positivity to our own lives.

Andy and Bryan also discuss:

Replacing negative thoughts with more positive ones
The power of handshakes and eye contact
Carrying burdens and being kind
Apologies and forgiveness
How to apologize to inaccessible people
Being a "24-Hour person"
Using overtime to avoid our lives outside of work
How to manage anxiety
Casting a future
Andy Holt's Outdoor University

To get in touch with Andy, visit https://toprate.com/ or call (706)-888-2332. You can also email Andy at andy@toprate.com.

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.

Furnace Commissioning w/ MeasureQuick 2.0 Oct 27, 2022

Show notes

Jim Bergmann returns to the podcast to talk about furnace commissioning procedures and the development of measureQuick 2.0.

MeasureQuick 2.0 has been a collaborative effort between Jim Bergmann and Joe Medosch, and it comes with an upgraded user interface that allows for faster operation and easier system data access and storage, and it works with more tool manufacturers' tools.

Gas furnaces need to be commissioned to reach their maximum potential (and lifespan). MeasureQuick 2.0 provides commissioning instructions and recommends starting with a visual inspection, including the flame rectification system (rod, circuit board, and grounding). Electricity is conducted during the flame rectification process—only in the microamp scale—so a dedicated circuit is crucial to keep it working as it should.

When commissioning a high-efficiency furnace, we should make sure the condensate drain cannot become clogged. The filter should block the airstream completely and not allow for any bypass, which could make the secondary heat exchanger, condensate drain, or circuit board dirty. The combustion air zone (CAZ) is also important; we don't want contaminants in there, as those could create acids that rot out your furnace components.

Jim has also recently worked with the folks at TEC to make MeasureQuick 2.0 compatible with the TrueFlow grid and DG8. This integration allows you to identify airflow issues much more quickly and easily than before. MeasureQuick 2.0 also stores a lot more historical data, especially as it relates to the built-in visual inspection checklist.

Jim and Bryan also discuss:

The history and methodology of measureQuick 2.0
What technicians tend to miss the most
Furnace circuit boards
Electrical signals and flame rectification
Filtration best practices
IAQ accessories and pressure drop
Combustion air zone (CAZ)
Evolution of airflow measurement with measureQuick
Venting termination considerations
Clocking the meter and setting the fuel pressure
CO and CO air-free PPM
Low-level CO protection
Checking manifold and inlet pressure
Is the industry ready for universal heat pumps?

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Check out our handy calculators HERE.

Light Commercial PM Process Oct 20, 2022

Show notes

Mike Klokus and Jeff Crable walk us through Kalos Services' light commercial PM process.

First, we verify that everyone is clear on the agreement. Then, we start the PM with a thorough visual inspection, taking copious notes about things that look concerning.

Once we've done a visual inspection, we clean the condensers. We try to use only water when possible, though safe cleaners may be necessary in some cases.

When checking the electrical components, we make sure the wires are neat and have tight connections. We take our electrical readings and check the capacitor.

Then, we check the system's refrigerant temperatures and pressures. We measure the superheat, subcooling, and pressures throughout the system and record those.

Once we move indoors, we check and replace the filter in accordance with the agreement. We do another visual inspection at the air handler, paying special attention to blower wheel cleanliness, panel insulation, and wire routing and connections.

When cleaning the evaporator, we want to try to stick with water or self-rinse cleaners. We want to make sure that we use very mild chemicals, and any foaming cleaners should be diluted appropriately and rinsed entirely.

Drain cleaning is one of the most critical parts of a PM. We check for double traps and to make sure that the drain lines are properly pitched, trapped, and vented; vents should be uncapped, but cleanouts must be capped.

We finish with a final inspection, making sure all disconnects are back in, cleaning up all trash and tools, and sharing any notes with the customer.

Mike and Jeff also cover:

Cleaning microchannel and multi-row coils
Critical electrical readings
How to replace panels carefully
Filter replacement
Modifying ductwork and return boxes for accessibility
Cleaning drain pans thoroughly
Pulling and cleaning blower wheels
Common drains and condensate pumps
Traps, cleanouts, and vents
Testing heat strips
Finishing up calls

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Check out our handy calculators HERE.

Electrical Myth - Wire Length Code - Short #155 Oct 18, 2022

Show notes

In this short podcast, Bryan covers a common electrical myth about wire length and its relationship with the National Electrical Code. The NEC is concerned with safety—protecting buildings and people—but less so with making sure things work.

Wire sizing is a common topic, and length is important because it can contribute to the voltage drop in a circuit. In many cases, we refer to the MCA (minimum circuit ampacity) to select an appropriate wire size.

If you run more current through an undersized conductor, it gets hotter and will experience a voltage drop—though not proportionally. It's worth noting that nothing in the circuit is fixed; voltage, amperage, and resistance all follow Ohm's law but are variable as different things start happening in a circuit.

In many cases, the NEC generally doesn't require us to size conductors to accommodate for voltage drop. Conductors have some degree of resistance, so longer wires will result in a greater voltage drop than you would see in a shorter wire. It makes sense for the wire to overheat, but that won't happen because the greater resistance in the circuit will reduce the current. There is less work being done.

Longer wires and circuits that are sized correctly shouldn't overheat or present a safety issue. The NEC recommends but does not require voltage drop to stay below 5% across a conductor. That is a performance recommendation, not a safety concern. We need equipment to perform correctly, but NEC won't prevent electricians from setting up branch circuits that are longer than the ideal length. Excessively long branch circuits are common in commercial structures, and it's up to HVAC technicians to notice that and measure the voltage drop to make sure it's not negatively affecting the equipment.

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Why CO2 Matters w/ Trevor Matthews Oct 13, 2022

Show notes

Trevor Matthews, the founder of Refrigeration Mentor, returns to the podcast to talk about why CO2 matters in commercial refrigeration and even HVAC applications.

CO2 (R-744) has entered the residential HVAC sphere in some places around the world, though it hasn't come to the North American markets yet. CO2 is one of the most eco-friendly refrigerants on the market, with a GWP of 1, and it's very good at moving heat. However, CO2 has some challenges, including its low critical point and higher pressures.

CO2 comes with some safety concerns, and its systems have a complicated infrastructure. Since CO2 can exist as a liquid, vapor, or solid under operating conditions, you could end up with dry ice in the system. These issues require skilled, attentive technicians.

As the industry moves to natural refrigerants like CO2 and hydrocarbons, we need to stop the race to the bottom. Technicians need to learn how to take their time and do the job right when they work on CO2 equipment so that they can be safe and save energy.

The future of troubleshooting will eventually lie in electronic controls that take measurements constantly. Technicians won't lose their necessity with these changes, but it will be easier for them to respond to those measurements directly without connecting gauges. Technicians will also be able to access performance logs, which can help diagnose long-term problems.

Trevor and Bryan also discuss:

Trevor's history working with CO2
Refrigerant regulations
Transcritical CO2 and climate
The skills and proficiency of young technicians
Dry ice in CO2 systems
Pressure transducers and pressure release valves
Manufacturer support and quality control
Data logging and electronic controls in commercial refrigeration
Trevor's recommended resources for CO2 education and training

Check out Trevor's mentorship and training initiative at refrigerationmentor.com.

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.

Electrical Basics Oct 06, 2022

Show notes

This podcast is Bryan's full-length electrical basics class for the Kalos technicians. He covers electrical theory and circuit basics.

Volts, resistance, and amps all affect the behavior of electricity in circuits. These are also critical factors in electrical safety. Watts and kilowatts come from the multiplication of the volts and amps, though not every volt-amp does work; the power factor indicates how much work the volt-amps are actually doing. Some of the volt-amps are reactive (kVAR) and don't do the real power of watts.

Electrons move by interacting with other atoms. Substances can be conductors or insulators, and conductors have very few valence electrons, which move in and out of other atoms easily. Insulators have many valence electrons and are more stable. Insulators have high resistance, and conductors tend to have low resistance.

Circuits consist of loads, switches, and power supplies. Loads actually do things and consist of light bulbs and motors. Switches pass power and don't do work. Power supplies can be finite, like batteries, but also include transformers that take power from the utility company. Open circuits don't move electricity, but closed circuits create a complete path that allows electrons to move. Electricity takes all available paths, not just the path of least resistance.

Bryan also covers:

Electricity and the body
GFCIs and AFCIs
Shock and arc flash protection
Lockout/tagout
Electricity and fall hazards
Energy transfer
Resistive vs. inductive loads
Magnetism and flux
Direct current (DC) vs. alternating current (AC)
How power companies and generators work
Open vs. short circuits
"Path of least resistance"
Tripping breakers
Electrical units of measurement
Step-up and step-down transformers
Electrical frequency (hertz)
Variable frequency drives (VFDs)
Microfarads and capacitors
Parallel and series circuits
Becoming more proficient at reading diagrams

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.

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