HVAC School - For Techs, By Techs

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Giving Kids The Tools For Any Job They Want Jun 23, 2022

Show notes

Bryan explains how parents and educators can succeed at giving kids the tools for any job they want. This podcast was originally a presentation at the 2022 FPEA Florida Homeschool Convention.

Jobs, careers, and vocations have changed a lot over the years. Even though those have changed over the years, parents still want their kids' vocations to develop character, foster growth, and bring joy. While kids are young, parents can instill values of grit and diligence; however, parents have to overcome the challenges presented by the instant gratification provided by technology.

Interest-guided learning is a double-edged sword, as it allows a child to pursue their interests but can cut them off from the interest of others. Developing the values of kindness and deference can temper the negative effects of interest-guided learning while maintaining the benefits of interest-guided learning. If a child has an interest in something and can pursue that interest on their own by demonstrating autodidactism, they open themself up to a lot of vocational options.

Nowadays, it's a lot more common for people to hold many different jobs or vocations over their lifetime. Encouraging a child to learn different skills allows them to explore non-linear career paths more easily than children who don't learn useful skills. When teaching children, developing mental models and an appreciation for learning is another key to success across vocations.

Bryan also talks about:

Vocation vs. avocation
Grit vs. talent in the pursuit of success
Modeling and practicing gratefulness
Transferable skills
Feeling "stuck" in a vocation
Visualizing average molecular velocity
Learning about humidity and electrical movement
Striking a balance between joy, service, and passion
Expectations vs. standards
Pursuing college, business ownership, and other career opportunities

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ERV & HRV - Short #148 Jun 21, 2022

Show notes

In this short podcast episode, Bryan talks about ERV and HRV technologies, including their appropriate applications and limitations.

HRVs are heat recovery ventilators (not to be confused with heat recovery units or HRUs), and ERVs are energy recovery ventilators. The main difference between these two lies in the type of heat they move; HRVs only move sensible BTUs, whereas ERVs move sensible and latent BTUs.

As you bring air in from outside, you're discharging roughly the same amount of air (though modern technologies allow you to manipulate the pressure a bit more). The goal of the HRV or ERV is to recover some energy from the air exiting the structure and incorporate it into the incoming airstream. The airstreams cross over each other, and there is heat transfer but not air mixing. (ERVs also allow for the exchange of moisture.) Two fans drive the direction of energy flow, and a mesh or a porous desiccant medium facilitates the interaction between the airstreams.

You will get some energy savings with an HRV or ERV, but savings are dictated by the amount of air moved and the temperature differential between the airstreams. In general, you will see HRVs up north (in low-humidity markets) and ERVs down south (in higher latent-heat markets). However, even ERVs aren't very effective in conditions with low energy transfer and high moisture UNLESS they're used with a ventilating dehumidifier.

Bringing in fresh air is good for indoor health and safety, as it helps dilute the presence of VOCs, viruses, and harmful gases. HRVs and ERVs help us manage the air we bring in.

Bryan also covers:

Integrating ERVs with bathroom ventilation
Safety considerations to consider for outdoor air
Positive pressurization
Demand ventilation with CO2 sensors
Learning about ASHRAE 62.2

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Refrigerant Changes Coming & The Helix w/ Emerson Jun 16, 2022

Show notes

Rajan Rajendran and Jennifer Butsch from Emerson join the podcast to discuss the Helix and some refrigerant changes that are coming. Jennifer is the Director of Regulatory Affairs, and Rajan is the Global Vice President for Environmental Sustainability and former director of the Emerson Helix.

Lately, there have been more environmental efforts to reduce greenhouse gas emissions, and plenty of large corporations have "net zero" initiatives. Sustainability requires a holistic, systemic approach in our industry; the Helix Innovation Center conducts the research needed for us to handle these sustainability initiatives as effectively and safely as possible.

However, the sustainability initiatives frustrate a lot of technicians. There will likely be multiple refrigerant transitions as our industry progresses. Education and knowledge provided by manufacturers and HVAC organizations will be the key to smooth transitions.

Many of the replacement refrigerants, including R-32 and R-454B, are A2Ls. These mildly flammable refrigerants have different handling, transportation, and charging procedures than what we're used to. However, we are unlikely to see changes in oils; POE and PVE oil will likely remain dominant in the market.

Eventually, we may see more GWP changes. We would also be prudent to focus on preventing and rectifying equipment leaks. Proper maintenance will help us navigate current and possible future changes.

Rajan, Jennifer, and Bryan also discuss:

The AIM Act and HFC reduction in 2024
GWP-limit petitions in HVAC vs. refrigeration
Refrigerants that manufacturers are embracing
Refrigerant testing processes
Natural refrigerants
The weight of refrigerants vs. the weight of air
Evaporator coil manufacturing and leakage
Built-in leak detection
Refrigerant pricing

To learn more about these coming refrigerant changes, check out the AHRI Safe Refrigerant Transition Task Force's resources HERE or Emerson's E360 Platform HERE.

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Pilot Controls - Short #147 Jun 14, 2022

Show notes

In this short podcast episode, Bryan talks about pilot controls. He talks about the old-school ignition systems on gas appliances and some similar pilot functions on residential A/C units and heat pumps.

When we think about a pilot light on a gas appliance, we can think of it as a small standing flame that sits there ready to ignite the burner whenever gas is flowing. Pilot lights were necessary for old-school gas furnaces, and many of those pilot lights worked with a thermocouple. In many older furnaces, pilots also prevent excessive carbon monoxide from unspent gas. In other words, the pilot is not the main burner; it merely sets up the main burner.

On a typical A/C system, the 24v power is similar to a pilot on a gas appliance; the 24v "pilot" control energizes the system and has a small amount of voltage (compared to the high voltage needed for all of the components to work).

The reversing valve on heat pumps also has a pilot valve; the 24v signal activates the pilot valve with the solenoid, which redirects system pressure to allow discharge gas to slide the valve. That's also why you can't shift the operating mode when the system is off. Solenoid valves in general tend to have pilot functions; they rely on a refrigerant pressure differential that results from 24v electrical signals, not the signal itself.

In short, we don't rely on the pilot light or the 24v electrical signal to power the entire equipment. Pilot controls merely help the equipment get started; they have less load on them and trigger or control parts and processes that are more complicated.

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Ethics - Grit and Discipline Jun 09, 2022

Show notes

Bryan and Robert Orr continue their discussion about ethics by talking about what it means to have grit and discipline in business. They talk about what those characteristics look like in business and in life, and they mention some good books.

Grit is a trait that can contribute to an ethical way of life; showing grit means that you follow through with a project until you get the results you want. Both physical and emotional grit are strengths, and those things tend to be more important than talent in our field.

Compared to discipline, grit is a lot more closely intertwined with a person's emotional condition. When we encounter overwhelming negative emotions, grit is the quality that allows us to power through the current state of affairs. Discipline and grit are both based on commitment and resolve, but discipline deals more with actions rather than feelings. Discipline is more about habits, balance, and wisdom.

A belief system or set of guidance is what drives discipline. Discipline can also be repetitious and boring, but it can take you farther than raw talent if you dedicate yourself to your belief system, sources of guidance, and goals. Developing discipline requires us to establish habits and sequence those habits. Good leaders and parents are the ones who establish those habits for employees or children.

However, something to keep in mind is that both grit and discipline can amplify a person's bad characteristics.

Robert and Bryan also discuss:

Grit vs. talent (Angela Duckworth)
Does grit count as an ethic?
Discipline and delaying gratification
Developing grit over time
"Real" vs. "true" emotions and thoughts
The downfalls of raw talent
Thinking about obstacles in a healthy way

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.

Ethics - Integrity Jun 02, 2022

Show notes

Bryan and Robert Orr talk about ethics and what it means to have integrity when running a family business. Robert is a lifelong tradesman who is a licensed construction contractor, and he has overseen the construction side of Kalos for many years.

Robert initially started off at the Air Force Academy and realized that he didn't feel that the military was right for him. While in Florida, Robert fell into the trades and learned both hard skills and ethics in the process. He started his own house-wiring business at age 21. Later, he went into home inspection and eventually started a business with his son (Bryan) and his brother-in-law (Keith)

Kalos was co-founded by Bryan, Robert, and Keith, all of whom were tradesmen. Even when naming their business, they wanted to focus on ideals that extend beyond them and their individual legacies. They settled on the name "Kalos," which is the Greek word for "integrity."

Having integrity in business is a lot more than just following rules and "having principles." Real integrity is authentic and honest; you're transparent about who you are and deliver on the promises you make. Integrity and customer service are NOT the same thing, but you tend to yield higher customer satisfaction if integrity is at the forefront of your business.

Evaluating yourself is also a component of integrity: reflecting on your desires, confronting greed, caring for employees, and choosing to do the right thing. In many small businesses that haven't fully found their stride, integrity can be compromised by fear.

Robert and Bryan also discuss:

Christianity in business
Integrity as it relates to pricing expectations
What it means to be savvy
Taking responsibility

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Check out our handy calculators HERE.

Distributors and External Equalizers - Short #146 May 31, 2022

Show notes

In this short podcast, Bryan talks about distributors and external equalizers and why we need to use them together.

When older Carrier heat pumps (with pistons) would run in heat mode, the metering device would be outside. In those cases, the port on the liquid line would be on the opposite side of the metering device. So, you wouldn't actually be measuring the liquid line pressure (high-side) if you measured it at that port while the system runs in heat mode.

However, that pressure would be higher than the common suction pressure. That's because distributors and distributor tubes also have a pressure drop associated with them AFTER the metering device.

Nowadays, TXV systems have external equalizers, which create an equalizing force inside the valve. The bulb pressure forces the valve open, and the equalizer pushes against that pressure to create a closing force. An internal equalizer would work fine on a system without a distributor or distributor tubes; however, those systems are few and far between. We need an external equalizer on systems with distributors because the pressure at the end of the evaporator coil is significantly lower than the pressure picked up by the valve. Without closing force, the TXV would theoretically force itself all the way open and flood the evaporator coil.

External equalizers can get clogged, which results in a pressure buildup during the off cycle and forces the valve closed. They can sometimes get clogged when used on a Schrader port without a Schrader depressor inside the equalizer.

Some people attempt to fabricate distributors in the field. It works in some cases, but in many cases, it's best to use an engineered distributor for the best performance and efficiency. The distributors are individually designed to create an individual pressure drop.

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Check out our handy calculators HERE.

Center-Tapped Transformers - Short #145 May 24, 2022

Show notes

In this short podcast episode, Bryan talks even more about sine waves and center-tapped transformers.

Power is generated at the power plant when an energy source (such as steam) is used to drive a drive shaft. The resulting current can be mapped as sine waves, which actually represent points on a circle; there is a rotational magnetic field around stationary conductors, and the sine waves allow us to envision the positive and negative alternations as the rotation happens.

Center-tapped transformers use "neutral" as a reference point. The secondary winding on a center-tapped transformer may have 240v power, but the center tap splits that 240v power into two legs of 120v power. There are two sine waves completely out of phase with each other, so we get 240v from peak to peak. Both sine waves cross at neutral.

Even though the split-phase power consists of two separate sine waves, an oscilloscope would interpret the voltage as a single up-and-down wave with a higher peak and a lower valley. Center-tapped transformers do not necessarily create another phase of power; they merely turn neutral into a reference. If we were to measure that split-phase power as a single 120v sine wave with an oscilloscope, we would have to use neutral as our reference. To measure the separate sine waves for a total of 240v, we would need three probes: a reference at neutral and one reference on each side.

Many European countries only use a single sine wave; center-tapped transformers are not commonplace in those countries, and neither is split-phase power. However, the split-phase power in the USA allows for more versatility; we can supply power to 120v appliances where we would otherwise need to use 240v ones.

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Beer & Power Factor - Short #144 May 17, 2022

Show notes

Bryan describes the tricky concept of power factor and why we should care about it. He also compares power factor to a beer mug to make the topic easier to understand.

Power is often represented on a sine wave, which is a curvy line that marks the state of electrical energy at different points on a circle. Power gets stronger and weaker, and it goes above and below the neutral line depending on the excess or deficit of electrons.

Unity power factor refers to a power factor of 1, indicating that voltage and amperage are perfectly balanced; there is no lag. However, an inductance (a form of resistance) opposes the current and causes an imbalance between current and voltage. Power loss or quality refers to the difference between the input and output power that results.

Apparent power refers to volt-amps, which we'd traditionally consider to be the wattage; however, in an inductive load, the true or real power (wattage) accounts for that power loss and comes from volts x amps x power factor. We can imagine power factor as a mug of beer: apparent power (VA) is the entire mug, the foam is reactive power (wasted), and the beer itself is real power. The power company only charges for the real power, not the reactive power. However, a power factor closer to unity can help prevent motor windings or wires from overheating.

To get closer to unity power factor, we need to make sure we have a run capacitor of the correct size. You can measure power factor with a power quality meter.

Bryan also covers:

Voltage and current
Root mean square
Inductive reactance
Capacitance and how capacitors work
Transformer VA ratings

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.

Motor Speed Facts - Short #143 May 10, 2022

Show notes

Bryan lays down some motor speed facts in about 10 minutes in this short podcast episode.

We can figure out how quickly a single-phase motor (PSC) will run if we understand how many cycles it will make per second. In the USA, the standard hertz is 60 Hz (60 rotations or magnetic alternations per second). Motors are inductive loads that create an electromagnetic field with a spinning rotor and stationary stator; the amount of poles on the stator determines how quickly the rotor spins (RPM).

In the RPM counts, there are some allowances for slip. Slip varies depending on the load, with excessive loads causing more slip. Some multi-tap blowers have additional winding resistance and decreased current (due to the extra taps), which increase the slip. The rated load RPM usually accounts for the RPM at high speed, not medium or low speed with added resistance.

On the other hand, variable-speed motors or ECMs are powered by a variable frequency (sometimes a variable frequency drive or VFD). The motor control takes the incoming electrical frequency and converts it into a new frequency (turning AC power to DC and controlling the cycle rate). These motors also tend to be more efficient as a result. The RPM is more variable on these motors with VFDs, whereas we could only manipulate the RPM of single-phase motors by changing the number of poles.

When replacing a motor, you can't use a replacement motor with a higher rated RPM than the original motor. The only way to change the RPM is to get a new motor with a different number of poles, increase slip to make it slower or decrease slip to bring it closer to synchronous speed, or adjust the frequency.

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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