HVAC School - For Techs, By Techs

Latest Episodes:

Starting an Internal Training Program w/ Trevor Dec 23, 2021

Show notes

Trevor Matthews, the founder of Refrigeration Mentor, returns to the podcast to talk about starting up an internal training program for an HVAC/R company.

In some cases, the best lead technicians don't want to be head trainers if the responsibility is forced upon them. However, when there is a solid training plan in place, those senior technicians might actually find the task enjoyable.

The first step to starting a training program is to ask the apprentices and technicians where their skills are at and how they want to develop their skills. That way, you can map out a program that works for the technician and figure out how to make time for thorough training.

When you grow people within your company, you'll likely see more success than when you outsource training. It takes longer to develop the relevant skills in outsourced people; so, when you develop a solid internal training program, you can sustain it with the people who pioneered it.

We also need to focus on evaluation in training. When we assess our techs' skills, we add accountability to our training programs. However, it takes time for techs to grow from a training program, and we need to make sure we're rewarding progress.

Training also works best as a team approach. When we look at the techs' strengths, we can diversify the training program and make sure that several skill bases are covered.

Trevor and Bryan also discuss:

Common excuses to avoid training
Motivated trainers and technicians
Labor shortage and skills gap
Visual, auditory, and kinesthetic learning preferences
Prevention-based training
Managerial involvement in training

Learn more about Refrigeration Mentor at https://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.

Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

Flame "sensing" - Short 136 Dec 21, 2021

Show notes

In this short podcast, Bryan explains the basics of flame sensing, also known as flame rectification.

Flame sensing/rectification is a form of proving flame. When you can't prove flame, your furnace might be dumping unspent gas into the heat exchanger, which can cause an explosion.

Flame sensing rods are common in hot-surface (HSI) and intermittent-spark (ISI) ignition. These rods stick out into the flame and connect to the furnace board. The flame creates a path between the rod and ground, which allows a very small current to flow to the board. Without a flame, there is voltage but no path, so the board can't sense a current and will shut the gas valve off to try again.

Sensing rods can fail when they short out due to a cracked insulator, are physically broken, aren't placed in the flame, or get covered in silica or carbon. If the furnace or burner assembly isn't properly grounded, then the flame sensor also won't work.

Flame sensing rods are often confused with thermopiles or thermocouples; the latter devices generate voltage and have a coating that can rub off with improper cleaning. Flame sensing rods don't have either of these features, so you can clean these by any means necessary (without breaking them or creating grooves or pits).

To test a flame sensing rod, begin by making sure the furnace is properly grounded. Then, make sure the rod is in the right spot and that the burner assembly is in good order. Get a microamp meter (with a resolution that reads tenths of microamps). Then, connect your leads in series with the flame rod.

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.

Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

Grow a Business Through Customer Experience - Throwback Bonus Dec 16, 2021

Show notes

This podcast episode is a throwback to one of Bryan's first small business podcasts. In this old episode, Australian electrician and businessman Joshua Nicholls explains how he built a business by focusing on customer experience and branding. Bryan grew Kalos similarly, so they talk about the journey of going from "man-in-a-van" businesses to larger businesses with several employees.

Joshua wanted to bring old-school manners and integrity to the business world, and that's how he branded his business. The focus on customer service over marketing earned the customers' respect, and customers were happy to remain loyal to the business and recommend it to friends. The repeat business and referrals allow you to maintain a client base AND grow it without spending too much money on advertising.

Eventually, the business grew big enough to require Joshua to change some of his internal processes. He needed to understand when to bring external help into the business, whether those helpers were financial advisors or mentors.

Joshua reached a point where he got bored with his business, so he went to a conference in New Zealand and decided to start franchising the business. The business worked without him, and he decided to give a chance for young entrepreneurs to share in his business's success and spread his business all over the country.

Joshua and Bryan also discuss:

Joshua's origin story
Authenticity in business
What to do after the growth boom
Profitability vs. work-life balance
Turning customers into raving fans
Scheduling appointments in a service business
Knowing your numbers in business finance
The "One Van, One Child" initiative

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.

Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

Refrigeration Defrost Termination & Fail Safe - Short 135 Dec 14, 2021

Show notes

In this short podcast episode, Bryan covers the differences between defrost termination and failsafe. He also covers the basics of defrost in refrigeration applications.

In medium-temp applications (also called coolers), the box stays above freezing temperatures, but the coil may drop below freezing. When the air is above freezing, we can use off-cycle defrost. The coil defrosts when the system naturally cycles off. We may also use timed defrost, which pumps down or cycles the compressor off at set times to force a defrost cycle.

In low-temperature applications, the box will typically be below freezing. We may use electric heat to melt ice off the evaporator coil, and the fan stays off; this method is usually accompanied by a pump-down to remove refrigerant from the coil. We may also use hot gas defrost, which pumps discharge gas through the coil to melt the ice off it. (Kool gas may use a warm fluid instead of hot gas.)

We want to stop the defrost as soon as the coil is ice-free; we don't want to keep adding heat when we don't need to melt anything. A defrost thermostat detects when the coil is free of ice and terminates the defrost when the temperature reaches around 55 degrees Fahrenheit; this is called defrost termination. We rely on a failsafe to terminate the defrost in case the defrost termination fails; the failsafe is the maximum amount of time a system is allowed to remain in defrost.

Demand defrost uses time and temperature to tell the controls when to put the system into defrost; this method uses trend analysis and sensors to force the system into defrost at set times and intervals.

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.

Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

Intro to Project Management - Throwback Bonus Dec 09, 2021

Show notes

This podcast episode is a throwback to one of Bryan's first podcasts about small businesses. Cesar Abeid, former VP of construction camera company Remontech, joined this podcast to discuss the basics of project management and a book that can help you step into that side of the business.

Project management is a framework or set of tools to turn an idea into reality. Projects have a beginning and end to create something new, and project management is how we get from the beginning to the end while factoring in schedules and a budget. In essence, project management is a system.

Effective project management requires a business to create processes and procedures for its services. For example, Remontech needs to plan the actual camera installation, but the company also has a bunch of internal processes to set up servers for recording. The key to project management is to remember what must be done and assign tasks to people as needed.

One of the issues Cesar saw with project management books was the dryness and corporate nature of their language. As a project manager, Cesar used stories from his life to make his book more relatable and accessible to small business owners.

Cesar and Bryan also discuss:

Contractor-client communication
External vs. internal processes
Cesar's book: Project Management for You
Cesar's preferred leisure activities
Wasting time or learning?

Purchase Cesar's book or learn more at https://pmforthemasses.com/product/project-management-for-you-bundle-1/.

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.

Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

Dealing with Imposter Syndrome - Short 134 Dec 07, 2021

Show notes

Bryan discusses impostor syndrome, what it is, and how it may actually be useful for us.

When we feel that we're frauds and that others wouldn't like to be led by us if they knew how much we don't know, we're experiencing impostor syndrome. Contrary to what others might believe, impostor syndrome isn't all that bad and may even be necessary for a healthy self-image.

On the other side, we have the Dunning-Kruger effect, which is when people are confident in the things they have very little actual knowledge of. They think they're experts and close themselves off to other sources of knowledge. On the other side of the Dunning-Kruger effect spectrum, true experts are acutely aware of what they still don't know. We would be wise to know what the edges of our knowledge are and give others a chance to share their expertise when we reach those limits.

When people learn more about a subject, they become much more aware of what they don't know. Wisdom comes from knowing what you don't know. However, if you feel that feeling of inferiority, you can still share the knowledge you have while seeking feedback and deferring to others who know more than you. (That's especially true of Bryan, who has a summary knowledge of industrial refrigeration and defers to others who know more about it.)

In the end, we're seeking authenticity and self-awareness. Rather than avoiding impostor syndrome, we can embrace it and understand how it can lead to self-awareness, wisdom, and especially self-improvement. "Fake it till you make it" can only help you up to a certain point.

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.

Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

Transforming Grocery and Cold Storage with Data Dec 02, 2021

Show notes

Amrit Robbins of Axiom comes on the podcast to discuss how we can use data science to transform grocery and cold storage.

Axiom Cloud uses cloud analytics and AI to map data and analyze trends on refrigeration racks. It can be particularly useful to keep track of readings all the time because it's impractical to rely on a human to take and record readings 24/7.

Grocery stores are unique because they have so much product at stake and are relatively inflexible in their usage of energy. If something goes wrong on a rack, thousands of dollars worth of products may be lost.

If we could collect and review data at our fingertips, we could spot potential problems before the store loses money. These systems may also have alarms for case temperature problems, floodback conditions, and even some less immediate issues, such as a lack of floating suction.

Axiom Cloud also monitors when systems go into defrost, so you can assess the cycles of case groups and figure out if they correspond to any issues.

When you have data collection, you're not relying on a "virtual technician" to automate HVAC work. Instead, data science can empower HVAC technicians and help them do their jobs more efficiently so that they can respond to issues before they become emergencies and serve customers better. After all, computer-based systems can't repair or clean units!

Amrit and Bryan also discuss:

Generating value on behalf of the customer
Compressor failures
Technician labor shortage
Creating sustainable working hours
Developing more flexible energy usage
Monitoring temperature rise across cases
Thermal banking
Preparing for data analytics to come to the industry

Learn more at axiomcloud.ai.

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.

Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

Superheat Talk - Short 133 Nov 23, 2021

Show notes

In this short podcast, Bryan goes over the basics of superheat and explains why it matters to us.

Superheat is the temperature increase above a substance's saturation temperature or boiling point. When a substance is superheated, that means it is 100% vapor; there is no liquid at all. We can look at our superheat to determine how much refrigerant is feeding our evaporator coil.

A lower superheat indicates that our evaporator is more full of refrigerant than a high superheat, meaning that the refrigerant is feeding the evaporator coil well. Generally, a lower superheat value will be more efficient, but if the superheat gets too low, we can get liquid in the suction line and compressor.

An evaporator can maintain roughly the same temperature throughout the bulk of the coil because the temperature stays the same during a phase change. As the refrigerant boils off from its liquid state, it remains at the boiling point. You generally want to see no less than 6 degrees of superheat, especially at the compressor. Zero superheat indicates that you have some liquid refrigerant (or that the system is off).

Superheat can get tricky when we use refrigerant blends with glide. The different refrigerants in a blend have different boiling points, so the evaporator temperature can drift up. When determining the superheat of blends, we use the dew point to calculate the superheat (and bubble point for subcooling).

We get superheat in the evaporator (suction line at the evaporator outlet) and the compressor (suction line at the compressor inlet). The latter will be higher because some sensible heat will be absorbed in the suction line.

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.

Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

Liquid Quality vs. Subcooling Nov 18, 2021

Show notes

In this podcast episode, Bryan and Eric Mele talk about sight glasses, the significance of subcooling in refrigeration, and liquid quality.

While we measure subcooling quite often in HVAC work, we rely on sight glasses and liquid line receivers far more often in refrigeration. You need a sight glass to determine the liquid quality in a refrigeration system. Subcooling is one way to assure liquid quality without a sight glass or a receiver.

Subcooling refers to the temperature drop below liquid saturation. Head pressure can dictate subcooling, and several other factors can dictate the condensing temperature, including stacking. We use sight glasses because a clear sight glass can tell us that we have a full column of liquid (therefore subcooling) without hooking up gauges.

In HVAC, we care about having a certain level of subcooling because we want to make sure the refrigerant is fully liquid when it reaches the metering device; no bubbles should be present by the time it reaches the metering device. Like the suction line, the liquid line is a place where heat can be absorbed into the refrigerant. So, some manufacturers recommend insulating the liquid line to prevent heat from transferring to the refrigerant in the liquid line.

Unit orientation also affects subcooling. For example, you can shorten the liquid line sizing if your liquid line goes downhill to the air handler. Conversely, longer lines and uphill liquid lines require special considerations when it comes to subcooling.

Eric and Bryan also discuss:

Liquid line receiver fill standards
Subcooling and efficiency
Sight glass placement
Stacking liquid in the condenser
Pump down strategies
Mechanical subcooling
Flash gas
"Free" subcooling
Ambient temperatures

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.

Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

Aluminum Repair Tips - Short 132 Nov 16, 2021

Show notes

In this short podcast, Bryan explains the basics of repairing aluminum, such as on coils or tubing.

Repairing aluminum can save lots of time on mission-critical calls and can help stop refrigerant leaks that lead to ozone layer depletion or global warming. Soldering makes almost all of the aluminum repair work we will do. (Brazing is possible, as aluminum has a melting point of 1200 degrees, but that's still a bit too close to the brazing threshold.)

When working with aluminum, we need to recognize that it melts at a lower temperature than brass, steel, and copper, and it doesn't change color. Aluminum is also thinner and almost fades away under excess heat.

First, you'll want to figure out how to get the base temperature to the right temperature, usually with a flux. (Some fluxes require cleaning, some don't; either way, we recommend cleaning.) The powder flux should go clear, and then you'll be ready to apply the rod. In many cases, indirect heating can be difficult if not impossible.

After you choose your alloy, you need to choose your torch. We recommend using a swirl-tip air-acetylene torch. (It's good to use a 3 tip for microchannel.) When working with an air-acetylene torch, you will run lower temperatures than oxyacetylene torches, but you will experience more convective heat. (Heat control is the key!)

When doing a repair, you want products that will make a solid bond to the outside of the joint. Make sure your products are for repairs, not for joining aluminum tubing.

If you do aluminum repairs on an evaporator or condenser coil, cut the fins out of the way. Make sure your work area is exposed and clean.

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.

Check out information on the 2022 HVACR Training Symposium at https://hvacrschool.com/symposium/.

Our TOPPODCAST Picks

Follow Us

Stay Connected

HVAC School – For Techs, By Techs

Related Podcasts

Links

Stay Connected