In Florida, there are not many gas furnaces, At least not as many as up North. Sometimes we can look like real dummies compared to techs who work on them every day.

One thing to know about 80% gas furnaces with cased evaporator coils is that you can often check the evaporator coil by removing the high limit and running an inspection camera up through the opening.

You may also be able to use a mirror and flashlight but you usually won’t see much due to the heat exchanger being in the way. Otherwise, you are stuck removing the entire blower assembly… and that’s no fun at all.

Another practice is bench marking the static pressure drop across a new coil when it is dry and wet when installed or during the first service call. You can then easily watch coil loading over time without the need to look at the coil visually.

— Bryan

Let’s get something out of the way right off the top. Saying that we learn best “hands-on” is sorta like saying we prefer to breathe air…


David Sandler wrote the book “You can’t teach a kid to ride a bike in a seminar” and the same is certainly true for the trades.

But there is a distinction that needs to be made between “learning to ride a bike in a seminar” and “learning more about bikes in a seminar” or “learning about better riding technique in a seminar”  because these both could be valuable once you’ve already been riding a while.

This article is about HVAC training, but it’s also about things I’ve learned running a business, being homeschooled myself and home educating our kids as well as having a large family.

This is the perspective of one man so take it with a grain of salt.

I’m more of a hands-on learner

Inevitably when I teach a class, or give a seminar, or send an article or make a video or podcast or suggest that someone RTFM… there is someone who says some version of “I’m more of a hands-on learner”

Which… to be clear… is totally cool and should never be disregarded especially when learning an entirely new concept.

I went with my kids to the science museum the other day and the “Bernoulli table” with balls floating on high-velocity air streams created the “hands-on” and visual experience to illustrate Bernoulli’s principal.

It was a lot of fun and very interesting to see the balls suspended in the air, but imagine if I started to explain the principals of pressure and velocity and mass to the kids using words and they just look blankly and say “I’m more of a hands-on learner”.

Do you see the issue?

This is hands-on learning… it just isn’t ONLY hands-on learning.. almost nothing is ONLY hands-on learning if you want to understand what is going on.

Language needs to be used to explain the “why” behind something we can experience hands-on and if you refuse to listen or read the manual or plaque then you are left with experiences and observations that have no context or meaning.

To some degree, we are all hands-on learners but to really understand we would be well served to become, attentive readers and listeners as well.

You must be so patient 

It’s no secret that Leilani and I have 10 kids. When Leilani goes to the grocery store she gets three comments from people most often

  1. I don’t know how you do it
  2. You must be a saint
  3. You must have so much patience

We laugh because we ARE NOT naturally patient people AT ALL and we have no secret magical powers or heavenly bestowed holiness. People imagine that to have 10 kids and remain (mostly) sane you must have some special gift.

The truth is much more boring and mundane.

You don’t need a huge dose of natural patience, but you do need to work at being patient. You don’t need to be a saint but you do need to work to control your emotions when life gets crazy.

In the same way, you don’t need to be naturally gifted at listening or reading to learn, but it sure helps if you work at it

Obviously, some people are more academically gifted naturally than others and some people have learning challenges and disabilities. This isn’t to downplay that reality but I do think you would be better served to stop using it as an excuse.

Becoming a Visual Problem Solver

A visual problem solver is much like a hands-on learner in that they prefer to have a problem in front of them to find the solution rather than using words to describe it.

Some of the BEST problem solvers I’ve ever met weren’t big talkers, instead, they create images in their mind of a problem, structure or machine and work over the problem using the visual centers of their brain.

If you think about it, converting ideas and mental pictures to language is actually pretty inefficient if there is no reason to do so.

The challenge comes in when you need to communicate those ideas to another human.

If you start describing a problem to a visual problem solver they may request to take a look, or have a photo or screenshot sent to them, these are ways the visual problem solver has found to get around the challenge of translating things to language all the time.

They will often draw diagrams or ask you to draw diagrams and they may stare at them a bit as they build the visual model or “cartoon” in their head.

The visual problem solver doesn’t make excuses about how they prefer to learn. They don’t make it someone else’s fault that they aren’t getting a concept.

The visual problem solver finds workarounds to get things out of words and into their head where they work on it and ultimately SOLVE THE PROBLEM.

Take responsibility for the translation gap 

Good teachers find ways to meet their students where they are and teach to their learning style. The BEST teachers do the same and then ALSO teaches their students how to translate a world that doesn’t always cater to their learning style.

As a learner, it is our responsibility to take what we can from all sources and methods we can to learn how to problem-solve. I would argue that visual problem solvers actually have a HUGE advantage in our trade because by it’s very nature it is visual and hands-on.

It doesn’t change the fact that reading manuals is often the only way to get certain information and may continue to be a bit of a struggle. Where the person who always repeats that they are a “hands-on learner” may wait for someone to translate words on the page for them, the visual problem solver may build a cartoon in their head or doodle a diagram… whatever it takes to the solve the problem.

— Bryan




There are many examples of teaching using metaphor to help someone get a grasp of how something works without being EXACTLY correct.

Some examples are how we often use water flow to explain electrical flow or refrigerant circuit dynamics. It’s enough like the way it works to get our heads wrapped around it but there are many differences and the metaphors eventually break down.

This is definitely the case with air and nitrogen “absorbing” water

I’ve done podcasts and videos about how air can “hold” less moisture when it is cooler and more when it is hotter. You have likely heard old school techs talk about triple evacuation and sweeping with nitrogen to “absorb” the moisture from the system.

News Flash, Air and Nitrogen DO NOT absorb or hold moisture… They ignore one another at parties and they certainly don’t shake hands.

Water vapor in the air behaves much like all the other gasses contained in the air with the notable exception that water exists in both vapor and liquid states at atmospheric pressure and temperature.

When the temperature of water vapor is higher, a higher percentage of the air by volume can CONTAIN water vapor, but the air itself isn’t what is holding it. It does interact with it as the molecules move and bounce around and the percentage of water vapor in the air does impact the mass/weight of the air by volume (water vapor weighs less than dry air) so there are certainly impacts to the makeup of the air based on moisture content.

The percentage of the air around us that is moisture can vary from almost zero In cold arctic & Antarctic climates to nearly 4% in hot, tropical climates.

When teaching it we speak as though the air is a sponge and the hotter the air the bigger the sponge. This certainly helps us remember but it isn’t really how it works. In reality water in the air is all about the saturation temperature and pressure of the water and the air has little to do with it.

By Greg Benson

This is the same sort of thinking when a tech is having a hard time pulling a vacuum and they add dry nitrogen to the system to “absorb” the moisture. First off, you will want to sweep the nitrogen through the system, not just pressurize. Secondly, the nitrogen has no special properties that allow it to “grab” moisture. It can entrain the water vapor using Bernoulli’s principle, it will warm up the system a bit, it will certainly add in a bit of turbulence which can help move the oil around and potentially release some trapped moisture… but nothing more than that.

Don’t get me wrong, there is nothing wrong with sweeping with dry nitrogen, even better to use a heat gun and warm the compressor crankcase, receivers and accumulator and coils during a deep vacuum on a large system to help speed up the vaporization of moisture.

It doesn’t change the fact that air and nitrogen don’t “hold” moisture.

— Bryan


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