Klein Trade Program — Week 1
Welcome to HVAC: Maybe We Need to Back Up
Saturday, March 14, 2026
NATE Ready-to-Work Course & Exam
Welcome to Week 1 of the Klein Trade Program.
And when we say Week 1…
We mean Week 1.
For the guys sitting in the shop that first Saturday, this was their first real introduction to air conditioning.
They came in knowing very little about HVAC.
Which I knew.
At least I thought I knew.
Then I started teaching.
And about five minutes later I realized:
Okay. I need to back WAY up.
Welcome to the Klein Trade Program.
Okay… Maybe We Need to Back Up
We have an HVAC system in our shop that we use for training.
So naturally, one of the first things I did was bring everybody over to it.
Perfect.
Real equipment.
I can show them exactly what we’re talking about.
I started pointing things out and explaining the system like I’ve done a thousand times.
Here’s the indoor equipment.
Here’s the evaporator coil.
Here’s the outdoor unit.
We’ve got our refrigerant lines running between…
Then I looked around the room.
Blank stares.
Not:
“I’m having trouble understanding the refrigeration cycle.”
More like:
“Sir, I don’t even know what an evaporator coil is.”
😂
Oh.
Right.
I’ve been doing this long enough that I’d forgotten what an air-conditioning system looks like to somebody who has never had a reason to think about one before.
I’m talking about indoor and outdoor equipment like these guys have spent their lives wondering what happens when they move the thermostat from 75 to 72.
They haven’t.
Why would they?
Before getting into HVAC, most people know approximately three things about their air conditioner:
There’s a thermostat on the wall.
There’s a big metal box outside.
And when the thing quits working, the house gets hot.
That’s a perfectly reasonable amount of HVAC knowledge for somebody who isn’t an HVAC technician.
So…
Okay. Back up.
Let’s Start REALLY Basic
Forget superheat.
Forget subcooling.
Forget saturation temperature.
Forget diagnosing anything.
Let’s start here:
This is an air conditioner.
There is equipment inside the building.
There is equipment outside the building.
They’re connected.
Air from the house comes back to the indoor equipment.
The system removes heat from the indoor air.
The blower moves the conditioned air back into the house.
And the refrigeration system moves that heat outside.
That’s an incredibly simplified explanation.
Good.
It’s Week 1.
We’ll ruin the simplicity soon enough.
😂
But first, everybody needs to see the big picture.
This Week in the Field: Everybody Starts Somewhere
That first interaction actually taught me something too.
When you’ve worked in a trade long enough, you forget how much information has become automatic.
I can look at an HVAC system and immediately start identifying equipment, components and potential problems.
But nobody is born knowing that stuff.
Somebody taught me.
And somebody taught the person who taught me.
Every experienced technician was once standing in front of an air conditioner having absolutely no idea what they were looking at.
That’s worth remembering.
Especially when you’re teaching.
Our students didn’t need me explaining HVAC from where I was.
They needed me explaining HVAC from where they were.
And on Week 1?
That meant starting at the actual beginning.
What Are We Learning This Week?
Our first class was built around the NATE Ready-to-Work course and exam.
It’s an entry-level introduction to the HVAC trade, which made it a great place to start.
And despite being an introductory course, it covers a surprising amount of information.
Students were introduced to things like:
- Basic HVAC terminology
- Common HVAC equipment
- Major system components
- Basic heating and cooling concepts
- Airflow
- Refrigeration fundamentals
- Basic electrical concepts
- HVAC tools
- Safety
- The role of an HVAC technician
That’s quite a bit to throw at somebody who started the morning wondering what the big metal box does.
But something cool started happening as we went.
The blank stares started disappearing.
Meet the Equipment
As we worked through the course, we kept coming back to the actual HVAC system sitting in our shop.
That’s one of the advantages of teaching HVAC in an HVAC shop.
We don’t always have to stare at a picture on a screen.
We can walk over and look at the real thing.
What’s the indoor equipment?
There it is.
What’s the outdoor unit?
There it is.
Where does the return air come from?
Let’s follow it.
Where does the supply air go?
Let’s look.
What are those copper lines connecting the indoor and outdoor equipment?
Let’s go find them.
Where’s the drain?
Why does an air conditioner even need a drain?
Now we’re asking questions.
And that’s where the pieces start connecting.
Follow the Air
One of the first basic concepts we introduced was airflow.
Your air conditioner isn’t just a machine sitting somewhere making cold air.
We need to move air through it.
Air from the conditioned space comes back through the return.
The blower moves that air through the equipment.
During cooling, heat is removed from the air.
Then the conditioned air is distributed back into the building through the supply.
That’s the basic idea.
There are approximately 9,000 details we’re leaving out.
Again:
Week 1.
We’ll get there.
The important thing today is that students start seeing the equipment as a system.
Follow the Refrigerant
There’s another loop happening at the same time.
The refrigeration circuit.
We started introducing components and words these guys are going to hear approximately eleven billion times if they stay in this trade:
Compressor.
Condenser.
Metering device.
Evaporator.
Refrigerant.
We weren’t calculating superheat.
Nobody was diagnosing a TXV.
We weren’t hooking up gauges and pretending a few hours of class had magically created service technicians.
We were learning the basic concept:
Air conditioning is about moving heat.
That’s enough for now.
We’ll spend plenty of Saturdays making that considerably more complicated.
And Then There’s Electricity
Surprise!
There’s quite a bit of electricity involved in air conditioning.
Week 1 gave students an introduction to basic electrical concepts and components.
Nothing crazy.
We’re going to spend a lot more time on electricity later.
But we need to start hearing the language.
Voltage.
Current.
Resistance.
Circuits.
Loads.
Motors.
Controls.
We’re building familiarity.
And we’re establishing something else from the beginning:
Electricity deserves respect.
The cool troubleshooting stuff comes later.
First, learn what you’re working around.
Tools, Safety & Working in the Trade
Then there are the tools.
Meters.
Gauges.
Thermometers.
Nut drivers.
Wire strippers.
Crimpers.
Tubing cutters.
Vacuum pumps.
Torches.
Recovery machines.
And enough other crap to eventually make your tool bag weigh approximately 700 pounds.
Nobody needs to master those tools on Day One.
We’re introducing them.
Same with safety.
HVAC technicians work around electricity, pressurized refrigerant, moving equipment, sharp sheet metal, torches, ladders, roofs, crawlspaces and attics.
And because we’re in Florida, sometimes those attics feel like someone scheduled your service call approximately six feet from the sun.
Working safely isn’t separate from learning HVAC.
It’s part of learning HVAC.
Hands-On: Make the Course Real
Week 1 wasn’t a full hands-on lab.
That comes later.
But we did something we’ll continue throughout the entire Klein Trade Program:
Connect the lesson to real equipment.
When we talked about something in the NATE material, we could walk over to the shop system and find it.
That’s important.
Because our goal isn’t:
Memorize this word until the test is over.
It’s:
Understand what this thing is because eventually you’re going to work on it.
Today we’re pointing at the component.
Later we’ll explain exactly what it does.
Then we’ll test it.
Eventually we’ll replace it.
Later still, we’ll diagnose it when it fails.
One layer at a time.
Keep Learning
Week 1 was our first look at an air-conditioning system as a whole.
Before we start breaking that system down into individual components over the coming weeks, there’s one big-picture lesson worth reading:
→ KEEP LEARNING:
How Air Conditioning Works 101
What is an air conditioner actually doing?
This A/C University lesson walks through the basic principle that an air conditioner moves heat rather than simply “making cold.” It also introduces the major components and gives you a simple look at the cooling cycle.
If you’re brand new to HVAC, don’t worry if every part doesn’t make sense yet.
A few hours ago, the guys in this class were giving me blank stares too. 😂
That’s what the next 19 weeks are for.
Read How Air Conditioning Works 101 →
And Then We Took the Test
After a pretty intense introduction to HVAC, it was time for the NATE Ready-to-Work exam.
Think about that for a second.
These guys started the day with very little HVAC knowledge.
A few hours earlier, I was standing in front of our shop system talking like they’d spent their entire lives thinking about air conditioners…
while they stared back at me like:
“What the hell is this guy talking about?”
😂
Then we went through the material.
We looked at the equipment.
We asked questions.
We connected the words to actual components.
And they absorbed an absolutely ridiculous amount of new information in a very short period of time.
Then they sat down and took the exam.
Every single one of them passed.
That’s a hell of a first Saturday.
And we were proud of them.
Not because passing an entry-level exam suddenly makes somebody an HVAC technician.
It doesn’t.
We’ve got a long way to go.
But because a group of guys walked through our door knowing very little about this trade, spent the day learning something completely new and proved before they went home that they’d actually learned it.
Not bad for Day One.
Stuff That Isn’t in the Manual
Ask the Stupid Question
There probably isn’t a better lesson for Week 1.
You don’t know HVAC yet.
Good.
That’s why you’re here.
If I point at something and use a word you’ve never heard before?
Ask.
If everybody else seems to understand something and you don’t?
Ask.
If you have a question that seems so basic you’re embarrassed to say it out loud?
Definitely ask that one.
There’s a pretty good chance somebody else in the room is wondering the exact same thing.
And this lesson doesn’t disappear when you become experienced.
Eventually the questions just get harder.
There is nothing wrong with saying:
“I don’t know.”
Read the manual.
Ask another technician.
Call technical support.
Look it up.
Figure it out.
The dangerous technician isn’t the person who doesn’t know something.
It’s the person who doesn’t know something and pretends they do.
We can always work with:
“I don’t know yet.”
The important word is:
Yet.
Stuff That Isn’t in the Manual — Instructor Edition
I learned something too.
Don’t teach from where you are. Teach from where the student is.
Those blank stares were actually useful.
They told me immediately:
You’re starting too far ahead.
Back up.
Explain it differently.
Show them the equipment.
Make it make sense.
That’s part of teaching a trade too.
Knowing HVAC and teaching HVAC aren’t exactly the same skill.
We’re learning both.
What Should a Student Know After Week 1?
Quite a bit more than they knew when they walked through the door.
That’s the win.
We’re not expecting anyone to diagnose an air conditioner after one class.
We’re building skills.
By the end of Week 1, students should be more comfortable with:
- Basic HVAC terminology
- Indoor and outdoor HVAC equipment
- Major system components
- Basic airflow concepts
- Introductory refrigeration concepts
- Basic electrical terminology
- Common HVAC tools
- Basic HVAC safety
- Looking at an HVAC system and beginning to understand how the pieces work together
And every student finished the day having passed the NATE Ready-to-Work exam.
That’s a pretty solid start.
We’re Not Just Teaching Air Conditioning
Week 1 wasn’t about creating HVAC technicians in a few hours.
It was about starting them.
These guys walked into the shop knowing very little about HVAC.
By the end of the day, they’d learned an incredible amount, looked at real equipment, started learning the language of the trade and passed their first industry exam.
Now we have something to build on.
There will be electrical.
Refrigeration.
Airflow.
Components.
Tools.
Brazing.
Troubleshooting.
Installation.
Mistakes.
Callbacks.
Things that don’t work the first time.
Things that finally click after the tenth time.
Somebody is going to wire something wrong.
Somebody is going to make an absolutely hideous braze joint.
Somebody is going to confidently diagnose something incorrectly.
Probably all of us at some point.
That’s learning a trade.
But everybody has to start somewhere.
For these guys, it started with an air conditioner in our shop, a bunch of blank stares and me realizing:
Okay… maybe I need to back up.
A few hours later?
Everybody passed.
Week 1 complete.
See You in Week 2
We’re documenting the Klein Trade Program week by week inside A/C University.
As the program grows, the subjects introduced in these classes will become their own deeper lessons. We’ll connect those lessons to real equipment, real jobs, real customer interactions, real mistakes and the things we’ve learned actually doing HVAC for a living.
So whether you’re one of our students, thinking about joining a future class, a technician who stumbled onto this page, or one of our customers wondering what exactly we’re doing every Saturday:
Learn with us.
And if something here helps you?
Use it.
Good information should be shared.