HVAC From Scratch: A Free HVAC Course
By BRIX Editorial Team · Updated
HVAC From Scratch is a free, self-paced HVAC course in 9 modules: orientation, fundamentals, refrigeration, refrigerants and regulation, heating, air distribution, troubleshooting, certifications, and lead-tech skills. Each lesson teaches one concept with worked examples and check questions, links practice tests and licensing pages, and saves progress in your browser.
Key takeaways
- 9 modules and 36 planned lessons, in the order a new tech needs them.
- Lessons are free, need no account, and save your progress in your browser only.
- Refrigeration and regulation modules lead straight into EPA 608 practice questions.
- The last module bridges to running your own shop: the Tech-to-Owner path.
Who is this HVAC course for?
Three kinds of people: someone thinking about HVAC as a career who wants to know what the work involves before paying for school; an apprentice or helper who wants the theory behind what they're doing on calls; and a working tech brushing up before an EPA 608, NATE or state exam. It isn't a replacement for a training program, supervised field hours or a license. It's the explanations, worked examples and practice that make those faster.
The work is in demand. The Bureau of Labor Statistics reports a median annual wage of $61,010 for HVAC mechanics and installers in May 2025, about 440,900 jobs in 2025, and projected employment growth of 11% from 2025 to 2035. BLS also notes that EPA requires nearly all HVAC technicians to be certified in refrigerant handling.
What's in the HVAC From Scratch track?
| Module | What you'll be able to do | Lessons |
|---|---|---|
| 0. Orientation | Know what the job is, what to carry and how not to get hurt. | What HVAC techs do and the career ladder; Tools and PPE; Safety basics: electrical, refrigerant, confined spaces |
| 1. Fundamentals | Heat, pressure and electricity: the physics every diagnosis rests on. | How an air conditioner works; Heat, temperature and BTUs; Pressure and the pressure-temperature relationship; Electricity for HVAC: volts, amps, ohms; Reading wiring diagrams; Meters and gauges: multimeter, clamp meter, manifold |
| 2. Refrigeration | Follow the refrigerant around the system and judge the charge from gauge readings. | The refrigeration cycle; How to read a PT chart; Compressors, condensers, metering devices, evaporators; Superheat and subcooling; Recovery, evacuation and charging; Leak detection |
| 3. Refrigerants and regulation | Which refrigerant is which, the A2L transition, and what Section 608 requires of you. | CFC, HCFC, HFC and HFO: how we got here; A2L refrigerants (R-454B, R-32) and safe handling; Clean Air Act Section 608 rules; EPA 608 prep: Core, Type I, Type II, Type III |
| 4. Heating | Furnaces, heat pumps and boilers: sequence of operation and what goes wrong. | Gas furnaces and sequence of operation; Combustion and venting; Heat pumps: reversing valve and defrost; Hydronics and boilers: an introduction |
| 5. Air distribution and comfort | Airflow first: static pressure, ducts, load calculations and indoor air quality. | Airflow and static pressure; Duct design basics; Manual J, S and D: an overview; Indoor air quality: filters, ventilation, humidity |
| 6. Controls and troubleshooting | Low-voltage controls and a repeatable way to find the fault. | Thermostats and low-voltage controls; Systematic troubleshooting; Common failures: capacitors, contactors, igniters |
| 7. Certifications and licensing | The cards and licenses that let you work, and how to pass the exams. | NATE: Ready-to-Work, Support Tech, Core and specialty; Your state's HVAC license; Journeyman and master exam strategy |
| 8. From tech to lead tech | The customer side of the job, and the bridge to running your own shop. | Talking to customers on the call; Presenting options and pricing; Maintenance agreements |
Which order should I take the lessons in?
Start at module 0 and go in order if you're new. Each module assumes the one before it: you can't read a PT chart without the pressure-temperature relationship from module 1, and you can't judge a charge without the PT chart. If you already work in the field, use one of the paths below and skip what you know.
- 1
Path 1: Zero to EPA 608.
Module 0 (safety), module 1 (pressure and temperature), module 2 (refrigeration cycle, PT charts, recovery and charging), then module 3 (refrigerants and Section 608 rules). Finish with the EPA 608 Core practice test and the Type I, II or III section that matches your work.
- 2
Path 2: Helper to service tech.
Modules 1, 2 and 6: electricity and meters, the refrigeration cycle, superheat and subcooling, then systematic troubleshooting and common failures. Add module 4 before your first heating season.
- 3
Path 3: Licensed tech to lead tech.
Modules 7 and 8: state licensing and exam strategy, then talking to customers, presenting options and selling maintenance agreements. Those are the skills that carry over when you run your own jobs.
- 4
Path 4: Tech to owner.
After module 8, the Tech-to-Owner path covers the business side: how to start an HVAC business, licensing as a contractor, pricing your first jobs and getting the phone to ring.
How does each lesson work?
- Why it matters on a call. Every lesson starts with the service problem the concept solves.
- The concept, then a worked example. Numbers are computed, not typed: the superheat lesson's examples come from the same PT tables as our R-454B PT chart.
- Common mistakes. What techs get wrong in the field, and how to avoid it.
- Five check questions with answers, so you know whether it stuck.
- A printable cheat sheet to keep in the truck.
- Links out: the matching practice questions and the state licensing page for the credential the lesson supports.
Your progress
0 of 1 lessons complete- Module 2: RefrigerationSuperheat and subcoolingNot started
Saved in this browser only. No account, nothing sent to us.
Certifications and licenses along the way
Two credentials matter early. EPA Section 608 certification is federal: EPA requires technicians who maintain, service, repair or dispose of equipment that could release refrigerant to be certified under 40 CFR Part 82, Subpart F, in Core plus Type 1 (small appliances), Type 2 (high-pressure) or Type 3 (low-pressure). EPA doesn't issue the cards itself; approved certifying organizations do. See EPA 608 certification.
State licensing varies. Some states license HVAC technicians and contractors statewide and others leave it to cities and counties. Texas, for example, has TDLR issue an air conditioning and refrigeration contractor license and register and certify technicians: see HVAC licensing in Texas. Module 7 covers how to find your state's rules from the official board.
Frequently asked questions
Is this HVAC course really free?
Yes. Every lesson, check question and cheat sheet is free and there's no signup. Progress is saved in your browser, so nothing is sent to us. BRIX makes software for trades businesses, and the academy is how we help people get into the trade and, later, run their own shop.
Can I become an HVAC technician just by taking an online course?
Not on its own. Most techs learn through a training program, an apprenticeship or on-the-job training, and you'll need EPA 608 certification to handle refrigerant plus any license your state or city requires. An online course is the theory and practice that makes that training faster.
How long does the HVAC From Scratch track take?
Each lesson is written to take about 15 to 30 minutes including the check questions, and there are 36 lessons planned across 9 modules. Most people go faster through the material they already use at work and slower through refrigeration and electrical theory.
Does this course prepare me for the EPA 608 exam?
Modules 2 and 3 cover the refrigeration and regulation topics the Section 608 exam is built around, and they link to our free EPA 608 practice tests. Use the official EPA page and your certifying organization's study material as the final word on what's tested.
Do I need to create an account to save my progress?
No. Mark a lesson complete and it's saved in this browser's local storage. If you clear your browser data or switch devices, the progress resets. That's the trade-off for not asking for an email.
Related
- Superheat and Subcooling, Explained with Worked ExamplesSuperheat and subcooling explained with worked R-454B and R-32 examples: which PT column to use, the formulas, common mistakes and five check questions.
- R-454B PT Chart (Pressure-Temperature)R-454B pressure-temperature chart from −40°F to 150°F with bubble (liquid) and dew (vapor) psig, a quick lookup, °F/°C toggle and how to read glide.
- Free EPA 608 Core Practice TestFree EPA 608 Core practice test: 36 original questions with explanations, study and exam modes, and a score by topic. No sign-up.
- EPA 608 Certification: Who Needs It and How to Get ItEPA 608 certification explained: who needs it, Type I, II, III and Universal, test format and passing scores, how to replace a lost card, and A2L changes.
- How to Get an HVAC License in Texas: TDLR Registration, Certification and Contractor ClassesTexas HVAC licensing from technician registration to Class A and B ACR contractor: TDLR experience, fees, insurance and CE, each linked to TDLR.
- How to Start an HVAC Business in 2026 (Costs, Licenses and First Customers)Start an HVAC business in 2026: startup cost calculator, EPA 608 and state license rules, HVAC insurance costs, service pricing and a launch checklist.
- HVAC Software That Answers the Phone, Books the Tech and Keeps the BooksHVAC software that answers every no-heat and no-cool call, books the tech, follows up on replacement quotes, chases invoices and keeps QuickBooks clean.
Sources
- U.S. Bureau of Labor Statistics, Occupational Outlook Handbook: Heating, Air Conditioning, and Refrigeration Mechanics and Installers (checked October 24, 2026)
- U.S. EPA: Section 608 Technician Certification (checked October 24, 2026)
- Texas Department of Licensing and Regulation: Air Conditioning and Refrigeration (checked October 24, 2026)