I was going to add the EPA 608 as well. Not only does it allow you to buy/use refrigerant, but it usually counts for warranties for HVAC equipment. Mini-splits and things like that usually want a 'certified technician' to do the install (or at least the refrigerant work), and your EPA number qualifies you. My state doesn't even have the concept of an HVAC licensed contractor, only the EPA cert applies.

Note: the EPA 608 has multiple levels. For mini splits under about 2 tons, you might be able to get by with just your EPA 608 core and Type 1 (small appliances, <5lb of refrigerant) Type 1 + core can be done online, open-book, and costs $25. Nobody should install a mini split without it!

That's awesome. I want to get HVAC certified. First I'll knock out welding though.

You can do it without the cert, it's just the recyclers usually won't take your reclaimed refrigerant.

I'd feel worse about it, but generally the HVAC companies in an area are extremely predatory and only quote out new systems when a simple repair would suffice.

How long did the certification take and how did you go about getting it?

I got the cert 10 years ago (EPA 608, not automotive EPA 609). 60 minutes of studying two different study packets I found online. Found a local test-giver, and called them up to schedule the test.

And after that you felt competent to do your own repairs? If so I know what I am doing the next few weekends.

I watched a lot of videos made by technicians and did a lot of reading. It doesn't take too long to study enough to get the basic certification, but that is not the whole story. I have done lots of electronic prototyping and test system creation, copper plumbing, etc., so I felt comfortable with tools and electro-mechanical systems. If your entire career has been behind a keyboard, you have a lot more than an hour of studying ahead of you.

Correct me if I'm wrong but I think 80% of it boils down to "do not release refrigerant gas into the atmosphere"

You're not wrong.

The test does not cover how to do repairs or fix HVACs. I learned that elsewhere.

The test (and studying for the test) does not cover how to do repairs or fix HVACs. I learned that elsewhere.