I am very much a DIY'er and doing my own HVAC repairs have never been out of the question. Actually, I have rebuilt a couple of systems, less the pressurized parts of the system.
HVACs are great until they aren't and the need for repairs always comes up at the worst possible time. It would be nice to know more details for those reasons.
If you ignore the direct question about charging an HVAC, there could actually be a small, slow leak in my system as it stands. That'll get troubleshot in due time. (Still, I don't think I have ever had a system that didn't need the system to be topped off after a few years, even with no detectable leaks...)
It doesn't seem difficult: Ensure system is at correct temperature; attach a gauge; depressurize/pressurize as needed.
There has to be some "gotchas" in there somewhere. The equipment is cheap enough and I am fairly sure I can source the correct refrigerant easy enough.
Aside from needing to store and manage a small supply of refrigerant and that there are some annoying risks (like a system freezing over, etc..), what cost factor and equipment am I not taking into account?
Sure thing! Yeah the type I cert is an easy choice, same as 609 MVAC. If you’re considering the trade, you might choose universal (I, II, III) to save time. Exam is longer, closed book, and proctored, but not hard.
Among skilled trades, HVAC is notoriously demanding physically (especially residential, where you’ll spend a lot of time in attics and crawl spaces in hot weather) but consensus on hvac forums is that pay’s good and you’ll never be out of a job as long as you take care of your body.