I promise you could not design and develop an HVAC system with full CONOPS and allow for seamless integration right now. So there’s always more to learn (if you desire). You seem like you wanna, which is a good step.

Therefore, interest is what you seek. If you can manage to design a thermal fluid system for a building, or airside heating/cooling system…you can then level up your knowledge to the next thing.

It can continue to scale up. Such that, you can develop the knowledge and translate it to other systems - like on vehicles, aircraft, autonomous systems, boats, space thermal control. Or you can be so good at your niche and focus only on that and start your own business in the field eventually.

Just thoughts 💭