Which course is better HVAC or piping?

I need little bit clarification for your question. Your mentioned piping, that’s Hvac chilled water piping or plumbing system or oil and gas piping?.

If your mentioned Hvac piping, it’s important for Hvac system design bcoz your Hvac system required Hvac chilled water piping for supply air preparation purpose. All the air handling equipment required chilled water or refrigerant to making supply air.

If your mentioned plumbing piping system, it also a good service. The water supply system little bit easy compare to the drainage system. As a mechanical engineer you don’t omit all the mechanical services in MEP system like Hvac, plumbing, fire fighting..

For Hvac your using the following mechanical engineering subjects like thermal engineering, thermo Dynamics, heat and mass transfer and fluid mechanics. So try to learn all the mechanical related package like Hvac, Plumbing and Fire fighting for good carrier.

If you learning this three subjects you will be getting jobs in all the MEP Consultant or MEP contractors very easily also you will earn good job satisfaction.