I enjoyed being trusted and given design work that was going to be implemented in the real world. It was rewarding knowing that I was making a difference in the project I was assigned on.
What I wish was different
I wish I was able to gain more experience designing, but the HVAC industry has a steep learning curve, so I was only ready to design systems towards the end of my internship.
Advice
I would advise another intern to ask a lot of questions and don't be afraid to ask for more work or help with said work.