[A930Rocket]

Somehow, you need to add returns on the second floor and attic. Heat rises and the upper rooms get hotter.

Is there anyway to add a chase from the upper levels to the basement, where the air handler is? Located in a closet or corner, as straight as possible?

Having the ductwork with electronic dampers will help direct airflow as needed as well. Instead of sending it to the basement, he goes to the rooms/floors needed.