Installing Central Air using existing heat ducts
I have an existing forced hot air heating system with furnace in basement. I'd like to install a central air system in my small 3-bedroom ranch house(I have full attic too). My question: I was thinking of using the existing heating ducts for the central air system, but the ducts are about 8 inches off the floor on the walls. Is this going to be a problem. Isn't cool air suppose to come from top, and heat from bottom? Is it better to install new ductwork for central air on the cealing from my attic? Any pros, cons, ideas?