Due to the energy crisis all new HVAC systems need to be better insulated, higher efficiencies and better designed. Ducts are the biggest loss of air and effecicy to a system. If your ducts look like silver card board, then they are Asbestos ducts.
The thinnest type of insulation ever used. If you did not know, Asbestos fibers are a known cancer causing particle. The frail ducts disintegrate when touched, and in older homes people have gone into their attics, not knowing the dangers to themselves and family. Even worse, a service person working /crawling around breaking the ducts in your attic exposing you and your family.
