We are looking at buy a 3 year old Champion, frame-on modular home, but the HVAC system (mechanical) will have to be completely replaced (long story........but it is unfortunately true.) A tech looked at it today and he made a comment about the duct work in the ceiling. Does anyone know what size duct work that Champion put(s) in their higher-end, frame on Modular homes through the ceiling with a 4-ton system? If it is important, the home is a 2015 model.