Thanks, The problem was the cut plane settings.
I had the RELATIVE FLOOR PLAN RANGE so high the it was picking up the ductwork in the floor above.
BTW, I print to PDF and annotate with Adobe Acrobat.
Still do not understand why the printed output showed different than the screen display
Once again, thanks for your help
Win 10 Home Premium - AMD Phenom IIX6 1090T Processor 3.20 GHZ 8.00 GB RAM 64-bit Opp. Sys NVIDIA Quadro 4000 AC 22, MEP