ddunn_home said:
...Here is a floorplan sketch...
Thank you. You do have a problematic set up!
Any possibility you can find/use lower noise fans?
Here is my solution, which I think you may find unacceptable:
Assuming the fan noise you have is only high frequency(mainly air rushing noise, for example), please refer to my attached image. I used your image and added some items in the color of purple. The units that are solid purple are attached to the walls. The unit that is grey/purple is not a permanent fixture. It is one of those tall, three part decorative folding screens(it must be solid, or you can use 1/4" plywood on one side of it for a backing/blocker). You can attach the acoustic dampening materials to one side. Fold out the panel only when you watch TV, as shown. Not shown, but
maybe important, is that you have mounted a dampening panel on the ceiling in the doorway to reduce the ceiling reflections that will breach the screen(the screen is not reaching all the way to the ceiling, but it must reach most of the way). I also assume that the floor has at least a medium to thick carpet and padding. If not, then a small area rug of moderate thickness should be placed in the doorway.
http://www.linaeum.com/images/sounddivider_1.gif
-Chris