After years from my install, I finally decided to get central air. Since I did not want the ac air blowing over the woodfurnace, I'm rerouting my ductwork. I ended up using 2-6" dampers attached to a piece of sheetmetal that I broke the edges for rigidity and a purchased a section of hinge and made a damper. For the first damper that will go off the ducting for the new central furnace and the damper with the round dampers attached will isolate the woodfurnace from the central furnace. It will be much easier for the wife and kids to operate the system this way. The woodfurnace damper will have a winter/summer setting on it. It took a few minutes of my time and a few dollars to make the dampers. Wednesday is the install of the new furnace/ac and I'll install the damper then.