Classic problem I suppose. The bedroom duct furthest from the furnace puts out very little air. There is a return near that sucks very strong. The duct is 8'x6" that converts to 6" round inside the wall, but even in the basement, the duct itself isnt warm to the touch when the heat is on. There is a little air movement, but really not very much.

I cant really run new ducts all over the place, so I was thinking about some kind of booster fan. Think that would help?