I have read similar topics on this matter. I have a three speed blower wood stove insert in my basement. My return is about 6 feet away from the unit. My duct work is not in the attic. My duct work is between up and downstairs. Would I get better results heating my 3000 square feet house by running my central fan? My central fan has three speeds. If the answer is that the central fan should be on, what speed should I have it on? Thanks