Hi, I have a 6 year old 2,400 sq ft ranch with a basement with 1,400 sq ft finished. I have ceiling heating and cooling ducts in the basement area. The finished portion is divided into 4 rooms. I heat and cool a total of 3,800 sq ft. I do not have zone heating. I live in Wisconsin. The only thermostat is on the main floor. the stairway to the basement is open. In the winter the basement is at least 5 degrees cooler than the main floor. If we have the thermostat set at 68 it is only 63 or cooler in the basement. We have used electric baseboard heaters but they are very expensive to run. I already partially close the main floor registers and open the basement ones completely. In the summer the opposite occurs, the basement is much cooler than the main floor when the ac is on. I of course close the basement registers in summer and open up the main floor. I can't do much with the duct work as the ceiling is finished in drywall. Is there anything I can do with the current forced air gas system to make the heating more balanced? Do I need to add a second furnance and ac unit to set up zone heating? Is there a supplemental heating source that is cheaper to run than electic baseboard heaters? I am more concerned with the heat in the winter than the cooling in the summer. Thanks for your help.