Currently I have a 2200sqft home (4400sqft total) with full finished basement alll being heating and cooled from 1 5ton heat pump unit. I have 22 runs coming from the main trunk with 6inch metal duct to the vents for the upstairs. I have approx 6 6inch insulated flex going to drop ceiling diffusers(will be changing from flex to steel since I don't really feel much air I think they are loosing the cfm due to the flex duct) I don't think I can really add more ducts downstairs due to the limits of the cfm the system can push. I am wanting to have the ability to heat the basement better. I was thinking if I could zone controll 2 zones from one furnace and have a thermostat upstairs and downstairs. I would need automatic dampeners in each duct and an additional thermostat downstairs. My idea is I can call for heat downstairs and shut off the upstairs so I would then be able to dump more heat down and open the dampeners when the upstairs called for heat. Vice Verse in the summer since the basement stays cool. Currently with the heat set on 68-70degrees upstairs it is around 58-60degrees downstairs. Also this is an all tile floor which doesn't seem to help things out. I live in mid-Missouri so winters are around freezing point.