Fall means putting away white clothes and firing up the furnace to warm up chilly nights. This year, take a few minutes early in the season to fine-tune your system for maximum efficiency, minimum energy consumption and balanced warmth in every room. First, open dampers in main ducts near the furnace, lining the handle with the duct in the open position. A furnace operates best with all dampers open, allowing maximum air flow. After a few hours, check to see if any rooms are too warm. If so, close the dampers leading to that room. Wait another hour or two and check again. Small rooms heat up faster and big rooms with high ceilings take a while. Keep tweaking damper settings for each, until temperatures equalize. You can also vent louvers to fine-tune air flow to eliminate hot and cold spots, improve comfort and save energy dollars