have an energy audit done! they should look at your power bills, check your insulation, measure duct flow, do infrared pictures, run a blower door test. sometimes subsidized by state or power company. winter is best time to have one done. they will tell be able to tell you where to put your money to make your home more comfortable and energy efficient.
you might have bad duct connections and are blowing conditioning air into wall cavities or perhaps your duct is running in unconditioned space and you are losing heat.
** Political signature removed - Tim330i **
I always have to laugh when I see a thread described as "Not Work Safe." Is there anything on the OT forum that's really "work safe"? If I were your boss, I'd be mad if you spent any time on this forum at work at all. How is a picture of a naked girl any less work safe than, say, a picture of a matador getting gored in the *** by an angry bull? - VaderDave