I have a brand new gas fireplace in my living room, which is where I spend most of my time after work in the winter. Which is more cost effective, to keep my gas fireplace at a comfortable but low level, or to keep my furnace at an equally low/comfortable level?

At first I thought the fireplace would be better because I'm only in the one room, BUT it's a continual flame as opposed to the furnace only kicking on and burning really hot for how ever long (I try to never go above 65). I've closed all the other vents in the house. AND it's a very old furnace.

What do you think?

Thanks,

~Margee