It's natural for people to want to try to "move the hot air" out f the room, but it works far better to push the cold air into the room and let convection currents naturally move the hot air to where it needs to be.
Hmm. Not sure if I can easily draw up a floorplan at work. Basically, it's a two-story colonial with stairs right in the middle of the house. Rectangular footprint. Fireplace is on the main floor, on one side. The middle of the main floor is taken up by the stairs and a powder room, but otherwise the whole floor is open-concept -- i.e., you can walk in a big circle around the exterior walls of the main floor without going through a doorway. Main floor is approximately 850 sq. ft.
We position one fan at the top of the stairs, pointing
down toward the main floor, pushing cool air down. At the bottom of the stairs, there is another small fan at floor level, pushing cool air
toward the fireplace.
How good are your overnight burns? When we started, I found we had n problems with daytime burns, but it took some time to keep the furnace from coming on in the wee hours. It's thoes hours between midnight and waking that will kill you on oil. The fire dies down and the furnace kicks in if the temps drop low enough. On the same train, where is your thermostat? Ours is right near the insert in our LR, so it naturally tends to stop the furnace from starting up.
Our typical day is something like this: I wake up before everyone else and get the fire going (like 5:30-6:00am). Insert has heated up and the blower has kicked on by the time everyone else gets up. We keep the fire going all day, trying to do complete burn cycles, as opposed to feeding it every hour or two. We let the fire die out in the early evening, which means the blower keeps pushing out warm air until about bedtime.
I was trying for overnight burns at the beginning and was having some success, but haven't been trying lately. It seemed wasteful to me to keep the fire going all night, because that resulted in the main floor (unoccupied at night) being warmer than it needed to be. It seemed to make more sense to let the main floor cool down overnight (from, say 70-72 degrees down to 57-58 degrees), relying on the boiler to keep it from getting too frigid, and then heating the space up again in the morning.
Admittedly, this means that the boiler works overnight to keep the upstairs bedrooms comfortable at night. I expected that, and therefore knew that we weren't going entirely off of oil.
Each floor has its own thermostat. The main floor's thermostat is about 10-15 feet away from the fireplace.
Do you have any way of data logging your furnace run times? It would be great to see when it's coming on to figure out what's going on.
That would be a very useful piece of data, but I have no idea how to gather it.