I must have too much time on my hands!
My last "posted" improvement, was to add the plenum and duct to the first floor. While this was a vast improvement in getting the heat out of the basement, stove room, it didn't get it out into the house, without some help of a fan in the fireplace room.
Then I took the floor register out temporarily, and added an elbow with some flex duct over to the step, by the vents I had put in. This seemed to work better. Now I was pondering about adding a duct to the hot air furnace system or putting a register in the face of the stoop, by the vents. The problem with the vents, register and stoop, was that I was sucking cold air off the floor and sending it to the basement stove room and the heat would be coming out in the same area. The temporary system, with the flex duct above the floor worked OK.
I decided to take the easy route of running a flex duct from the floor register by the fireplace, between the joists and over to a grill in the face of the stoop. However, I was concerned about running the regular Mylar flex duct with the temperatures, which might be expected. My answer to this, was to create some higher temp. flex duct, using 6" aluminum dryer vent and the insulation sleeving, which can be gotten at HD.
Next, I cut out the opening for the 2-1/2" x 12" boot. After I got this cut out, I reached back in, between the joists, with a telescoping pruning saw and cut out one set of bridging (I didn't feel that the removal of the bridging would be a problem, as the joists are full 2" x 10", and only 10' long). I had fastened the boot to the flex duct, so was able to attach a rope and pull the whole thing through the joist cavity to the opening in the stoop. Next, was to attach an elbow and marry it to the 6" pipe/plenum in the vent hole above the stove/in front of the fireplace. The hot air is being pushed from the stove through the duct, which is running with the red arrows. The vent on the right is closed, ... it was just too close to the heat. The vent on the left is pulling cold air off the floor and sending it via fan to the stove room.
After building a fire this morning and trying the new design, I decided that the proximity of the right floor vent and the hot air register were too close, so closed the floor vent ("hind sight", says I didn't need it). Currently, the hot air duct is producing 148*F. output, the dinning room is at 76*F., the far end of the house is at 72*F. and the stove room is at about 76*F.
While everybody's situation is different, somebody might get an idea from this saga. My heating for the winter of my 2600 square feet includes, coal consumption of about 1-1/2 tons, in addition to a tank of oil, which is used mainly in the morning, before a drag myself from bed. Typically, I would burn a tank of oil per month, in the heating season.
BTW, the stove is burning like a dandy!
OTOH, the coal kinda sucks.