Here is a thread dedicated to my burning nut coal in my 1537G Hotblast furnace. I have been burning wood for 2 winters so far and when a buddy started talking about burning coal, I got very intrigued!
Here is my set up:
and the chimney:
The chimney is 25 feet from the "T". There are 2 - 3 foot horizontal sections, the 90 and about 40" to a 45 into the furnace.
I have since added a baro draft regulator, went with a Field controls model B-34TJ. With the draft set for the lowest draft in the furnace I am still seeing .1 or slightly higher, My gauge may be reading off a little as I am on the very low end of the scale. My plan is to get a better manometer for this. I do have an awesome draft as long as the chimney is warm.
Here is how the flue pipe is setup...where I measure both draft and temp:
As you can see I am running just over .1" WC and a little over 400 degrees F in the flue. House is at 72 and outside temp is about 20 with no wind. I am heating about 2400 square feet (counting basement) with minimal insulation. I have put in about 100# of coal so far. Started burning this morning at 9:30 and have only put in 2 or 3 small shovel fulls so far!