I grew up in a house which formerly had a "coal room" - and a manually fired coal furnace.
The builder/originator of the house had the house built in 1902 - and he was the coal and oil dealer in town - having bought the business from a great-uncle (who effectively drove the business in to the ground before sale - a family story.)
The furnace was "centered" in the house. "Gravity air" it took its air supply from a 24" diameter concrete flue which started outside under the semi-circular front steps. As children we took delight in the "tunnel" thus created when the furnace was removed. But today I think of how "dry" that house must have been in the winter with outside dewpoints below freezing.
The coal room was adjacent to the furnace in that cellar and the furnace was fed manually using a wheelbarrow. The room was notable in being "planked" on the three exposed sides with "tongue & groove" planking - to keep the dust in.
But the actual coal was slid in through a cellar window - no chute, no hopper - not even a proper door. A tilt up sash with "wavy" glass much like the rest of the cellar windows.
Once the coal furnace was removed (NEW oil furnace - 1960) and the "tunnel" filled in, it left about a 6 x 10 "sandbox" in the floor which became for a while the play area for a five year old me. Dad later mixed up wheelbarrow loads of concrete and "covered" the play area - much to my consternation.
"Dad, it was a lot more fun with the tunnel - why didn't you leave it that way."
1902 and done by the fuel dealer, there was not a stitch of insulation in that house - not even storm windows. Fuel was free (effectively) for him. Dad spent MANY weekends knocking out the fire stops (balloon construction) and pouring in loose insulation from the attic. He later found a complete set of large pane matching period storm windows from a house recycler in New Bedford.
Mom said the first winter in the kitchen she spend in "galoshes" trying to keep her feet warm.
Dad used to joke "The oil furnace came 'on' in Mid-October, and stayed on until mid-April." IIRC, the first year's fuel bill was over $1K - and this with oil at 17 cents a gallon. (5000 gallons of oil?) With the insulation and improvements he cut this down to about $250. (1400 gallons) It was a 14 room house on three floors.
Joe K