I’m headed down to pick up the Daka furnace from centennial60 today, but I know it will be at least a couple of weeks before I can get it installed… maybe a month. That means I’m gonna’ haf’ta get along with the “stovace” through most or all of February… so I’ve still been working with it. I went all “old school” on the thing and have it heating better and longer from the fire, and especially from the coal bed.
About a month ago I changed the firebrick lining the sides and back; the way it was they stood on end and sat on top of the firebrick floor, I changed them so they stood on their side and down lower… the floor bricks laid inside them. That made sort of a shallow pan for the fire to burn in, and left a goodly portion of the sides and back unlined. This had the effect of increasing heat transfer rate… especially from the coal bed.
Well, I figured if a little helped, maybe more can’t hurt… and Sunday I removed all firebricks from the sides and back. I also opened the draft control wide open and started controlling the fire strictly by the flue damper. Yesterday I filled the fire box before work and the wife kept the house warm all day by just stirring and raking the coal bed (said she added just one split all day, just to get a little flame going late morning)… it was 73[sup]o[/sup] in the house when I got home at 5:30. It wasn’t arctic cold yesterday, around 20[sup]o[/sup], but with the 30 MPH winds that performance ain’t bad. Last night I filled the firebox around midnight… and now (5:00 AM) it’s 4[sup]o[/sup] outside and dropping, the house is 71[sup]o[/sup]… and all I had to do was stir/rake the coal bed to get it heating again.
Now, I understand the purpose of the firebrick… to hold heat, keep firebox temps high, and protect the steel. But here’s the thing…
I don’t want it to “hold” heat… I want it to rapidly transfer heat to the air jacket around the firebox.
I can keep firebox temps high with the flue damper control… after all, I need it high to transfer heat.
I’m not overly concerned about the steel… all that air being forced by the outside of the firebox keeps the steel at a manageable temperature (but I suppose there is the danger of a “hot spot”).
By leaving the draft control wide open and “choking” the fire with the flue damper (rather than “starving” it with the draft), both burn time and heating time have been increased… although part of the increase in heating time can be attributed to the firebrick removal (i.e. I’m transferring heat from the coal bed at a faster rate). Also, it appears the coal build up problem has been reduced somewhat… probably because we’re not adding as much wood, as often. Still requires babysitting though… still haf’ta constantly stir and rake the coal bed to keep it producing high heat.
And yeah… the secondary burn still kicks in; very little (if any) smoke from the chimney when it does. In fact, it seems like the secondary burns longer now. Too bad there ain’t a practical way to get the fire up on a grate system with some air coming in under it; that would keep the coal bed heating and ash separation simple (with an ash collection pan). But short of using a cutting torch and welder…
About a month ago I changed the firebrick lining the sides and back; the way it was they stood on end and sat on top of the firebrick floor, I changed them so they stood on their side and down lower… the floor bricks laid inside them. That made sort of a shallow pan for the fire to burn in, and left a goodly portion of the sides and back unlined. This had the effect of increasing heat transfer rate… especially from the coal bed.
Well, I figured if a little helped, maybe more can’t hurt… and Sunday I removed all firebricks from the sides and back. I also opened the draft control wide open and started controlling the fire strictly by the flue damper. Yesterday I filled the fire box before work and the wife kept the house warm all day by just stirring and raking the coal bed (said she added just one split all day, just to get a little flame going late morning)… it was 73[sup]o[/sup] in the house when I got home at 5:30. It wasn’t arctic cold yesterday, around 20[sup]o[/sup], but with the 30 MPH winds that performance ain’t bad. Last night I filled the firebox around midnight… and now (5:00 AM) it’s 4[sup]o[/sup] outside and dropping, the house is 71[sup]o[/sup]… and all I had to do was stir/rake the coal bed to get it heating again.
Now, I understand the purpose of the firebrick… to hold heat, keep firebox temps high, and protect the steel. But here’s the thing…
I don’t want it to “hold” heat… I want it to rapidly transfer heat to the air jacket around the firebox.
I can keep firebox temps high with the flue damper control… after all, I need it high to transfer heat.
I’m not overly concerned about the steel… all that air being forced by the outside of the firebox keeps the steel at a manageable temperature (but I suppose there is the danger of a “hot spot”).
By leaving the draft control wide open and “choking” the fire with the flue damper (rather than “starving” it with the draft), both burn time and heating time have been increased… although part of the increase in heating time can be attributed to the firebrick removal (i.e. I’m transferring heat from the coal bed at a faster rate). Also, it appears the coal build up problem has been reduced somewhat… probably because we’re not adding as much wood, as often. Still requires babysitting though… still haf’ta constantly stir and rake the coal bed to keep it producing high heat.
And yeah… the secondary burn still kicks in; very little (if any) smoke from the chimney when it does. In fact, it seems like the secondary burns longer now. Too bad there ain’t a practical way to get the fire up on a grate system with some air coming in under it; that would keep the coal bed heating and ash separation simple (with an ash collection pan). But short of using a cutting torch and welder…
