hotblast1357 wrote:Couldn't you somehow leave cracks inbetween the fire bricks of our new stoves to do what that does
The small gaps between the bricks get filled in by ash material in a matter of a couple days because of the attitude of the sloped fire bricks AND the ledge that the grate frame sits on... Its interesting you bring this up. With a brand new fire after a total clean out, It takes a couple days for my furnace to achieve its best efficiency. I see this with the variance of temperature between the flue pipe and the over the load door temperature. During the first day of a brand new fire after clean out, the difference between the pipe and over the door temp is only 50 or 60 degrees. For example, I'll have 160 degrees on the pipe with 210 degrees over the load door.. As the days progress, this temperature gap will widen. After a week, I'll see a 90 - 100 degree spread. With 160 on the pipe I'll see 250 - 260 over the load door. I've seen as much as a 150 degree spread while pushing it hotter after a full week of use. Like 200 on the pipe and 350 over the load door.
I've come to the following conclusion about this..
During the first day, some combustion air misses the coal bed by taking paths thru gaps in between the bricks and also gaps around the grate frame, causing a loss of usable combustion air.. This unused combustion air is also carrying heat up and out the chimney making for a loss of overall heat output to the living space.
After a week, ash has settled into everywhere causing incoming combustion air to take a path up thru the grates and into the center of the coal bed exclusively. In this situation as much of the available oxygen is used for combustion as possible, making it more efficient.
I see this temperature gap widen inside the first week with every new fire after a total clean out..
That's my observation on that whole thing..