BPatrick wrote:"And, what about the Glenwood non-base heater back pipe option stoves that come with pipe, or without ? Their extra flue length is all outside the stove body. The pipe adds several feet of pipe length at least before the MPD. I don't remember hearing reports of it affecting how the stoves burn either way.
I doubt you'd be able to remove so much heat with a few extra feet of pipe that you'd see much difference in how well the stove burns, but you very likely will see a difference in room temp. "
Sunnyboy, there is a big difference in how a base heater with a suspended fire pot and an inner barrel pulling the exhaust gases completely around the firepot and underneath it and dumping it at the bottom of the back pipe. You get a more complete burn and much longer burn times and the ash comes out like a fine powder. A lot of the base heaters have that back pipe but have a mpd inside the top of the stove on the inside of the backpipe where, when shut, the exhaust is re-routed and dumps out at the bottom of the back pipe. The extra length of pipe isn't what's extracting the heat, the path through the inner barrel and around and under the fire pot is extracting the heat. You can hold the exhaust pipe BEFORE, NOT AFTER, the mpd and it's warm to the touch. changing the location of the mpd farther away from the stove doesn't extract the heat any differently, as it's a different process.
BP, yes, I'm aware of how the base heaters work and that they are very different. I said, "non-base heater option back pipe stoves".
I mentioned ranges and the back pipe stoves because with their not channeling flue gases around the firepot, they are more like what the OP wants to accomplish by moving the MPD down stream in the pipe. And, they don't suffer from too much heat loss because of the longer flue and pipe lengths before getting to the MPD.
With my range in indirect mode, the MPD is about 11 feet from the firebox. And, that's with a much smaller firebox and about 10-15% more stove heat radiating area then some of the bigger base burner or back pipe stoves have. It draws and heats fine.
This morning when I came down stairs, the pipe was 104 degrees on the stove side of the MPD and the top of the stove at the firebox end was in the mid 600 degrees with the primary's closed to a sliver, the MPD fully closed, but with the check damper open about 15-20%, . . . and it still had a mano reading of .01.