Mansfield owners: What are your "normal" efficient temperatures?

[mikeathens]

Seemed appropriate to start a new topic on this one...just wondering if maybe my Mansfield is acting sluggish on the secondary burn becasue I'm trying to run it too low.

I've gotten the best results with a stack temp (probe thermometer) of 600 or so. This is with the primary air control nearly 1/2 open. If I close it much more than this, the secondaries peter out pretty quick, and the stack will pretty quickly cool to <400, resuting in a nice plume of smoke coming out the chimney. Maintaining these 600 F stack temps over a long period will eventually have my stovetop up to 600 also. Not so good for long sustained burns.

Any similar experiences, or can any of you run your stack temp at low temperatures and still have a good secondary burn? I guess I'm asking: what does your stack temp hover around through the first hour or two of placing a fresh load in the stove?

Still going to rule out high moisture content in my wood when my meter comes (oh, boy, a new toy!!), but just started to wonder if this is how this beast typically operates.

 

[04RevX]

My Homestead produces nice secondary burns with stovetop temps anywhere above 350* with a good bed of coals and dry charred load of wood. I can close the intake all the way down at this point and the temp will then climb up about 50* and hold pretty steady for a couple of hours and get a good secondary burn for about an hour depending on the size of the load. Sorry, I don't know what the stack temps are since mine is in a fireplace. To achieve a good secondary burn I believe the temp you need to worry about is in the firebox, not necessarily in the stack. How is your wood?

 

[mikeathens]

The wood quality has come up bofore. Though I can't rule it out, I will be REALLY surprised if it's the wood. It will be checked out pretty soon. As far as stove temps, I agree it is important, but I have noticed the stack temp is an indicator of whether secondary is occurring or not. Like I said, if the stack maintains 600 or so, that's when I've got nice dancing flames.

 

[edthedawg]

It's probably need asked and answered before, but what do you have for chimney out the back of the Mansfield, all the way out? is it dampered / insulated? how does it compare to the "max flue length" in the manual?

 

[edthedawg]

It's probably been asked and answered before, but what do you have for chimney out the back of the Mansfield, all the way out? is it dampered / insulated? how does it compare to the "max flue length" in the manual?

 

[edthedawg]

poo - sorry for the double-click on that Admin! Mod! Help

 

[mikeathens]

Man, must be an important point you're trying to make.

Well, don't really know if it matters, but the pipe is simply up and out the roof. 4' single-wall connector, 12' selkirk SSII; 10' of that is completely outside (flat roof).

I guess I'm just trying to get a feel for what pipe temps people typically see with a good secondary going on. (for instance, are there people out the running a mansfield with a flue temp of 300 or 400 and still seeing good secondary combustion?)

Edit: and I think this might be strictly applicable to the manfield. It's been said that big firebox stoves operate a little differently than other stoves, especially when related to how far you can close down the primary air control.

 

[Vic99]

As I'm thinking of switching to a mansfield next year, I had wondered how similar the operation would be with a larger firebox. My plan will be to have one more 90 degree bend in the stack than I do now. Currently have one 90 degree and one chimney twist (probably 30 degrees). I'll add a flue damper as well for potentially more control. My current setup seems to draft a bit to hard and I can't realistically add a flue damper.

I hoped that I could fill the firebox and cruise between 450 and 550 like I do on the Homestead, or whatever temp is appropriate to give me mre heat so that I can handle colder than the 20F limit that I seem to have now.

 

[brian_in_idaho]

I find that the firebox temperature has much more of an impact than stack temps. Upon starting a fire I try to run hot, with the air wide open for 20 minutes or so, gradually shutting the air inlet all the way off in 40 minutes or so. With a full firebox, there is good, hot secondary combustion and no visible smoke even with the air all the way down. The stovetop temp usually runs 550-600 or so once it is burning well. I find that the stove heats well, keeps the hottest stovetop temperature and uses the least wood when I load it right up, shut the intake (once it's hot) and then let it burn down. I allow the stove temps to drop significantly before reloading (usually 4-8 hours or more depending on outside temps). IMO, these stoves want a full firebox and don't burn well with just a small fire, it takes too much air to maintain the fire and sends too much heat up the chimney, resulting in cooler firebox temps. I'll check stove pipe temps, but IIRC they are running around 400 when operated as above. I see good secondary combustion when the stovetop is above 350-400.

I have a very open floorplan, operated this way, the thermal damping of the soapstone keeps the room temperatures pretty even. I really like this stove, we had a long winter last year, I heat a 2100SF home almost exclusively with wood, and burned around 3 1/2 full cords.

YMMV depending on installation and fuel. Most of my firewood is Douglas Fir, with a bit of larch and pine.

 

[Heat Miser]

I agree with brian_in_idaho. Once the firebox is hot the stove just hums along. My stove cruises along around 500 degrees with stack temps around 400 degrees and no smoke with good secondary combustion. I will run the stove up to 600 degrees with damper half open when I want to crank out a lot of heat. Otherwise, I keep it near low with a slightly open damper and it makes no smoke except towards the tail end of the burn cycle. I also agree that this stove likes to have a full firebox as well.

As an experiment, I tried some wetter wood earlier this year in the stove. I found that I had to run the damper open much further and the stove had a harder time keeping a good running temperature. So if you are still having problems with the stove, it could be the wood is too wet.