flue temperature

[woodwoman]

what temp should the flu be running at with the stove top about 475? is it true that the thermometor on the single walled black stovepipe (that i have), is actually twice what it is reading inside temp of the pipe?







mid moe allnighter

 

[begreen]

It really depends on the stove and the flue setup. Ideally one wants the flue gases exiting the top of the chimney to be over 250 degrees when the wood is in the outgasing stage. But none of us has a thermometer up there at the chimney cap. At least not that I know of.

If you have an interior flue and chimney, then maybe try to keep the surface flue temp at least 250+ degrees until the wood is at the coaling stage. If the stove vents into an exterior chimney I would want it to be at least 300 degrees. And yes, surface temps on the single wall pipe are about double the interior center of the flue temps. So double those temps if you have a flue probe thermometer.

Typically on our stove it runs at about 400-500 actual temp (interior probe thermometer) until I start to damper down and secondary burning kicks in. Then, the stove temp goes up and the flue temp goes down to about 300 (interior flue).

 

[webbie]

That stove has no baffle and pretty much sends the flame directly up the chimney.
My suggestion would be to install a stack damper a foot or so up the pipe so you can hold some of the heat into the stove.

 

[Backwoods Savage]

BeGreen, it is a very simple thing to sit on the roof and hold a thermometer over the flue to check. Naturally, you should always do this in the dark, lest your neighbors think something or someone has gone whacky!

 

[Diabel]

Typically on our stove it runs at about 400-500 actual temp (interior probe thermometer) until I start to damper down and secondary burning kicks in. Then, the stove temp goes up and the flue temp goes down to about 300 (interior flue).

That is almost unbelievable....at 400-500 interior temp. With my downdraft I have to maintain at least 350* exterior (approx 700* interior) temp otherwise the secondary will stall. Often it will run at 500*-600* exterior flue temp. then I will wonder how much energy is going up the pipe.

Maybe I should install a flue damper...btw how do you install one in a telescopic pipe?

 

[begreen]

As noted, it depend on the stove and the flue. Our Castine had even lower flue temps. I agree that I'd want my stack temps cooler. Why heat the outdoors? If I recall correctly, the pipe is only rated at 900 degrees continuous operation.

For Simpson DVL, you don't put the damper in the telescoping pipe. It comes in a special 6" double-wall starter pipe, part# 8679.

 

[Diabel]

Thanks for the damper info.

As for the temps... I just checked the sticker on my pipe & it says "do not exceed 650*C, so that would be 1200*F interior of around 600* exterior. I often run it at 500* exterior. Should I be worried?

 

[begreen]

It was 43 this morning so I just loaded up our stove with a full load of wood for the first time this season. Stove is cruising at 675 stove top and 400 stack temp.

I think double wall connector pipe is rated for continuous duty up to 1200 degrees, but my preference is to keep it much lower. I'm not sure if a damper would help, but maybe. Can you describe the whole flue system on the stove?

 

[woodwoman]

yes, we do have a damper on the stove pipe. right now the stove top temp is 500 and the stove pipe is about 225 on the dial. what a heat machine! it's 22 degrees here in central ny and it is heating out 1200 sq ft ranch all the way, 75 in the farthest bedroom from the stove! yeeee haaaaa, i live wood heat!

thanks everyone
happy burning