Do I need a flue damper?

[Osagebndr]

I've been burning my summit 24/7 since install ( 12/3/14) and I've noticed at times when the stove top is at 700-750 my flue temps will pretty much match temp wise. I have an 8" flue that was used for the reg buck I had before. It's 14ft from stove top to top of flue. Should I use a flue damper? This does not always happen mostly when it's very cold outside.

 

[Osagebndr]

Ok so maybe this should have been an over fire thread . Stove top ( one side of flue ) is at 825 other side is at 750 so put my fan behind the stove to move the heat away quicker and it's slowly working .that was a trouser filler tho. Dry wood will really take off on ya

 

[begreen]

14 ft is not a lot of flue. Some stoves would be unhappy with that. This sounds more like loading dry wood too early on a hot coal bed or leaving the air open too long before closing it down.

 

[pen]

A damper won't hurt to play with, but if it's not needed, then it's just an obstacle for cleaning.

With a relatively short chimney, and 8 inches to boot, I'd be surprised if you needed one unless your wood is extremely dry / split small-ish, loading in a way that provides a lot of airflow through the wood, loading prematurely on hot coals, leaving the air open too long before closing it down in stages to maintain a cruise, etc.

pen

 

[Osagebndr]

Could be . Most of my oak has been question able but I may have gotten into some real dry stuff. Just checked with my ir gun and it was at 650-700 for the most part.

 

[Osagebndr]

A damper won't hurt to play with, but if it's not needed, then it's just an obstacle for cleaning.

With a relatively short chimney, and 8 inches to boot, I'd be surprised if you needed one unless your wood is extremely dry / split small-ish, loading in a way that provides a lot of airflow through the wood, loading prematurely on hot coals, leaving the air open too long before closing it down in stages to maintain a cruise, etc.

pen

I may have waited a little too long . Coal bed looked good . I've been having lots of problems keeping secondaries going after shut down so I'll wait until 475-500 to shut down .

 

[begreen]

I've been having lots of problems keeping secondaries going after shut down so I'll wait until 475-500 to shut down .

That could be weak draft. A key damper would just make that worse. I am often turning down the stove at 300F with no issue. Try turning it down earlier. Turn it down until the flames get lazy, then wait for the flames to regain strength. Then turn down again till the flames get lazy.

 

[pen]

I may have waited a little too long . Coal bed looked good . I've been having lots of problems keeping secondaries going after shut down so I'll wait until 475-500 to shut down .

So long as what's coming out the chimney is clean (your nose, knows) then you don't need raging secondaries. Just focus on learning what it takes to make the sucker burn cleanly, and go from there.

I can take a load of wood that is too wet, get it screaming hot, and close the air down in one shot, and get nice secondaries for a while,,,, but that only looks pretty. Having good dry wood, and learning where on your thermometers you need to start closing things down in stages to keep a manageable burn, is key.

I don't usually get much rolling secondary action (especially from the back of the stove) until I have the air set at the cruise position and have walked about for about a 1/2 hour or so, that's when things start to build again. If the secondaries take off with the flick of the air control, you waited too long.

Remember, it's not all about secondary action, finding the right blend of primary against secondary is what's key. For me and my setup, I only ever close the air down fully if I've screwed something up, and that's for a short stint to get things under control. If I close the air down in stages correctly, my air control is usually left about 3/8 inch out or so.

 

[Osagebndr]

I'll try that BG. I think my wood was a little drier than I gave it credit for being also.

 

[Osagebndr]

I normally shut down at night and keep it open during the day. My day fires are smaller than night fires also. But I typically have a 550-650 stove top no matter how I burn

 

[begreen]

The air control should usually be shut down to as far as possible without smoldering the fire. That will actually encourage more efficient secondary burning. Our wood is nice and dry so often I can go straight from a fully engaged fire to almost all the way closed. But with less ideal wood it may take a couple steps as described earlier. If more heat is needed, opening it up a 1/4" makes a big difference, but I get 650F stove top temps with it almost all the way closed.

 

[pen]

I normally shut down at night and keep it open during the day. My day fires are smaller than night fires also. But I typically have a 550-650 stove top no matter how I burn

That's kind of an old school mentality. With a modern stove, it's generally better to focus on burning in cycles and not just closing things up for the night and burning things off in the morning, in the event it was closed down too much for the night.

As BG said, with good dry wood, closing things down to the point that it doesn't smoulder makes for a more efficient burn.

However, each stove and chimney setup varies, and for me, If I go from raging hot by leaving the air open too long, down to the cruise setting, I'll stall the stove and I am using wood that is very dry too, at 2.5 years split and stacked without seeing a drop of water.

See what works for you.

pen

 

[Osagebndr]

By smoldering do you mean no secondaries or flame present? If so I try to avoid that at all costs. I usually have the air open 1/4-1/2" sometimes less and get very good burns (no smoke) .

 

[pen]

By smoldering do you mean no secondaries or flame present? If so I try to avoid that at all costs. I usually have the air open 1/4-1/2" sometimes less and get very good burns (no smoke) .

Yes, smoldering would be anytime the fuel as insufficient air to burn cleanly.

 

[Osagebndr]

So now the question would be how full
Do you load your stove? If I load mine to within an inch or two of the baffle and got good start up I haven't been able to shut it down or close the air up too much before 450* or it stalls out on me

 

[begreen]

It depends. We have been mild lately so I am only doing 1/2 to 2/3d loads. Otherwise I too am up within an inch or two of the baffle. No problem turning it down at a much lower temp, but my wood is very dry. Doug fir burns hot and easy.

 

[Osagebndr]

I got into some real dry oak, apple cherry. I didn't check the mc because it was CSS when my questionable oak was CSS . After checking it it's 15-18% mc . I'll be keeping
An eye on it a little better from now on. I put 4 large splits in and a medium tonite 2/3 full cut my air way back at 300 and slowed it down. Well see how that works for me tonite

 

[begreen]

Are there still lazy flames present after turning it all the way down? If so it should pick up steam and heat in a short while.

 

[Osagebndr]

Yes it slowed way down and after awhile it picked back up and started throwing the heat . Stove top got to 600* and flue (internal ) was at 550

 

[pen]

Oh hell, didn't realize you were taking internal pipe temps. You have double wall pipe with a probe?

If so, those temps sound spot on to me.

pen

 

[Osagebndr]

They are good usually 450-650* that night however they were hitting 800* during the burn cycle and rising. Stove top hit 825*