Shoulder Season heating with a non-cat stove

[SpaceBus]

I have an easier way- have 18" thick rubblestone walls, poorly insulated attic, leaky doors and windows. Then, burn full tilt all the way through shoulder season, never gets too hot. Just no more 3 am reloads to keep warm. It's wonderful sleeping through the night!

What do you do when it's really cold? I have to burn my little Morso at full tilt basically all winter. Thankfully our house is well insulated. You must have a big stove!

 

[Easy Livin’ 3000]

What do you do when it's really cold? I have to burn my little Morso at full tilt basically all winter. Thankfully our house is well insulated. You just have a big stove!

Shiver a lot, and huddle close to the stove as much as possible.

 

[2fireplacesinSC]

Ok. Good advice.

So what is the typical condensation point in a flue?

What temp do you keep the flue at or above?

How do you know if you don’t have a flue thermometer?

So do I have this right? To char a load is to burn it hot with lots of flames for 20 minutes or so? Or is it to get the wood all burning? Black char colored? Help a newb out

 

[begreen]

So what is the typical condensation point in a flue?

What temp do you keep the flue at or above?

How do you know if you don’t have a flue thermometer?

I moved this to the non-cat thread. The charring examples are primarily for a catalytic stove. In a non-cat you can follow that procedure, it won't hurt as long as flue temps don't exceed the liner rating, but it often wastes a lot of heat up the flue. If the wood is fully seasoned this is not necessary. Having a flue thermometer really helps. Can you put a surface thermometer as high up on your stove connector as possible and still be visible? Or consider a digital probe in the stove pipe if that is awkward for you F3CB in a fireplace. With a flue thermometer you can start turning down the air around 400-500º on a probe thermometer and 250º on a surface thermometer.

Creosote condensation begins when temps in the chimney drop to below around 250º F. There is no set perfect temp. As hinted earlier the temp one keeps the stove pipe thermometer at will depend on a number of factors like whether it is a surface or probe thermometer, the length of the chimney or flue liner, whether it is insulated or not, whether it is interior or exterior and on the outdoor temps. For example:
a 300º probe temp on double-wall stove pipe on a 16' interior flue system may be fine, especially with say 45º outside temps because the exiting flue gases are still above 250º. But change that scenario to say a stove feeding single wall pipe into a 25' exterior chimney at 25º outside and it may take a 250-300º surface temp reading (500-600º flue gas temp) to avoid condensation at the upper part of the chimney.

But remember, for a non-cat this is only up until the coaling stage. When the flames have all died down the volatile creosote producing gases have been burned out. Then it's ok for the flue temps to drop, even if below 250º at the top of the chimney. A good guidance will be the following chimney cleaning. If there is mostly soot and dust in the chimney then all is well. If the upper part of the chimney is showing tarry or glassy baked on deposits then the flue gases have cooled too much.

Because of all the variables it takes a bit of experience to know what is the right cruising temp for your flue in your installation. Fully seasoned, dry wood is your best insurance policy.

 

[Woody Stover]

With a flue thermometer you can start turning down the air around 400-500º on a probe thermometer and 250º on a surface thermometer.

Are you usually seeing secondary burning before you start cutting the air? Is it your goal to keep that going as you cut the air? Is it possible to get secondary burning without seeing flame? Doesn't seem likely...
Also, is it possible to overwhelm the secondary with volatiles? i.e. can smoke escape the flue if you have secondary flames, but not enough? Or does cutting the air also cut the volatiles to a level that the secondary can handle?

 

[begreen]

Are you usually seeing secondary burning before you start cutting the air?

Not always, but sometime yes. I start turning down the air when the flue temp is right and when the fire looks strong enough to be reduced and yet have enough strength to rebuild full flame in a few minutes.

Also, is it possible to overwhelm the secondary with volatiles? i.e. can smoke escape the flue if you have secondary flames, but not enough? Or does cutting the air also cut the volatiles to a level that the secondary can handle?

I'd be guessing but theoretically if one loaded a stove load of kindling or split construction scraps then perhaps possible, but not likely in daily burning.

 

[Woody Stover]

I start turning down the air when the flue temp is right and when the fire looks strong enough to be reduced and yet have enough strength to rebuild full flame in a few minutes.

So the secondaries start later, when more wood gets involved? I guess the more dense the wood, the longer it takes to get it gassing well and producing secondaries?