small loads in a big stove

[Ashful]

I have planted a lot of oaks in key positions on my property, where other things had died a decade ago. I'm really hoping these don't get wiped out, as well.

But you guys lamenting one having to use oak as firewood? Get your heads checked! Oak is the ultimate firewood, for anyone who has time to let it properly dry! Massive BTU punch, and easy to maximize burn times, no matter what your rig.

 

[weee123]

But you guys lamenting one having to use oak as firewood? Get your heads checked! Oak is the ultimate firewood, for anyone who has time to let it properly dry! Massive BTU punch, and easy to maximize burn times, no matter what your rig.

Oh I’m not saying I’m unhappy with it as firewood it’s just definitely not ideal for small fires in a large stove as it doesn’t heat up quickly enough for the stove to burn properly

 

[Prometeo]

However on a considerable bed of embers, and a good draft, I can go ahead even with partial loads, a good piece of wood, unique, very dry, it doesn't produce a sudden bomb of fuel but a little at a time and I think it's very efficient, of course the flame must start immediately

 

[joop]

i'd kill for oak,not literally lol wellll maybe

 

[oilcan1001]

Now, after a few weeks of burning and using some of the suggestions from this thread, I'm getting to know my stove much better and gaining more confidence each burn.

1. for a cold start I use my dry pine with lots of kindling to get stove 'up to temp' as quick as possible (this is important)
2. once heated up I can burn smaller loads (of harder wood) with no problem and still maintain secondary burning

I really appreciate all the knowledgeable people and helpful contributions in these forums.

 

[Caw]

Coming from an Osburn 1600 (1.8cuft) to a stove twice it’s size with the 32NC (3.5cuft), it definitely is harder to make a small fire and have it burn right. You really need to use small (2”-3”) splits for it the burn hot enough to light off the secondaries.

When I use normal size splits it won’t get hot enough to light off secondaries, but then again I am still trying to figure this stove out as I’ve only run it a month and a half and not during the shoulder season.

Half load and above it runs great though.

You abandoned my baby?!?! 🥺

I'm still rocking the 1600 and love it. I wouldn't mind a 2.4 cu ft option but no need to swap it's only 4 years old. Maybe down the line.

 

[weee123]

You abandoned my baby?!?! 🥺

I'm still rocking the 1600 and love it. I wouldn't mind a 2.4 cu ft option but no need to swap it's only 4 years old. Maybe down the line.

Lol mine was 20-30 years old. Tested to 1989 EPA regs. I sold it to my buddy and I’m very tempted to buy it back

 

[Pinesmoke]

I'll let you guys know how the Mansfield does when I get my arms around her quirks. I'll have some burn time in the next 10 days.

Last weekend on Saturday morning, the embers where still on the cats. Ran a 2-3 small split fire all day that way. I'm not sure how smoothly that would go from a cold box. I DO need to get that pinned down.

 

[Caw]

Lol mine was 20-30 years old. Tested to 1989 EPA regs. I sold it to my buddy and I’m very tempted to buy it back

Ok fair enough. Mine is a 2019 so slightly different lol. Skirted the 2020 regs! It's rated 4.4 g/hr so it's not like it's egregious I don't feel badly about it at all. Got a good deal since it was purchased in April 2020 and it was the last pre 2020 the guy had in stock.

 

[Solarguy3500]

@Ashful good call on the points you bring up.

I have suggested to some that they can burn smaller loads in a big firebox. Thinking about it more in this context, I should be prefacing that advice with a caveat that they need to make sure to have truly dry wood and get some experience under their belt with their stove to make sure they can achieve a clean burn with a smaller load. I think you're right that many receiving such advice are likely to be newbies and could end up burning inefficiently if they are not aware of the intricacies of the stove they are using.

To that point, I am something of a newbie myself, though after spending the last 3 years on Hearth.com prior to getting my stove installed reading countless posts about the right and wrong way to burn wood, I had hoped to go into it with an advantage in knowledge. I do feel like I'm doing pretty well so far and having truly dry, 3 year seasoned wood is a big help since I also spent those 3 years processing wood to have it ready when I eventually did get the stove going. I have been burning smaller loads myself mostly because it has been pretty mild here so far, and also I have pretty strong draft so I'm a bit nervous to load up the box and get into trouble. I've been running some smaller loads of 3 splits, but mostly running 5 splits at a time. I feel like I'm getting good secondaries, but since I don't have a lot of experience, I could be wrong.

I currently have 3 splits in the stove, Auber probe at flue collar reading 710°, STT 500°. Are these good secondaries I'm seeing or is that just primary and I haven't gotten to the good stuff yet?

I want to make sure I'm burning efficiently myself.

Edit: I have looked outside at my chimney when burning and see almost no visible smoke. Sometimes nothing visible. I compare this to my neighbors whose houses I drive by on my way up my road with clouds of thick smoke and steam billowing out of their chimneys. I shake my head knowing they are burning wet wood.

 

[danrclem]

I'm glad this subject came up because I'm trying to pick a stove and need to know what size to get. I usually equate bigger with better even though I know it's not always true.

I'm currently using a very old woodstove without a glass door so it's hard to know what's going on inside and I have to judge by the heat of the stove what to do. I see "secondary burn" mentioned in this thread but at the moment I really don't know exactly what it means. I need to do a little searching to find out.

 

[30WCF]

Had a larger than needed non cat stove. All I could ever burn out if it was two splits at a time. Three would run you out and be over 600 STT on a large surface stove. Englander says 600 max in that stove.
It burned clean and hot. Was there way too much O2 in there without packing the box? I don’t know.

 

[weee123]

I'm glad this subject came up because I'm trying to pick a stove and need to know what size to get. I usually equate bigger with better even though I know it's not always true.

I'm currently using a very old woodstove without a glass door so it's hard to know what's going on inside and I have to judge by the heat of the stove what to do. I see "secondary burn" mentioned in this thread but at the moment I really don't know exactly what it means. I need to do a little searching to find out.

Secondary reburn stoves have a baffle, with air tubes underneath that tie into air supply intakes that has air in it that gets preheated from the stove burn chamber. It then moves into the tubes that have holes in it like a propane grill burner. Extremely hot air flows out and it will ignite and burn the smoke to extract more BTU’s from the burn and clean the exhaust up.

 

[weee123]

Had a larger than needed non cat stove. All I could ever burn out if it was two splits at a time. Three would run you out and be over 600 STT on a large surface stove. Englander says 600 max in that stove.
It burned clean and hot. Was there way too much O2 in there without packing the box? I don’t know.

Which stove did you have? A d what was your chimney setup?

 

[Caw]

Had a larger than needed non cat stove. All I could ever burn out if it was two splits at a time. Three would run you out and be over 600 STT on a large surface stove. Englander says 600 max in that stove.
It burned clean and hot. Was there way too much O2 in there without packing the box? I don’t know.

Max of 600 STT? Was it a cast iron model? That is very low for steel. My Osburn likes to be around 700 STT when cruising. SBI says 840 STT is considered an over fire.

Keep in mind I'm reading STT at the hottest spot on the firebox which is a few square inches. The rest of the stovetop is 50-100 degrees cooler on average.

 

[begreen]

600ºF is low for steel or cast iron. Both our past cast iron Jotuls and our current steel bodied T6 have frequently operated above that temp. 700º is a more practical limit as long as flue temps are not a lot higher. Soapstone is more like 600º.

 

[Solarguy3500]

600ºF is low for steel or cast iron. Both our past cast iron Jotuls and our current steel bodied T6 have frequently operated above that temp. 700º is a more practical limit as long as flue temps are not a lot higher. Soapstone is more like 600º.

I'm typically seeing STT in the 400°-550°F range but my flue Temps are often 800° and above. But that is mostly because with a blockoff plate, my only option for installing the flue probe was right at the flue collar in the stove top adapter. I know the ideal placement is around 18" up the flue so I try not to let a 900° flue temp on the Auber freak me out too much, but is that wrong? Should I not be letting the flue temp get that high?

I'm trying to burn hot and clean and not make a bunch of creosote.

 

[begreen]

You are right to watch it. Easy breathing stoves on taller flues can be a challenge without a draft damper. The best thing to do is pack the firebox tightly with large splits and smaller splits filling the gaps. Turn down the air aggressively as the fire builds strength.

 

[EbS-P]

I have found fat shorter splits burn well with good secondary combustion.

I'm typically seeing STT in the 400°-550°F range but my flue Temps are often 800° and above. But that is mostly because with a blockoff plate, my only option for installing the flue probe was right at the flue collar in the stove top adapter. I know the ideal placement is around 18" up the flue so I try not to let a 900° flue temp on the Auber freak me out too much, but is that wrong? Should I not be letting the flue temp get that high?

I'm trying to burn hot and clean and not make a bunch of creosote.

i to have an Auber AT ( Drolet 1800i ) in the appliance adapter and right next to a damper. Flue gas temps regularly are 999+. My alarm temp is 1050. I can get over that on a hot reload damper full closed. Without the damper I was going north of 1399 and stove tops were 425.

I don’t have a good sense of what temps to shoot for when measuring at the collar. I decided at below 1100 seemed ok but have nothing to back that decision up with.

 

[begreen]

I rarely see over 800 unless I am slow at the air control. Today's packed stove hit 780º briefly on startup.

As a test for Hearth.com I added a flue damper to our setup this year on our 20 ft tall flue system. Normally it isn't necessary, but enough people here do need one so I will experiment with it. I had to buy a regular 6" section of DVL and put it in myself because DuraVent only sells it in the DVL flue collar adapter version and that fits too loosely. A couple of weeks ago I had a loose packed load try to take off on me. It got over 900º because I got distracted here answering posts. Closing the air all the way and closing the flue damper calmed things down in a couple minutes. I closed it off on today's load once the fire was fully engaged. It does add an extra margin of control.

 

[EbS-P]

I rarely see over 800 unless I am slow at the air control. Today's packed stove hit 780º briefly on startup.

As a test for Hearth.com I added a flue damper to our setup this year on our 20 ft tall flue system. Normally it isn't necessary, but enough people here do need one so I will experiment with it. I had to buy a regular 6" section of DVL and put it in myself because DuraVent only sells it in the DVL flue collar adapter version and that fits too loosely. A couple of weeks ago I had a loose packed load try to take off on me. It got over 900º because I got distracted here answering posts. Closing the air all the way and closing the flue damper calmed things down in a couple minutes. I closed it off on today's load once the fire was fully engaged. It does add an extra margin of control.

Was there much difference between collar and 18 inches up. ??

I like data.

 

[begreen]

I would expect so, but I have only had the flue temperature probe about 18-21" above the stove.

 

[Ashful]

Was there much difference between collar and 18 inches up. ??

I like data.

I experimented with this about 10-12 years ago, and the answer is "yes", but I don't have any numerical data recorded that I can remember. I was testing with a surface thermometer on single wall pipe, not a probe thermometer, and I think it's back when I was running Jotul Firelight 12's.

 

[weee123]

Was there much difference between collar and 18 inches up. ??

I like data.

Going based off IR temp on single wall surface, yes. It is a significant difference of a couple to a few hundred degrees. I will get you a temp next time I burn.

 

[Todd]

I’ve been playing around blocking some of my secondary air with magnets. I rarely see any internal flue temps over 600. She usually cruises 400-500 and the stove top is usually 100 degrees more.