The Blaze King Performance Thread

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Osburning

New Member
Dec 9, 2011
58
Southern NJ
Repost from another post to not hijack a post:This year it seems the King has arrived(Good and Bad), and that in itself promotes stoves like the Progress Hybrid etc. which is great for competition among stove brands cat and secondary.

Be nice to hear BK owners with temp readings from start to finish, outdoor temps, and how many splits went in for that time. All we really see now is: just got a 40 hr burn- high five man, 20hrs with a couple -awesome, etc. There’s no real perspective of performance other than long burn times.

Lets just keep it facts and info rather than vs some other type etc. Hey I just put in 5 splits of xx wood, 25* out, set it to 1.5 and getting 300* stove top, house is cooking, etc.
 
So many variables..house size..insulation...flue.

WindandSolar and I both had Bkk non cat stoves before our cat ones.

He is saving almost half the wood he used to use..I'm thinking I'm at a 33% savings.

Pretty sure someone on here went from a tube stove to a BKK cat and said he is saving some wood also..for sure not saving as much as someone coming from a smoke dragon.

But to try and answer your question.

Shoulder season avg temp for a 24 hour period..32f..I burn about 60-80 lbs off wood(one load) in a 24 hour period.
Now the last few hours might be raking the coals forward and burning those on high....sometimes not.
In the deep freeze 12 hours easy.
I don't think there is a lot of diff between the amount of wood used in the deep of winter between the two types.
It's the shoulder that the BKK shines in...but will git er done in any weather.
2500sf two story house built in 1986..good insulation and windows.
Oh..and size does matter!
You can put a bunch of fuel sticks in a BKK.
 
HotCoals said:
So many variables..house size..insulation...flue.

WindandSolar and I both had Bkk non cat stoves before our cat ones.

He is saving almost half the wood he used to use..I'm thinking I'm at a 33% savings.

Pretty sure someone on here went from a tube stove to a BKK cat and said he is saving some wood also..for sure not saving as much as someone coming from a smoke dragon.

But to try and answer your question.

Shoulder season avg temp for a 24 hour period..32f..I burn about 60-80 lbs off wood(one load) in a 24 hour period.
Now the last few hours might be raking the coals forward and burning those on high....sometimes not.
In the deep freeze 12 hours easy.
I don't think there is a lot of diff between the amount of wood used in the deep of winter between the two types.
It's the shoulder that the BKK shines in...but will git er done in any weather.
2500sf two story house built in 1986..good insulation and windows.

Perfect. Lets pick a night like tonight. How cold is it at home and how many splits did you have to put in at x.x setting to heat the house with the stove running smooth at 000*.
 
-5 last night, full load around 80 lbs ± at 10PM last night. med stat setting. (2.25 on my stove) fan mid range.
Noon today, 5 °f, raked the big coals forward & added 3 med splits, 25 lbs ±. med stat setting (2.5) up just a little. fan mid + range
6 PM, -3 °f, raked coals forward, 1 small split E/W on top of the coals. High stat setting (3) Fan high range.
2225 sq ft house. Basement install.
Fire wood: 2 year seasoned birch.
Will be adding a full load in about an hour ± for the night, 80 lb ± on top of hot coals. Temp now 3.7 °f, light snow. House, this floor is 71.2 ° f
Stove don't have a temp, active cat zone probe. Don't pay too much attention to it except on new loads, I run stat at 3.5 until it mid range in the active zone the adj stat to 2.25 when below zero like last night & tonight.
Pic of Christmas present:
 

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It's like 45f out..warm.
I loaded it about 10:00pm ..2/3 or a little more.
I have the t-stat below one..I know the flapper is shut and will probably stay that way through the whole load.
Anyways after I loaded it and charred it for maybe 15 mins the cat probe was at 2/3-3/4..stove top around 500f.
Then maybe a half hour 45 mins later the stove top went to 600f with the probe just about all the way...lots of off gassing going on and the cat is pigging out.

Then another 45 mins goes by and she is not off gassing so much and the temps are headed down for the low cruise.

I just went and looked and my IR says 450 by the cat probe and the probe is around 2/3 again..it will prolly drop down to like 350 stove top in a few more hours and stay there for a long time.

Now if I had the t-stat set a little higher..1.5 to maybe 2..the stove would maintain more stove top then 350 easy.
But it's warm out and it's 75 in the room next to the stove and maybe 80 in the stove room.
Around 70 upstairs where the bedrooms are...and I have the door shut in my bedroom which is the same size as my stove room..27x16..including the master bath.

If it's any warmer then this I truly believe I should just run the heat pump..but I hate the blower running.
And the power company gets to much of my money as it is..lol.

I'm burning ash css real early spring..mc about 15-20 usually.
Saving my good stuff.

I have next seasons wood curing out back!
 
Just know that when I talk stove top temps that is the temp right next to the cat probe..temps on the stove top drop off pretty good 6 inches away from there.
But there is a lot of mass to this stove.
 
I will post temps tomorrow again some time...maybe towards noon.
That will be about 14 hours into it...then 10 tomorrow night..all the same load.
Just realized it's already tomorrow!
 
Osburning said:
how many splits did you have to put in

I don't look at it that way as I fill the stove to the top every time. Mild temps, I get 24 hours out of a load of punk junk and uglies. Moderate temps, I get 12 hours out of punk junk and uglies. Moderate temps, I get 24 hours out of mid range stuff that is straight enough and proper length to fill the stove. Extreme temps, I get 12 hours out of the good stuff. Keep in mind too that I light in September and let it go out in May. So, there is only one cold start and the rest are just burn cycles.

When talking about the burn times, I think it gets lost just how big the firebox on the King is and that you can load every last inch of it without fear of it running away from you even with Pine. 100 pounds of wood is a lot to burn in a stove over 12 hours or even 24 if you have a system that puts the heat in the house instead of up the stack.
 

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Glad to see you started another thread, maybe you can find what you're looking for. As I posted in that other thread I am curious why people are asking for this type of detailed information though. I've never seen this many details asked for with regarding other stoves. When someone says their 30, Summit or whatever other stove burned 15 hours I've never seen anyone ask for the details.

Does it seem like we’re making stuff up and people want more details because of it? :coolgrin:

I'll try to get you what you're looking for without my wife thinking I've gone off the deep end. :lol:
 
Ok..since I loaded it at 10:00 last night..not full ..about 2/3 it has been warm..I think down to 38f and now back to like 45f.
186f stack temp..maybe 18" up.
But I do have less wood then I usually do..still no prob to get 20 hours in these warm temps.
If I knew ahead of that reload that I was gong to do this,I would have loaded it really full..lol.
 

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If you noticed my cat probe is at half...stove top near it 300f.
Is the cat active..I don't know.
Because the top is 300 I figure the cat is at 600f or so.
It's supposed to be active I think at 400 and above.
I see just a little wisp of smoke now and then out of the chimney.
House is really even in temps right now..around 75.
 

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I think I'm showing you can burn the BKK in shoulder temps and not heat yourself out of the house and burn fairly clean.
I have been burning 24/7 since early oct...I doubt 3 face cords...we have had some cold and windy spells.
Between the basement and garage I started with about 12 face cords..we will see at the end of the burn season where I'm at.
I can tell you I'm hooked on a cat stove because the shoulder seasons here are more then half the battle.

Also I know in the shoulder I go through about 60-70 lbs of wood in 24 hours usually...ash.
About 2.7 lbs a hour.
Is that useful info..I don't know.
Maybe the guys good at numbers could run those figures.
 
Ok I read where dry wood has around 7000 btu's/pound.
7000 x 2.7lbs/hour = 16,900 btu's/hour avg. right?

Per BK.
Minimum Heat Output 8,400 Btu’s/hr
Average High Heat Output 47,000 Btu’s/hr
Overall Efficiency 82.5%
Emissions 1.76gr/hr
Wood Length 17â€/23â€
Low Burn Time 40 Hours
Unit Dimensions

Width 30†/ 762mm
Height 34†/ 863.6mm
Depth 30†/ 762mm
Weight 435# / 197.3kg
Flue Diameter 8†/ 203mm


So I'm avg twice the min output but half the high output.
I think the high output is very conservative.
 
If you put 80 lbs of wood in a stove..x 7000 btu's divided by 40 hours I get 14,000 btu's per hour...just a little under my avg.
I should weigh a load of ash because I doubt it is 80 lbs.
I'm sure a more dense wood probably does.
 
rdust said:
Glad to see you started another thread, maybe you can find what you're looking for. As I posted in that other thread I am curious why people are asking for this type of detailed information though. I've never seen this many details asked for with regarding other stoves. When someone says their 30, Summit or whatever other stove burned 15 hours I've never seen anyone ask for the details.

Does it seem like we’re making stuff up and people want more details because of it? :coolgrin:

I'll try to get you what you're looking for without my wife thinking I've gone off the deep end. :lol:

Just trying to make things clear. I'm sure most people understand how a secondary tube stove performs cause most people have them. But I personally really am not quite sure the heat ranges people with BK's are operating at, when the cat starts working on a start from cold, when it stops working, are stove top temps linear, etc.
 
rdust said:
Does it seem like we’re making stuff up...

Yes. :lol: :lol: :lol:
 
Osburning said:
Just trying to make things clear. I'm sure most people understand how a secondary tube stove performs cause most people have them. But I personally really am not quite sure the heat ranges people with BK's are operating at, when the cat starts working on a start from cold, when it stops working, are stove top temps linear, etc.

I loaded last night around 9 or 10 with a pretty much full load of silver maple. I just pulled the sides into the center about an hour ago and the stove top is around 340-350 with it set on 1.75, it's 12:25 right now). Honestly I don't think stove top temps show the whole picture since these stoves burn at such a steady temp but it's really all we have I guess. I'll be heading out tonight but tomorrow morning I'll load up and try to record as much data as I can for the burn.(if I can function :lol: )
 
Osburning said:
rdust said:
Glad to see you started another thread, maybe you can find what you're looking for. As I posted in that other thread I am curious why people are asking for this type of detailed information though. I've never seen this many details asked for with regarding other stoves. When someone says their 30, Summit or whatever other stove burned 15 hours I've never seen anyone ask for the details.

Does it seem like we’re making stuff up and people want more details because of it? :coolgrin:

I'll try to get you what you're looking for without my wife thinking I've gone off the deep end. :lol:

Just trying to make things clear. I'm sure most people understand how a secondary tube stove performs cause most people have them. But I personally really am not quite sure the heat ranges people with BK's are operating at, when the cat starts working on a start from cold, when it stops working, are stove top temps linear, etc.

All woods stoves very in performance due to conditions.
If you want a long slow burn the cat is for you...a tube can not do it as good..no way.
In the deep freeze they are closer together.

How many btu's per hour are you averaging in warmer temps?

I'm pretty sure I'm around 19,000 or lower on low burn in the shoulder.
To be more accurate I'm going to have to weigh a load of my ash before burning.
Now that I understand the numbers more I'll do a better test some day.
 
rdust said:
Osburning said:
Just trying to make things clear. I'm sure most people understand how a secondary tube stove performs cause most people have them. But I personally really am not quite sure the heat ranges people with BK's are operating at, when the cat starts working on a start from cold, when it stops working, are stove top temps linear, etc.

I loaded last night around 9 or 10 with a pretty much full load of silver maple. I just pulled the sides into the center about an hour ago and the stove top is around 340-350 with it set on 1.75, it's 12:25 right now). Honestly I don't think stove top temps show the whole picture since these stoves burn at such a steady temp but it's really all we have I guess. I'll be heading out tonight but tomorrow morning I'll load up and try to record as much data as I can for the burn.(if I can function :lol: )

We seem to coincide pretty closely from last nights load.
I just have more fuel because of bigger box..that's all..but it was not really full.
 
HotCoals said:
If you put 80 lbs of wood in a stove..x 7000 btu's divided by 40 hours I get 14,000 btu's per hour...just a little under my avg.
I should weigh a load of ash because I doubt it is 80 lbs.
I'm sure a more dense wood probably does.

I think you have to compute your efficiency of 82% from that 7000 BTU number? Probably lots of other variables to consider but I'm thinking the t-stat/cat combination keeps the BTU's in check at the beginning of the burn where most other stoves outgas most of the BTU's the first couple hours.
 
Todd said:
HotCoals said:
If you put 80 lbs of wood in a stove..x 7000 btu's divided by 40 hours I get 14,000 btu's per hour...just a little under my avg.
I should weigh a load of ash because I doubt it is 80 lbs.
I'm sure a more dense wood probably does.

I think you have to compute your efficiency of 82% from that 7000 BTU number? Probably lots of other variables to consider but I'm thinking the t-stat/cat combination keeps the BTU's in check at the beginning of the burn where most other stoves outgas most of the BTU's the first couple hours.
I concur.

But I also think it's useful if I weigh the load before burning.
It seems all wood puts out around 7000 btu's a hour.
Just takes a lot more pine wood to equal oak.

Weigh the load..multiply it by 7000.
Burn the load till it gets down to just coals to where there is decent heat yet and would fire off a reload without coaching it.

So if you had 60 lbs of wood x 7000 that would be 420,000 btu's.
Divide into that the hours burned..say 20 hours.
that would give you a avg. of 21,000 btu's per hour.
10 hours would be 42,000 per hour.

I know it's not perfect but I think you could compare stoves some what.

It would be nice to know avg. outside temp for that period.

But yes..it is just a wild thought to really try to compare diff stoves in diff locals in diff houses..lol.
 
rdust said:
I loaded last night around 9 or 10 with a pretty much full load of silver maple. I just pulled the sides into the center about an hour ago and the stove top is around 340-350 with it set on 1.75, it's 12:25 right now). Honestly I don't think stove top temps show the whole picture since these stoves burn at such a steady temp but it's really all we have I guess. I'll be heading out tonight but tomorrow morning I'll load up and try to record as much data as I can for the burn.(if I can function :lol: )

It's now 3:00pm, stove top is 29x near the cat probe, just turned it up to 3.5 to warm the coals up so I can reload before going out. Hallway leading to the stove is 70* outside temp 38*. Roughly 17-18 hours since I loaded the stove with a stove temp still near 300*. :coolsmile:

Edit: Last one for me and I'm out for the night.

3:30 stove top back to 300 from burning down coals, loaded up with silver maple and some black walnut.

4:15 stove top hot spot 599, stove dial down to 1 fans off 36* according to accuweather.
 
Pictures of coals before reloading and fresh load of wood.
 

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Todd said:
HotCoals said:
If you put 80 lbs of wood in a stove..x 7000 btu's divided by 40 hours I get 14,000 btu's per hour...just a little under my avg.
I should weigh a load of ash because I doubt it is 80 lbs.
I'm sure a more dense wood probably does.

I think you have to compute your efficiency of 82% from that 7000 BTU number? Probably lots of other variables to consider but I'm thinking the t-stat/cat combination keeps the BTU's in check at the beginning of the burn where most other stoves outgas most of the BTU's the first couple hours.

Sure efficiency plays a big role.

If I'm averaging 14,000 btu's a hour x.82..that would mean I'm getting somewhere around 11,480 btu's into the house per hour.

I can buy into that.
 
I put up a thread about the chinook I'll be updating once it gets colder out.
Right now I'm just burning off uglies and garbage wood.
So far the only test I actually did was 45lbs of cottonwood, and got 27 hours but I ran it on high for a couple of those hours to heat the house. So I could've got much much longer if I didn't have to do that. It was 40-45 out during the burn, house held ~72.

I actually used some pallet wood last night to see how well it would handle it, and to make sure it wouldn't run away if I filled it right up. I put in 10 4x4 Oak pieces (each were about 3.5lbs so figure ~35lbs of wood). It burned for 26 hours on low before it was time for a reload, I usually reload when there's a pretty small amount of coals left... More than enough to relite, but not completely covered the firebox floor. That filled the firebox less than half way, and I stacked it in there "log cabin" style 2 stacks high. So I can definitely see loading 25-30 pieces in there for a good 90-100lbs of wood. Which compared to the 35lbs I put in last night, it should yield a rather long burn time. It was about 30 last night... House stayed about 72 all day/night.

It seems like whenever I put the stove on "1" It will maintain whatever temp the house is reguardless of outside temperature. I run the stove on 2 or 3 when I reload for about 10-20 mins depending on how many coals were left to char all the wood. So that heats the house up a bit, then when I shut it down to 1 it will hold that temperature in the house until it's time for reload... then it will drop some as the stove cools down. We haven't seen any teens yet, low 20s is the coldest it's been so far this year... so time will tell if I have to turn it up at night yet.
 
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