BK vs Secondary Combustion Stoves?

[BeachBumm]

I am narrowing my choice for a new stove (or maybe an insert). Blaze King sounds too good to be true, but I am trying to make sense of it. I hope someone can help me with my confusion regarding flue gassed cooling and the making of creosote.

Blaze King has printed in their literature the following:

"Burn 33% less wood. The combination of our exclusive thermostat and catalytic combustor technology makes your Blaze King insert one of the most efficient wood inserts in the world. The proof of this is in our flue temperatures. Non Blaze King inserts have flue temperatures of between 600° F and 900° F while your Blaze King flue temperatures are between 200° F and 300° F. Non Blaze King inserts pump valuable heat up the flue while your Blaze King keeps the heat in your home saving you money. Our highly efficient inserts will burn up to 33% less wood. So you cut, stack, load and clean 33% less wood."

Don't those higher flue temps keep the creosote to a minimum? If Blaze King has cooler flue temps, why aren't the liners full of creosote?

A salesman told me today (he sells a lot of brands including BK), 'the only difference between a secondary combustion stove and a BK are the BK's long running times. If you want a 30 hr burn - it's BK. If you don't mind stoking the fire every 8 - 10 hrs, it's a secondary combustible stove. That's the only difference.'

Help?

 

[Squirrely]

There will be plenty of long burn stories as there are a lot of BK fans here. That and clean burning are likely their strongest points. It's worth your time to also read about the issues people in this forum have had with catalysts (expensive, broken, damaged, can't obtain them, gaskets, etc.)


Greg

 

[kennyp2339]

I feel like your asking the same round about question in different threads expecting to hear something totally different.
So the epa lists the amount of grams per hour a stove can emit, all certified stoves (stoves that can be sold brand new) I believe right now is 4.5 grams of particulate matter per hour.
The BK's and air tube re-burn stoves meet those guidelines, its just the technology to meet those guidelines is different.
In an epa approved air tube re-burn stove, the stove relies on burning off the smoke with secondary combustion, in order to get the secondary combustion you need a hot fire box (primary combustion) the unburnt smoke (heavier because its unburnt fuel) gets recycled back into the stove box to get re-burnt, this again can only happen with high fire box temps, when you burn at high temps you go through fuel faster, also because the technology isn't quite there yet (price points) high fire box temps lead to high stack temps.
In the BK stoves, the stove is designed to burn low and slow (think of smoldering or very low flames) the t-stat air control is calibrated to the fire box temps, this is to maintain smoke to feed the catalytic converter, the cat placement in the stove allows for optimal heat recovery / transfer to your inside living place. So essentially you burn / smolder your load, the cat eats the smoke, the by product of the cat eating the smoke is heat which gets transferred to the top of the stove and either blown or radiated into the room. It is a common occurrence when burning these stoves on low that your window get creosoted over, to clean it you simply run the stove on high and the higher fire box temps burn off the creosote that builds up in the fire box. Because the cat is proportionately sized for the Bk companies standards, all the smoke particles that are produced gets eaten up and the by-product of the exhaust is primarily heat and water vapor, the heat is transferred to the stove top so your left with water vapor and lower flue temps.
Now don't be fooled by long burn times all the time, when burning low you will have long burn times (+15 +20hrs) but if you burn on medium / high the stove becomes just like any other wood stove, your burn times will reflect how high you burn the stove.
Also part of that 33% in wood savings is the consistent heat the stove produces, rather than have short but higher heat curves like that of a air tube re-burn stove, you can have a lower, but longer consistent heat, I use to burn a air tube re-burn stove and I feel as though now with owning a BK my house stays much warmer because I have a consistent steady flow of heat. On average when temps dip from to the low teens at night to the upper 20's during the day I load the stove twice a day, so 12 hr reloads. My old epa re-burn stove I would 4 times during the same weather conditions, when its warmer out I really cash in on the wood saving, only doing one load a day.
Address the cat issue, BK warranties the cat for 10 years, mine lasted only 4 full burning seasons, I literally lite my stove at the end of October and burn to the end of April, that dam near 6 months of 24/7 burning. The cat costs in the ball park of $250.00 to replace, I could spare that every 5th year if its going to keep my place warm and cozy, all gaskets on every stove will wear out, the nice thing about the bk is the door adjustment is easy, the by-pass adjustment is easy and the knife edge around the door is awesome.

 

[Highbeam]

You should visit the Woodstock site and read a few of their excellent articles about why ALL of their stoves use catalysts to provide the most efficient, lowest emissions, and longest living stove that they can. I don't own a Woodstock but their articles are quite good.

To try and briefly answer your questions: flue temps above 214 will prevent the condensation of water and creosote. So long as you stay above that you'll be fine. Anything above say 250 is wasted heat. These are internal temperatures, not surface temperatures.

Cat stoves eat way more stuff from the exhaust than a noncat can. Weird compounds that aren't even regulated since they aren't particulates but are pollution and do produce heat when burned. Think methane and carbon monoxide.

My cat replacement is 168$ every 12000 hours which for me is 3 years. I save enough wood with higher efficiency to easily pay for the cat.

I currently own both types and am amazed how quickly the noncat can chew through 3.5 c.f. of wood in three hours!

Your salesman wasn't too far off. Don't underestimate the value of long burn times. The long cat burn time is a direct result of being able to control heat output from very low to very high. You can't do that with a noncat. It's like your oven is stuck on 450, great for pizza but useless for thanksgiving turkey!

 

[begreen]

Lots of old threads here that have already covered this topic. It comes up annually. Cat stoves are great in milder weather. The difference in burning technology becomes somewhat moot when the stove is pushed for heat.
https://www.hearth.com/talk/threads/cat-vs-noncat.115601/
https://www.hearth.com/talk/threads/cat-vs-non-cat.127681/

 

[BeachBumm]

"Cat stoves are great in milder weather. The difference in burning technology becomes somewhat moot when the stove is pushed for heat."

All good info from all of you. Thanks very much!

BG - If Cat stoves technology becomes a moot point when pushed for heat, why do all those Alaskans insist on BK?

 

[begreen]

They don't all insist on it. Believe it or not, other stoves are popular in AK too. It's also worth noting that the climate in Anchorage or Juneau is very different than the inland climate of Fairbanks, so the heating and housing needs vary.

That said, a BK Ashford could be good for your heating needs as long as the flue system can provide adequate draft.

 

[BeachBumm]

That said, a BK Ashford could be good for your heating needs as long as the flue system can provide adequate draft.

I'm working on that! I've got 10' now (to the top of the stove) and I am talking to a fireplace mason Saturday regarding removing the front of our fireplace and making an alcove so it will a straight shot "up" 10'. My chimney guy says he can add a 4' section of Class A to the top of my masonry chimney (connecting the SS liner to it) and I'd have 14'. It's not 16' though, which is what the Jotul & PC tech's said they test at.

 

[begreen]

It's hard to say how 14' will work with the Ashford, but you are taking the right steps. It might be ok. As noted in other threads, 14' will work with the Shelburne, PE and Enviro stoves.

 

[BeachBumm]

It's hard to say how 14' will work with the Ashford, but you are taking the right steps. It might be ok. As noted in other threads, 14' will work with the Shelburne, PE and Enviro stoves.

I've decided against the Shelburn, as I think it is just too much stove for our small space. I "think" I've got it whittled down to a Newcastle 1.6 (or their 1.6 insert) or a BK Chinook or Ashford.

 

[Squirrely]

I like the upright compact small footprint design of the Newcastle because you can stack wood underneath it. It also doesn't look like a 1970's microwave or an old picture tube television set.

 

[BeachBumm]

I like the upright compact small footprint design of the Newcastle because you can stack wood underneath it. It also doesn't look like a 1970's microwave or an old picture tube television set.

View attachment 199944

I like the Newcastle also because the top cast cladding slid away and you can heat food on it if the electricity goes out. Small point, but a worthy point for me.

 

[begreen]

Note that the Ashford's convection top lifts off for direct stovetop cooking too.

 

[WoodyIsGoody]

Note that the Ashford's convection top lifts off for direct stovetop cooking too.

Does removing the top change the minimum distance to combustibles?

 

[begreen]

Does removing the top change the minimum distance to combustibles?

That is a good question for @BKVP.

 

[lsucet]

BeachBumm , it is hard to say what will work or not for you. When is true that BK can burn high and low and do both very well is also true that it is not for everyone. I think that if you are not going to be running 90% of the time the BK in low to medium because you require higher heat demand all the time, then BK is not different to other stove but in my personal opinion still giving you a big, wide, controllable range of operation and savings. Floor plan play a big role. My floor plan was bad, Not open at all. The center wall of this house from the front all the way to the back is an insulated wall cause used to be an outside wall. they added that other part of the house and the upstair without made it an inside wall. It has the stucco and everything. lol. Just based on the way of the house is, is hard to take heat over that side. always is 8-12 degrees difference with the upstair sometime more.

BK help me to keep more steady temp and gain 2-3 degrees in that other part of the house, How? I don't know. But i never saw again the stove area at 90 or 90+ degrees like with the other stoves and nothing to do about it, plus the other part of the house not gaining much from all that heat. I know there are lots of things that can be done, fan blowing to the stove area, this and that. I did many of those but still. In the way that i see it is that when there is way of do something i was not up to all that. My decision was that i need to get into the core of the house and make some improvements. For the last two summer, I performed some remodeling including adding insulation to some areas and to the upper room ceiling plus creating a more open floor plan. Last winter i saw big improvement. This winter everything should be better but I added another BK to that area to run everything always in low maybe 90-95% of the time?

You see, based on the deficiency of the house when real cold outside. i run the stove a little harder than normal to can handle that other area and i still have longer burn times and more control over the stove area about the temp swings and yes, using less wood.

 

[Squirrely]

I like the Newcastle also because the top cast cladding slid away and you can heat food on it if the electricity goes out. Small point, but a worthy point for me.

We cook on the cast iron top of our Squirrel and it works great. A clear cooking surface is one reason we use the rear flue outlet instead of the top. A wood stove is a genuine blessing when the power goes out. In an emergency you can cook food, heat water for washing, and boil water for drinking. A wood stove can even provide light.

Greg

 

[begreen]

We cook on the cast iron top of our Squirrel and it works great. A clear cooking surface is one reason we use the rear flue outlet instead of the top. A wood stove is a genuine blessing when the power goes out. In an emergency you can cook food, heat water for washing, and boil water for drinking. A wood stove can even provide light.

True, though not a lot of fun when it's 85F outside. We also have a propane cooktop as a backup. It's good to have redundant systems in earthquake country.

 

[BeachBumm]

If a BK and a secondary burner were both loaded with the same dry wood, same amount and burned on low all winter long - does anybody know how each respective chimney would look?

BG - Yep, a propane backup for the backup is a good way to go!

 

[lsucet]

We cook on the cast iron top of our Squirrel and it works great. A clear cooking surface is one reason we use the rear flue outlet instead of the top. A wood stove is a genuine blessing when the power goes out. In an emergency you can cook food, heat water for washing, and boil water for drinking. A wood stove can even provide light.

Greg

I really think those are stronger points to look into it when purchase a stove or any other products. That's why what work for some don't work for others regardless how remarkable a product can be.
I am on propane for cooking and water heater. That make me not look into a stove with those details. BG has a good point also. Power can go out any time. In hot weather draft can be stablished if burning on high but the house will be insane hot plus the chance of overfire..

 

[lsucet]

If a BK and a secondary burner were both loaded with the same dry wood, same amount and burned on low all winter long - does anybody know how each respective chimney would look?

BG - Yep, a propane backup for the backup is a good way to go!

I don't think that comparing both technology in the way you are doing is a good way. Let's forget about BK and let's go with the technologies. They require different temperature point to work. Cat Stoves you can smoldering cause is what the technology works/allows and just need 500 degrees. Non cat you can not smolder and secondary burn required higher temperatures to work. About 1100 degrees. Both can burn clean and creosote should not be a problem. On one the cat takes care that and the other one secondaries takes care of that also.

 

[Squirrely]

I am on propane for cooking and water heater.

We also have propane for your uses as well as also for laundry drying. Propane enjoys an advantage in that you can still cook and have hot water even with no electricity. Although in an emergency situation we would conserve the propane and use the wood stove because of an unlimited supply of firewood.. For low tech non electric laundry drying we have a clothesline.

Greg

 

[Squirrely]

True, though not a lot of fun when it's 85F outside. We also have a propane cooktop as a backup. It's good to have redundant systems in earthquake country.

We have a small portable wood stove for outdoor cooking in hot weather...



...and I'm also building a stationary rocket stove using of a concrete cassion form, similar to this design but larger in diameter so it's thicker..



Greg

 

[BeachBumm]

I don't think that comparing both technology in the way you are doing is a good way. Let's forget about BK and let's go with the technologies. They require different temperature point to work. Cat Stoves you can smoldering cause is what the technology works/allows and just need 500 degrees. Non cat you can not smolder and secondary burn required higher temperatures to work. About 1100 degrees. Both can burn clean and creosote should not be a problem. On one the cat takes care that and the other one secondaries takes care of that also.

If a Cat burner is "smoldering" is it giving out enough heat to 'heat'? If a secondary burner is at 1100°, is it warm, hot, or very hot?

 

[lsucet]

We also have propane for your uses as well as also for laundry drying. Propane enjoys an advantage in that you can still cook and have hot water even with no electricity. Although in an emergency situation we would conserve the propane and use the wood stove because of an unlimited supply of firewood.. For low tech non electric laundry drying we have a clothesline.

Greg

That is what I saw all my life growing up in my country. That's what we have here also. this time of the year we do all the drying outside when here. Dryer only use on winter sometimes. The wife loves the clothesline. Reminded her of the Grandma.