Hello from BKVP

[Marshy]

Froling is already using O2 sensors in their boilers. It's a damn shame their product is so costly though. That level of complexity is likely going to become a necessary evil at the rate we are headed though.

I was wondering, how does efficiency of the cat and flue velocity relate, inversely I assume or is it more complex?

 

[bkvp]

Flue velocity (draft) plays a huge and vital role. It is possible in a manually controlled stove to reach an "overfire" situation. In a cat stove, optimal draft allows for higher (controlled with a thermostat ) temperatures. More importantly is how it allows the cat to remain active all extremely low burn rates. Efficiency is not always a mirror of emissions, but in our experience you acheive improved efficiency in lower burn rates. "Your results may differ etc..."

 

[Oldman47]

The effect I can see of a cat would be to become more efficient at removing combustibles right up to the point that there is no more fuel/air mix for the cat to burn. As an example if you have a cat that is 4 inches thick and the flow is such that by the 2 inch point everything that can be burned has been burned, changing the flow rate up or down will have no effect. Once the flow is high enough to exceed the 4 inch point, you lose some of the combustion on the cat because you have left over fuel/air mix at the cat's exit. Please note: I have no idea the real dimensions of a typical cat. I am using 4 inches for illustrative purposes.

 

[bkvp]

The effect I can see of a cat would be to become more efficient at removing combustibles right up to the point that there is no more fuel/air mix for the cat to burn. As an example if you have a cat that is 4 inches thick and the flow is such that by the 2 inch point everything that can be burned has been burned, changing the flow rate up or down will have no effect. Once the flow is high enough to exceed the 4 inch point, you lose some of the combustion on the cat because you have left over fuel/air mix at the cat's exit. Please note: I have no idea the real dimensions of a typical cat. I am using 4 inches for illustrative purposes.

Thickness is typically 2". However, thickness would be far more accurately referred to if we say surface area. A reticulated foam combustor (looks like a loofa sponge) has so much surface area, being 1" thick may provide sufficient surface area to provide large reduction in pm.

Redundant cats applied in series has also been played with. Unfortunately there is a deminishing point of return and the cost factor just keeps going up.

All....for the next day or two my wife and I will be alone in Alaska. Don't panic, I'll be back. Can't get rid of me that easy.

 

[Ronaldo]

Thickness is typically 2". However, thickness would be far more accurately referred to if we say surface area. A reticulated foam combustor (looks like a loofa sponge) has so much surface area, being 1" thick may provide sufficient surface area to provide large reduction in pm.

Redundant cats applied in series has also been played with. Unfortunately there is a deminishing point of return and the cost factor just keeps going up.

All....for the next day or two my wife and I will be alone in Alaska. Don't panic, I'll be back. Can't get rid of me that easy.

Have Fun!

 

[Blowncrewcab]

we'll Wait........ Your Knowledge is worth it.....

 

[unclemoustache]

Got that right. Maybe we can get BKVP and WhiteSpider to go at it about moisture meters or something.

 

[Idahonative]

Talk on this and other forums has me thinking I better start saving my money to buy a spare BK stove before the EPA ruins them. I realize the stove manufacturers are at their mercy but I don't want a computer controlled stove. Especially one that runs "on the grid". I don't want to have to gas up the generator in the middle of the night when we lose power. I also don't want it to be like modern cars when the engine light comes on and shop can't figure out what's wrong with it. Electronic controls can make our life better but they can also be a nightmare.

EDIT: If I had the money, I would buy a couple King Ultra's just to store until (years down the road), I might need to install another. Yes, I love that stove that much!

 

[stihly dan]

Talk on this and other forums has me thinking I better start saving my money to buy a spare BK stove before the EPA ruins them. I realize the stove manufacturers are at their mercy but I don't want a computer controlled stove. Especially one that runs "on the grid". I don't want to have to gas up the generator in the middle of the night when we lose power. I also don't want it to be like modern cars when the engine light comes on and shop can't figure out what's wrong with it. Electronic controls can make our life better but they can also be a nightmare.

EDIT: If I had the money, I would buy a couple King Ultra's just to store until (years down the road), I might need to install another. Yes, I love that stove that much!

Why? I have one and it works awesome, works good during power outages too.

 

[Idahonative]

Why? I have one and it works awesome, works good during power outages too.

Because I already have a wood stove that works awesome without electronic controls. I'll ask you the same question, why would I want one?

 

[stihly dan]

You have a fantastic stove. Everything can improve though, don't be afraid of technology.

 

[Idahonative]

You have a fantastic stove. Everything can improve though, don't be afraid of technology.

Haha, I hear what you're saying. But I will probably burn energy logs before I own an electronically controlled wood stove (and everyone knows that isn't happening).

Technology is everywhere now days. Heck, I spent 15 years working in a class 1 clean room in the semi conductor industry. I find myself needing to hold onto a few basic things in life. Cutting and burning wood is real important to me. It feels good to be self sufficient by not relying on big business to heat our home. It's one of the few things in life we can still control. Even though I was involved in making micro processors, I wouldn't know the first thing about how to diagnose and fix problems with the electronics on a stove. A cat stove is about as high tech as I can get.

 

[blades]

Heat and electronics do not play together well. Not that it can't be done but puts me at mercy of utilities- which I try to avoid as much as possible. The power grid over all is getting quite poor interference wise and that is bad ju ju for electronics. Couple that with almost no filter system in power conversion sections of most electronics spells problems for consumers. 25 years of field service work.

 

[ChoppyChoppy]

One of the reason I put a stove in my house was to be "off grid" when the power us out.
It's common to be without power for at least a day or two when it gets windy (often).
-20, wind blowing 70mph, no power... well least I'm warm.

 

[NSMaple1]

I wouldn't be afraid of electronics either.

They have lots of potential to improve the burn through the whole cycle, and if the power goes out, it would just likely default to what is 'normal' stove operation today.

You'd likely have to get pickier though about the chimney setup meeting stringent draft specs.

 

[blades]

yep flue draft big effect on burn , previous stove had it own damper built in for draft- now called by pass I suppose, tube type reburn unit, mfg succumbed to epa requirements- didn't want to invest time money on that- as stove were a side line of the main business. still have stove just to small for current place.

 

[HarvestMan]

For those of us who do not have the luxury of the BK auto-damper, what are the tried and true techniques for achieving "low and slow" burns with a cat stove. Here are the variables that I am trying to manage so as to get the longest burn times with low heat output :

1. primary air control
2. key damper in 1 foot pipe between stove and thimble (28 foot chimney on high ground)
3. wood species (MI - so basically eastern species)
4. split shape and size
5. firebox load (max 2.2 cu ft in my case)
6. char time after re-load

I read a lot of wood burning forums and it seems that so many people take quite a while to figure out their stoves. Hoping to reduce this time as I have a new WS Fireview. I've read all the Fireview threads (on multiple sites) and I cannot recall a thread where the owners are trying to achieve long burn times with low heat output as I am trying to do (for me, all winter is "shoulder" season it seems).

Thanks.

EDIT: I guess I am most interested in how I should use the primary air control and the key damper to maximize burn times. In my old Hearthstone, they called the key damper a "throttle", so clearly it is a control even though most stove companies say you don't need one with the new EPA stoves.

 

[Idahonative]

For those of us who do not have the luxury of the BK auto-damper, what are the tried and true techniques for achieving "low and slow" burns with a cat stove. Here are the variables that I am trying to manage so as to get the longest burn times with low heat output :

1. primary air control
2. key damper in 1 foot pipe between stove and thimble (28 foot chimney on high ground)
3. wood species (MI - so basically eastern species)
4. split shape and size
5. firebox load (max 2.2 cu ft in my case)
6. char time after re-load

I read a lot of wood burning forums and it seems that so many people take quite a while to figure out their stoves. Hoping to reduce this time as I have a new WS Fireview. I've read all the Fireview threads (on multiple sites) and I cannot recall a thread where the owners are trying to achieve long burn times with low heat output as I am trying to do (for me, all winter is "shoulder" season it seems).

Thanks.

It obviously will help a lot to burn good hardwood. We don't have that luxury as all we burn is conifer.

Firebox size is also important and getting long burns (& real world heat) out of a 2.2 cf firebox will be a challenge in my opinion. It can't be understated the importance of split size either. My avatar shows some typical splits that we feed our stove. They are BIG and definitely a component to long slow burns. BTW: when I say long slow burn, I'm not only referring to how long a stove will burn but how long it will produce heat sufficient to heat our home to 70*+.

 

[showrguy]

Idahonative,
Lets just say, if you did clean your chimney, would you have to remove the stove pipe from the King, or is that not necessary ??
I'm lookin at a 32+ ft. stainless chimney, so there's gonna be some weight there............I think disconnecting everything would be a major PITA.....

 

[bkvp]

Use a double wall slip connector with double wall pipe. The slip connector works a bit like a periscope in that you can slide it up easily. That section should connect to the ceiling support box. Then the all-fuel will connect on the top side of the ceiling support box.

Chris