2016-17 Blaze King Performance Thread (Everything BK)

[kf6hap]

This is my take on cat vs air tube efficiency:

High Fire: cat and air tube close in efficiency. Both burn clean, have same burn times.
Medium Fire: Cat wins somewhat in efficiency and burn time. Both burn clean .
Medium low: Cat a clear winner in burn time, efficiency particulates decrease. Air tube stoves secondary combustion starts to fail, particulates increase
Low Fire: Cat stove has outstanding efficiency and particulates, air tube poor efficiency and smoky
Low Low fire: Cat stove excellent efficiency, burn times and particulate. Air tube operate in smoke dragon mode.

The above is from my own, somewhat limited, experience with wood stoves. Exceptions to the above-yes but generally is true. Cat stove=a BK cat stove only.

 

[drz1050]

Sometimes if I load the stove up with extra smoky wood, the cat cannot burn it all at high burn rates. The cat will be glowing bright red, but go outside and there is a lot of smoke escaping. If I turn down the thermostat, the exhaust gets clear. Not really sure what makes some wood smoke more than others, but I was burning those ecobricks last year, and they also smoke a ton, so at high burn rates they were overloading the cat as well. I don't think this is an issue for tube stoves.

So for your list, I'd argue that on a high fire, air tube stoves can burn cleaner than cat stoves, sometimes.

 

[Ashful]

You and Ashful should get on just fine.

Funny... I was just going to offer up some Flir images of an Ashford 30.1, or two.

 

[tarzan]

Sometimes if I load the stove up with extra smoky wood, the cat cannot burn it all at high burn rates. The cat will be glowing bright red, but go outside and there is a lot of smoke escaping. If I turn down the thermostat, the exhaust gets clear. Not really sure what makes some wood smoke more than others, but I was burning those ecobricks last year, and they also smoke a ton, so at high burn rates they were overloading the cat as well. I don't think this is an issue for tube stoves.

So for your list, I'd argue that on a high fire, air tube stoves can burn cleaner than cat stoves, sometimes.

It's all about resident time in the cat. The cat can't keep up with the off gassing of a fresh load on a high burn.

 

[black smoke signals]

Funny... I was just going to offer up some Flir images of an Ashford 30.1, or two.

Quiet! All of us are waiting for the Lambo and the VW to show up.

 

[Highbeam]

This is my take on cat vs air tube efficiency:

High Fire: cat and air tube close in efficiency. Both burn clean, have same burn times.
Medium Fire: Cat wins somewhat in efficiency and burn time. Both burn clean .
Medium low: Cat a clear winner in burn time, efficiency particulates decrease. Air tube stoves secondary combustion starts to fail, particulates increase
Low Fire: Cat stove has outstanding efficiency and particulates, air tube poor efficiency and smoky
Low Low fire: Cat stove excellent efficiency, burn times and particulate. Air tube operate in smoke dragon mode.

The above is from my own, somewhat limited, experience with wood stoves. Exceptions to the above-yes but generally is true. Cat stove=a BK cat stove only.

I run a non cat in my shop at high output all the time. I can turn a full firebox 3.5 c.f. to ash in three hours. So burn time and efficiency go to crap at high.

 

[Smoky Stoker]

It's all about resident time in the cat. The cat can't keep up with the off gassing of a fresh load on a high burn.

Tarzan nailed it, the gasses need a certain amount of resident time exposed to the substrate on the CAT. The higher the amount of gasses passing through the cells on the CAT, the less efficient a CAT stove becomes.

I found this article helpful, "The Complete Catalytic Combustor" by Chris Neufeld. In that article there is a table comparing OEM submitted data on CAT and NON-CAT stove performance. I give the caveat that this is a small snapshot from 2009, but still helpful for this discussion. The table shows that a CAT stove has a significant increase it's particulate output (decreased efficiency) when running on high. The NON-CAT data shows that it has a dramatic decrease in particulate output on high (better efficiency), compared to it's low burn output.

 

[Ashful]

When you say hearth gloves do you actually mean welding gloves? I have seen a lot of welding gloves recommended but not any special hearth gloves. Are they better or worse?


Sent from my iPad using Tapatalk

My hearth gloves are very similar to my welding gloves, maybe just a tad lighter, but look much nicer sitting on the hearth. They're brown suede, versus the usual welding glove gray or blue. I buy them at Ace Hardware.

 

[Ashful]

Tarzan nailed it, the gasses need a certain amount of resident time exposed to the substrate on the CAT. The higher the amount of gasses passing through the cells on the CAT, the less efficient a CAT stove becomes.

I found this article helpful, "The Complete Catalytic Combustor" by Chris Neufeld. In that article there is a table comparing OEM submitted data on CAT and NON-CAT stove performance. I give the caveat that this is a small snapshot from 2009, but still helpful for this discussion. The table shows that a CAT stove has a significant increase it's particulate output (decreased efficiency) when running on high. The NON-CAT data shows that it has a dramatic decrease in particulate output on high (better efficiency), compared to it's low burn output.


View attachment 191609

Summary, you have to damn near whoop your stove to the glowing point to get the average cat stove emissions anywhere near as high as the non-cat. Where stoves operate 80% of the time, the advantage of the cat is dramatic.

If they hadn't used a bogus "3-5" kg/hr range for the "high" setting, we could calculate the cross-over point.

 

[jetsam]

Even in cold weather, my cat stove runs on low or medium settings most of the time, because between going to work and sleeping, I am I unavailable for stovetending at least 18 hours a day. I usually set a 12 hour burn when I go to work, and an 8 hour burn when I go to bed.

If the house is colder than 75, it gets some high output time when I'm home and awake, though!

 

[tarzan]

Another thing to consider in real life situations with the BK's is we do usually run our stoves on a low to medium burn so when we do a high burn on a fresh load there's often creosote build up burning off in the box.

Anyone who's ever witnessed a chimney fire probably remembers the amount of smoke burning creosote puts off.

 

[scum]

I wish I could keep my home in the 70s on a lower setting. I will admit, the stove is doing a pretty good job of keeping it in the mid 60s and dropping to 60 by morning. My stove is on the main level of a 3 story, about 4300 heated sqft. My central air (heatpump) setup is such that I can draw hot air from the vaulted room the stove is in and distribute it downstairs only. That central fan runs constant on low-low (barely feel it) only for the basement. The upstairs stays low 70s, basement and main stay about 63-65.

I run the stove almost constantly on the high end (5-6 o'clock) to keep this heat unless outside temps are above high 20s, then I can back it off a little more to take advantage of the long cycle times. I rarely run the stove fans as my cycle time goes to crap when I do. When it droppes to -temps outside, this stove really struggles to keep up. It's taken me a bit to learn how to get this heat out of it (2nd season on this stove - tube burner previously) and I'm hopeful I'll learn to squeeze more out as it would be nice to have my main in the 70s too. I burn mostly lodgepole pine and a bit of fir as well. It's a very well insulated/sealed home with a mix of spray foam and blown in but I know I lose a lot of heat out of the 2 story wall of windows right behind the stove. The upside to the windows is the winter sun hits them perfectly and adds a good amount of heat during the day. I don't (yet) have a cak and often wonder if it would help.

So, yes I realize I ask a lot of the stove and it really is impressive what it's doing. I had to fight the wife on installing this 'ugly beast' over the hearthstone equinox. It took her a while, but she's come to appreciate the beauty of the King (the stove, not me).

Couple of questions. I have read a few times that the stove pipe on these stay cool. As I run this on high all the time, my double wall pipe is often very hot. Should it be? After reading of people's cooler pipes, I wonder if my bypass isnt properly sealed.

Also, I have the ultra. My cat probe is constantly hitting the fins of the blower as there is no clearance. When the cat temps spike, the indicator will hit the fins and either pop the probe out of place or actually rotate the probe so it's wonky. Does anyone else have this problem? Is there a way to adjust the fins forward so there a bit of clearance? I attached a pic of it so hopefully you can see the clearance. I'm assuming this hole goes directly to the cat so I worry that when it pops out it draws cool air and can cause thermal shock. I can't imagine BK would have designed it with such low clearance but I can't see a way to adjust it or correct it.

 

[Marshy]

I wish I could keep my home in the 70s on a lower setting. I will admit, the stove is doing a pretty good job of keeping it in the mid 60s and dropping to 60 by morning. My stove is on the main level of a 3 story, about 4300 heated sqft. My central air (heatpump) setup is such that I can draw hot air from the vaulted room the stove is in and distribute it downstairs only. That central fan runs constant on low-low (barely feel it) only for the basement. The upstairs stays low 70s, basement and main stay about 63-65..

Sounds like a similar battle that I am having regarding getting the desired heat from the unit. If you go back a page you can see the thermal images I posted of my stove while it's running 100% on a fresh reload. The cat thermometer is pegged high like in your pic and I took a pic of my double wall DVL pipe 24" above the flue collar of the stove and it was 200F. How is your chimney/pipe configured? Does it go straight up from the stove all the way through the roof of the house or does it go through an exterior wall to class A chimney pipe, or is it connected to a masonry chimney with/without a liner? Bases solely on the sqft of the space you are trying to heat you are pushing the capabilities (3-4000sqft).
Regardless, good info about what happens while using the fans. Ive been burning mine on hi and know more heat is available if I get the fans. It would be a shame if the cycle times dropped significantly while running it on high with the fan kit.

Do the fans have a variable speed?

BTW, idk why you are having an issue with your cat thermometer. Looks like there is plenty of room to spear the fins on that convection deck on mine. If your arrow is going that far outside of the active range on the dial you are running g that thing very hot. Go back a page or two and look at the stove temps I was getting with the needle at the top of that active zone with no fans running, it's approaching 775F with no fans.

 

[Highbeam]

Tarzan nailed it, the gasses need a certain amount of resident time exposed to the substrate on the CAT. The higher the amount of gasses passing through the cells on the CAT, the less efficient a CAT stove becomes.

I found this article helpful, "The Complete Catalytic Combustor" by Chris Neufeld. In that article there is a table comparing OEM submitted data on CAT and NON-CAT stove performance. I give the caveat that this is a small snapshot from 2009, but still helpful for this discussion. The table shows that a CAT stove has a significant increase it's particulate output (decreased efficiency) when running on high. The NON-CAT data shows that it has a dramatic decrease in particulate output on high (better efficiency), compared to it's low burn output.


View attachment 191609

Be careful not to confuse low emissions with efficiency. They are not as related as you might think. Very clean burning stoves like my old hearthstone can be very inefficient because the noncat at very high temperatures burns very cleanly but pukes enormous amount of heat up the flue which is NOT efficient.

A high level article written for a scientific audience could use the term efficiency to describe combustion efficiency but when read by us regular people in this context we might mistake combustion efficiency for the overall thermal efficiency.

 

[Highbeam]

I wish I could keep my home in the 70s on a lower setting. I will admit, the stove is doing a pretty good job of keeping it in the mid 60s and dropping to 60 by morning. My stove is on the main level of a 3 story, about 4300 heated sqft. My central air (heatpump) setup is such that I can draw hot air from the vaulted room the stove is in and distribute it downstairs only. That central fan runs constant on low-low (barely feel it) only for the basement. The upstairs stays low 70s, basement and main stay about 63-65.

I run the stove almost constantly on the high end (5-6 o'clock) to keep this heat unless outside temps are above high 20s, then I can back it off a little more to take advantage of the long cycle times. I rarely run the stove fans as my cycle time goes to crap when I do. When it droppes to -temps outside, this stove really struggles to keep up. It's taken me a bit to learn how to get this heat out of it (2nd season on this stove - tube burner previously) and I'm hopeful I'll learn to squeeze more out as it would be nice to have my main in the 70s too. I burn mostly lodgepole pine and a bit of fir as well. It's a very well insulated/sealed home with a mix of spray foam and blown in but I know I lose a lot of heat out of the 2 story wall of windows right behind the stove. The upside to the windows is the winter sun hits them perfectly and adds a good amount of heat during the day. I don't (yet) have a cak and often wonder if it would help.

So, yes I realize I ask a lot of the stove and it really is impressive what it's doing. I had to fight the wife on installing this 'ugly beast' over the hearthstone equinox. It took her a while, but she's come to appreciate the beauty of the King (the stove, not me).

Couple of questions. I have read a few times that the stove pipe on these stay cool. As I run this on high all the time, my double wall pipe is often very hot. Should it be? After reading of people's cooler pipes, I wonder if my bypass isnt properly sealed.

Also, I have the ultra. My cat probe is constantly hitting the fins of the blower as there is no clearance. When the cat temps spike, the indicator will hit the fins and either pop the probe out of place or actually rotate the probe so it's wonky. Does anyone else have this problem? Is there a way to adjust the fins forward so there a bit of clearance? I attached a pic of it so hopefully you can see the clearance. I'm assuming this hole goes directly to the cat so I worry that when it pops out it draws cool air and can cause thermal shock. I can't imagine BK would have designed it with such low clearance but I can't see a way to adjust it or correct it.

On my princess ultra, the convection deck sits too close to the cat probe too. I just spin the dial 180 degrees so that it's upside down but the needle clears. This is a design mistake by bk.

 

[tarzan]

Be careful not to confuse low emissions with efficiency. They are not as related as you might think. Very clean burning stoves like my old hearthstone can be very inefficient because the noncat at very high temperatures burns very cleanly but pukes enormous amount of heat up the flue which is NOT efficient.

A high level article written for a scientific audience could use the term efficiency to describe combustion efficiency but when read by us regular people in this context we might mistake combustion efficiency for the overall thermal efficiency.

Yep, my tube stove was very clean burning when ran correctly but there's no doubt I could have quickly cooked a rotisserie chicken over the flue exit.

 

[scum]

Marshy,
My pipe runs up through the vault and out the roof. There is a short 45 bend right before the vaulted ceiling. It's doublewall then triple through the ceiling then I believe single out the top? I wish I didn't have the 45 as when I clean (sooteater), that 45 tends to collect all the creosote from above. I've had a couple of small chimney fires start from that. I've since learned not to leave the bypass open and full throttle too long to avoid sparks catching right there. I also do my best to clean at the 45 to knock everything down.

I saw your thermal pics. Pretty slick. I don't have a way to check but it sure feels like the pipe is hotter than 200. I've been tempted to get a probe stat but I'm not anxious to drill a hole in my double wall.

My fans are variable. I kick them on when I need quick heat pushed through the house. From what I've read, the fan cools the top, so the tstat opens up for more air to maintain the higher temp resulting in throwing a lot more BTUs out. Result is chewing through the wood faster.

I wish my cat probe had the clearance yours did. Odd that it's different. I guess process variation is a bit high when they're building. Would be fine if it was adjustable but it appears fixed.

Highbeam,
Sorry, but I can't quite visualize how flipping 180 fixes the problem? I'll fiddle with it next time it's cool to see if I can get it.

 

[showrguy]

Sounds like a similar battle that I am having regarding getting the desired heat from the unit. If you go back a page you can see the thermal images I posted of my stove while it's running 100% on a fresh reload. The cat thermometer is pegged high like in your pic and I took a pic of my double wall DVL pipe 24" above the flue collar of the stove and it was 200F. How is your chimney/pipe configured? Does it go straight up from the stove all the way through the roof of the house or does it go through an exterior wall to class A chimney pipe, or is it connected to a masonry chimney with/without a liner? Bases solely on the sqft of the space you are trying to heat you are pushing the capabilities (3-4000sqft).
Regardless, good info about what happens while using the fans. Ive been burning mine on hi and know more heat is available if I get the fans. It would be a shame if the cycle times dropped significantly while running it on high with the fan kit.

Do the fans have a variable speed?

BTW, idk why you are having an issue with your cat thermometer. Looks like there is plenty of room to spear the fins on that convection deck on mine. If your arrow is going that far outside of the active range on the dial you are running g that thing very hot. Go back a page or two and look at the stove temps I was getting with the needle at the top of that active zone with no fans running, it's approaching 775F with no fans.
View attachment 191635

Marshy, if you wanna try the fan kit I would offer to ship you mine to try..
There are 2 of them, and yes, they are variable speed..
They do cut down on your burn times by quite a bit also..

 

[Marshy]

@scum, Can you take a picture of the pipe and post it for us? From my understanding you have one of the most ideal pipe configurations (straight up with minimal elbows). The pipe through the roof and above should not be single wall. It's doubtful it is so posting a picture we should be able to tell you what it is. If you are getting creosote then you have another issue that needs resolving like wet wood. I don't burn pine but everything I've read seems creosote isn't an issue with pine as long as it's seasoned properly.

 

[scum]

I know it's triple through the ceiling. I just assumed single wall from roof to cap but I don't know and refuse to climb up to find out. It's a 3 story drop with a metal roof.

My cap used to plug with creosote before I had the installer cut bigger holes in it. Last year I cleaned mid season and end of season and got few cups worth each time. My first chimney fire was right after I cleaned. That's when I realized the 45 was catching the crud from the cap. The fires have been small I think. No visible sparks out the top but sounds like hail popping in the pipe. Just choke down the air and within a min it's calmed down.

 

[Marshy]

Marshy, if you wanna try the fan kit I would offer to ship you mine to try..
There are 2 of them, and yes, they are variable speed..
They do cut down on your burn times by quite a bit also..

I might take you up on that. It's the last step for me to determine if the stove is going to be adequate for me or not.

Part of the other concern I had (still have,) is creosote buildup. My chimney is not lined and is a masonry with 8x8 clay liner. I'm having a light layer of creosote in the top 12" of the liner where it's cools and mixes with the outside air. There is approx 30 ft of masonry clay lined chimney. I have pictures of the chimney after 3 months of burning that I will post. I was partially relieved when I saw how little there was. I was fearing there might be 10-12 feet of creosote. Running the stove on high keeps the flue temp warmer and helps mitigate the buildup. However, we haven't hit our coldest part of winter yet so there is a chance it could be greater than. 12" in the next 2-3 months.
Before you all jump on my case about not using an insulated liner, let me say, I had a length conversation with an individual at BK about my chimney configuration and they did not express much of any concern. It was only after I purchased, installed, and ran it for a few weeks that I called back seeking help about low performance that I spoke with BKVP and he expressed concerns with creosote buildup. While they appear to be minimal given the circumstances it's still a concern of mine. That combined with my demand for heat might force me to consider a different stove. I haven't made my full conclusion yet. Like I said, the fans are the next step and to monitor any buildup.

You can see the only buildup is at the top and half way to the joint, ~12". Everything below that is ash.

 

[Marshy]

@scum, if the pipe through the penetration is tripple wall then it's the same up to the cap. No professional installer would switch from the double wall DLV like you have up to your ceiling, to tripple wall for through the ceiling, and then single wall up to your cap. If they did then they should be locked in jail (maybe a little extreme).

I'm surprised you can run the stove on high and get creosote. Do you know the moisture content of your wood? Have you tested it with a moisture meeter? How long does it get seasoned? Do you purchase processed "seasoned" wood from a seller? How do you store it prior to burning (under roof or tarp, stacked)? Sorry, lots of variable to consider to figure out your issues.

 

[Marshy]

Just a thought, could the poping just be thermal expansion of the pipe? You increase 30' of that stove pipe by 150-200F I bet it moves some. Ever hear a hot exhaust on a motorcycle click and pop from thermal expansion/contraction? If you really do have a chimney fire they don't go out unless they burn out or get starved of oxygen (I believe). If it is a chimney fire your chimney should blow thick black/grey smoke like an old steam train and sound like a tornado...

 

[scum]

Last I measured it was varying around 17% moisture. I cut through the year and stack out on pallets under a tarp then pull it under the porch for winter. About 1/2 of my wood this year is stuff I cut this summer (standing dead lodgepole). The other half is wood from last year. So, not super ideal but not terrible either. The wood I'm burning right now is from this summer's cut. When I get a chance I'll measure the moisture on it.

Trust me, it was much more than just heat expansion ticking. I really don't get a lot of creosote build up other than my cap. It was just collecting at that 45. So the fires Ive had were not that bad - just burning off that little collection of creosote dust. At least that's my theory. My creosote build up hasn't really been a concern to me once I learned I have to pay special attention to the 45 when cleaning.

When I get brave and the stove is cool, I'm going to try to lift the pipe off the stove to check the bypass is sealing and check the backside of the cat. I suspect a leaky bypass is why my pipe runs so hot.

On a side note. I'm curious if anyone has ever tried connecting a traditional wire chimney brush to the end of a sooteater. The whip ends are cool and all but it seems like you'd get a seriously thorough clean with an actual brush spinning in there.

 

[Marshy]

I have not experience with a spot eater as I use a wire brush.

If you really are interested in measuring the temp of the pipe then you can buy a cheap pyrometer at harbor freight. They are digital and battery operated, shoot a laser at what your are measuring and will display surface temp. Same concept at the FLIR gun I was using except I get a thermal image and can see the theme gradient.