2018-19 Blaze King Performance Thread Part 1 (Everything BK)

[Woody Stover]

So glowing is not confirmation of a working Cat.

Yes it is, provided you don't have flames hitting the face of the cat to raise it over 900 degrees. The only other way it can get that hot is if it is burning something (smoke.)

 

[chazcarr]

My 30 foot chimney pulled more than 3x the maximum allowable water column for my BK, so while things can vary, I’m betting this is your number 1 issue. Thankfully, I had an identical stove in the same house, burning identical wood on a 15 foot chimney, to help me identify the chimney height as the source of my troubles.

Get a Magnehelic and a key damper on there, already!

SO basically my draft is too strong and the fire is burning too hot because of it?

 

[lsucet]

To much draft can work on different ways, sometimes it doesn't make the fire burn hotter. Sometimes can cause overfire sometimes can just go through wood fast and not that much temperature out of the stove. Everything is depends on the flow rate creating by excess of draft.

 

[Ryan723]

I don't think you could get it to glow if it was dead, but I am not sure why the durn things glow in the first place. I understand that the surface is a wash coat of alumina (melting point 5000+, shouldn't be near to glowing at 1500) with palladium (melting point 2800) on it. Maybe the glow of a functioning cat is not incandescence at all, but rather combustion? Or is the glow incandescing palladium?

The color the cat glows is mostly related to the temperature...and fairly independent of that material, whether ceramic, steel, or the catalytic coating.

Some good info here:
https://www.hearth.com/talk/wiki/know-temperature-when-metal-glows-red/

So glowing is not confirmation of a working Cat.

I would say that the glowing of a catalyst is a sign that it is HOT enough to burn smoke, but not necessarily that it got there through a catalytic reaction.

Or rather in an aging cat, that as it got closer to the light-off temperature of those gasses, the remaining bits of catalyst not masked/destroyed/etc were able to push it over the the edge and get it hot enough to self-maintain the burning of those gasses.

I'll go out on a limb and say that if it is glowing, it is a safe bet that you're burning the volatiles in the exhaust as they pass through the cat, which is providing a lot of hot surface area for those to ignite.

I'm not an expert on catalytic combustors, but I would think short of something catastrophic for it (extreme overfiring, burning something with metals that mask the surface or poison the cat, etc), it isn't a "working" vs "non-working" scenario for the cat. Rather, as it ages, you get to the point where conditions have to be more and more optimal for the cat to light off and sustain itself.

This can be somewhat compensated by running the stove hotter. But without a reasonably functional catalyst, as the BK thermostatic control drops airflow, the stove cools, and then tries to climb again in temperature when cooler and the stat opens up, it may not get hot enough to re-light off the catalyst.

For some with perfect wood, proper draft, etc, that decreasing performance threshold where you consider it 'non-working' may be very different than someone burning wet wood, marginal draft, and trying to turn the stove way down.

 

[lsucet]

But without a functional catalyst, as the BK thermostatic control drops airflow, the stove cools, and then tries to climb again in temperature when cooler and the stat opens up, it may not get hot enough to re-light off the catalyst

I don't know much neither but I will tell you something. When I come back from work as an example. I have plenty on chunks in there, black charcoal. I raked them from the sides to the center and as front as I can. Shut down everything and let the air wide open. Went outside and comeback half of an hour later. The probe was at the end of the scale and the cat was not light up.
At that stage the the wood is not releasing the chemical reaction that makes the cat light off

 

[claybe]

Stove coming out in two days. Had dropped out of this thread as no sense in beating this horse, but a notification email popped in with your post and….. finally, someone who has described exactly what I am experiencing with a BKP.

So before stove comes out in a couple of days, why not ask a fellow Coloradan with a BKP, where is the smoke smell coming from? Do you know? In a closed system, OAK to chimney cap, this should never happen. Having spent a lot of time tracing this smoke emission, to the left fan vent which makes zero sense for a lot of reasons, but that is where it strongly locates to.

Anyway, there are other issues but on this, would be curious to learn your opinion on where this smoke smell emits from in your stove??

And yes, I know BKVP could have helped.. but there are other events that occurred leading up to by the time I got to hearth.com, well, I explained those to him privately.

tx

I am sorry but I haven’t used an OAK and don’t know where or how that would connect, especially on an insert. On my insert the intake is on the right side of the stove behind the thermostat dial. I don’t know how an oak could get into this space so I can’t be of any help there. Also I haven’t really tried to search out where the smoke smell comes from as I had thought it was a draft issue because when I choke down the air too far the smoke escapes (I think from the flapper) but when I open the flapper a little past ticking closed the smoke smell is gone.

@jetsam I have NO idea how you are getting these burn times. You must have perfect conditions! That’s awesome.

 

[jetsam]

So glowing is not confirmation of a working Cat.

I assume that it IS a confirmation that the cat is alive, waiting for someone to explain why it glows at all though. We have folks here that are likely to know.

I reason that a glowing cat is a live cat because you would have to heat aluminum oxide to well beyond the melting point of steel to get the aluminum oxide to glow.

Edit: It's been pointed out to me that this is dumb because stuff doesn't glow when it's near melting, it glows when its component bits are excited until they emit energy at a frequency that corresponds with the part of the EM spectrum that our eyeballs can detect- so almost everything glows at the same temperature.

https://en.m.wikipedia.org/wiki/Incandescence

 

[-goose-]

Speaking of door seals I’ve got a new King Ultra and the door seal seems very tight. When the door is about 4 inches from being closed I have to push it with both hands to close it. The seal is very tight on the door hinge side. I assume this will wear in

Got my king this fall, had the same issue. I ended up loosening the door latch 4 turns. About once a week i got 1 turn in till back to where it started. After being shut and burning 3 days it was a lot easier to shut the door.

 

[wannabewarm]

We purchased a fire chief 1000 last year. There are ZERO controls except the thermostat on the wall and the doors on the front. Its heating our house, but no doubt building creosote as it tends to smoke out the chimney when I shut the fuel door. We usually have to go back to the basement 3 or 4 times to get it burning correctly.

Just be thankful you have some control over your fire. This thing is efficient for a 6 to 7 hour burn tops, but the house is cold after 4 or 5. And it takes quite awhile to warm it up in after.

We are definitely considering taking it out. We have had so many problems that HYC will take it back. We originally were going to order a Drolet tundra. I havent heard a bad thing about them and the glass front would be SO helpful.

We never dreamed buying a new wood furnace would leave us frustrated and chilly. We thought wood heat was wood heat and we would be warm.

 

[pjohnson]

Got my king this fall, had the same issue. I ended up loosening the door latch 4 turns. About once a week i got 1 turn in till back to where it started. After being shut and burning 3 days it was a lot easier to shut the door.

Thanks Goose it’s tight on hinge side so hated to loosen latch guess I’ll see what happens after a few burns

 

[pjohnson]

Grandson checking out the new King Ultra capacity

 

[tarzan]

View attachment 234308 Grandson checking out the new King Ultra capacity

His name wouldn’t happen to be Hansel would it?

 

[jetsam]

@jetsam I have NO idea how you are getting these burn times. You must have perfect conditions! That’s awesome.

Nope! Start with a hot stove. Pack it full of dry oak including some big splits. Turn the fan off and turn the thermostat way down. Come back tomorrow.

The brochure says 27 hours, and I believe they do their testing with fir.

20+ hour burns are kind of irrelevant to real world stove operation for me, though. I need it to be better than 12 or 14 for work, and I tend to reload at that point no matter how much fuel is left in the firebox.

Some people use them often though. Ashful for example runs one of his Ashfords on a 24 hour cycle almost all season.

 

[jetsam]

View attachment 234308 Grandson checking out the new King Ultra capacity

I am deeply jealous of your stove.

 

[kf6hap]

Cat observation. If the cat is glowing and the holy plate is not, the cat is working-it proves activity. How well it is working is another story. Month 2 of season 3 mine still glows immediately at bypass rollover and still remains active at very low fire late in the burn. A little more smoke than year 1 at rollover. I might get a new one for season 4, just to have on standby as my stove lives at low fire. Small house. Wife still likes it 80 in here.

 

[chazcarr]

Nope! Start with a hot stove. Pack it full of dry oak including some big splits. Turn the fan off and turn the thermostat way down. Come back tomorrow.

The brochure says 27 hours, and I believe they do their testing with fir.

20+ hour burns are kind of irrelevant to real world stove operation for me, though. I need it to be better than 12 or 14 for work, and I tend to reload at that point no matter how much fuel is left in the firebox.

Some people use them often though. Ashful for example runs one of his Ashfords on a 24 hour cycle almost all season.

See, there is my issue I think. If I turn the fan off, then the rest of the house gets cold. Last night I went from 10pm to 8am with an active cat. Fan on lowest setting and stat one dot up from lowest. That seems to be the best I can do with my current situation. That is 10 hours of consistent heat. Not bad.

So here is how it is playing out for me now. When I get home from work, I make a small hot fire, usually of pine splits that last me from 6pm to 10pm with fan on medium. At 10pm I load it with the best and driest hardwoods I have and got from 10pm to 7am fan on lowest. In the morning I load up a mix of hardwood and pine and go from 7am to 6pm with the fan on low-medium speed.

That is not terrible, three loads a day where my Regency would take about 5-6, including waking up in the middle of the night for one of them.
When I get up in the morning, there is a faint smoky smell in the house though. I am not at all sure where that could be coming from.

 

[pjohnson]

I am deeply jealous of your stove.

Don’t be too jealous the credit card bill just came in the mail scared to open it.

 

[kf6hap]

If I turn the fan off, then the rest of the house gets cold.

When the fan is on more air is being heated. The ratio of radiant-to-convective heat shifts more towards the convective withe fans on.

One thing is for sure, my Ashford heats the adjacent rooms far better than the other radiant stoves as the iron cladding makes a lot of hot air that naturally rises up and then convects/diffuses laterally into other rooms. The radiant stoves heated the walls nicely tho.

For the same thermostat setting with the fans on more BTUs are being released into the house.

 

[jetsam]

Don’t be too jealous the credit card bill just came in the mail scared to open it.

At 4.3 cf, the King can hold a LOT of credit card bills.

You're not supposed to burn mail in there because of the plastic and glue and colored inks, but I bet they'd make an exception for that one.

 

[Ashful]

See, there is my issue I think. If I turn the fan off, then the rest of the house gets cold.

To be clear, I’m doing daily 24 hour burns with the fans on, but on a low setting. I’ve also done over 30 hours active cat many, many times, with fans on. I am burning almost 100% oak the last few years, so while I don’t keep a log book of what’s in the stove, I’d be willing to bet it was oak on each 30+ hour occasion.

Any time I have ever quoted with my BK’s is with the fans on. I turn them on in October, and generally don’t remember to turn them back off until June.

I liked Ryan’s post, a glowing cat is going to be close to 1000F, a temperature likely sufficient to provide secondary combustion, with or without any catalyst remaining on the combustor.

As to why they glow, that’s basic thermal radiation. All objects above 0K radiate all the time, but the wavelength varies with temperature. This wavelength of radiation is a spectrum with a peak, not a single frequency point, and the location of that peak has nothing to do with material. It is dependent only on temperature (jetsam), and at room temperature this peak is in the infrared, outside of the visible spectrum. When you heat it, the peak of the radiation curve moves into the visible part of the spectrum.

However, since all materials have emissivity that varies with wavelength, and metals have lower absorption (and thus emissivity) in the visible spectrum than ceramic, this peak can be more suppressed in ceramic. In other words, the ceramic cat will glow at the same temperature as a steelcat, with or without its plating, but the intensity of it may be too low to detect in a room with ambient lighting.

Oh, I should add, I’m just an engineer, albeit a very expensively-educated one. “The Oompa Loompa’s of the scientific community,” according to Sheldon Cooper. For a real explanation of this phenomena, we would want to consult a real physicist, but then there’s the problem of getting them to explain it in terms we can all understand...

 

[jetsam]

Cat observation. If the cat is glowing and the holy plate is not, the cat is working

I didn't get the point on my first read.

He's saying that the flame guard and the cat are in the same airflow, and the flame guard is closer to the fire. If the cat is glowing and the flame guard is not, the cat is most likely making significant heat.

Good point!

 

[jetsam]

I liked Ryan’s post, a glowing cat is going to be close to 1000F, a temperature likely sufficient to provide secondary combustion, with or without any catalyst remaining on the combustor.

As to why they glow, that’s basic thermal radiation. All objects above 0K radiate all the time, but the wavelength varies with temperature. This wavelength of radiation is a spectrum with a peak, not a single frequency point, and the location of that peak has nothing to do with material. It is dependent only on temperature (jetsam), and at room temperature this peak is in the infrared, outside of the visible spectrum. When you heat it, the peak of the radiation curve moves into the visible part of the spectrum.

However, since all materials have emissivity that varies with wavelength, and metals have lower absorption (and thus emissivity) in the visible spectrum than ceramic, this peak can be more suppressed in ceramic. In other words, the ceramic cat will glow at the same temperature as a steelcat, with or without its plating, but the intensity of it may be too low to detect in a room with ambient lighting.

Oh, I should add, I’m just an engineer, albeit a very expensively-educated one. “The Oompa Loompa’s of the scientific community,” according to Sheldon Cooper. For a real explanation of this phenomena, we would want to consult a real physicist, but then there’s the problem of getting them to explain it in terms we can all understand...

We're puttin' that degree to work edjumicatin' all the jetsams of the internet here! Thanks to you and @Ryan723 for un-dumbing me on the subject of black-body radiation. I went a long time just assuming that stuff glowed near its melting point (an idea I should have challenged early on from observing common materials like mercury, but oh well).

 

[Ryan723]

Oh, I should add, I’m just an engineer, albeit a very expensively-educated one. .... For a real explanation of this phenomena, we would want to consult a real physicist, but then there’s the problem of getting them to explain it in terms we can all understand...

As a physicist (at least by undergrad education, but now i work mostly as an engineer/geologist/geophysicist) i think you did a fine job explaining it in your post above.

As there seems to be some interested and since it impacts how we interpret our stoves operation, here are a few more thoughts:

The color we see as visible 'red' light is part of the energy released by the hot material. So, hot solid steel at 1100 deg F glows about the same as molten aluminum at 1100 deg F, and about the same as most other materials at 1100 deg F, whether solid or liquid. To complicate things a little more, our eyes seem to perceive anything very bright as more 'white' that they really are....so molten steel in a foundry may look whiter due to how much energy is coming off it, even though the actual spectrum of light emitted is more in the yellow/orange range.

This figure shows the approximate color for a given temperature for a 'perfect' material. Temperature is in Kelvin, so add 273 degees to get Celsius:
https://en.wikipedia.org/wiki/Black-body_radiation#/media/File:PlanckianLocus.png

And a bit of good discussion on the colors we see from hot metals here:
https://physics.stackexchange.com/q...e-do-black-body-color-at-the-same-temperature

Anyways, the takeaway point i wanted to make in my post:
I'd suggest we not think of our catalytic combustors as a lightbulb--it isn't either functional vs burned out. Short of major failure (crumbled/melted/totally masked), your cat isn't either 'working' or 'not working', but rather performance degrades until a point where it doesn't work for YOUR application and conditions.

Glowing means something but it doesn't have to mean you have acceptable cat performance.

Also consider that as we need to turn up our stoves more to prevent cat stalls due to degraded performance of an older cat, we're increasing the amount of exhaust pulled through the cat at any given time. That means the exhaust is moving faster and traverses that 2" of the cat element in less time...that lowers 'residence time' that the exhaust spends within the cat, which means less of the smoke gets burned....lowering efficiency and putting more smoke out the stack or sticking to the flue as creosote.

Fascinating stuff....

 

[tarzan]

To be clear, I’m doing daily 24 hour burns with the fans on, but on a low setting. I’ve also done over 30 hours active cat many, many times, with fans on. I am burning almost 100% oak the last few years, so while I don’t keep a log book of what’s in the stove, I’d be willing to bet it was oak on each 30+ hour occasion.

Any time I have ever quoted with my BK’s is with the fans on. I turn them on in October, and generally don’t remember to turn them back off until June.

I liked Ryan’s post, a glowing cat is going to be close to 1000F, a temperature likely sufficient to provide secondary combustion, with or without any catalyst remaining on the combustor.

As to why they glow, that’s basic thermal radiation. All objects above 0K radiate all the time, but the wavelength varies with temperature. This wavelength of radiation is a spectrum with a peak, not a single frequency point, and the location of that peak has nothing to do with material. It is dependent only on temperature (jetsam), and at room temperature this peak is in the infrared, outside of the visible spectrum. When you heat it, the peak of the radiation curve moves into the visible part of the spectrum.

However, since all materials have emissivity that varies with wavelength, and metals have lower absorption (and thus emissivity) in the visible spectrum than ceramic, this peak can be more suppressed in ceramic. In other words, the ceramic cat will glow at the same temperature as a steelcat, with or without its plating, but the intensity of it may be too low to detect in a room with ambient lighting.

Oh, I should add, I’m just an engineer, albeit a very expensively-educated one. “The Oompa Loompa’s of the scientific community,” according to Sheldon Cooper. For a real explanation of this phenomena, we would want to consult a real physicist, but then there’s the problem of getting them to explain it in terms we can all understand...

I didn’t understand a word of that but gave it a like for the Sheldon Cooper reference.

 

[claybe]

Nope! Start with a hot stove. Pack it full of dry oak including some big splits. Turn the fan off and turn the thermostat way down. Come back tomorrow.

The brochure says 27 hours, and I believe they do their testing with fir.

20+ hour burns are kind of irrelevant to real world stove operation for me, though. I need it to be better than 12 or 14 for work, and I tend to reload at that point no matter how much fuel is left in the firebox.

Some people use them often though. Ashful for example runs one of his Ashfords on a 24 hour cycle almost all season.

I am usually on a 8-10 hour cycle using not great pine. I would love to run this thing with some real dry oak. That would be fun and I am sure would greatly improve performance!