2017-18 Blaze King Performance Thread PART 2 (Everything BK)

[oldbluedeer]

Yes. The pressure differential is between the stove's interior and the room.

The below charts tell you the "draw". Flow is not needed to produce draw. Draw decreases with flow due to the pipe's resistance. Pressure drops across a resistance more with increasing flow. All pipes have resistance.

The Thermostat's damper, very unlike old stoves, is quite small so it has little influence on the stove's interior pressure. I know this by test.

Draft is vacuum in column inches and flow is CFM.

Hope this helps.

Thank you. It does help. Thank you.

I still believe that the flowing mass of air in the chimney system increases the practical or effective draw in terms of keeping smoke moving through the system, perhaps because of the inertia that exists with the body of moving air. Here's why I think that:

What you're saying is that draw is slightly less with increasing air flow. I agree in theory, it is understandable when comparing it to water flowing through a pipe. Yet what I experience with the stove is the opposite: When the damper is fully open and the air flow is greatest, I have no smoke smell. When I damper it down, and reduce the air flow, that is when the smoke smell becomes intolerable.

I am BK compliant with chimney height, wood MC, and burning with the cat meter well in the active zone. And then there is Highbeam, content with 12' of chimney.

 

[Highbeam]

Thank you. It does help. Thank you.

I still believe that the flowing mass of air in the chimney system increases the practical or effective draw in terms of keeping smoke moving through the system, perhaps because of the inertia that exists with the body of moving air. Here's why I think that:

What you're saying is that draw is slightly less with increasing air flow. I agree in theory, it is understandable when comparing it to water flowing through a pipe. Yet what I experience with the stove is the opposite: When the damper is fully open and the air flow is greatest, I have no smoke smell. When I damper it down, and reduce the air flow, that is when the smoke smell becomes intolerable.

I am BK compliant with chimney height, wood MC, and burning with the cat meter well in the active zone. And then there is Highbeam, content with 12' of chimney.

Highbeam doesn’t have an Ashford. My 12’ was bk compliant when I installed it but it is also totally vertical.

 

[oldbluedeer]

The instrument is a .25" full scale Magnehelic. The drop across the cat is ~.004" WC, barely readable and effectively nil. The cat is like a wide open pipe and causes almost no pressure drop. Measured via the ash plug and the cat thermometer probe hole. Measuring the stove internal pressure (vacuum) at the cat hole is a valid reading, provided the cat is not plugged. It is mechanical but has no hysteresis as the pointer assembly literally floats on a magnetic field.



Even with a cool stove it will read something in the order of .02" as it is winter and the warm house causes draw.



The stove control positions make nil difference in the strength of the draft, Stack height and flue gas temperature determine draw. Physics.



Opening and closing the thermostat makes only a tiny insignificant change in firebox pressure.

The Magnehelic can be had from Amazon. ~$75.00 Two barbed fittings will be needed to attach 1/4' rubber hose. 3/18" copper pipe fits the cat hole. This is refrigeration (high side) tubing. Hardware stores do not normally carry it.

My setup runs .1" at 400F as indicated by the flue probe. 17'x6", straight up.

@kf6hap Is this the one you recommend:

https://www.amazon.com/dp/B009P9EF62/?tag=hearthamazon-20

 

[oldbluedeer]

Thank you. It does help. Thank you.

I still believe that the flowing mass of air in the chimney system increases the practical or effective draw in terms of keeping smoke moving through the system, perhaps because of the inertia that exists with the body of moving air. Here's why I think that:

What you're saying is that draw is slightly less with increasing air flow. I agree in theory, it is understandable when comparing it to water flowing through a pipe. Yet what I experience with the stove is the opposite: When the damper is fully open and the air flow is greatest, I have no smoke smell. When I damper it down, and reduce the air flow, that is when the smoke smell becomes intolerable.

I am BK compliant with chimney height, wood MC, and burning with the cat meter well in the active zone. And then there is Highbeam, content with 12' of chimney.

Okay, what I was trying to describe is how the higher air flow increases the effective draw in the stove. Perhaps this is the Venturi effect, where the moving column of air through a constricted pipe creates a lower pressure, which creates a draw or suction that can draw other materials into that moving column.

Here's a web page that gives some practical demonstrations of this effect. This may explain the seeming paradox, as to why there is no smoke smell coming from my stove with open damper and high air flow, but there is when the air flow is reduced by lowering the damper setting.

http://woodgears.ca/physics/venturi.html

 

[oldbluedeer]

You can sign me up for the smoke smell problem as well, @oldbluedeer ; new Sirocco 30.1 this season that replaced my PE.

When sniffing around the hinge side of door, it is apparent that this is where it is coming from. My door gasket seam is right in the middle of the vertical rise of door on the hinge side. I believe this to be a fail on the gasket install from the factory and will likely proceed with replacing it.

I'm burning hardwood that's 14-17%, chimney is 20+ feet of Class A running right through the middle of house from the main floor, and terminating well above peak. Draft is not an issue in this house. Unlike some, my collar welds were clean and smooth - no splatter, and my ICC Ultrablack fit beautifully.

I get the smell if Tstat is set around 3:30-4 with a nicely charred full load of wood. When the stove is cold, I can hear the throttle plate click shut at about 2:30...seemingly anything from 12-2:30 is wasted dial space. Seems strange to have a dial that spins 180, yet only 90 degrees is usable. Is this common with the stats on BK stoves?

Hoping to solve this as well since the stove was not cheap. Lately, the smell hasn't been an issue since I was running the stove a little hard to keep up with the low temps outside.

@burninwood I appreciate your post.

Since you have 20' class A chimney running straight up, it makes it clear the problem exists even with chimney pipes exceeding BK recommendations and no 45 bends in the stack. And it suggests pretty strongly that draft alone is not the cause or the cure in some situations.

 

[begreen]

The problem is real, whatever we see here is just a sampling of the rest of the market. Please do follow up with this report request so this bug can be tracked down and fixed for good:
https://www.hearth.com/talk/threads...t-2-everything-bk.164477/page-31#post-2221340

 

[oldbluedeer]

@MissMac and @burninwood

One thing we have in common is we each have the BK Sirocco model.

One thing I notice on my Sirocco, there is a lip of steel at the front of the stove, inside just above the door, that causes air to wash over the inside face of the door glass. After I damper down the stove for the long burn, there is sometimes visible unburnt smoke inside the stove, and I can see a long, lazy, and constant circulation of smoky air up from the burning logs to the top of the stove, then forward along the top to where the cat is, then on to the front of the stove, and then down and along the full length of the inside of the glass door. I presume some of it does enter the cat, but a lot of it just continues in that circulation, due to the airflow up into the stove and up the chimney.

I think this is typical for stoves that wash the the glass with air to keep it cleaner, but it also seems to invite a problem with smoke smell escaping, if there is any imperfection in the door gasket seal, the seal of the glass in the door, the precision cut holes where the hinge posts are inserted through the front face of the stove, and any other pin hole opening that might exist.

If there are any other Sirocco owners (and owners of other models, but I would particularly like to hear from Sirocco owners) having the problem with smoke smell who are quietly listening to this thread, please do speak up. It is important to understand the extent of the problem, and maybe we can collaborate to figure out the reason.

Ashford owners, do you also have this lip that redirects a wash over the inside of the stove door and glass?

 

[kf6hap]

I am at startup and the thermostat has been full open for 15 minutes. Slamming it shut increases the draw by .001", but then it quickly drops by ~.004" as the stack gasses are now cooler. The draw, being .12", this change is nil. What has changed is the window airwash went from lots of clean air to smoky air. I can smell it after the closure, but not before. So, by actual measurement, the draw changes only by a tiny amount.

 

[kf6hap]

@kf6hap Is this the one you recommend:

No. The full scale reading is one full inch. You want the one that is .25" full scale for the increased accuracy at these pressures.

 

[Poindexter]

The 30 and 20 boxes all have the same internals and differ only in external cosmetics.

Old blue, your new stove doesnt have a damper. Smoke dragons had dampers. Your new stove has a thermostat. They are similar, but NOT the same.

Consider also the gas volume exiting your stove is higher, lots higher, than the volume of air entering the stove through your thermostat. How big a trash can do you need to hold all the ash from one cord of wood, and how much does that weigh?

There is a school of thought for EPA stoves that suggests removing rather than adding pipe when an operator has low draft. Having a shorter well insulated pipe means the tip-top of the pipe will be hotter than the old higher tip, so the average gas temp will be higher so draft will be improved, even though the stack is shorter.

There is an excellent thesis "draft management" in the current VC manuals, i think pp28 in the Defiant model.

The nuance here is stack height and average gas temperature are the two most important variables for total draft, for most people most of the time in calm winds.

 

[Poindexter]

I am at startup and the thermostat has been full open for 15 minutes. Slamming it shut increases the draw by .001", but then it quickly drops by ~.004" as the stack gasses are now cooler. The draw, being .12", this change is nil. What has changed is the window airwash went from lots of clean air to smoky air. I can smell it after the closure, but not before. So, by actual measurement, the draw changes only by a tiny amount.

That is fascinating. May i inquire what two pressures you are comparing to get the .12" reading?

 

[kf6hap]

One pipe is in the cat thermometer hole, the other is in the room.

A better gasket is in order. Any Ideas ????

 

[oldbluedeer]

I am at startup and the thermostat has been full open for 15 minutes. Slamming it shut increases the draw by .001", but then it quickly drops by ~.004" as the stack gasses are now cooler. The draw, being .12", this change is nil. What has changed is the window airwash went from lots of clean air to smoky air. I can smell it after the closure, but not before. So, by actual measurement, the draw changes only by a tiny amount.

Where are you smelling the smoke from after you slam the damper shut?

 

[oldbluedeer]

No. The full scale reading is one full inch. You want the one that is .25" full scale for the increased accuracy at these pressures.

Thank you.

 

[oldbluedeer]

The 30 and 20 boxes all have the same internals and differ only in external cosmetics.

Old blue, your new stove doesnt have a damper. Smoke dragons had dampers. Your new stove has a thermostat. They are similar, but NOT the same.

Consider also the gas volume exiting your stove is higher, lots higher, than the volume of air entering the stove through your thermostat. How big a trash can do you need to hold all the ash from one cord of wood, and how much does that weigh?

There is a school of thought for EPA stoves that suggests removing rather than adding pipe when an operator has low draft. Having a shorter well insulated pipe means the tip-top of the pipe will be hotter than the old higher tip, so the average gas temp will be higher so draft will be improved, even though the stack is shorter.

There is an excellent thesis "draft management" in the current VC manuals, i think pp28 in the Defiant model.

The nuance here is stack height and average gas temperature are the two most important variables for total draft, for most people most of the time in calm winds.

I said "damper" because I had heard it referred to as a "thermostatic damper". Oh well, I can say thermostat just as easy I guess.

As for the ash, it depends upon a lot of things, the type of wood, how hot your burn, when you empty the ashes out of the stove, how often, etc. I can't give you a measurement right now. Another member says he burns fir and hardly ever empties the ash pan, but it could be that continually burning over the top of old ashes breaks them down and they exit as smoke.

I started with 12' of pipe and two 45 bends below the ceiling support box late October when I began burning, feeling optimistic. But pretty shortly thereafter installed a 3 foot piece, which did not help the smoke smell problem at all. Then I replaced the stovetop adapter, and cleaned up the weld blob on the stove collar, which helped quite a bit in reducing the smoke smell in the room, and it eliminated the smoke smell that I was getting when sniffing above the stove collar. Then I added another 2' to the stack, which is now 17', and that did noting to improve the smoke smell in the room. Since we have another member with a Sirocco and 20' of straight class A chimney pipe who has the smoke smell problem, and adding 5' to my stack did not improve it, and I have no plans to add more since I am compliant with BK recommendations.

 

[kf6hap]

Where are you smelling the smoke from after you slam the damper shut?

Just above the loading door in the front. Somewhat more on the hinge side but some on the latch side too. Weakly in the middle. Nowhere else.

 

[BKVP]

@MissMac and @burninwood

One thing we have in common is we each have the BK Sirocco model.

One thing I notice on my Sirocco, there is a lip of steel at the front of the stove, inside just above the door, that causes air to wash over the inside face of the door glass. After I damper down the stove for the long burn, there is sometimes visible unburnt smoke inside the stove, and I can see a long, lazy, and constant circulation of smoky air up from the burning logs to the top of the stove, then forward along the top to where the cat is, then on to the front of the stove, and then down and along the full length of the inside of the glass door. I presume some of it does enter the cat, but a lot of it just continues in that circulation, due to the airflow up into the stove and up the chimney.

I think this is typical for stoves that wash the the glass with air to keep it cleaner, but it also seems to invite a problem with smoke smell escaping, if there is any imperfection in the door gasket seal, the seal of the glass in the door, the precision cut holes where the hinge posts are inserted through the front face of the stove, and any other pin hole opening that might exist.

If there are any other Sirocco owners (and owners of other models, but I would particularly like to hear from Sirocco owners) having the problem with smoke smell who are quietly listening to this thread, please do speak up. It is important to understand the extent of the problem, and maybe we can collaborate to figure out the reason.

Ashford owners, do you also have this lip that redirects a wash over the inside of the stove door and glass?

All our models have the same airways design. As you know first hand, we are trying to resolve the problem for those few that exist, that was the purpose of my post earlier.

We are throwing resources at this and have an in-situ case we are studying.

I reiterate, if anyone has a problem with smoke smell, they can pm me the information I requested. Since my post, we have heard from the 5 parties (including your situation).

We will get to the bottom of this and work with each owner to their satisfaction. We have sold thousands of these units and if even one needs addressing, we will do so.

Guaranteed.

Merry Christmas and Happy Holidays to all.

 

[kf6hap]

I said "damper" because I had heard it referred to as a "thermostatic damper"

Just semantics. Don't worry about it. The distinction between a smoke dragon's key damper and a thermostatically controlled combustion system are very dissimilar in operation, though. A "damper" in the usual wood stove context is usually manual and part of an open loop but the "damper" in a BK is an actuated device in a proportional closed loop temperature controller. Way cool.

 

[oldbluedeer]

All our models have the same airways design. As you know first hand, we are trying to resolve the problem for those few that exist, that was the purpose of my post earlier.

We are throwing resources at this and have an in-situ case we are studying.

I reiterate, if anyone has a problem with smoke smell, they can pm me the information I requested. Since my post, we have heard from the 5 parties (including your situation).

We will get to the bottom of this and work with each owner to their satisfaction. We have sold thousands of these units and if even one needs addressing, we will do so.

Guaranteed.

Merry Christmas and Happy Holidays to all.

@BKVP Thank you, that guarantee helps with peace of mind!

I was going to wait until I had done a lot of testing, but now I feel better about sharing preliminary Yuletide results of the new stove door that you arranged for me to pick up.

The fit of the new door on my existing stove was flawless. The new door gasket was darker, perhaps of a different material.

After one hot burn, followed by turning the tstat down to 3 pm for the long burn, I can not smell any smoke coming from the stove. Amazing how pleasant the wood heat is when not aggravated by the effects of smoke smell in the room. By the difference in air it is also clear that the old door was leaking a little even during the hotter part of the burn cycle, just not enough to cause much discomfort.

I plan to test it for a few of weeks, under different conditions and various types of wood, and mainly to make sure that it is still performing after the gasket is fully seated and compressed.

Two photos attached, the lighter color gasket is on the original door, while the darker is on the new one. The cause has at least been narrowed down. I will call Francisco and arrange to ship the old door back to BK after I am done testing, unless you want it earlier.

 

[Poindexter]

After 22.5 hours on one load with the tsat set to 1.25 (let the swoosh debate resume) the wife turned the tsat up to high, ran in bypass for 5 minutes, opened the loading door and found there was too much wood still in the box to bother reloading the stove. So she closed the loading door, engaged the combustor and turned the tstat down to medium. Love that woman.

At 23:56 i think i have plenty of burn time left.

These back to back 24 hour burns are on spruce with the deck fans off.

I am thinking about turning it back down and letting it go until morning just to see what happens.

 

[estepracing]

After 22.5 hours on one load with the tsat set to 1.25 (let the swoosh debate resume) the wife turned the tsat up to high, ran in bypass for 5 minutes, opened the loading door and found there was too much wood still in the box to bother reloading the stove. So she closed the loading door, engaged the combustor and turned the tstat down to medium. Love that woman.

At 23:56 i think i have plenty of burn time left.

View attachment 218508 View attachment 218509

These back to back 24 hour burns are on spruce with the deck fans off.

I am thinking about turning it back down and letting it go until morning just to see what happens.

Is your flu guard temperature on the flu or on the top deck.

Sent from my XT1585 using Tapatalk

 

[w00zy]

I was cleaning my chimney and stove today and a piece of (I think) my cat gasket fell out, it's about 4" long and must have come from the top because the sides and bottom look well gasketed.

My thought is to order some more and next time I'm that deep in the stove pull the cat and redo the gasket, does that sound good? Or should I order some and do it as soon as it's in? Supposed to be bitter cold next week, I don't want to turn on the electric heat. Or just don't worry about it?

The stove is a one year old Ashford 30.1.

 

[Nigel459]

Sometimes after an overnight burn with tstat set low, by morning the cat probe has slipped into inactive but there is still some heat and one or two medium quarter log chunks right in the back. Since the house is warm and I don’t need/want to reload fully, or am headed out, I have tried two things:

1. Simply crank the tstat to high. After a few minutes the chunk(s) is/are glowing red and sometimes even goes into the active zone for a while before the coals are totally gone. Just leave bypass closed as (I’ve read) at the coaling stage there’s no more gunk.

2. If I want more heat quicker, I open the bypass, and after a minute or two rake the coals and the chunk(s) up to the front and turn the tstat to high. Pretty instantly I get hot glowing and flame, and can re engage the cat. Even though I know it may not have any more gunk/volatiles to eat.

Is either one a better practice? Is either one better/worse for the cat in the long run or no harm either way? Cheers

 

[Ashful]

After 22.5 hours on one load with the tsat set to 1.25 (let the swoosh debate resume) the wife turned the tsat up to high, ran in bypass for 5 minutes, opened the loading door and found there was too much wood still in the box to bother reloading the stove. So she closed the loading door, engaged the combustor and turned the tstat down to medium. Love that woman.

At 23:56 i think i have plenty of burn time left.

View attachment 218508 View attachment 218509

These back to back 24 hour burns are on spruce with the deck fans off.

I am thinking about turning it back down and letting it go until morning just to see what happens.

Don’t tell @Woody Stover, he says it’s just a myth.

 

[MissMac]

@BKVP Thank you, that guarantee helps with peace of mind!

I was going to wait until I had done a lot of testing, but now I feel better about sharing preliminary Yuletide results of the new stove door that you arranged for me to pick up.

The fit of the new door on my existing stove was flawless. The new door gasket was darker, perhaps of a different material.

After one hot burn, followed by turning the tstat down to 3 pm for the long burn, I can not smell any smoke coming from the stove. Amazing how pleasant the wood heat is when not aggravated by the effects of smoke smell in the room. By the difference in air it is also clear that the old door was leaking a little even during the hotter part of the burn cycle, just not enough to cause much discomfort.

I plan to test it for a few of weeks, under different conditions and various types of wood, and mainly to make sure that it is still performing after the gasket is fully seated and compressed.

Two photos attached, the lighter color gasket is on the original door, while the darker is on the new one. The cause has at least been narrowed down. I will call Francisco and arrange to ship the old door back to BK after I am done testing, unless you want it earlier.


View attachment 218470 View attachment 218471

Glad to hear maybe you’ve gotten to the root of your problem! Had you tried replacing your door gasket before you got the whole new door? What was the issue with the old door? It’s minus 30 * C here so I’m using the stove. Will tolerate the smell to get the heat. I’m curious to know what replacing the door did for you? Is there something in particular I could inspect on mine?