my BK Princess ok with single-wall connector ?

[RustyShackleford]

Folks, I have been running my new BK Princess for about a week now and I am delighted.
Because I couldn't quite decide how far I want to set it out from the stucco'd cinderblock
wall (behind it), I went ahead and just connected it with the single-wall pipe left over from
my old Dutchwest. There is a 4" gap between the rear of the stove and the wall. I do not
have fans or rear shield, so it's this close only where the thermostat and air intake stick out.
Recall this distance is an issue, despite the fact there are no combustibles nearby, because
the radiation from the wall can supposedly confuse the thermostat - it doesn't re-open enough
when the fire cools off.

So, I'm trying to decide if I'm satisfied with the 4" and the single-wall.

So far, I'm easily getting 12hour burns, meaning I've got LOTS of glowing coals in the
morning and the catalytic is still active (the thermometer is maybe 1/2" into the active
zone). This is without using really dense splits or totally packing the stove. And it MIGHT
go longer. I've just added wood when I wake up. If I DID let it go longer, I'm not sure
if the cat would go inactive, or if it would exhaust the fuel supply, first.

So what might springing for the double-wall connector buy me ? I think its main function
is to improve the draft when the stove is burning very low. So maybe the cat would remain
active for longer - but if I'm happy with 12 hours, who cares ? I was told that BK recs the
double-wall mainly because they were tired of getting compliants about smoke coming out
the door on re-loading. I don't have much issue with this - I guess my chimney draft is
really good.

Meanwhile, it seems like the double-wall might hurt my efficiency, simple because I wouldn't
be getting as much radiation from the connector. Despite BK's claims, that pipe is QUITE
hot, even when the cat is active.

Thoughts ?

 

[53flyer]

Well I don't own one but I agree that you'd lose the radiation heat from the single wall and it sounds like you already have a good draft. I've read about having too much draft but I'm really not sure how someone would ever know if they were in that boat? I guess a safety benefit could be a benefit if you had children around.

Despite BK’s claims, that pipe is QUITE hot, even when the cat is active.

I've wondered about this myself and have seen the dealer demo of having an opening (about a foot off the stove top) in the single wall pipe that you can put your hand in and observe the "realitively" cool temp.

 

[daleeper]

I've wondered about this myself and have seen the dealer demo of having an opening (about a foot off the stove top) in the single wall pipe that you can put your hand in and observe the "realitively" cool temp.

[/quote]

I have been in a store that had one of these set up, and personally seen it done, during a low slow burn setting.

 

[RustyShackleford]

Hmm, last night I lost catalytic activity after about 13 hours or so (still
plenty of good coals, though); had a HELL of a fire going before I turned
her down, too. I wonder if BK's burn-time claims just mean you still
have hot coals after X hours, or that the catalyst is still active too ?

I wonder if a double-wall connector would have kept the catalyst
engaged longer ? I wonder if 4" is too close and the thermostat
didn't re-open as much as it should've ? Sometimes I worry
that I worry too much ...

 

[daleeper]

Hmm, last night I lost catalytic activity after about 13 hours or so (still
plenty of good coals, though); had a HELL of a fire going before I turned
her down, too. I wonder if BK's burn-time claims just mean you still
have hot coals after X hours, or that the catalyst is still active too ?

I wonder if a double-wall connector would have kept the catalyst
engaged longer ? I wonder if 4" is too close and the thermostat
didn't re-open as much as it should've ? Sometimes I worry
that I worry too much ...

I wish I still had one of their old brochures, as there used to be a chart that showed one of those long burn cycles. If I remember correctly, the burn was based on heat that the stove was giving off. I'll see if I still have that thing around here.

I would think that the double-wall connector is to keep the flue gasses warm enough to draft well during a low slow burn. If you are not experiencing draft problems, then it shouldn't be a real issue. Keep in mind that I'm not an expert, and I didn't stay at the Holiday Inn last night either. I do believe that the stove being that close to the wall could be affecting the response of the thermostat. Since you just have single wall pipe, why not stick an extra section in it and see how the stove responds? That way you will know, instead of just worrying.

 

[RustyShackleford]

Hmm, last night I lost catalytic activity after about 13 hours or so (still
plenty of good coals, though); had a HELL of a fire going before I turned
her down, too. I wonder if BK's burn-time claims just mean you still
have hot coals after X hours, or that the catalyst is still active too ?

I wonder if a double-wall connector would have kept the catalyst
engaged longer ? I wonder if 4" is too close and the thermostat
didn't re-open as much as it should've ? Sometimes I worry
that I worry too much ...

I wish I still had one of their old brochures, as there used to be a chart that showed one of those long burn cycles. If I remember correctly, the burn was based on heat that the stove was giving off. I'll see if I still have that thing around here.

That'd be cool. Sounds like your recollection is the cat wasn't necessaraily active at the end ?

I would think that the double-wall connector is to keep the flue gasses warm enough to draft well during a low slow burn. If you are not experiencing draft problems, then it shouldn't be a real issue.

Yep, that's what it's supposed to do. I GUESS I'm not experiencing draft problems, based on not having smoke pour out
the door when I reload during a low burn. But who knows, maybe dbl-wall would help. Expensive experiment though,
and another downside - less radiant heat from the pipe - if it is unnecessary.

I do believe that the stove being that close to the wall could be affecting the response of the thermostat. Since you just have single wall pipe, why not stick an extra section in it and see how the stove responds? That way you will know, instead of just worrying.

But I LIKE worrying Yeah, I'll try moving it out sometime. Although the wood is mostly used up in the AM.
Maybe I need to cut some shorter wood and load it NS so I can pack it in better.

 

[daleeper]

Hmm, last night I lost catalytic activity after about 13 hours or so (still
plenty of good coals, though); had a HELL of a fire going before I turned
her down, too. I wonder if BK's burn-time claims just mean you still
have hot coals after X hours, or that the catalyst is still active too ?

I wonder if a double-wall connector would have kept the catalyst
engaged longer ? I wonder if 4" is too close and the thermostat
didn't re-open as much as it should've ? Sometimes I worry
that I worry too much ...

I wish I still had one of their old brochures, as there used to be a chart that showed one of those long burn cycles. If I remember correctly, the burn was based on heat that the stove was giving off. I'll see if I still have that thing around here.

That'd be cool. Sounds like your recollection is the cat wasn't necessaraily active at the end ?

Sorry, I can't seem to get the quotes set up the way I wanted, lost a bracket somewhere.

The older stove brochures were evidently victims of a rage of housecleaning. I wish I could remember what the notations were on the tail end, as to whether the cat was active, but I don't remember, and hate to record something here that is not correct. What I did find interesting is the first part of the cycle, that the spike in temperature was a few hours (iirc) after the cat had been engaged. After the spike, then the temperature dropped down to reflect the low thermostat setting, and leveled out at a lower temperature, and stayed there for a significant number of hours, and finally tapered off at the end. The chart showed that the cat feeds off the smoke created by smoldering effect of shutting down the air. Too bad they have taken that chart out of their current brochures.

 

[Wet1]

Attached is a link to the BKK info where they trace the temp through the burn, you'll notice the cat is active through the vast majority of the burn...
(broken link removed to http://www.blazeking.com/Brochures-En/WoodProductPDF/KingWoodStove.pdf)

 

[daleeper]

Attached is a link to the BKK info where they trace the temp through the burn, you'll notice the cat is active through the vast majority of the burn...
(broken link removed to http://www.blazeking.com/Brochures-En/WoodProductPDF/KingWoodStove.pdf)

Thanks Wet1, that is the chart I was looking for. I thought it was on the Princess brochure also, but it is not, only on the King, which would be the one with longest burns anyway.

 

[53flyer]

I wonder if 4" is too close and the thermostat didn't re-open as much as it should've? ...

I wish I still had one of their old brochures, as there used to be a chart that showed one of those long burn cycles. If I remember correctly, the burn was based on heat that the stove was giving off. I'll see if I still have that thing around here...I do believe that the stove being that close to the wall could be affecting the response of the thermostat...

This got me to wondering: If the thermostat could have issues in this type of set up wouldn't it also have big issues in an insert application where most of the stove is behind a surround???...

 

[RustyShackleford]

Thanks for the graph, guys, that's pretty cool !

I wonder if 4" is too close and the thermostat didn't re-open as much as it should've? ...

I wish I still had one of their old brochures, as there used to be a chart that showed one of those long burn cycles. If I remember correctly, the burn was based on heat that the stove was giving off. I'll see if I still have that thing around here...I do believe that the stove being that close to the wall could be affecting the response of the thermostat...

This got me to wondering: If the thermostat could have issues in this type of set up wouldn't it also have big issues in an insert application where most of the stove is behind a surround???...

Sure seems like it. I wonder what Chris at BK would say - I believe he's the guy that told me
about this problem.

I think my problem is more likely not enough wood of high enough density. I'm loading
EW because my wood is long, and I suspect loading it NS allows more to be loaded (there's
no way I'm getting anywhere near 60lb in there now).

 

[RustyShackleford]

I think I've pretty much decided to go single-wall for now.

I only have 2ft rise before hitting my 8" offset (two 45 elbows);
that's below spec too (they say 3ft) and again I wonder if I could
expect much improvement, over the status quo which seems to
be working quite well, if I increased it to 3ft ?

 

[learnin to burn]

Rusty, If it works well don't wast the time or money changing it around. Like you said you don't have a smoke issue with the door open so you have a good draft.
Yes the burn times are for how long the cat is active.