King KE40 as an insert?

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P0234

New Member
Nov 17, 2023
12
NoVA
Hi all, long time lurker, first time poster. I currently have a VC1280 and an Osburn 3500. I inherited the VC1280 through the house purchase, the Osburn was my choice. Truthfully, the VC1280 is a good unit, when run hot, it puts out the heat I need BUT I have to wake up in the middle of the night to refuel. It does not do low and slow well, and with its limited capacity, just won't put out the heat I need. I can get an all night burn in the Osburn however it just puts out too much heat when its not quite so cold. I can choke it down more but we get into a not so efficient zone and I'm getting a steady stream of smoke as the secondary burn just isn't happening.

I'd love something like the KE40, I could stuff it full of wood and let it do its thing all night and maybe even longer. I know the princess exists, but I'm greedy and want the extra burn time/capacity.

Has anyone installed a KE40 inside a firebox? I've got the room, its 41W, 29H and 21D" as well as about 16 inches of hearth. I'm not concerned about the appearance. I know there are clearance specs for the unit, however sitting inside a firebox seems to negate those as some units can be run as a stove or insert.

*worth noting is the VC1280 has a 6 foot of 8" pipe up to a metal plate that connects to the clay flue inside the chimney. I'm hopping I can just connect the king to this setup.
 
The issues I see are, the thermostat is not designed to operate in the hotter environment of the fireplace. The effect will be reduced heat output. Second it needs a full 8” and preferably insulated liner.
 
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I would be inclined to give it a try. I have got a K40 that I am on my 4th year of burning with an 8 X 12 oval masonry chimney about 19 ft. high. I was told by people here that it would not burn well with this, but I talked to a BK dealer who was burning with that exact kind of chimney who said that his burned fine. Mine is burning just fine too.

In regard to the thermostat controlling the heat in the enclosed space, you could install it pulled out into the room some. You might have to extend the hearth. The other thing you could do is install an external fan outside pointed into the fireplace space to circulate the hot air out and the cooler air in.
 
Thanks guys, I was expecting to get a few naysayers given some other threads! Good points about air circulation, I will probably incorporate some sort of fan setup, I was thinking of at least a squirrel cage tucked inside the top of the firebox to move that hot air out into the room.
 
The KE 40 is too tall. Even with the classic base kit it's 32 5/8" high.
 
I wasn't planning on using the base, just sitting it in the firebox like an insert.
Go download BK40 the manual. Give a good read. You want less heat out of your current insert. That’s simple enough. Add a second layer brick to the bottom for shoulder season and build smaller fires.

Sure you can do what you are asking about but I doubt you will find much support going down that path.
 
I wasn't planning on using the base, just sitting it in the firebox like an insert.
At 41" wide, there would only be 5" clear on a side if the stove was centered, not including the bypass control arm. Is the fireplace 41" wide at the rear of the fireplace too? It sounds like operating the bypass control would be a knuckle scraper. It might work, but thermostat at the back would read wrong in the hot cavity of the fireplace and the knob would hard to reach, especially alongside of a hot stove body.

The Princess or Ashford insert would get the job done and are designed for fireplace operation.
 
Why not just get a buck 91? Seems like it would work. A full 8" liner will be needed regardless
 
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Why not just get a buck 91? Seems like it would work. A full 8" liner will be needed regardless
Thanks for the suggestion, that indeed looks like an interesting option, how is the 91 at a slow burn? That's what attracted me to the KE40, big capacity and long slow burn times or can roll hot if needed.
 
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Go download BK40 the manual. Give a good read. You want less heat out of your current insert. That’s simple enough. Add a second layer brick to the bottom for shoulder season and build smaller fires.

Sure you can do what you are asking about but I doubt you will find much support going down that path.
I don't want less heat, I want a longer burn time so I need more capacity. My current unit can only really fit about 1-1.2cu ft of wood.
 
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Thanks for the suggestion, that indeed looks like an interesting option, how is the 91 at a slow burn? That's what attracted me to the KE40, big capacity and long slow burn times or can roll hot if needed.
It doesn't really sound like you want long slow burns at all.
 
I don't want less heat, I want a longer burn time so I need more capacity. My current unit can only really fit about 1-1.2cu ft of wood.
The Princess or Ashford insert have well over twice that capacity, the Buck 91 over 3 times.
 
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Besides the T-stat not functioning as designed due to the potential thermal mass storage of the masonry, daily operations could also be affected due to the by-pass handle being located center upper right quadrant of the stove, make sure at the minimum that you will have the clearance and long enough arms to reach in there to open and close the by-pass for loading purposes.
 
It doesn't really sound like you want long slow burns at all.
????

If I wanted hot and short, I'd get another Osburn 3500. It'll eat 3.5 cubic feet of wood in 3 hours if you let it. I can get about 8 hours of good heat out of it, but my goal is to have something that will put out about 25-30k BTU for the duration of a 12 hour burn.

To make is extra clear, I'd like something I can fill with wood and get 12 hours of 25-30k BTU/hr. Bonus points for being able to crank it down even lower when it warms up a bit.
 
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Besides the T-stat not functioning as designed due to the potential thermal mass storage of the masonry, daily operations could also be affected due to the by-pass handle being located center upper right quadrant of the stove, make sure at the minimum that you will have the clearance and long enough arms to reach in there to open and close the by-pass for loading purposes.
Yeah, I will have to do a lot of measurement and likely get my paws on a KE40 to make sure it will fit and be usable before I commit. Honestly I was more worries about people saying it was going to be a terrible idea to put it in a firebox but I understand the controls may not be ideal or work at all.
 
Yeah, I will have to do a lot of measurement and likely get my paws on a KE40 to make sure it will fit and be usable before I commit. Honestly I was more worries about people saying it was going to be a terrible idea to put it in a firebox but I understand the controls may not be ideal or work at all.
It's not going to work properly. Get an insert designed for your application. A princess or the big buck will do what you want far better than a king. And the princess will only need a 6" liner
 
A princess or the big buck will do what you want far better than a king.
A Princess insert, not the freestanding version, which would have the same issues as the King.
 
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A Princess insert, not the freestanding version, which would have the same issues as the King.
Yes absolutely I should have been more clear
 
Probably been mentioned already or at least alluded to, but the long slow burns will not put out similar heat to your VC on high. The website states 12-16 hours on high at 57k btus but maybe only 17k on low which will get you about 40 hours. Just something to keep In mind. If you have to run a blaze king at too high of a thermostat setting I believe you trade off the benefits of a cat stove. Just my opinion.
 
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Probably been mentioned already or at least alluded to, but the long slow burns will not put out similar heat to your VC on high. The website states 12-16 hours on high at 57k btus but maybe only 17k on low which will get you about 40 hours. Just something to keep In mind. If you have to run a blaze king at too high of a thermostat setting I believe you trade off the benefits of a cat stove. Just my opinion.
I'd love 12 hours of 57k! I don't think I'm getting even 50k out of the VC, my heat pump is about 60k and in similar weather will run about 30-40% duty cycle to keep the house the same temp, so I'm guessing I'm getting closer to 30k out of the VC over the average of the entire burn.

The biggest issue here gentlemen is the capacity of the VC. If you use 24" logs, get lucky on the perfect fit, you can cram 2 cubes in. On average I'm fitting in about 1.2. And as much as I like the princess and the fact that it will be a no fuss install, its rated capacity is 2.57, so only 28% more capacity, while it will probably go low and slow enough to get me through the night, what I need is a KE40 insert!
 
All great points. Let me weigh in here.

Our stoves are not tested to be operated without a base! All clearances to combustibles are established using a base. The group here is correct, the thermostat will not operate or function as intended when stuffed into a masonry fireplace. Number 3, BeGreen is correct in that all the controls are on the right hand side of the firebox and won't be accessible to all but the smallest hands.

I also what to clarify the comment that "Cat stoves give you longer burn times by burning less hot". I can't speak for the other cat stoves on the market, but our thermostat is why you get longer burn times. Yes, with catalytic technology you can often operate the stove at a lower burn rate, but not always. Some "low" burn rates on cat stoves are above 1.0 kg/hr. Ours are lower, yes.

Regardless of the burn rate, whether it is low or high, the thermostat responds to the setting for heat output of the customer. Wood does not have a metered property, it burns erratically because that is how it burns. The thermostat responds to these ebbs and tides and automatically adjusts the air input to stay in the same burn rate set by the user. It is this "straightening out" of the burn curves that stretches the burn times.

Otherwise, everything here is spot on.

BKVP
 
All great points. Let me weigh in here.

Our stoves are not tested to be operated without a base! All clearances to combustibles are established using a base. The group here is correct, the thermostat will not operate or function as intended when stuffed into a masonry fireplace. Number 3, BeGreen is correct in that all the controls are on the right hand side of the firebox and won't be accessible to all but the smallest hands.

I also what to clarify the comment that "Cat stoves give you longer burn times by burning less hot". I can't speak for the other cat stoves on the market, but our thermostat is why you get longer burn times. Yes, with catalytic technology you can often operate the stove at a lower burn rate, but not always. Some "low" burn rates on cat stoves are above 1.0 kg/hr. Ours are lower, yes.

Regardless of the burn rate, whether it is low or high, the thermostat responds to the setting for heat output of the customer. Wood does not have a metered property, it burns erratically because that is how it burns. The thermostat responds to these ebbs and tides and automatically adjusts the air input to stay in the same burn rate set by the user. It is this "straightening out" of the burn curves that stretches the burn times.

Otherwise, everything here is spot on.

BKVP
I was hoping you might weigh in. Have there ever been any discussions of making the KE40 as an insert? I'd sign up to be a beta tester :cool:
 
I was hoping you might weigh in. Have there ever been any discussions of making the KE40 as an insert? I'd sign up to be a beta tester :cool:
You know, EPA still allows for beta-testing! Unfortunately, the demand for such a large insert (based on real-world fireplace sizes) is fairly limited. And no one is building huge masonry fireplaces. But I'll put you on the list of 4 or 5 guys that have asked to be on the King Insert Beta Test list....

BKVP
 
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