Large Cat question (Buck Stove 91 vs Kuma Sequoia vs. Lopi Hybrid-Fyre)

[Judd]

I am considering a wood burning insert for my fireplace (I am a beginner in the wood stove/insert world). We currently have a traditional fireplace with what I have seen called a heatform or heatilator metal liner but no vents coming through the brick. The fireplace is completely inside the house and is centrally located in a vaulted 2 story central living room with all the other rooms coming off of it. The house is about 3500 sq ft and built in 1978 (moderately energy efficient). I was considering a larger catalytic insert. The two that I have been leaning toward the most were the Buck Stove 91 and the Kuma Sequoia (inside diameter of the chimney is 11"x16" when measured from the roof side, so I think an 8" flue should be fine). I was wondering if anyone has any idea of significant differences between those two stoves based on personal experience with both (or even speculation about significant advantages of one over the other). Also, as one of its selling points, the Sequoia has "natural convection", but they also offer an optional variable speed 160 cubic ft/minute fan. If I have two ceiling fans moving air in the living room, do you think the natural convection will be sufficient, or do you think an insert in that scenario will always need a fan. I was hoping someone might have experience with that. Finally, I was also intrigued by the Lopi large flush hybrid-fyre insert. I was wondering if it simply burns like a non-cat insert with a catalyst to clean things up a bit, or could it be run more like a large cat stove with lower temperatures and longer burn times. I am not sure I quite understand the technology if it can truly do both. I have enjoyed looking at the website for a few weeks now. Its a great resource.

 

[Heatsource]

I really like the Kuma, but Im yet to sell or install one. (just put it in the showroom at the end of the season)

 

[begreen]

I like the big Kuma too.

Judd, with two ceiling fans in the room an effective way to help winter air circulation is to have one blowing up and one blowing down. That should establish a nice convection loop.

 

[mellow]

I would say either would do the job, but I would look at putting in a rear vent free standing stove, something like the yet to be released woodstock steel hybrid if you can fit it on your hearth.

 

[Woody Stover]

I run a 91 and it's a great heater and a good-looking stove. I haven't gotten a look at the Sequoia yet; Closest dealer is 3 hrs. away. Pretty sure the Buck looks cooler, though. Can you look at both stoves in person, maybe even see them burn? You are going to want the biggest firebox you can get. Ignore mfgr. claims; Despite claiming 4.4 cu.ft. I measured the useable space in the firebox closer to 3. Inserts are limited by the fact that they have to be squat to fit into fireplaces. I agree with mellow, consider putting a big free-stander in to get the biggest firebox and more radiant heat as well as convective.
The blower types looks different, the Sequoia has the long, skinny one and might be quieter, I don't know. The Buck isn't loud on low, but noise increases with speed. Of course, in that big room the sound will get swallowed up somewhat; I have the Buck in a 13x20 room. I think that with any stove you put in there, you are going to need a blower to pull more heat off the stove (depending on how much of your heat you want to replace with stove heat) and get that heat moving through the house. Sounds like you have a decent layout....
The Buck has an ash pan, but the Sequoia has all the vowels except 'y' in its name, whereas the Model 91 Bay Heater has only three, plus the 'y.' I don't like shoveling out ashes to begin with, but it's gonna be hard not to get ash flying around when shoveling out an insert, with it's shorter door opening, unless you have great draft (which it sounds like you may....how tall is the chimney?) And you'll need to shovel often if the floor isn't deep.
Looking at the manual, the Kuma has a sheet metal baffle protecting the cat and it looks like it might be hard to tell how much flame in the box is too much. On the Buck, I can see through the airwash channel holes how far the flame is sucking around the heat shield toward the cat. Again, it would be great to look at both stoves in person if you could.
Being a west coast guy, maybe begreen has seen the Kuma in a stove shop or burning and can expound on what he likes about it. A1Stoves has one there, so maybe between them, they can fill us in on useable firebox, blower noise, firebox shape (Buck is trapezoidal,) etc.

Buck 620 lbs. Kuma 515. I wonder what accounts for that difference?

 

[HybridFyre]

I have the large hybrid fyre flush mount. I have a hard time keeping my open floor plan house above 66 degrees when it's below 30 degrees outside (without augmenting with oil furnace) and I have 2,500 sq ft. I'm not sure it will heat your 3,500 sq ft very well if you get cold temps where you are.

 

[Woody Stover]

I have the large hybrid fyre flush mount. I have a hard time keeping my open floor plan house above 66 degrees when it's below 30 degrees outside (without augmenting with oil furnace) and I have 2,500 sq ft. I'm not sure it will heat your 3,500 sq ft very well if you get cold temps where you are.

Moderate temps where he is, about like here, but he's further south. The lowest average low here in January is about 20 degrees. This winter is an outlier....

Buck 620 lbs. Kuma 515. I wonder what accounts for that difference?

Part of it is probably the cast iron cat frame in the Buck. I'm not sure if the Kuma has the thick plate-steel top on the convection chamber like the Buck does....

 

[hman]

The Kuma that I have has firebrick as the baffle with a fiber blanket on top of the brick.I don't know what the Sequoia has.
I had at one time a Buck model 18 as an insert and the steel baffle warped.I filled the fire box full up against the secondary burn tubes,that might have caused it to warp.I never over fired it.
I have filled the fire box full on the Kuma and never had any problems out of the burn tubes.The firebrick that is the baffle all look like new.

 

[jolby]

hman, I have had the same experience with my Buck 81 steel baffle warping. I visited a Buck dealer about 6 weeks ago and checked out a Model 81. Instead of a one piece metal baffle, it was 2 pieces of ceramic fiber board or some similar material. Not sure about the Buck 91

 

[hman]

The steel baffle in the model 18 was just one piece and was 1/4 or 5/16 thick and laid directly on top of the secondary burn tubes.This was back in the late nineties.Buck has probably change that baffle to some other material now.It was a good little stove.

 

[_CY_]

I have the large hybrid fyre flush mount. I have a hard time keeping my open floor plan house above 66 degrees when it's below 30 degrees outside (without augmenting with oil furnace) and I have 2,500 sq ft. I'm not sure it will heat your 3,500 sq ft very well if you get cold temps where you are.

running a buck 91 with open floor plan also 2500sf. insert located inside a huge outside fireplace. home built early 50's with excellent insulation. first winter with buck 91 and had problems keeping room above 68f when temps drop below 30f ..

got the buck 91 used so didn't know history .. changed out to new ceramic combustor with little to no improvement.
told my problems to buck technical with no help. explained problems of a buck 91 not heating a 2500sf after purchasing a new combustor from them.
the old timer installer suggested filling entire fireplace with insulation so heat will have no where to go except forward via fan. he had done same thing 20 years back with buck 91 and other installs. he used std fiberglass insulation with no problems.

not wanting to take a chance .. chased down mineral wool insulation rated to 2000f .. then stuffed entire firebox and damper full of mineral wood.
acts like a completely new stove ... heats up faster, holds heat better, puts out way more heat. all for $40 costs of high temp insulation.
this may not fix your problems .. but it sure fixed mine.

https://www.hearth.com/talk/threads...neral-wool-instead-of-block-off-plate.124737/





(broken image removed) (broken image removed)

 

[Woody Stover]

The Kuma is EPA rated at slightly higher output, but I've found you have to take the EPA ratings with a grain of salt. That's apparently the '100' model but there's another listed, the K-100B and they rate the output on that about 10,000 BTUs higher than the Sequoia and the Buck 91.
The Kuma appears to have a thick steel top like the Buck so I'm not sure what accounts for the weight difference. That "natural convection" may work but I think you'll still want the blower on to help move cool air back to the stove. I'm guessing here, if you haven't guessed.... The blower is standard on the Buck, optional on the Kuma.

There are a few reviews of the 91 in the stove review section here, but none on the Sequoia. There are also other big inserts from other companies but I haven't had cause to check into it, and I don't know what all is available in your area.

 

[_CY_]

my Buck 91 is probably 20 years old and didn't come with firebricks on sidewalls.
firebox is substantially larger than newer buck 91 with full lined firebrick.
it also didn't hold heat well until external insulation was added.

fits 24in x 10in diameter logs .. it's at least 4.5 cu ft
weight is from good ole fashion thick steel ... top measures .3045 in thick

 

[Woody Stover]

my Buck 91 is probably 20 years old and didn't come with firebricks on sidewalls.
firebox is substantially larger than newer buck 91 with full lined firebrick.
it also didn't hold heat well until external insulation was added.

fits 24in x 10in diameter logs .. it's at least 4.5 cu ft
weight is from good ole fashion thick steel ... top measures .3045 in thick

Mine is an '08. The only way you can get to the advertised 4.4 is if you take out the cat shield, the cat and all the firebrick.
Yep, the top is 5/16", as is the top of the firebox. Thing is a tank!

 

[HybridFyre]

running a buck 91 with open floor plan also 2500sf. insert located inside a huge outside fireplace. home built early 50's with excellent insulation. first winter with buck 91 and had problems keeping room above 68f when temps drop below 30f ..

got the buck 91 used so didn't know history .. changed out to new ceramic combustor with little to no improvement.
told my problems to buck technical with no help. explained problems of a buck 91 not heating a 2500sf after purchasing a new combustor from them.
the old timer installer suggested filling entire fireplace with insulation so heat will have no where to go except forward via fan. he had done same thing 20 years back with buck 91 and other installs. he used std fiberglass insulation with no problems.

not wanting to take a chance .. chased down mineral wool insulation rated to 2000f .. then stuffed entire firebox and damper full of mineral wood.
acts like a completely new stove ... heats up faster, holds heat better, puts out way more heat. all for $40 costs of high temp insulation.
this may not fix your problems .. but it sure fixed mine.

https://www.hearth.com/talk/threads...neral-wool-instead-of-block-off-plate.124737/





(broken image removed) (broken image removed)

Thanks man. I already was planning on doing that as soon as it warms up. I don't have nearly as much air gap around it, I only have a few inches...but i'm hoping for the same effect!

 

[Woody Stover]

it also didn't hold heat well until external insulation was added.

I don't know if that would help at my MIL's...chimney is internal. What I am gonna do is plastic every window in the 13x20 stove room (3-1/4 walls covered with glass,) and cut my way into the gable, where I bet I find no insulation above the stove room (9-1/2' ceilings in the house.) I'm tired of burning up all my hard work and not being able roast the old girl out, even though the stove is at one end of the house, and there's no wall insulation. I guess it's hard to roast out a 92 y.o. woman, though....

 

[_CY_]

Mine is an '08. The only way you can get to the advertised 4.4 is if you take out the cat shield, the cat and all the firebrick.
Yep, the top is 5/16", as is the top of the firebox. Thing is a tank!

mine is from 1993 era .. mine is so old that combustor has different dimensions. it's 1/4in wider than modern buck 91
shut off plate/rails are completely different .. it's really a different stove from newer buck 91. inside firebox shape is different too.
but same 5/16in steel construction .. that's one heavy ass stove!

 

[_CY_]

Thanks man. I already was planning on doing that as soon as it warms up. I don't have nearly as much air gap around it, I only have a few inches...but i'm hoping for the same effect!

be sure to stuff lots of insulation at least 2-3 ft past damper .. use 2in non backed mineral wood rated to 2000f
costs all of $40 for 10 pieces of 2in x 24in x 48in which was plenty to do my huge fireplace.

is your fireplace located on outside wall?

 

[Judd]

I appreciate all the input. The site is a wealth of knowledge.

I would say either would do the job, but I would look at putting in a rear vent free standing stove, something like the yet to be released woodstock steel hybrid if you can fit it on your hearth.

I looked at the clearances for the beta version of the stove and I saw someone listed 31" minimum height with the legs at the lowest level, and my fireplace height is only 28". In addition, no matter how practical, I am afraid that setup might not pass the aesthetic test with my wife.

Can you look at both stoves in person, maybe even see them burn?

There is a Buck Stove dealer in my city, so I plan to go by there (not sure if I will be able to see it burn), but the closest Kuma dealer is at least a couple hours away. When I called that Kuma dealer, they said they rarely sell them, so they don't keep any in stock. It doesn't sound I will really have a good opportunity to see one in person, which makes the information I glean for you guys even more valuable.

I think that with any stove you put in there, you are going to need a blower to pull more heat off the stove

I was afraid you might say that. I was hopeful that I could get away with not adding it because it will be a bit of a pain to add electrical to that location. Also, I like the idea of quiet, and I hoped that a pair of low noise ceiling fans would be enough with the convection to move things around. I asked the Kuma manufacturers for a rough estimation of average cubic feet / minute produced by their "natural convection" so I could compare it to the 160 cf/min fan. Unfortunately, that information is not available. I also wondered if the fan turned off would interfere with said convection, and they said it would probably decrease it some.

The Buck has an ash pan

I noticed that the Sequoia doesn't have an ash pan (they just added an ash lip in their 2012 update), but I also have read conflicting opinions regarding the usefulness of the ash pan.

it's gonna be hard not to get ash flying around when shoveling out an insert, with it's shorter door opening, unless you have great draft (which it sounds like you may....how tall is the chimney?)

I don't know exactly how chimneys are typically measured, but from the top of the fireplace opening to the top of the clay tiles on top of the chimney is 18 1/2 feet.

I have the large hybrid fyre flush mount. I have a hard time keeping my open floor plan house above 66 degrees when it's below 30 degrees outside (without augmenting with oil furnace) and I have 2,500 sq ft. I'm not sure it will heat your 3,500 sq ft very well if you get cold temps where you are.

Hopefully that can improve with the insulation suggestion or something similar. I really appreciate your information, though. That product seems relatively new (compared to the Buck 91 and Sequoia), so those real world experiences are very helpful. I am still intrigued by hybrid idea, though, and wonder if it can be used to work as both a catalytic (longer/cooler) or non-catalytic, or if it is really a non-catalytic with a catalyst added to keep the air cleaner.

be sure to stuff lots of insulation at least 2-3 ft past damper .. use 2in non backed mineral wood rated to 2000f
costs all of $40 for 10 pieces of 2in x 24in x 48in which was plenty to do my huge fireplace.

That sounds like a good idea. My fireplace is completely inside (very center of house), so I am not sure that it will matter quite as much as someone with an exterior wall fireplace. Having not ever installed an insert, I may not quite understand. I understand about filling the sides and back with insulation, but I don't understand above it. Do you mean that insulation is placed 2-3 ft. above a block off plate, or is there no block off plate in this instance, or is the block off plate farther up.. If it is below the block off plate (or without one), does water not come down from above and get into the insulation (or is there a cap that keeps it from entering)? Obviously, I am green.

Finally, the other thing I noticed was that the Sequoia doesn't have a glass air wash claim (although some of their other smaller inserts do), so I was wondering if any Sequoia users have input about how annoying this is for them (or how easily it gets nasty). In contrast, the Buck Stove 91 claims air-wash (although it sounds like it works best for the large central glass, but not the two side ones). The Lopi Hybrid-Fyre has such a nice viewing area and they claim a strong air wash. The aesthetics are a significant aspect for my better half, so the size and clarity of the viewing area figures into the calculation.

Again, I appreciate all the information you guys share.

 

[_CY_]

That sounds like a good idea. My fireplace is completely inside (very center of house), so I am not sure that it will matter quite as much as someone with an exterior wall fireplace. Having not ever installed an insert, I may not quite understand. I understand about filling the sides and back with insulation, but I don't understand above it. Do you mean that insulation is placed 2-3 ft. above a block off plate, or is there no block off plate in this instance, or is the block off plate farther up.. If it is below the block off plate (or without one), does water not come down from above and get into the insulation (or is there a cap that keeps it from entering)? Obviously, I am green..

yup my fireplace is located outside wall so not sure if same procedure would be necessary for you. mine is stuffed with mineral wool rated to 2000f several ft above damper so no block off plate is necessary. top of chimney has a huge cap so no rain water can get in.

reason for insulating my Buck 91 was low heat output issues .. a major chunk of heat was going up the chimney and into outside masonry.
Buck 91 is a proven 20+ year old design that's known to heat large square feet. some successfully with 3500sf homes.

so heating a 2500sf single level home like mine should have been no sweat for a Buck 91 .. headed for 19f low tonight .. 8f low tomorrow night .. we'll see how Buck 91 does now.

 

[Woody Stover]

I was afraid you might say that. I was hopeful that I could get away with not adding it because it will be a bit of a pain to add electrical to that location.

I don't have a dedicated outlet there but the cord is able to reach a nearby wall outlet. You could even run an extension cord....it doesn't draw much amp.

I noticed that the Sequoia doesn't have an ash pan (they just added an ash lip in their 2012 update), but I also have read conflicting opinions regarding the usefulness of the ash pan.

The best ash-handling system by far is a grate in the floor of the firebox; You just swirl a poker through the coals and the fine ash falls through into the pan, leaving the coals in the stove. The Buck ash dump is more work to use but I still prefer it to shoveling 'em out and having to take coals out every time. At least with the dump, you can burn a few loads before you have to pull the pan and take it out. The dump is 3.5"x5.5". I just shovel under the coals to get the finer ash, tilt the shovel to leave the bigger coals in the stove, and dump the ash. I had an issue with some air leakage where the ends of the ash pan gasket meet (most other operators of the 91 report no such problem.)This was causing the left side of the load to burn fast, resulting in the cat probe pushing 1800 a couple of times, which they say to avoid. I got that gap in the gasket ends fixed, and when I'm done dumping the ashes and close the lid I pack some ash down around the hinge area. Then when I load, I shove some coals over the center-most edge of the ash dump lid to eat any air the comes in, thereby evening out the burn between the left and right sides. I usually load her stove and leave but to my knowledge, cat probe hasn't gone high since I made those adjustments.
Todd reports that the new Condar cat probes have been re-calibrated, so in reality the occasional 1800 reading on the old probe may have erred on the high side and been nothing to concern myself with.

I don't know exactly how chimneys are typically measured, but from the top of the fireplace opening to the top of the clay tiles on top of the chimney is 18 1/2 feet.

Exactly what I have at MIL's house. Good draft, but you still have to open and close the door slowly to avoid sucking a little smoke smell into the room.

That product seems relatively new (compared to the Buck 91 and Sequoia), so those real world experiences are very helpful. I am still intrigued by hybrid idea, though, and wonder if it can be used to work as both a catalytic (longer/cooler) or non-catalytic, or if it is really a non-catalytic with a catalyst added to keep the air cleaner.

I'm reading that most of the hybrids seem to burn in secondary mode more at the beginning of the burn. The Woodstock Ideal Steel seems to be more controllable in this regard, the beta versions anyway....

Finally, the other thing I noticed was that the Sequoia doesn't have a glass air wash claim (although some of their other smaller inserts do), so I was wondering if any Sequoia users have input about how annoying this is for them (or how easily it gets nasty). In contrast, the Buck Stove 91 claims air-wash (although it sounds like it works best for the large central glass, but not the two side ones). The Lopi Hybrid-Fyre has such a nice viewing area and they claim a strong air wash. The aesthetics are a significant aspect for my better half, so the size and clarity of the viewing area figures into the calculation.

Yeah, forget about ever seeing anything through the Buck bay windows. If I could that would be so cool.... The door glass stays pretty clean if you're burning dry wood....some deposits in the lower corners on mine, but not bad. I tend to use the 'shot gun air' (boost air) to get the stove up to temp, and that burns hotter in the center. It's a breeze to touch up the glass once in a while....
I don't recall seeing any posts by anyone burning a Sequoia....maybe I missed it.
As far as the wife's ideas about a stove, sometimes you just have to TTBTR.

But that size house is going to be a tall order for any single stove....the heat may have to kick on toward the end of the load when the output drops off. Until I can do some more weatherizing at my MIL's, her furnace kicks on at the end, but her bill from the power company (gas and electric) went from $300+ (with a cold house) to $100 and a much warmer house. I can only imagine what a straight furnace bill over there would be in this freakish winter.

 

[HybridFyre]

be sure to stuff lots of insulation at least 2-3 ft past damper .. use 2in non backed mineral wood rated to 2000f
costs all of $40 for 10 pieces of 2in x 24in x 48in which was plenty to do my huge fireplace.

is your fireplace located on outside wall?

It's not it's an inside chimney. That's why I'm expecting moderate gains from insulating but nothing mind blowing.