Contemplating a Blaze King Princess Insert - Help us think it through

DuaeGuttae

Minister of Fire
Oct 26, 2016
658
Texas
Our current stove is a Lopi Revere Insert on its sixth season, in great shape and still going strong. We had it professionally installed six years ago before I had spent so many hours on Hearth.com. Our liner is uninsulated on an exterior masonry chimney (on a somewhat north wall). We've talked about pulling it out to insulate, and we've finally decided that we want to do it, or rather have it done. We know it's not something we can tackle ourselves, even with help. (We also figure we'll work on insulating the fireplace and building a blockoff plate; that's more manageable for us.)

In debating whether we would pay to have our setup reinstalled, we've said to ourselves, "If we were to want to switch stoves, this would be the time." We've been discussing it for months, and we both really like our current stove, so we really haven't been sure, and we still aren't sure.

What brings me to this point is that I got a great offer on an older but still new Blaze King Princess Insert (less than half the cost of what I was quoted other places). It's a long drive, but we have no local dealers. This one is just less local than the more expensive options.

The Revere is located in our finished walk-out basement (lots of living space here). We originally purchased it to be just a space heater because the basement was never warm enough in winter. After a couple of seasons it basically took over as the primary heat. It's a little undersized for our entire house (2,500 square feet), but we have great insulation and air sealing, and it has done admirably, and we are really quite pleased with it.

The attraction of the Princess is the possibility of running it low and slow and saving on wood usage. We have a natural gas heat pump, and we don't mind using it in the coldest of winter to take care of what wood heat just can't do. (The corner bedrooms in a ranch-style house one floor up from the insert can need a little help.) In shoulder season if we just rely on the heat pump, folks feel cold again, especially as the basement starts to be colder than the upstairs. We do burn therefore during the shoulder season, but it's small fires that we let go out.

I've read lots and lots of threads here (I have even followed the Blaze King Performance thread for a couple of seasons), so I think I know that people love their stoves. I'm just trying to think things through, and I'm open to feedback that you think may help us decide whether to go ahead with this. We plan to be in this house for another 20 years, I think, so we're thinking pretty long term.

Here are some questions:
We know our basement can have negative pressure. We've not had a problem with the Revere. Would this be something to which we should not subject a Princess? (The chimney is about 24 feet, and it would be insulated.)

Our wood is good. We have lots of oak, but also get cherry, hickory, beech, maple, black gum and pine. We get 10-hour burns (good coals at the end) on our 2.2 cubic foot firebox. What kind of burn times have Princess Insert users seen? I'd love as much description in this area as you'd be willing to type. (I'm not doubting the capabilities of Blaze Kings to go low and slow or crank out heat on high, but I'd love to see more information from insert users.)

What is involved in cleaning from below with a Sooteater? On our Revere we only have to open the bypass. Is it that easy on the Princess, or is it more complicated?

One thing that steered us away from cat stoves initially was the worry that we would poison the cat by inadvertently burning metal in our wood. We scrounge in suburbia, and our wood is from yard trees. In our years of doing this, we've not actually found metal inside our stove (but we also don't hunt for it), but if we burned wood that had nails or something buried in it, would that kill the cat or is that unfounded cat negativity?

We also this year laid in a supply of Liberty Bricks (high quality pure compressed wood) because of an injury that made it hard for me to haul our cordwood. We're looking to have a lot leftover for next season. I'm pretty sure that BKVP has said it's most efficient to burn a mixture of bricks and cordwood. What are your experiences on that for those who have done both?

Also, if you've switched from a tube stove to a similarly size BK, what kind of wood savings have you seen?

I'm sure there's more that I can ask but I'll stop here. Please help me think this through. Thank you!
 

weatherguy

Minister of Fire
Feb 20, 2009
5,758
Central Mass
I'd do it since you're going to have the liner insulated and you're getting it at a great price I wouldn't even think twice. You'll be getting a bigger stove with longer burn times, you shouldn't have a draft problem with a liner that long, mine was a basement install with 26 feet and drafted like hell. If you don't do it you'll be kicking yourself.
 

begreen

Mooderator
Staff member
Nov 18, 2005
84,265
South Puget Sound, WA
Sounds like a great deal. My main question would be dealer support. It sounds like may be quite distant. What do you do if something is not right?
 

DuaeGuttae

Minister of Fire
Oct 26, 2016
658
Texas
Thanks for your input, Weatherguy. It does seem like a great opportunity, and as much as we've been toying with the idea, we didn't really think such a chance would come along reasonably. It's good to hear of a successful basement install.


Sounds like a great deal. My main question would be dealer support. It sounds like may be quite distant. What do you do if something is not right?
We've been talking about the same thing, Begreen, and trying to figure out what weight to put on it. As a new purchase, we would have the warranty but we are outside the dealer's service area. It seems we are outside every dealer's area, too. I'd love to hear from Blaze King owners your thoughts about this.

Thanks.
 

kennyp2339

Minister of Fire
Feb 16, 2014
5,142
07462
I'm a huge proponent of BK products but if I were you i'd stick with your current insert. Yes I would insulate the liner, build a block off plate, look into insulating the fire box walls.
The main issue I see is the basement install with a known negative pressure problem. trying to run the BK low and slow might be a challenge and become frustrating. You say that the existing insert is to small for the existing house but if you do the block off plate you may see a 15% increase in additional heat coming into the living space.
 
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DuaeGuttae

Minister of Fire
Oct 26, 2016
658
Texas
I'm a huge proponent of BK products but if I were you i'd stick with your current insert. Yes I would insulate the liner, build a block off plate, look into insulating the fire box walls.
The main issue I see is the basement install with a known negative pressure problem. trying to run the BK low and slow might be a challenge and become frustrating. You say that the existing insert is to small for the existing house but if you do the block off plate you may see a 15% increase in additional heat coming into the living space.
Thanks for that input. I appreciate it.

It gave me a chuckle that a Woodstock owner tells me to get a BK, and a BK owner tells me not to. Please no one try to start the perennial debates here. I just wanted to comment on my chuckle.
 

moresnow

Minister of Fire
Jan 13, 2015
1,276
Iowa
Not sure dealer support is a real concern with all the info/advice/tips found here! Sounds like you are getting decent burn times and performance out of your current setup.
If you have a significant negative pressure problem it would have likely caused trouble already.
Not sure I'd sweat the occasional bit of metal in your wood supply.

No scientific measure of wood saved. The amount saved this year is impressive. Enough saved that I have re-evaluated how much wood I have on hand and how much I need to keep gathering. My BK is freestanding. Hopefully the insert guys will chime in.
 

rwhite

Minister of Fire
Nov 8, 2011
1,633
North Central Idaho
Were it me I'd keep your current set up. Not that I don't think BK are a great stove (Love mine). But if your getting 10 hr burns and it's heating your home why change? With a basement install trying to heat your home I would suspect that you'll run a BK a bit higher and not have a considerable saving on wood. If you do go the BK route I'd stash your Lopi away for a season to make sure your happy. Stoves, especially BK, seem to have a pretty good resale so you might have nothing to lose trying it. If it doesn't perform as well just resale it.
 

DuaeGuttae

Minister of Fire
Oct 26, 2016
658
Texas
Thank you both for your thoughts.

Getting input helps us keep refocusing our own discussions and really clarify why we're entertaining the idea. It helps, and I'm grateful. Thank you.
 

jetsam

Minister of Fire
Dec 12, 2015
4,737
Long Island, NY
youtu.be
The Revere is located in our finished walk-out basement (lots of living space here). We originally purchased it to be just a space heater because the basement was never warm enough in winter. After a couple of seasons it basically took over as the primary heat. It's a little undersized for our entire house (2,500 square feet), but we have great insulation and air sealing, and it has done admirably, and we are really quite pleased with it.
My PI is the only heat for about 2300 SF (do have an oil burner, but it hasn't kicked on once this year). It is honestly a little undersized on cold days for what I ask of it ("keep the house warm while nobody is home for 12+ hours a day")- but it keeps up. A larger freestanding stove would do better.

The attraction of the Princess is the possibility of running it low and slow and saving on wood usage. ... In shoulder season if we just rely on the heat pump, folks feel cold again, especially as the basement starts to be colder than the upstairs. We do burn therefore during the shoulder season, but it's small fires that we let go out.
I know nothing about your stove, but the PI is amazing in this area. I burn 24/7 from whenever the house gets colder than 70 to whenever it stays above 70 with no heat. That was about 9 months last year. I burn though shoulder season when it's 60+. :)

We know our basement can have negative pressure. We've not had a problem with the Revere. Would this be something to which we should not subject a Princess? (The chimney is about 24 feet, and it would be insulated.)
I would definitely be concerned about this because you are talking about switching to a stove that you want to move a much lower volume of air through 6 months a year. Outside Air kits can also be problematic in a basement install, and I don't know if the PI has an intake for an OAK. I would take a very close look at this question if I was in your shoes.

What kind of burn times have Princess Insert users seen? I'd love as much description in this area as you'd be willing to type.
Even with suboptimal wood, I can hit 24 hours with the fan off and the thermostat set low. (A 'burn' is over for me when the cat goes inactive.) 12 hours is the top end with the fan on low and the thermostat set high enough that the fan doesn't kill the cat. Of course, it all depends how much heat you are asking for; I get 24 hour burns only in shoulder season. Today, a weekend morning coming off a -5°F night, I did a 4 hour burn when I got up (and it is toasty warm, in here, might I add. :). )

What is involved in cleaning from below with a Sooteater? On our Revere we only have to open the bypass. Is it that easy on the Princess, or is it more complicated?
I don't know for sure, but I sweep from above. When I do, I put a work light in the cold stove before I go up top, and I can see the light from the top of the flue.

One thing that steered us away from cat stoves initially was the worry that we would poison the cat by inadvertently burning metal in our wood. We scrounge in suburbia, and our wood is from yard trees. In our years of doing this, we've not actually found metal inside our stove (but we also don't hunt for it), but if we burned wood that had nails or something buried in it, would that kill the cat or is that unfounded cat negativity?
In theory, yes, that'd be bad.

In practice, if it's small enough that you didn't find it with your chainsaw or splitting tools, I wouldn't worry about it. (Watch, now that I've said that, I'm going to find a section of 3/4" galvanized pipe in my ashes.)

I really doubt that burning a couple rusty nails would kill a cat, though.

On cat replacement: Keep it in perspective. We're talking about a $200 consumeable part in a $2000 stove that is saving me at least $2500 a year in oil. If you plan to keep it 30 years and burn 9 months a year, you are planning to replace it an absolute minimum of 2 times due to old age, likely more. You would also expect a hardworking tube stove would to cost you some baffles and tubes during a 30 year run. Treat your cat right and then don't worry about it until its performance goes downhill.
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
22,152
central pa
That was about 9 months last year.
You really burnt 9 months last year in Long Island? I am pretty much the same climate and last year was extremely short I didn't heat 6 months much less 9.
 

jetsam

Minister of Fire
Dec 12, 2015
4,737
Long Island, NY
youtu.be
You really burnt 9 months last year in Long Island? I am pretty much the same climate and last year was extremely short I didn't heat 6 months much less 9.
Who knows, my memory is always iffy. Let's fact check...

2016 temperatures say I stopped burning in the fourth week of May... Let's skip to August... Wow, very hot end of August... But I would have started up in the second week of September.

So more like 8.5 months last year.

I burn so long not because it's freezing cold a lot, but because I can burn very, very low and I like it 70+ in the house. :)

(Today, I am burning because it is cold indeed on Long Island. -5 with windchill last night, same tonight.)

Having lived inland most of my life, I'd say that the island is similar to a similar latitude inland, but more moderate. Highs are lower, lows are higher. This is unusually cold even for the middle of winter here.
 

DuaeGuttae

Minister of Fire
Oct 26, 2016
658
Texas
I'll write more later with more detailed questions, but for now, Jetsam, would you be able to tell me how much of your suboptimal wood you've used in the winters you've had your Princess Insert if you try to keep track of those things?

The PI has no OAK, by the way. Negative pressure is one of our concerns, but we're not sure how much of a concern it is since we don't actually have problems with it. We just know it's there because an open window sucks in air. Hmmm.
 

Highbeam

Minister of Fire
Dec 28, 2006
17,659
Mt. Rainier Foothills, WA
Sounds like a great deal. My main question would be dealer support. It sounds like may be quite distant. What do you do if something is not right?
Ha! Dealer support? What's that? This is not a Cadillac from 1970. I have no need or want for dealer support for anything. Are people that helpless?
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
22,152
central pa
Ha! Dealer support? What's that? This is not a Cadillac from 1970. I have no need or want for dealer support for anything. Are people that helpless?
Yes many people are
 

DuaeGuttae

Minister of Fire
Oct 26, 2016
658
Texas
Ha! Dealer support? What's that? This is not a Cadillac from 1970. I have no need or want for dealer support for anything. Are people that helpless?
I will say that we haven't needed any dealer support with our current setup, but BK requires you to work through the dealer for any warranty issues, it seems. Buying at such a long distance would make that hard. One would hope it wouldn't be necessary, but it is something we're considering.


Highbeam, do you purchase your replacement cats and gaskets online? Have you used your dealer with those issues at all?
 

DuaeGuttae

Minister of Fire
Oct 26, 2016
658
Texas
I'm a huge proponent of BK products but if I were you i'd stick with your current insert. Yes I would insulate the liner, build a block off plate, look into insulating the fire box walls.
The main issue I see is the basement install with a known negative pressure problem. trying to run the BK low and slow might be a challenge and become frustrating. You say that the existing insert is to small for the existing house but if you do the block off plate you may see a 15% increase in additional heat coming into the living space.

We'd be glad to increase the efficiency of our current setup, even though we aren't really dissatisfied with it. We just know it's not as good as it could be. We have also become convinced that we want the insulated liner for safety reasons. The more I've read about clearance to combustibles (thanks, bholler), the more I like the security in case of a chimney fire.

I think our thoughts on changing don't have so much to do with total heat output as with leveling off the heat peaks and valleys. We really only load our insert full for overnight burns. Otherwise we'd overheat our basement which is where we spend a lot of time. The Princess Insert is rated for the size of our house (2,500 sq. feet) but seems to carry the possibility of burning at a more even low rate to make the basement. But then there is the whole negative pressure issue, which I'm not sure I fully understand. I just know it's there.
 

DuaeGuttae

Minister of Fire
Oct 26, 2016
658
Texas
Were it me I'd keep your current set up. Not that I don't think BK are a great stove (Love mine). But if your getting 10 hr burns and it's heating your home why change? With a basement install trying to heat your home I would suspect that you'll run a BK a bit higher and not have a considerable saving on wood. If you do go the BK route I'd stash your Lopi away for a season to make sure your happy. Stoves, especially BK, seem to have a pretty good resale so you might have nothing to lose trying it. If it doesn't perform as well just resale it.

Perhaps I should clarify that we don't burn for ten hours on every burn. We control the temperature of the downstairs (basement) by building small fires during the day, so we reload more often. When we want the maximum burn time we load up the whole firebox before bed, but it gets the temperature too warm for comfort if we were actually spending time down there. We were thinking that the ability to keep a more uniform temperature for a longer period of time might be desirable, and there would be less necessity to load the stove as frequently. I do enjoy reloading actually, but there are times in life when I don't want to throw on a few splits just to keep the coals going until I really want to reload, but I do it anyway because I don't like cold starts so much.

Also, shoulder season is a consideration. Our natural gas furnace isn't expensive, but it won't heat our basement sufficiently when our upstairs is warm enough (we have good solar heat gain upstairs). The kids clamor for the stove sometimes when we won't light it because it will get too warm (and of course that could happen even with a BK too), but we are wondering if the BK might not be better for our original purpose of having a space heater in the basement when it needs it. The basement is almost half our living space. It's where my kids play or do work and where my husband has his office.

If we were to go with the BK (and it's still a big question), we would definitely hold on to the Lopi until we knew which one worked better for us.

Maybe I could summarize this way. We're looking for a way to even out peaks and valleys in our heating during the winter and to heat our basement comfortably during shoulder season. We're thinking that we would have to push the BK during winter at time in the same way that we do our Lopi, but we would hope that more of the BTU's would go into our envelope rather than up the chimney or into the masonry (and either way we go, we do plan to do the upgrades to our setup that I mentioned at the very beginning. It's the necessity of having some professional help with that that makes us raise the question of an insert change at this time.)
 

DuaeGuttae

Minister of Fire
Oct 26, 2016
658
Texas
I know nothing about your stove, but the PI is amazing in this area. I burn 24/7 from whenever the house gets colder than 70 to whenever it stays above 70 with no heat. That was about 9 months last year. I burn though shoulder season when it's 60+. :)

We find that when it's cloudy and cool we need some additional heat in the basement, and that's one of the attractions of the BK low and slow if our setup would support it. (That's the question I have about the negative pressure issue.)


I would definitely be concerned about this because you are talking about switching to a stove that you want to move a much lower volume of air through 6 months a year. Outside Air kits can also be problematic in a basement install, and I don't know if the PI has an intake for an OAK. I would take a very close look at this question if I was in your shoes.



On cat replacement: Keep it in perspective. We're talking about a $200 consumeable part in a $2000 stove that is saving me at least $2500 a year in oil. If you plan to keep it 30 years and burn 9 months a year, you are planning to replace it an absolute minimum of 2 times due to old age, likely more. You would also expect a hardworking tube stove would to cost you some baffles and tubes during a 30 year run. Treat your cat right and then don't worry about it until its performance goes downhill.
I recognize that on things one uses long and hard there is necessary maintenance. That isn't what concerns me. It was just that I had the idea that if we burned yard trees we'd be murdering our cat frequently, and that's a different matter. I think I've seen over our years of wood processing that it isn't so likely as I had feared.

Thanks for taking the time to answer all my many questions. I'm grateful.
 

jetsam

Minister of Fire
Dec 12, 2015
4,737
Long Island, NY
youtu.be
I'll write more later with more detailed questions, but for now, Jetsam, would you be able to tell me how much of your suboptimal wood you've used in the winters you've had your Princess Insert if you try to keep track of those things?
Nope! I'm on my second year in a new house with a new princess insert, and the first year I had zero wood laid in, so I burned standing dead stuff straight out of the woods all year. Got a couple cords ahead doing that, and went into this burning season with about 9 cords of oak, maple, and pine CSS.

The problem is that I keep supplementing the CSS wood, which still needs a year or two to dry, with stuff from the woods this year, so I can't look at what I have left and gauge how much I used.

Ask me again in a couple years and I'll have proper numbers. :). At a (very innacurate) guess, I'll say 2.5-3 cords this year so far.

The PI has no OAK, by the way. Negative pressure is one of our concerns, but we're not sure how much of a concern it is since we don't actually have problems with it. We just know it's there because an open window sucks in air. Hmmm.
Ahhh, I didn't remember seeing an inlet, but I wasn't sure.

I would worry about that, but I suppose in shoulder season if you had problems, you could just crack a window in the stove room open a little bit. The
 
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Highbeam

Minister of Fire
Dec 28, 2006
17,659
Mt. Rainier Foothills, WA
I will say that we haven't needed any dealer support with our current setup, but BK requires you to work through the dealer for any warranty issues, it seems. Buying at such a long distance would make that hard. One would hope it wouldn't be necessary, but it is something we're considering.


Highbeam, do you purchase your replacement cats and gaskets online? Have you used your dealer with those issues at all?
I was forced to call and order a new door gasket through the dealer. After he added an enormous profit, the gasket was shipped directly from bk to my house. Another bitter dealer experience. New cat will be ordered direct from the manufacturer of the cat.
 
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aansorge

Minister of Fire
Aug 12, 2011
920
Southern Minnesota
You'd be spending a lot to gain a little. I've had a Lopi just like yours and now have a King (different house) and they both have plusses. The King has long burn times, the Lopi could go years without a sweep if the wood is dry. With a Blaze King you NEED to sweep once a year (minimum). I sweep myself so this is no big deal but it is a factor.

One thing that is true about the Blaze kings is that they really make burning wood year-round easy. You never feel as though you must get home to fill up the stove and the deep bellies mean that ash spill is a thing of the past. These two qualities really improved my wood-burning experience.
 

DuaeGuttae

Minister of Fire
Oct 26, 2016
658
Texas
You'd be spending a lot to gain a little. I've had a Lopi just like yours and now have a King (different house) and they both have plusses. The King has long burn times, the Lopi could go years without a sweep if the wood is dry. With a Blaze King you NEED to sweep once a year (minimum). I sweep myself so this is no big deal but it is a factor.

One thing that is true about the Blaze kings is that they really make burning wood year-round easy. You never feel as though you must get home to fill up the stove and the deep bellies mean that ash spill is a thing of the past. These two qualities really improved my wood-burning experience.
Thank you. It's good to hear from someone who has had both.

I think we wouldn't even be considering making the change if it weren't that we plan on hiring a sweep anyway to insulate our liner, and then we found this great deal on a Princess Insert which is about the only stove we'd consider changing to. (There's basically no markup on this stove any longer. The dealer just wants to get it out of the store. It's a 2011, I believe.) We do generally sweep ourselves which is why I was trying to find out if there's anything that makes that particularly challenging with the Princess. We love not having to disassemble anything from the Revere. (We hired a sweep after our first season of burning. He said that we could probably wait three seasons between cleanings, but that was before we converted to heating full-time. We sweep at least yearly.)

You can't really burn year-round in Minnesota, can you? Just the idea makes me wilt. Virginia is hot in late spring, all of summer, and early autumn. We go from stove use to air conditioning pretty quickly and vice versa.

Since we're looking at the Princess Insert, I don't think we'd have such a deep belly (still deeper than the Revere, though), and I think we'd still have to fill up the insert more than the freestander. I would hope it would be less than the Lopi, and I'm trying to get a better sense of that from owners. One of my big concerns is that with our Lopi (which is also a protruding insert like the Princess because we wanted it to be as much like a real stove as we could manage) we have to run the blowers to get heat moving to the upstairs of our house. I read that blowers drastically reduce burn time on the Princess Insert. I'd just hate to have worse burn times on the Princess than on my Lopi, but then I wonder if that is even possible given that it's a larger firebox.

One of the big things we're looking to gain is to burn less wood and still be able to heat the house. We're wondering if we're just sending too much heat up our flu at the beginning stages of our burn, and if the more even heating of a Blaze King wouldn't be an improvement. I've read lots of old threads, and it's the impression I've gotten, but it is a hard choice, which is part of why I'm here getting feedback and trying to make sure that if we do try to take advantage of this opportunity that we'd be doing it with our eyes wide open.
 

DuaeGuttae

Minister of Fire
Oct 26, 2016
658
Texas
Even with suboptimal wood, I can hit 24 hours with the fan off and the thermostat set low. (A 'burn' is over for me when the cat goes inactive.) 12 hours is the top end with the fan on low and the thermostat set high enough that the fan doesn't kill the cat. Of course, it all depends how much heat you are asking for; I get 24 hour burns only in shoulder season. Today, a weekend morning coming off a -5°F night, I did a 4 hour burn when I got up (and it is toasty warm, in here, might I add. :). )
.

I was thinking about this today and wondering about your 4 hour burn. How much wood was in the firebox? I'm assuming that it couldn't have been full, but maybe I'm wrong.

We couldn't manage a 4-hour burn with a full box on our 2.2 cubic foot non-cat without overfiring. Our stove likes to run hot, and we watch it carefully when loading full. I know the Blaze King's thermostat is supposed to prevent overfiring, but then I don't see how you could burn 2.5 cubic feet of wood in 4 hours. Will you clarify?

I'm also wondering about your fan use. I know you don't find the need to use them very much, and they lessen the burn time when you do use them. Our current insert sticks out from the hearth much like the Princess, and we find that we can warm the room it's in very well without the blowers, but with the blowers there's an incredible difference in the speed of the temperature change and how well the warm air moves into the rest of our house. We run the blowers a lot in cold weather and overnight.

I've read that one is supposed to coordinate the blower speed with the thermostat setting. Is that what you do? When you say that you're asking your stove to keep your house warm when no one is home for 12 or more hours a day, what does that mean? 70 degrees in the stove room and cooler everywhere else? We have five people in various locations in our house almost all day every day, so I'm very interested in details. I love details. Please, please give me more.

Thanks.
 

jetsam

Minister of Fire
Dec 12, 2015
4,737
Long Island, NY
youtu.be
I was thinking about this today and wondering about your 4 hour burn. How much wood was in the firebox? I'm assuming that it couldn't have been full, but maybe I'm wrong.

We couldn't manage a 4-hour burn with a full box on our 2.2 cubic foot non-cat without overfiring. Our stove likes to run hot, and we watch it carefully when loading full. I know the Blaze King's thermostat is supposed to prevent overfiring, but then I don't see how you could burn 2.5 cubic feet of wood in 4 hours. Will you clarify?
When it's cold (<30F), I usually run the stove on medium low with no fans when I go to work, and pack it full. I usually don't know exactly when I am coming home, and I know that the house will cool off a little on a cold day, but the stove will still be burning when I get back. If I am back after 11 or 14 hours, it's all the same. I could run it hotter and maintain the house temp better, but if I was running fans and higher thermostat settings, I'd be looking at low coals or maybe even lighting a fire when I got back.

When I get home I want to heat things up, so I toss a few splits on top of the coals and crank the thermostat and fans, which heats the house up rapidly; then it's time for another long overnight burn. (In shoulder season, it's just one 24 hour load a lot of the time.)

But yes, I think I could get through a full 2.5 CF of wood in 4 hours burning high with high fans. I guess I've never timed it, but that seems within reason. It would have to be exceptionally cold for that to happen, though. :)

I'm also wondering about your fan use. I know you don't find the need to use them very much, and they lessen the burn time when you do use them. Our current insert sticks out from the hearth much like the Princess, and we find that we can warm the room it's in very well without the blowers, but with the blowers there's an incredible difference in the speed of the temperature change and how well the warm air moves into the rest of our house. We run the blowers a lot in cold weather and overnight.

I've read that one is supposed to coordinate the blower speed with the thermostat setting. Is that what you do? When you say that you're asking your stove to keep your house warm when no one is home for 12 or more hours a day, what does that mean? 70 degrees in the stove room and cooler everywhere else? We have five people in various locations in our house almost all day every day, so I'm very interested in details. I love details. Please, please give me more.
It depends on the outside temperature. Most of the year, the PI is appropriately sized for my application, so I load it once or twice a day, set the thermostat, and don't worry about anything else. (If I had a King with a 5 cf firebox, I would use this exact plan all year regardless of weather.)

In freezing and colder weather, the PI is undersized to be a solo heater for the lengths of time I need it to, so I compromise. I run the stove room up to 75+, pack 'er full, and set the thermostat for a 14+ hour burn. On a sunny calm 32 degree day, I'll expect the stove room to be 70 when I come back; on a day like yesterday when it was exceptionally cold and windy, I'll expect a little less, and run a short hot load to warm things back up.

I only use the fan for catch-up work, never for long burns. (12 hours is about the longest burn you could expect with the fan on low, and shorter is likelier.)

One thing about BKs that doesn't get discussed a lot- it is frigging convenient to be able to do hot partial reloads whenever you feel like it without babysitting and worrying about an overfire. Stick some wood in there and set the thermostat and go do your thing. :) That one little thing has really helped the PI be my only heater, as opposed to its intended role of occasional backup heater. (
I grew up with open fireplaces and old pre-EPA stoves, and had no idea that 8+ hour burns were possible until I came to hearth.com to find out what stoves were like in this decade...).

I really don't measure temperatures outside of the stove room. I think it usually runs around 5 degrees cooler in the furthest upstairs room (our bedroom; I sometimes close the door to cool it down at night), maybe 15 cooler in the furthest downstairs room.

We really only use a few rooms in the house; I'd probably be using fans to push cold air around (and complaining about downstairs temperatures being hard to raise) if the whole house was occupied.