BK Princess in small home 720sq ft

[Kulshanburner]

Hey all. Looking to join the BK club. I was at the fireplace dealer the other day and saw a BK princess on clearance.

We currently run a small regency classic f1150 in the home. It is built in the 70s with vaulted ceilings and poly iso insulation above. House isn’t super sealed. 2x4 construction and fiberglass insulation in the walls.

Our unit is on second story above garage. It is small and our regency will often cook us out of the place except for in the colder days of December-February. Located in Western WA and get lots of wind at our place.

Anyways, I was looking at getting a 20 box BK. Because it’s smaller. But the 30 box princess on clearance may be too hard to pass up. Do you think it will cook us out of the house and be too big or no?

 

[bikedennis]

My house is 1100 sq ft. in Nor Cal. I have a Sirocco 30.2. Due to the thermostat and the ability to turn the stove down, I don't have issues with over heating. Low and slow.

 

[tabner]

i believe if you compare the BTU output on low with these stoves, the low output numbers are very similar between the 30 boxes and the 20 boxes. If you can get a princess on clearance, i say go for it.

 

[Ashful]

First, note that a Princes is not a BK30. The BK 30's include the Ashford, Chinook, and Sirocco. The Princess is an older design, not related at all to the 30's, other than being another thermostatic catalytic stove of similar size. Both have maximum burn times around 30 hours.

Second, I run one of my Ashford 30's in an addition that includes about 1300 sq.ft. of heated space, mostly as one large open kitchen/family room space of mixed 1890's and 1990's framed construction, with a lot of glass. We load that BK30 each night around dusk, and I have to watch the sun forecast for the next day before gauging how much to load, as it will easily cook us out if we get full sun on any day less than absolutely blistering cold.

In milder weather, you might manage it by just doing half loads each evening, and letting the thing wane or go out by noon the following day. In colder weather, you might load it up full and let it cruise on a setting that gets you 24 hour burns, or burn it on a higher setting overnight and then turn down before leaving the house in the morning. It's a lot of firepower for such a small space, but you can make it work.

The advantage of the BK20's would be that running half loads can be a little challenging. My 30's take a very long time to get up to light-off temperature on half loads, even with very dry wood. If I load less than half, they may never get there. Running a BK20 would completely eliminate this problem, by having the firebox fractionally "more filled".

This is advice from someone who has put more than 100 cords thru BK 30's, FWIW.

 

[Kulshanburner]

First, note that a Princes is not a BK30. The BK 30's include the Ashford, Chinook, and Sirocco. The Princess is an older design, not related at all to the 30's, other than being another thermostatic catalytic stove of similar size. Both have maximum burn times around 30 hours.

Second, I run one of my Ashford 30's in an addition that includes about 1300 sq.ft. of heated space, mostly as one large open kitchen/family room space of mixed 1890's and 1990's framed construction, with a lot of glass. We load that BK30 each night around dusk, and I have to watch the sun forecast for the next day before gauging how much to load, as it will easily cook us out if we get full sun on any day less than absolutely blistering cold.

In milder weather, you might manage it by just doing half loads each evening, and letting the thing wane or go out by noon the following day. In colder weather, you might load it up full and let it cruise on a setting that gets you 24 hour burns, or burn it on a higher setting overnight and then turn down before leaving the house in the morning. It's a lot of firepower for such a small space, but you can make it work.

The advantage of the BK20's would be that running half loads can be a little challenging. My 30's take a very long time to get up to light-off temperature on half loads, even with very dry wood. If I load less than half, they may never get there. Running a BK20 would completely eliminate this problem, by having the firebox fractionally "more filled".

This is advice from someone who has put more than 100 cords thru BK 30's, FWIW.

thanks for the advice on the half loads. I see you are in PA. I live in WA state and we have lots of softwoods here. I’m wondering if I load it up with Doug fir and hemlock in milder weather, this should create a shorter burn and maybe help with the not cooking us out?

Anybody with experience burning softwood in BKs? I’d like to do alder and maple when it is actually cold here (late Nov - February)

 

[Ashful]

Paging @Highbeam. He's in WA, and I think he may be putting almost as much wood through one BK as I'm putting through my two.

My underlying point was that, while these stoves can deliver constant output for up to 30 hours, very few people need constant heat for 30 hours. I have two in my house, and in the antique stone part of the house, it is ideal. The roughly 1-million pounds of stone just soak it up and radiate it back, like a giant capacitor or battery. But in the modern framed addition, we need much more heat at night than during the day, meaning either half loads overnight, or turning it up during the day and then down at night.

 

[Highbeam]

thanks for the advice on the half loads. I see you are in PA. I live in WA state and we have lots of softwoods here. I’m wondering if I load it up with Doug fir and hemlock in milder weather, this should create a shorter burn and maybe help with the not cooking us out?

Anybody with experience burning softwood in BKs? I’d like to do alder and maple when it is actually cold here (late Nov - February)

Loading full with a lower density wood will create a shorter burn than the same volume of a denser wood if you set the thermostat for the same heat output. It's just a math problem, wood has a pretty set number of BTUs per lb. Part loads with our lower density fuel seem to work great in my princess.

Fir, alder, hemlock, maple, and even our pine all have about the same density. The big difference you'll find with these fuels is that the evergreen species don't make much ash and ash helps to slow things down a little. Turns out, the evergreens are actually capable of making more heat if you really needed it since they don't ash up and they don't coal up much either.

Regardless, the BK can handle all of the PNW fuels just as well as any modern stove. Make sure they're dry.

I avoid cottonwood and red cedar. Both low density but the cedar causes lots of soot though it makes good smells and good kindling.

 

[Kulshanburner]

Thanks for the thoughts on wood species high beam. Curious what kind of burn times you get in your Princess with a partial/half load?

I think most of the time we would probably be doing partial loads except for maybe Dec-February when it can get wicked cold here at times. Past two winters we have had sunny days where highs were below 0 farenheit with windchill.

I avoid cottonwood, but love using cedar for kindling. Do you use cedar for kindling in your BK?

 

[NHWS]

Thanks for the thoughts on wood species high beam. Curious what kind of burn times you get in your Princess with a partial/half load?

It depends on the air setting, of course. Using around 1/2 load of very dry hemlock and/or alder on a very low air setting, I've still got enough coals for an easy hot reload after 12 to 14 hours.

 

[Tron]

The advantage of the BK20's would be that running half loads can be a little challenging. My 30's take a very long time to get up to light-off temperature on half loads, even with very dry wood. If I load less than half, they may never get there.

Is that really so with the Ashfords or with the BK30's as well?
I sometimes run less than half loads (3-4 splits) to combat the evening chill and because it doesn't have to run through the night. I light them up, run the stove at WOT with the bypass open for 15-20min, and by then the flue temperature is well above 1000F and the cat thermometer is about halfway to the active zone (we all know those are lagging quite a bit).
I then close the bypass and dial down the stove, and I'm convinced that I have good cat light-off since it immediately starts glowing orange.

So no, no real issues with burning small loads in a BK30.

 

[Highbeam]

Is that really so with the Ashfords or with the BK30's as well?
I sometimes run less than half loads (3-4 splits) to combat the evening chill and because it doesn't have to run through the night. I light them up, run the stove at WOT with the bypass open for 15-20min, and by then the flue temperature is well above 1000F and the cat thermometer is about halfway to the active zone (we all know those are lagging quite a bit).
I then close the bypass and dial down the stove, and I'm convinced that I have good cat light-off since it immediately starts glowing orange.

So no, no real issues with burning small loads in a BK30.

The ashford is a BK30.

I did a four split, plus kindling, half load in the princess today from a cold start and had no problem getting to active cat temperatures. Maybe our wood is drier, split smaller, and/or lower density than ashful's?

 

[BC_Josh]

Anyways, I was looking at getting a 20 box BK. Because it’s smaller. But the 30 box princess on clearance may be too hard to pass up. Do you think it will cook us out of the house and be too big or no?

Hi, I wish I could help you more, but I will tell you that I'm running a Sirocco 20 Blaze King in an 875 sq. ft home with older 2x4 construction and it is adequate. The thing is, a fireplace insert, isn't going to take up more space, most likely no matter if it's a 20 or a 30 model. I really don't know what the consequences of burning a lot of wood constantly with a half-filled firebox means. I would guess that it would be fine. I really appreciate how my BK does low and slow burns; it really does live up to it's claims and I love the stove.

I'm not into cold winter yet, up here about 450 miles east of you, in southern BC, but so far, it's been very mild in November and the smaller stove is fine. A bigger box would be convenient for not having to split pieces of wood up so small, though, and having a longer burn time. I'm just not sure it wouldn't run a bit too hot, and also take a long time to heat up the metal stove. I mean, Blaze King does specify the floor space that each model is appropriate for...... Hopefully someone will post who has experience with using a bigger stove than specified for.

Best of luck with whatever you decide.

 

[NHWS]

I did a four split, plus kindling, half load in the princess today from a cold start and had no problem getting to active cat temperatures. Maybe our wood is drier, split smaller, and/or lower density than ashful's?

Similar - I did a 3 split (hemlock) plus kindling load last night from a cold start. No problem getting to an active cat. On minimum air, the cat was still just barely active around 6 to 7 hours later.

 

[Ashful]

The ashford is a BK30.

I did a four split, plus kindling, half load in the princess today from a cold start and had no problem getting to active cat temperatures. Maybe our wood is drier, split smaller, and/or lower density than ashful's?

It's possible. My wood has been dried four summers under roof, you've seen the sheds, a roof and open on four sides. I'd say it's as dry as it's ever going to get, but I don't bother checking it with a MM anymore, after four years split and stacked under a roof. I'm mostly burning oak and hickory right now, in past years it was nearly all oak. Lots of 4-year ash on-deck, but I haven't gotten to those racks... yet. Oak is definitely slower to get going than just about anything else, it's dense and doesn't have the surface splintering you'll see on elm or hickory.

But I'm not the only one who has noticed this issue, you'll find other reports of the same on this forum, nor is it actually causing me any real problem. I know how to manage it and I'm getting reliable light-off, if only after maybe nearly double the time in bypass mode that's required with a full load. I was just mentioning it because it is more challenging to get a cat light-off with a partial load than a full load, no matter how you slice it.

One of our members (he can choose to "out" himself) reported adding extra layers of brick to the bottom of his stove to resolve this problem, raising the wood up closer to the combustor during the shoulder season. He removes the bricks when we get into the main burn season, where he's burning full loads. This would definitely help, but I'm not sure I'm willing to deal with the mess of that.

 

[Highbeam]

It's possible. My wood has been dried four summers under roof, you've seen the sheds, a roof and open on four sides. I'd say it's as dry as it's ever going to get, but I don't bother checking it with a MM anymore, after four years split and stacked under a roof. I'm mostly burning oak and hickory right now, in past years it was nearly all oak. Lots of 4-year ash on-deck, but I haven't gotten to those racks... yet. Oak is definitely slower to get going than just about anything else, it's dense and doesn't have the surface splintering you'll see on elm or hickory.

But I'm not the only one who has noticed this issue, you'll find other reports of the same on this forum, nor is it actually causing me any real problem. I know how to manage it and I'm getting reliable light-off, if only after maybe nearly double the time in bypass mode that's required with a full load. I was just mentioning it because it is more challenging to get a cat light-off with a partial load than a full load, no matter how you slice it.

One of our members (he can choose to "out" himself) reported adding extra layers of brick to the bottom of his stove to resolve this problem, raising the wood up closer to the combustor during the shoulder season. He removes the bricks when we get into the main burn season, where he's burning full loads. This would definitely help, but I'm not sure I'm willing to deal with the mess of that.

I’ve burned some dense wood, madrona, and it’s much slower to get going and never blows up into an inferno like the low density woods. Maybe that’s why you aren’t able to get good performance with half loads.

Top covered wood is wet wood in my area. Rain blows sideways. It’s not just being under a roof or cover but being inside a building that really made a difference for me.

Adding extra brick? That sounds weird. There’s already two layers on the bottom of a princess.

 

[Ashful]

That would make sense. But just to be clear, I never said I wasn't able to get good performance, just that it's going to be more challenging for some folks. As long as I load 4 splits or more, I can always get light-off, but it does take noticeably longer than a full load to get there.

I wasn't elaborating, but since there's interest, I will:

1. On the stove with the short chimney, I have no key damper. On this stove, start-up is a little longer with a short load, but the chimney gets hot and starts pulling hard, and so I can close the bypass when the chimney (single wall) reaches 300F external. Cat is way down in inactive still, so I'm essentially thermal-shocking it up to light-off, if I want to speed the process. I don't like to do this, so I'll usually let it run a little long, until chimney surface is at 500F (~1000F internal). This is similar to what Tron is seeing.

2. On the stove with the tall chimney, I usually dial the key damper down as things warm up, to keep draft right around 0.05"WC. This has the effect of getting the cat to active (500F) at the same time the flue probe reaches 500F, a real gentle warm up. However, this really slows down the warm-up phase with short loads.

3. I can leave the key damper more open on the stove with the tall chimney, during the warm-up phase, and it will indeed get there quicker. But again, then I'm either overheating the flue or thermal-shocking the cat up to light-off. I don't like doing either.

I've put about 80 cords thru this pair of BK30's so far, and there's not much about them that surprises me anymore. I'd be real surprised if there's many people on this forum more comfortable with the behavior of one stove model than I am with these stoves at this point, not because I'm a genius, but just out of sheer volume and repetition.

 

[Poindexter]

I ran a BK30 for 9 years, just moved this summer. I was using it for supplemental heat in 1200sqft with 2x6 construction, triple pane windows throughout and very good air sealing.

I did run half(ish) loads at the extreme ends of the burn season, usually in the evening when I got home from work to take the chill off the place while we were home and awake in the evening. You should be able to do this in a Princess or a King just fine too.

The main thing to be aware of here is the baking out of the remaining moisture in the fuel after the combustor is active and engaged. Join me at the hearth at the moment we flip over the lever and engage the combustor. Boom. We are now up on the cat. It is 600 degrees F inside the firebox, maybe even a little higher in some areas. The splits of cordwood are not necessarily heated up to even 450 dF all the way through, but all the water molecules in all the splits are feeling intense motivation to turn from water to steam.

While you are baking out the remaining moisture in your fuel, it is going to take some energy, some BTUs, some calories, some Joules, whatever, some effort to carry that extra water up the chimney and out over the back yard.

On my install in my microclimate I found the bakedown time on 20% fuel was about 28 minutes on high. The manual(s) of all the BK stoves I have read specify (ass/u/me-ing 20% MC fuel) 30 minutes on high throttle before starting to turn down the new fuel load towards desired cruise setting.

I ran spruce only at 12-16%MC for my last 6 years with that stove. Spruce is a beautiful thing in a BK stove, and mine had no trouble with Doug Fir offcuts from my woodworking hobby. I don't suggest buying 4x4 and 4x6 from the home store to load up your stove, that would be very expensive; but I would buy DF cordwood by the 18 wheeler load for my BK if the price was right.

When I hit my 14% MC target for spruce again this year, I could plan on turning the stove down from full throttle in sort of 18-22ish minutes.

The thing is you got to keep an eye on your stack. If your wood fuel is at or under 20% MC _and_ you are seeing wet greasy black goop inside your chimney you might (among other problems) be turning the throttle down too soon after lighting off the cat. You want to see dry fluffy grey brown stuff in your stack. It is going to have a few flecks of rock hard shiny black no matter what, but less of those is better.

For half loads I settled on building a log cabin of splits on the floor of the stove, kindling inside the cabin, light it off and just leave the throttle on wide open until it burns out. Tomorrow, rake the unburnt charcoal into the floor area of the new/next cabin, repeat.

I don't really have a good bead on western WA, 2x4 construction and unspecified air sealing. A Princess, in general, sounds like a lot of stove for 720 sqft. If you are planning to move into or build or buy a bigger place in the next 5 years or so it is definitely a stove that could move with you to a bigger place that scores at least 3 stars on the energy scale in your climate.

 

[Ashful]

28 minutes, Poindexter? Not 27 or 29? How are you gauging exactly how many minutes are required? Is it by plume alone?

As noted, I'm turning down when OEM cat probe thermometer reaches 12 o'clock, which is usually around 10 minutes after closing the bypass. I have never had issues with either combustor falling out of active from there, even with setting to a 24-hour burn time. But I'm also not dealing with the Fairbanks smoke police, or neighbors who might report me if they see a little steam escaping my chimney.

 

[Poindexter]

28 minutes, Poindexter? Not 27 or 29? How are you gauging exactly how many minutes are required? Is it by plume alone?

Yeah, I didn't like thermal shocking the cat either. It is not good for combustor life I think.

I really was not looking at my plume much in cold weather. Running around the house in shorts and a Tshirt and needing to run outdoors with flip-flops or other slip on shoes at -20dF to look at the plume is no bueno. I was looking at the crud I swept out of my stack real hard, and also just getting to know the stove.

Think of the car engine you did the most work on. Even if you left the cylinder heads bolted onto the long block you could replace the intake manifold, do a crap ton of work on the carburetor and maybe even do some minor porting on the exhaust ports where they meet the exhaust manifold. You're going to be invested in that motor. When you drop 4-5K $ on a BK stove, you should logically be invested in that motor too.

How does it run different in the rain? How does it run different when a low pressure front crosses the roofline of your house? What happens to your stove when the wind shifts from coming out of the NW to coming out of the SW?

The idea that a wood stove is a predictable appliance like an electric cook stove is not a thing. I have spent about 10 of my 27 year career dropping manometry probes with a bunch of pressure sensors on them into the esophagi of human patients. Let us imagine a human esophagus with a score of 0-1 is normal, while a manometric score of 1-2 suggests the patient will benefit from surgical intervention. Wood stove chimneys are expected to function correctly with manometric scores between roughly 0-20. On modern stoves with every thing else done correctly, some installs need a damper on them to run properly.

I am not sure what instrumentation might be required to get to know a stove. We as a species have been staring at fires for at least 10, 000 years. Is the stove going "huffa huffa huffa" or is it running smoothly? How big a chunk of charcoal do you find in the ash bed at the next reload? I think the best way to get to know a stove is to get it running and settle into a nearby comfortable chair, grab a good book and apply the tincture of time.

In my experience, when the moisture is burnt out of a fresh load of fuel the stove just settles down. Sort of like a small block chevy on the highway, somewhere up around 8k miles the whole motor just relaxes and runs smoother for the rest of its service life. Similar with draft horses, but it is more of a meal to meal time frame with horses.

You could do a hot reload and assume one of the yoga positions on the floor in front of your stove. Just repeat the mantra "alien technology" over and over until all of your chakras are in alignment with the burn.

 

[Poindexter]

. But I'm also not dealing with the Fairbanks smoke police, or neighbors who might report me if they see a little steam escaping my chimney.

Yep. Got a post card in the mail just today. It isn't my lungs the alphabet soup of government agencies care about, but at least they are being honest.

 

[Poindexter]

There is a formatting error above. It was I who said "Yeah, I don't like thermo shocking the cat either" but somehow that line is attributed incorrectly to Ashful when it is actually me.

 

[Poindexter]

As noted, I'm turning down when OEM cat probe thermometer reaches 12 o'clock, which is usually around 10 minutes after closing the bypass. I have never had issues with either combustor falling out of active from there, even with setting to a 24-hour burn time.

For you and I it is apples and oranges. We have the same stoves, but you are at least 30 degrees of latitude south from me. I am running softwood, you are running hardwood.

It is great we are both happy with the unit.

But even without the smoke police complication it is reasonable to expect we are going to operate the stove two different ways, both of us in search of doing the least amount of work for the highest possible number of BTUs in our respective envelopes.

You and I are probably among the 5-10 users here with the consistently driest wood. I mean really. Spruce at 14% MC year after year? Oak split and stacked four years ago? There are to be sure several others in the very dry wood club with us, but nobody in this club is having trouble with a BK stove. Highbeam, begreen, diabel, woodsplitter67 just off the top of my head.

No matter where you live, and no matter what species you got for fuel, if you are feeding a BK stove cordwood in the 13-18% MC range you will probably be ecstatic with the stove's performance.

 

[begreen]

There is a formatting error above. It was I who said "Yeah, I don't like thermo shocking the cat either" but somehow that line is attributed incorrectly to Ashful when it is actually me.

It happens when threads get numerous and deep. I've been called bholler more than once and likely he too.

but nobody in this club is having trouble with a BK stove. Highbeam, begreen, diabel, woodsplitter67 just off the top of my head.

I'm burning doug fir in a PE stove. No problems though. Our wood is pretty consistent at around 17% MC.
It's been a mild fall so the heat pump handles the shoulder season load. With daytime temps still in the low 50s and nighttime temps in the mid-40s, we've only burned on a few mornings this season so far.

 

[Ashful]

I've been called bholler more than once and likely he too.

So, which is the insult, and which is the compliment? Asking for a friend...

 

[NHWS]

So, which is the insult, and which is the compliment? Asking for a friend...

Maybe it isn't a dichotomy...