Stove manufacturer efficiency comparisons

Just a little data from that govt, report thanks Highbeam
Kuma sequoia 84% efficient $3500 requires 8 inch flue
Blazeking King 82% efficient 3250 requires 8 inch flue
Woodstock IS 82% efficient 2000 6 inch flue

prices are estimates for base models off Internet
Blaze king princess 80% efficient $2100 6 inch flue

Interesting all of above are all cat stoves... I only looked at Woodstoves not inserts

 

Woops, Blaze King king is 82% and has been for decades. Pricing is really hard to state since it varies so much on location. A Woodstock from VT delivered to WA adds several hundred and a BK on the east coast is also significantly more expensive than on the west.

 

Cat stoves make this easy. Burn time starts when cat meter says 500 and ends when it drops below 500. We have to keep this a generic stove specification and not a personal feeling of when the stove heats your personal house when it is some arbitrary temperature. Otherwise, in the summer, I could get a 3 month burn time!

 

fixed it .. thanks yeah those prices for BK are really from a VT dealer... the IS is on sale bare right now for 16?? is but was trying to be fair.. the factory is in New Hampshire now.. but your point is valid..

no Kuma dealer within 100 miles so that was starting at price trying to keep options down.. so starting points... but I love my ash pan!

 

Burn time is a stove performance specification. The performance specification is "maximum burn time" and can only occur at the minimum burn rate with the maximum load of fuel. It makes a lot of sense to begin the clock at ignition and end at some STT number like 200 degrees but with cat stoves we have a superior indicator with the cat temperature meter. When you're burning at the minimum burn rate it is safe to say that you are getting a cat only burn and when that cat goes inactive, your fuel supply is essentially gone so the burn is over.

Your lower burn times resulting from a higher burn rate in cold weather is of no value to anyone but you in your house. It is not a stove specific performance specification. In other words, when you increase burn rate for any reason you will not experience the maximum burn time. Yes, draft is stronger with colder weather but the effects on burn time are small on a cat stove and a cat stove with a thermostat will absorb this difference. Not sure about a hybrid with the fixed draft and secondary supply. Has anyone tried? If it's really cold out I crank up the stove, enjoy the heat, and endure the lower burn times.

When thinking about maximum burn time, think best case scenario. At all higher burn rates you will be depending on your stoves high efficiency to get the best bang for your buck.

Oh, even burning my low btu wood species I regularly exceed 24 hours of active cat time on one loading. Guys burning oak and other high density species are reporting well over 30 hours with the same stove. I just don't know many people with kings. The most valuable aspect of the BK brand to me is the very low minimum (clean, efficient, thermostatically regulated)burn rate and the resulting long burn times. If I needed high output all the time then I would have low burn times and might as well be burning a cheaper easier non-cat! That explains my shop stove choice, I run that thing balls out all the time. 3 hour reloads.

As BDF points out, I want my flue temps to remain above condensing to prevent accumulation of creosote. This higher burn rate also provides a healthy safety margin to avoid stalling my cat which can happen if you try to go too low with the burn rate.

I tried to monitor stove top temps. It doesn't work for me. See, the cat is about always cruising at 1200 so the temperature above the cat is always the same at say 600. When you increase the burn rate the cat temp stays the same but more of the stove gets to higher temperatures since there is more fire in the belly. I found it better to watch flue temps to assure efficiency and room temps for guidance on stove output settings. Bottom line is that with a thermostat, I don't need to pay much attention to the stove. I definitely monitor stove top temp on my non-cat, like to keep it at 750.

 

Yep, it would be great if everyone would standardize on something like that but 1) it ain't gonna' happen and 2) even with the same exact stove top temps, different stoves radiate different amounts of heat depending on size, window area, etc.., etc.

That is why I clearly stated what I consider a 'burn' and gave the reasons. Of course that is not useful to anyone else really unless I was to also test drive (test burn?) other stove types, which is not likely. Although truth be told, I would love another cubic foot of stove in the form on an Ideal Steel.... which is why I looked hard at the B.K. King and the Regency F5100, both are bigger than anything Woodstock makes by a fair margin.

Brian

 

I also looked hard at BK king and Regency 5100, ironic huh (for size alone) unfortunately economics came into play.. I had already installed 6 inch class a flue.. the Xtra grand for stove and 2 to replace flue put my payback period into unreasonable. I have oil hot water heat back up.. so I can leave for a few days and an extra 10 gallon of HHO a year doesn't cost that much

 

I'm trying to figure out how you can even run 5 cord through this stove in one season. The only way I can think of is that you effectively have a longer burning season. I was just talking about this with Hollywood the other day. I'm legitimately don't know how to run more than 3 cord through it. I'd end up shoveling hot coals out every day.

 

Great points.. I wonder how much of our personal experiences and where we live comes into play with our opinions.. I do not know your house but looked up average temps on western Washington.. that said Dec Jan Feb avg lows were 30ish highs 40 ish. in that environment I see why you are huge fan of your stove (please correct if wrong) and rightfully so Blaze King makes great stoves!

I am about 50 miles south of Montreal, my average low in January is 5 degrees average high is 15.. as I type this it's below 32 outside now 2 days before April the ground is snow covered and this is normal. I had a NC 13 type 2.2 cubic foot firebox before my IS, yes 3 hour reloads were common, in 14/15 I put 12 cord of sugar maple through that stove.. house was cool I did not sleep much.. getting ahead on firewood was impossible 3 years ahead would be 40 cord.. in new stove I am burning 5 cords or less house is warmer AND I get to sleep with my wife and not in stove room.. 3 years worth of wood out back now...

I love high efficient stoves! I am a firm believer in CAT stoves

 

It's our crazy life.. yes we are still burning now.. but not much loaded last night opened air at 8 am will have coals after dinner.. I am not sure I am running it right.. this year not burning any super hard woods ash elm popular.. common cold day. wife gets up 430 makes coffee.. opens cat up at 6 am puts in 2 or 3 splits of pine does not close cat this is to burn down coals.. I bring little one to school so about 8 am rake it out load it shut it down.. around 2pm I open air all the way... at 330pm i do a half load on hot coals get my little girl and work on homework in stove room.. load stove full at 8pm shut it down I go to work til 3am as of now used 4.25 cord still .25 cord on deck wondering if that's enough..

my house is weird, split level center stair way if stove room is 80 kitchen dining is 72.. bedrooms 65ish... basement thermostat 5 feet below and 40 feet from stove stays at 55 last few days were only days in march my STT dropped below 350.

my shoulder season is load at night leave it til 3 pm rake it 3 pieces of popular or pine then reload around 8 pm.. OK I got girls they like house warm..

 

What my area lack's in extreme low outdoor temperatures we make up for in length of burning season. It's warmed up to 42 right now. We have a 9 month burning season here from mid September to mid June, I'm not in Seattle but up in the foothills of the mountains far from the warming effects of the salt water. 4-5 cords per year.

I propose that once you get your normal size house properly insulated, a properly sized and constantly burning cat stove on low is plenty of heat for most folks. It's really the ideal situation since you then have the ability to crank it up for more heat but also because these cat stoves are most efficient at low burn rates.

 

Yeah, I am in that boat too but I would have used a 6" flue with a draft inducer for reloading and called it good. In the end, it was the designs of the different stoves that caused my choice: both the BK and the Regency had either no ash removal provisions or a knock- out plug and I much prefer a grated stove with ash pan. Two other points were the cost of a new combustor (I change them fairly often) and the ease of cleaning / replacing the combustor, and in all three areas the I.S. came out WAY ahead.

I hear you on the cost but I found a brand new but several year old BKK for sale at a very attractive price, and a brand new, shiny Regency with a hefty discount as well, both local. Still considerably more than the I.S. but not enough more to be a deal- killer.

Brian

 

Curious about this one...don't know what a combustor for an IS costs but not sure how the ease could be WAY ahead?

 

I haven't seen your local weather, but if you rock a 9 month burning season, so does BC, Alberta, Saskatchewan, Manitoba, and probably half of Ontario.

Heat degree days are a neat thing for comparison. How warm does it have to be for you not to make a fire?

 

IS combustor started at 125 now up to 175 iirc.. no tax in NH... as for easiness.. 2 minutes max .. lift lid, pull radiator.. pull cat no tools.. except gloves if stove is hot.. I vacuum every other week or so for fly ash.. less than 5 minutes.

 

I am somebody that heats entirely with wood. It's not about the outside temperature but about the inside temperature. I burn anytime the inside temperature is uncomfortable which usually means under 70 with no natural heating anticipated from the day's sun. I've often had fires with outdoor temps in the 60s. Mid 50s outside yesterday afternoon and I had a fire since it was only 70 inside and I expect outside temperatures to fall overnight. Mid 70s inside this morning.

Heat degree days and other such things mean very little to a person that heats 100% with wood. If it's cold inside, we burn.

 

There's a little cherry picking going on. The IS is a 3.2 (is it really?) CF stove and the BK princess is a real 2.85 CF stove. The princess cat is 186$ with no shipping or tax, same as the IS. It comes with a new gasket but if you want to remove the cat between replacements then you have to buy a new 6$ gasket each time. BDF is trying to compare the little IS with the King from BK at a real 4.3 CF with a significantly more expensive cat. Cat gaskets are the same 6$ if you are removing the thing and putting it back in.

 

Heat degree days are actually a very valid way to compare temperatures between different locations. Just because you don't believe them to mean anything, doesn't make them meaningless. It won't tell you how much wood you'll need to burn, or the difference between how well insulated (or not) your house is and could make a difference, or how solar gain will help (or not).

I think it's a lot more valid than "It's cold".

 

I find it fascinating that every single time I mention a Blaze King King, you 'correct' me by quoting some aspect of a Blaze King Princess. Please give me a link to the price of a Blaze King King (note the word King, not Princess) catalytic combustor, new, made of any material, from any legitimate source (i.e., not 'your cousin Vinny') that is anywhere near $186 dollars.

I wholeheartedly agree with you that there is a little bias here but it is not from me. As I have said in the past, more than once, I believe the Blaze King King (note: not the Princess) is a fine stove and I strongly considered buying one. That said, they do seem to have a tendency to crack at the four corners of the stove body, although I have no idea how many stoves have had that problem. But the BKK (the second K stands for King, not Princess) requires an 8" flue, has no grate to sift the ashes through and requires the stove be open and tools be used to R&R the combustor.

As far as size goes (Easy Boys!), you are quite correct in that the Blaze King King is considerably larger than the Woodstock Soapstone Ideal Steel. And I wanted the larger stove, which is why the three stoves on my short list were the Blaze King King (note the word King in there twice), the Regency F5100 (not some other, smaller stove) and the W.S. I.S.. For a variety of reasons, I chose the I.S. but not because the other stoves were 'bad', I just believe the I.S. was the better choice, at least for me.

As to any rational person reading this, I always suggest anyone / everyone perform his / her own research before buying any large ticket item such as a woodstove. I try to be as accurate as I can but no one should ever take my, or anyone else's statements as facts without back- checking with real data, such as that published by the manufacturer. Of course I cannot address the idea that one manufacturer uses "real" measurements while another uses fictitious measurements because that is rather conspiratorial and if we are going to go there, I think perhaps the designer of the Blaze King King (and by that I really mean Princess) shot Kennedy from the grassy knoll...... and

Brian (by which I mean Paul of course)

 

The combustor in an Ideal Steel is located above the firebox, directly under the top lid which has no fasteners; to see or vacuum the combustor, simply lift the stove top. The combustor in a Blaze King King is located inside the firebox, behind a flame shield which must be removed to access the combustor.

The combustor in an I.S. has a flange welded all the way around it and it simple sits in a hole. To remove it one merely needs to pick it up as there is nothing beyond gravity holding it in. There is no gasket on the combustor and the well it sits in is quite a bit larger so removal and reinstallation are effortless with nothing to be aligned, inserted (Boys!) or anything else.

The Blaze King King combustor is sealed by a wrap of fiber tape and is inserted into a somewhat tight fitting well to seal it. Nothing terribly pesky but it does take more time and care to get the combustor in place without tearing the tape, and a new piece of fiber tape has to be, or at least should be, used each time the combustor is R&R'd for cleaning.

Put this all together and it adds up to the fact that the combustor can be seen, cleaned (vacummed while still in the stove) or removed while the stove is still warm or even pretty hot, as long as the firebox is burned down to coals. That is not practical to do on any stove that has the combustor located inside the firebox IMO and IME.

I owned a stove that used a round combustor wrapped with fiber tape, located inside the firebox and I found it a PIA to clean and replace. I keep my combustor clean so I check it and vacuum it fairly often. Hence my use of the word "way" easier. If you only check a combustor every few years then of course it is not nearly as important.

A new combustor for an I.S. from Woodstock is $175. All of the combustors I priced two years ago for a Blaze King King were well over $300. I consider that a large difference in cost.

Brian