"max burn time" not even close in real life?????

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
Status
Not open for further replies.

rtv900

New Member
Nov 30, 2015
16
pennsylvania
I bought a Quadrafire Explorer III, and in the manual it lists a max burn time of something like 12-15 hours. I'm assuming that mean how long you can keep the stove burning with one 'load' of wood before refueling correct?
Well, my question is, do I need to be doing something specific to attain that? Because if I load it up once the stove is good and established with seasoned oak, as much as fits, I really only get around 4-5 hours with the damper all the way at it's minimum.
I'm trying to find a way to have the stove still going a little in the morning so I don't have to restart it from scratch.
Are these burn times realistic that the manufacturer states or is it bologna? Or am I missing something?
 
The numbers are inflated, I think they count if a single ember is still glowing. We usually use the firebox size to gauge how long it will actually heat. With a 3 cu ft firebox you should be getting 8 hours easily with actual dry oak. Maybe you are letting it burn to hot for too long eating up your fuel. What is your routine to getting the stove dampered down?
 
well, I don't have much of a routine yet as I just got the stove and have run it maybe 5 times. I'm not new to wood stoves, but my last one in my previous house was a home depot wood stove that I paid $350 for, so you can imagine the quality level. The draft control's range was basically wide open, or almost wide open, so there was no controlling the fire at all on that piece of junk.
On this one the draft control is on a whole different level and I can see/hear the difference immediately.
But what I try to do is:
load a bunch of new wood in, keep the draft at least half way up to let it get up to temp and start burning nicely, and then I put it all the way down, or maybe 10% up from the minimum travel.
 
  • Like
Reactions: rdust
Some of it may be marketing BS . . . the true issue is that many of us look at the glossy brochures and pretty pics and descriptions on line and see that Stove A has a "burn time" of X hours . . . but very few of us ever stop to ask the salesman or company what their definition of "burn time" is . . . heck, even here we've had discussions about what that definition is: a) the time from when the match is lit to when the stove is at the ambient temp of the room, b) the time from when the match is lit until there are no glowing coals, c) the time from when the stove is producing a measurable amount of heat at __ degrees F to the time when that temp falls below ___ degrees F? The thing is . . . there really is no set answer and certainly no one answer that all of the stove manufacturers agree to follow.

Then . . . add in the fact that even if Hearth.com member Joe Blow and I agree to the same definition and have the same stove, our results may vary . . . depending on the wood (species, how well seasoned it is, etc.) we put in the stove, the draft (i.e. does Joe Blow have a flue damper he can use or perhaps he has a very tall chimney that will eat up the wood quicker, etc.), how full we fill the firebox (i.e. I cut my wood mostly to 18 inches, but maybe JoeBlow is able to get another 5 or so inches of wood on each split into the firebox or conversely maybe his supplier only sells 16 inch splits), how we run the stove (i.e. when does Joe Blow reload, maybe Joe Blow turns down the air more than me or does so sooner in the burn, etc.) . . . and so results can vary.
 
I bought a Quadrafire Explorer III, and in the manual it lists a max burn time of something like 12-15 hours. I'm assuming that mean how long you can keep the stove burning with one 'load' of wood before refueling correct?
Well, my question is, do I need to be doing something specific to attain that? Because if I load it up once the stove is good and established with seasoned oak, as much as fits, I really only get around 4-5 hours with the damper all the way at it's minimum.
I'm trying to find a way to have the stove still going a little in the morning so I don't have to restart it from scratch.
Are these burn times realistic that the manufacturer states or is it bologna? Or am I missing something?

Have you measured the moisture content of the oak? If so, what % moisture was measured on a freshly split face? If not, how was it seasoned, and for how long?
 
Welcome to the forums. It seems "burn time" is a pretty subjective term, but one way to tell if your burn times are excessively short is to keep track of flue temps. If the flue temps are running high, then it could mean the system has excessive draft, or the stove is getting too much are (whether by controlled means or via a leak).

As the fire burns a bit faster due to this increased air flow, you lose some heat up the flue and get shorter burn cycles. And paradoxically, even though the air makes the fire burn hotter, you get less useful heat in the living space since you are losing it out the stack.

But assuming good dry wood and proper draft levels, it would be very unsusual to get 12 hours of truly useful heat fron one load of hardwood out of a stove like yours. Yes, the stove may be warm and you may have coals to rebuild a fire, but the stove will NOT be heating the house at that point.

The stoves that give the longest burns are catalytic, because the heat output during the peak of the burn cycle can be reduced even while keeping a clean burn, stretching out the length of the burn cycle. Your stove will give a higher output in the middle of the burn, whether you like it or not, because of the uncontrolled secondary air that burn tube technology requires.

Let us know what your stove top and/or flue temps are throughout your typical burn cycles are and we can give you a better idea of how its performance sounds. Are you still getting a pile of hot coals in the morning, or a dead cold stove? A full load of 2-3 yr-old oak overnight should yield coals, but as I said, not a ton of heat by morning.
 
  • Like
Reactions: Highbeam
You maybe able to improve your wood cycle times if you load on just a small amount of hot coals so you can get a full load of splits in the stove. Try and do restarts on a small amount hot coals using the additional help of kindling and a fire starter like a supercedar or another type of good firestarter. The kindling and firestarter on some hot coals will get the heat built up faster in the stove and let you start turning down your input air in small increments and getting this turn down completed quicker. As the small kindling on top of the big splits will burn with the door shuut and the input air shut down in faster increments. Increments of 1/4 ways each time should work. As each time you close that input air and the fire is still burning the heat builds faster in the stove and the heat isnt getting flush up the flue as much but more of it is staying in the firebox for a faster start up. Plus good dry wood makes these start up faster so you can get the heat built up in the fire box and the input air shut down to its all night burn setting quicker. If you let the stove get too hot and the heat built up too much before shutting the air back down the wood will burn much fast and limit the burn cycle time. As the cycle time includes the coal stage as it was once said half your heat in a load in during the coal stage and not much flame if any at all .

Looks like the stove takes 22" splits so if your not using the full length you wont get the full capacity of the stove.
 
You maybe able to improve your wood cycle times if you load on just a small amount of hot coals so you can get a full load of splits in the stove. Try and do restarts on a small amount hot coals using the additional help of kindling and a fire starter like a supercedar or another type of good firestarter. The kindling and firestarter on some hot coals will get the heat built up faster in the stove and let you start turning down your input air in small increments and getting this turn down completed quicker. As the small kindling on top of the big splits will burn with the door shuut and the input air shut down in faster increments. Increments of 1/4 ways each time should work. As each time you close that input air and the fire is still burning the heat builds faster in the stove and the heat isnt getting flush up the flue as much but more of it is staying in the firebox for a faster start up. Plus good dry wood makes these start up faster so you can get the heat built up in the fire box and the input air shut down to its all night burn setting quicker. If you let the stove get too hot and the heat built up too much before shutting the air back down the wood will burn much fast and limit the burn cycle time. As the cycle time includes the coal stage as it was once said half your heat in a load in during the coal stage and not much flame if any at all .

Looks like the stove takes 22" splits so if your not using the full length you wont get the full capacity of the stove.
 
Everything said above and.....a long time ago I stopped thinking about what it was supposed to be and pay attention to what it is. You have to get a good bed of coals going, it is instrumental in getting a hot burn. You have to get the flue temp up and the stove temp up to keep a good burn going once you go into secondary mode. You need to step down a few times from high hot to low intake with secondaries burning to get the whole package just right; and doing all that your burn time will be what it is. Of course you can try for "the longest burn" but that is not really the point. The point is to keep the burn cycle high enough, long enough to heat your house to an acceptable level, then refresh as best you can before bedtime: and that's what you get. After that its going to burn till it doesn't then cool down; we've been burning all our lives, two generations + and we are use to cool mornings around the place.
 
It always helps if your space retains some heat from the hot part of the burn cycle. On milder winter days im able to load only once a day around 9 or 10 PM ,burn all night and as the sun comes up and helps cut down the heat loss, i dont have to fire up again until 9 or 10. Those trying to satisfy a huge heat load with a not so huge stove will need to run it to the boards all day and night.
 
Thanks for all the replies everyone, that was a help.
As for my wood, maybe I shouldn't have said 'seasoned' as I know I'm stretching it. The thing is, I just moved, and the property I moved to had a bunch of downed trees from a storm the neighbors say was 7 or 8 years ago. I cut all that up into sections and stacked it the summer of 2014 (we built a house so I owned the land a year before construction started, permits), but I just split it at the end of this past summer. I know I know, I was pushing it but I couldn't resist burning wood this winter and I convinced myself that since the wood was very old, and at least sectioned up and stacked 1.5 years ago that it was good enough.
So bottom line, I know ideally it should be split and stacked for at least that long, and I am splitting well ahead already so that next winter I really have good seasoned wood, but that may be part of my issue.
I do think it is at least acceptable because it seems to burn well, starting it with oak kindling takes much longer than if I use poplar kindling. That stuff is great for starting. And beech is the only other type of wood in the mix.
 
It's bologna. Few manufacturers tell the truth on burn time. Some are really bad. You won't get 12 hours out of any non-cat stove, they just aren't built for long burn times they are built to burn cleanly at high output which they do very well.

Another common place that they lie is with firebox size. You may think you have 3 CF but go and measure it, even be conservative, and you almost certainly don't have 3cf.
 
I agree in part, specs are exaggerated by some manufacturers. Others are more accurate. It's safest to be skeptical and measure. I often go by firebrick layout and assume an 11" or 12" height for rough figuring. What I disagree on are burntimes. 8 hrs is typical for our 3 cu ft stove burning softwood, but when burning good hardwood like madrona or locust 10-12hr burn times are more typical. This year however I am working through a cord of super dry doug fir and it is burning up much faster than I am used to. Go figure. There are lots of variables in wood burning.
 
I'm burning well Seasoned fir here and on my overnight burn I'm able to say most of the time on a 9hr overnight 'burn' I'm able to re ignite off the coals. Some mornings I need to put kindling on to re-ignite and some mornings I can get by with smaller splits. This is my first month with this stove but I've burned wood my whole life. So I've been very impressed with the overnight heating capacity of this compared to the fire breathing wood sucking old uncertified stove it replaced.

I've been fanatical about this new stove at home. My family thinks I'm going nuts I think. Lol.

On topic though. I have some hardwoods curing split and tarped but I'm thinking I won't really try that wood out until next year. I burned a handful of splits and it's still got some moisture. I would expect on a decent maple or oak that I should be able to draw some better overnight burns than with fir.

8-9hr overnight time I guess.
 
Not mentioned, but first I would investigate potential air leaks - specifically the ash chute. Second I would reread the instructions for use and make sure that you are using the air controls properly. Thirdly, I would look for any other sources for air leaks, ie door(s) both front and top. Air leaks will decrease burn times.
 
For reference, the above two posters (BeGreen and Squisher) have the same stove but with different outer decoration.
 
It's bologna. Few manufacturers tell the truth on burn time. Some are really bad. You won't get 12 hours out of any non-cat stove, they just aren't built for long burn times they are built to burn cleanly at high output which they do very well.
I get 12 hours out of my Harman non-cat but then again its burn time rating is 17 hours, granted i still have burning coals at 17 hours but a stovetop temp in the 200s ,So yes i think its very possible to get 12 hours from some non-cat stoves. I cant get near those burn times with my englander 30, which is also rated 3CU Ft., but one factor is it seems i can get more wood in the harman as its a top loader.
 
Everything said above and.....a long time ago I stopped thinking about what it was supposed to be and pay attention to what it is. You have to get a good bed of coals going, it is instrumental in getting a hot burn. You have to get the flue temp up and the stove temp up to keep a good burn going once you go into secondary mode. You need to step down a few times from high hot to low intake with secondaries burning to get the whole package just right; and doing all that your burn time will be what it is. Of course you can try for "the longest burn" but that is not really the point. The point is to keep the burn cycle high enough, long enough to heat your house to an acceptable level, then refresh as best you can before bedtime: and that's what you get. After that its going to burn till it doesn't then cool down; we've been burning all our lives, two generations + and we are use to cool mornings around the place.
Swestall, that's a very good description of the process. I think the process is often confused by the advice to run a stove in "burn cycles," and not to restoke until the coals are reduced to the minimum necessary to refire. That process has negatives. First, the room temperature yo-yos. Secondly, it is more difficult to refire and avoid smoldering. Thirdly, it requires more operator time, waiting for the refire to reach the stage at which the air supply damper can be shut to minimum. If you can't wait around to restrict air supply, the fire consumes the fuel quickly, and then you have to start over. It is best to forget burn cycles and to build up a deep bed of red live coals by adding wood atop the coals as soon as space becomes available in the firebox, letting the coals burn low only overnight to allow for their removal from the front of the firebox, so coals can be raked from the rear to make space for new wood. That's one person's experience with a Mansfield. It is somewhat like I have always managed my 25 year old Resolute Acclaim. Building and maintaining a deep bed of coals is the secret.
 
  • Like
Reactions: realstihl
Swestall, that's a very good description of the process. I think the process is often confused by the advice to run a stove in "burn cycles," and not to restoke until the coals are reduced to the minimum necessary to refire. That process has negatives. First, the room temperature yo-yos. Secondly, it is more difficult to refire and avoid smoldering. Thirdly, it requires more operator time, waiting for the refire to reach the stage at which the air supply damper can be shut to minimum. If you can't wait around to restrict air supply, the fire consumes the fuel quickly, and then you have to start over. It is best to forget burn cycles and to build up a deep bed of red live coals by adding wood atop the coals as soon as space becomes available in the firebox, letting the coals burn low only overnight to allow for their removal from the front of the firebox, so coals can be raked from the rear to make space for new wood. That's one person's experience with a Mansfield. It is somewhat like I have always managed my 25 year old Resolute Acclaim. Building and maintaining a deep bed of coals is the secret.
I think it also depends on the firebox size and cycles. The big coal bed is nice if there's room. I also like the shorter cycles because it's easier to keep things going. You really summed it up nicely.
 
Burntime, The important thing is you found a system that works for you. I would say your house and stove setup lets you do that. If a person has a well insulated house it will hold heat longer and the big load of coals will put off enough heat to maintain a well insulated house. If a person needs more heat they will have to do the cycle so when they go to bed they have a good load of un burnt BTU's to burn thru the night. The coldest part of the night is right before daylight and its nice if the stove is still putting off some decent heat at that time. Cat stoves with longer cycle times is good for that.
The main purpose to let the coals burn down and its not that you have to burn down completely but I would say a inch or two of hot coals, this should restart a fire pretty good. If your wood is seasoned and less than 20% recommended moisture content then things should take off in 20-25 minutes and get the stove turned back down.
 
The numbers are inflated, I think they count if a single ember is still glowing. We usually use the firebox size to gauge how long it will actually heat. With a 3 cu ft firebox you should be getting 8 hours easily with actual dry oak. Maybe you are letting it burn to hot for too long eating up your fuel. What is your routine to getting the stove dampered down?
We see that with our stove, that has an 8 hour burn time, we get 3-4 hours of legitimate heating and then a re-startable ember pile inside the 8 hour window.
 
A
Everything said above and.....a long time ago I stopped thinking about what it was supposed to be and pay attention to what it is. You have to get a good bed of coals going, it is instrumental in getting a hot burn. You have to get the flue temp up and the stove temp up to keep a good burn going once you go into secondary mode. You need to step down a few times from high hot to low intake with secondaries burning to get the whole package just right; and doing all that your burn time will be what it is. Of course you can try for "the longest burn" but that is not really the point. The point is to keep the burn cycle high enough, long enough to heat your house to an acceptable level, then refresh as best you can before bedtime: and that's what you get. After that its going to burn till it doesn't then cool down; we've been burning all our lives, two generations + and we are use to cool mornings around the place.
Amen! Wood makes heat. It's not a perfect science. Some is higher in moisture, some burns faster. Burn what you have, safely, and enjoy the heat it makes. If you become obsessed with perfection you will certainly always be disappointed in the world of wood burning.
 
The lesson here is dont undersize the stove. Size matters. A large stove set on its lowest setting will certainly burn longer than small stove on any setting and deliver more heat. And who wants to be stoking the thing with wood 4 or 5 times a day. I have a small 2 Cu ft stove in a 600 Sq Ft Apt. and i love it, but it would never work in a larger space. Id never put anything less than a 3 Cu Ft stove in a 1200 SQ ft or larger Home.
 
Depends on the climate and the house. Our next door neighbor has the 2 cu ft Spectrum in a 1600 sq ft old farmhouse. They love the stove. The only complaint I've heard from him is that it's too much until it gets below 40F. One Christmas they had their older in-laws visiting and they like it warm. So he stoked the stove. It was in the twenties and he said it was like an oven in their living room. Father-in-law was sitting right next to the stove in a sweater.
 
Status
Not open for further replies.