Advertised max burn times? Likelihood of achieving it?

  • 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.
M

MnDave

Guest
One of the reasons I replaced my Kent Tile Fire with a Quadra Fire 5700 is the advertised "Max Burn Time" of 15-21 hrs. With the Tile Fire I may have gotten 6 hrs max on my best "not-so-great" wood.

I thought that if I can get 10 hrs between loads, that would be plenty because I go to bed around 10 and get up around 8 on weekends.

Well, I am able to get 6 hrs consistently, 8 hrs occassionally, and IMO I might get 10 hrs when I have better wood and it is cut to the 22" ideal length for this stove. I am sure glad that I opted for the bigger 3.0 cubic foot stove even though their literature suggests I could have bought the next model smaller.

I start with the house at 68-70. It is 10 PM. I load the stove full. The outside temps are dropping into the low teens here and windy.

By 4-5 AM the bedroom is getting noticeable cooler, say 67. By 5-6 AM it is say 65. Argh... go rebuild the fire or my wife is going to turn on the furnace when she gets up.

The stovepipe temp is 100-150F. If I used mainly hardwood I have plenty to start another fire with. If I used 1/2 softwood, I have to essentially start from scratch with kindling and small pieces.

I realize that outside temperature is a huge factor. When it was 25-35F outside, I was not having any issues mainly because the temp in the house would rarely drop below 67. Those days are gone and it will get much colder very soon.

I have better wood coming in 2015 but I still can't imagine getting the lower advertised time of 15 hrs.

I can't help but call BS on the advertised 21 hrs (not 20 mind you).

Anyone else feel this way about their stove as far as advertised max burn time?

MnDave
 
Depends on the definition of "burn time" . . . if a manufacturer defines this as the time from when you light the kindling to the time when there are no glowing embers or coals . . . sure . . . burn time may go that long with a nice, full load of qualitty BTU wood.

For those of us living in the real world . . . "burn time" is typically the time from when we're getting usable heat to the point where you have enough coals with enough heat to allow an easy re-light.
 
Woodstock errs on the side of conservatism with their published burn times...a nice policy. Same with square footage heated. No surprises here but good ones.
 
  • Like
Reactions: charly
I got what was promised by the manufacturer with the BK princess and even my previous Hearthstone heritage. They both advertise what I actually experienced. Of course, it is always assumed that the brochure will refer to the time between light up and when you can reload without matches. Anything else is silly coming from the manufacturer.

If you ever want to know the real truth about burn times you need to get it from the horse's mouth which is here at Hearth.com. Now you will be the data point for folks looking at the Quad 5700.
 
Yeah. With no standard as to what burn times mean you can really just throw the manufacturers spec on that out the window. Most overstate it some and some overstate it a lot. Regardless of what they claim, I would think you should easily be able to get 10 hours with a 3 cft stove! Of course, depending on your heat needs that is no guarantee you will get enough heat over those 10 hours.

Better wood will dinfitely make a nice difference.
 
Depends on the definition of "burn time" . . . if a manufacturer defines this as the time from when you light the kindling to the time when there are no glowing embers or coals . . . sure . . . burn time may go that long with a nice, full load of qualitty BTU wood.

For those of us living in the real world . . . "burn time" is typically the time from when we're getting usable heat to the point where you have enough coals with enough heat to allow an easy re-light.

Well put Jake. I notice that you live where winter is a serious matter, what are your real world burn times?

I did talk with a Lopi salesman who said that he subtracts 2 hrs from the advertised burn times. He also said that many companies conduct lots of test burns and then publish the best numbers.

I took the following from the Lopi Liberty specs.

"The Liberty™ is the largest stove made by Lopi. At only 2.6 grams of emissions per hour, it is also the cleanestburning large stove ever approved by the EPA. The Liberty has the biggest firebox of any large stove, which accepts 24 inch logs. It also features a single control to adjust air flow, making it easy to achieve burn times up to 12 hours long."

Given the 12 hours advertised max burn time, less 2 hours to account for "the real world"... and voila my Quad 5700 is probably in the same ballpark as the Lopi Liberty without the overly exaggerated burn times.

No surprise, they look very similar. I think that the Liberty has an even bigger door. I like my pedestal. I think that these stoves are priced about the same.

MnDave
 
Well....I have a Lopi Liberty and I can tell you the advertised burn times are a bunch of sh!t. I will usually load it up for the night around 9 or 10 and get up at 5 am to a few hot coals. The coals remaining are just enough to get another fire going. I would assume the heat output typically stops about 3am or so based on the amount of coals remaining. The advertised burn time is around 12 hours or so. Based on that this stove gets nowhere near what is advertised

And yes, this is with new gaskets on both the glass and door, so that's not a factor

Craig
 
With my Oslo Dave I generally load up around 9:30 p.m. and when I get up at 4:30 a.m. there are enough coals for an easy re-light . . . 7 hours . . . mix of wood such as elm, ash, maple, etc. . . I have yet to try black locust, oak or the primo woods.
 
Hearthstone claims "10 hrs burn time" and "14 hrs heat life"...

Here is what I have personally seen.

If you measure burn time as when you can reload with no matches, easily done from a full load with good wood and a full load. We go 9 hours almost every night on fair wood and a mostly full load. Maybe 70-80% of total available fire box volume.

If the heat life is measured by how long the stove stays above ambient room temp.. they are shorting themselves. Our stove top has been above 100F 18 hrs after the last reload before.
 
I got what was promised by the manufacturer with the BK princess and even my previous Hearthstone heritage. They both advertise what I actually experienced. Of course, it is always assumed that the brochure will refer to the time between light up and when you can reload without matches. Anything else is silly coming from the manufacturer.

If you ever want to know the real truth about burn times you need to get it from the horse's mouth which is here at Hearth.com. Now you will be the data point for folks looking at the Quad 5700.

Glad to hear that you are satisfied with your stoves Highbeam.

I actually did not shop around much when I bought the Quad 5700. It was part of a basement remodel that focussed mainly on the floor tile and stone surround. The ACC feature caught my eye. It was only after reading this forum that I realized how much wood burning technology had evolved from when I last selected a stove.

I definitely did not chose my stove by comparing burn times nor price.

I will continue to post on what I can achieve with the 5700. I have some 22" red elm for next season that should be fairly dry. I have 22" inch long hickory and oak coming in a couple seasons.

MnDave
 
Hearthstone claims "10 hrs burn time" and "14 hrs heat life"...

Here is what I have personally seen.

If you measure burn time as when you can reload with no matches, easily done from a full load with good wood and a full load. We go 9 hours almost every night on fair wood and a mostly full load. Maybe 70-80% of total available fire box volume.

If the heat life is measured by how long the stove stays above ambient room temp.. they are shorting themselves. Our stove top has been above 100F 18 hrs after the last reload before.

I now think that Quadra Fire may be advertising "max burn time" when it should be "max heat time". They probably use that well documented "Florida Bungalow" to conduct their test burns.

Phew. :( I feel much better now that the confusion is probably just a matter of symantics. I don't feel screwed anymore. :)

I guess that I got really pumped up thinking that this stove was going to be so much better than my Kent Tile Fire. The house is warmer and for longer so this is an improvement but the cost was significant.

MnDave

MnDave
 
With my Oslo Dave I generally load up around 9:30 p.m. and when I get up at 4:30 a.m. there are enough coals for an easy re-light . . . 7 hours . . . mix of wood such as elm, ash, maple, etc. . . I have yet to try black locust, oak or the primo woods.

I looked up the specs on the Jotul Oslo. They advertise a "burn time" of 9 hrs. IMO you are right on track at 7hrs with real world wood in a real world home in Maine no less.

Unfortunately it will be hard for Quadra Fire to clarify this information without causing a stir. But I think that they should do it or people may start to think that they are being purposely misleading or possibly guilty of fraud.

MnDave
 
Well....I have a Lopi Liberty and I can tell you the advertised burn times are a bunch of sh!t. I will usually load it up for the night around 9 or 10 and get up at 5 am to a few hot coals. The coals remaining are just enough to get another fire going. I would assume the heat output typically stops about 3am or so based on the amount of coals remaining. The advertised burn time is around 12 hours or so. Based on that this stove gets nowhere near what is advertised

And yes, this is with new gaskets on both the glass and door, so that's not a factor

Craig

Thanks Craig for the reality check.
 
Assuming that a stove can put out enough BTU's at the minimum burn rate to keep the home at a comfortable temperature, to get over 10 hours of real burn time (time between max loads), one has to do several things right.

1) Need a large stove firebox. My guess is a minimum of 3 cubic feet for a non-cat stove.
2) Use hardwood that is 15% or less moisture content and not split too small. Place one or two large rounds or squares in the center.
3) Have impeccable draft control so that a minimum burn rate can be achieved while still getting a good secondary burn (easier with a cat stove).
4) Start with a relatively hot firebox with the optimum amount of coals and position them so that the entire load does not ignite all at once.
5) Continually evaluate all aspects of the process to fine-tune the above.

Feel free to add more advise and share your experiences with how to get a long burn time (time between max loads).

MnDave
 
  • Like
Reactions: Christopix and Gark
I have achieved up to 11hr burn times in my 2.4 cubic foot Hampton HI300 insert. I think Hampton advertises 8hr burn time for that model, and I can easily achieve that. My definition of burn time is time from reload to next reload without needing to use matches or kindling to get the fire going again.

To reach 8 hrs requires reloading an already hot stove (around 300-350F), and stuffing it pretty full. To reach 11hrs requires excellent wood, large splits and alignment of the stars. I can't hit 11hrs with any consistency.

Jim
 
Two other minor tips are:

2A) Have the right length of splits so that they fill the box.
2B) Remove ashes that are not needed.

MnDave
 
I guess that I got really pumped up thinking that this stove was going to be so much better than my Kent Tile Fire.

Could be the Kent Tile Fire is so good, the QF only has a little room for improvement. I routinely get 9 hour burns ending with a large red coal bed. Then takes 30 secs to flame smaller splits. The KTF manual doesn't state burn times - could be before marketing was invented. LOL
 
One of the reasons I replaced my Kent Tile Fire with a Quadra Fire 5700 is the advertised "Max Burn Time" of 15-21 hrs. With the Tile Fire I may have gotten 6 hrs max on my best "not-so-great" wood.

I thought that if I can get 10 hrs between loads, that would be plenty because I go to bed around 10 and get up around 8 on weekends.

Well, I am able to get 6 hrs consistently, 8 hrs occassionally, and IMO I might get 10 hrs when I have better wood and it is cut to the 22" ideal length for this stove. I am sure glad that I opted for the bigger 3.0 cubic foot stove even though their literature suggests I could have bought the next model smaller.

I start with the house at 68-70. It is 10 PM. I load the stove full. The outside temps are dropping into the low teens here and windy.

By 4-5 AM the bedroom is getting noticeable cooler, say 67. By 5-6 AM it is say 65. Argh... go rebuild the fire or my wife is going to turn on the furnace when she gets up.

The stovepipe temp is 100-150F. If I used mainly hardwood I have plenty to start another fire with. If I used 1/2 softwood, I have to essentially start from scratch with kindling and small pieces.

I realize that outside temperature is a huge factor. When it was 25-35F outside, I was not having any issues mainly because the temp in the house would rarely drop below 67. Those days are gone and it will get much colder very soon.

I have better wood coming in 2015 but I still can't imagine getting the lower advertised time of 15 hrs.

I can't help but call BS on the advertised 21 hrs (not 20 mind you).

Anyone else feel this way about their stove as far as advertised max burn time?

MnDave
Burn times as advertised by stove manufacturers are under ideal conditions,imo,however, I would guess any stove at the end of its burn time as advertised is throwing no usable heat,and has only some coals covered in ash.,I for one am not into marathon burn times if I can get 12 hours of usable heat in ANY temperature encountered in NE Ohio,I'm happy,with what I'm burning it's a snap.Example in the thread Blaze King dogs load at 18 hours, I still had usable heat,temps were at 400*,both cat and stovetop as shown by pics,what more would anyone ever want?Today at 5 twenty four hours later I had enough small coals to fire off a puglie load shown in the hearth thread to give me instant ignition using primo 3 year old wood,alas stove temps were 200*cat dead was it still technically burning yes but not of much use.The house was still in 70's high mind you alot from solar gain from the windows facing south in front of the stove.I hope this rambling might give you a little insight as to burn times. Good luck.
 
  • Like
Reactions: MnDave
Mn Dave,
If you really want useful heat for 12 hours you will have to buy a BKK..12 hours is nothing for this stove.
cheers!
 
ohlongarm and HotCoals,
Yep Blaze King stoves are the cats pajamas.

If I had known about them I would have seriously considered the King or Princess.
Thermostatic control was one feature that I really wanted. I asked for it at all 3 local shops in Rochester, Mn.
Not one had a stove with thermostatic control and no one mentioned Blaze King.

The ACC feature on Quadra Fire was the closest thing to air control I could find at the time.

Think of the fun I will have trying to squeeze out 8-10 hrs of burn time on a 0F night. :)

In the mean time I have devised a temporary solution. At around 4 AM I will go downstairs and throw 4 specially selected splits in, set the controls to a little hottler than normal, set the ACC timer and go back to bed. I am very confident that the stove will not overfire under these conditions. The stovepipe damper was instrumental in this.

MnDave
 
The key to long heating burns in a big honkin N/S burner like the 5700 is split size. I have pretty much the same size firebox in the 30-NC and use large splits that fill the firebox side to side with three, max four, splits that are tall enough to reach or go over the height of the brick retainers. With the coal bed pulled to the front and the ends of the splits on top of it. With three year old oak splits last night I loaded it on the coals at nine, had it leveled out out at (back down from 725) 650 in a little over an hour and got up to a stove between 350 and 400 at nine this morning. In fact it was a problem because I needed to sweep the chimney today and at one this afternoon that 450 pound pile of steel and bricks was still at 300 with coals left to go long while. I ended up having to scoop them out at two o'clock and run the blower on high to cool it off and leave the door open to cool down the chimney.

It is all in what you feed it, how you feed it and how you set up the burn.

But advertised burn times are until the last coal in the thing goes out.
 
  • Like
Reactions: Christopix
ohlongarm and HotCoals,
Yep Blaze King stoves are the cats pajamas.

If I had known about them I would have seriously considered the King or Princess.
Thermostatic control was one feature that I really wanted. I asked for it at all 3 local shops in Rochester, Mn.
Not one had a stove with thermostatic control and no one mentioned Blaze King.

The ACC feature on Quadra Fire was the closest thing to air control I could find at the time.

Think of the fun I will have trying to squeeze out 8-10 hrs of burn time on a 0F night. :)

In the mean time I have devised a temporary solution. At around 4 AM I will go downstairs and throw 4 specially selected splits in, set the controls to a little hottler than normal, set the ACC timer and go back to bed. I am very confident that the stove will not overfire under these conditions. The stovepipe damper was instrumental in this.

MnDave
I am curious as to what that ACC doohickey thing is all about now!
 
I am curious as to what that ACC doohickey thing is all about now!

It is a timed device that gives the stove extra start up air and then shuts it off after the burn is established. Or is supposed to.
 
Status
Not open for further replies.