Define "Burn Time"

[7acres]

When a new stove hits the market everyone wants to know what its "burn time" is. How is this duration defined?

It probably starts when the stove is cold and has just been lit, right?

But when can you reasonably say the burn is over?

Here's why I ask:
On a full load my first night my stove was hot to the touch and had several live partially consumed splits down in the ash after over 20 hours. I lit it a little after 6p. The following afternoon around 3p I opened the stove door and raked the ash and coals around. Just in the time I did that a few of the partial logs brightened up to light orange and the live coal bed did the same. The house was already a tad warm so I just shut the door and left the air control on low. If I had turned the air lever up I'm sure I would have had flames from the wood I ignited 20 hours ago.

So when is the burn officially over for purposes of honestly characterizing a new stove model's "burn time"?

 

[Grisu]

When a new stove hits the market everyone wants to know what its "burn time" is. How is this duration defined?

You will need to ask the marketing department from the company that produces the stove you are looking at. There is no general accepted standard.

It probably starts when the stove is cold and has just been lit, right?

I count from reload to reload as startup fires are usually smaller to get the flu and stove hot.

But when can you reasonably say the burn is over?

Many people here use the definition of "enough coals left for an easy restart". Others may say "still throwing enough heat" or "blower still running". It's what is important to you.

Here's why I ask:
On a full load my first night my stove was hot to the touch and had several live partially consumed splits down in the ash after over 20 hours. I lit it a little after 6p. The following afternoon around 3p I opened the stove door and raked the ash and coals around. Just in the time I did that a few of the partial logs brightened up to light orange and the live coal bed did the same. The house was already a tad warm so I just shut the door and left the air control on low. If I had turned the air lever up I'm sure I would have had flames from the wood I ignited 20 hours ago.

So when is the burn officially over for purposes of honestly characterizing a new stove model's "burn time"?

Sounds like a 21 hr burn time to me.

 

[7acres]

Sounds like a 21 hr burn time to me.

Dang. I will consider my investment a sound one. That puts this stove up in the Blaze King range of burn times. And it is a non-cat too.

Yeah, the fan was still blowing. I switched it off because the house was too warm as it was.

 

[HotCoals]

Who knows but for me I like to think of "burn time" as the amount of time my stove will keep my house at a steady temp.
Of course that changes with the outdoor temps and wind.

My burn time can be as long as 40 hours and as little as 12..maybe even 10 if it's really cold!

 

[Chimney Smoke]

I consider burn time as the time between a full reload of a warm to hot stove and when the stove is still warm with enough coals for a full reload and easy restart.

 

[Rossco]

As long as the cat is in the 'Active' zone I guess.

 

[Frank625]

I think of "Burn Time" as the time I can leave a fully loaded stove unattended. For example the stove has been burning for quite some time, all day or overnight for example. I load it up and leave it unattended to go to work or bed. Come home 10 hours later and I can just throw some more wood on and it takes off no problem. I'm happy with a "10 hour Burn Time" when its cold out.

 

[Charles1981]

I think there is a synonym. Intangible.

 

[tarzan]

We usually have enough coals left to start a fresh fire after about 14 hours or more but in winter I define burn time as the time it takes the thermometer in the stove room to drop bellow 72F

 

[firefighterjake]

Burn time definition . . .

Before I bought my stove . . . thought it was from the time I lit the stove to when the flames were no longer still burning.

Now I suspect the stove manufacturer may have been defining it as the time from when the stove was lit until it had reached the point where the stove had to be loaded up.

Truthfully, it's hard to pin down what the definition is . . . for me . . . the time from when I get meaningful heat to when the stove needs to be reloaded to keep producing meaningful heat.

 

[BruceNorEast]

I'm new to heating with a wood stove, but obviously there's an inverse relationship between burn time and heat delivered per hour (if you stretch a load of wood out for a long burn, the amount of heat delivered per hour will be much less than if you burn it quickly).

It'll be nice to be able to start your stove from coals without having to get up very early.

But come January/February, I doubt many are going to be shooting for long burn times

Here's some related links:
https://www.hearth.com/econtent/index.php/articles/burn_time_calculator

http://www.calculator.net/btu-calcu...=50&temperatureunit=f&calctype=heat&x=75&y=14

PS: Congratulations on the stove!

 

[HotCoals]

I'm new to heating with a wood stove, but obviously there's an inverse relationship between burn time and heat delivered per hour (if you stretch a load of wood out for a long burn, the amount of heat delivered per hour will be much less than if you burn it quickly).

It'll be nice to be able to start your stove from coals without having to get up very early.

But come January/February, I doubt many are going to be shooting for long burn times

Here's some related links:
https://www.hearth.com/econtent/index.php/articles/burn_time_calculator

http://www.calculator.net/btu-calcu...=50&temperatureunit=f&calctype=heat&x=75&y=14

PS: Congratulations on the stove!

That where the BKK shines...thing can hold like 80# of wood!
12 hours of good heat no problem .

 

[BruceNorEast]

That where the BKK shines...thing can hold like 80# of wood!
12 hours of good heat no problem .

Holy mackerel!

And it's true, their website states that it can produce 51,580 BTUs per hour for 12 hours!
(broken link removed to http://www.blazeking.com/EN/wood-king.html)

Sorry to OP for going off topic, but wow! With specs like that (and EPA award for most efficient stoves in the world) etc., no wonder you guys rave about your stoves!

 

[BobUrban]

For me it is when the black steel box starts making heat until it cools enough that I need to add more fuel and is effected by many, many things inside and outside the box including but not exclusive to: Wood species, MC, load size, temp outside, wind velocity, how well my home is insulated(or lack there of) along with a myriad of other influencing factors.

Right now it is 63 in here and if I start a small, hot fire I will be blown out of this place by noon due to weather and solar gain. Same scenario in January and I wake to a 63 degree house with a 200 degree stove and nice coal bed to load onto and I am grateful. Todays little fire would have a 20+ hour burn time(heat producing time) January's will be in the 10-12hr range.

 

[7acres]

BruceNorEast,
Those calculators are awesome! Very good references.

I'm new to heating with a wood stove, but obviously there's an inverse relationship between burn time and heat delivered per hour (if you stretch a load of wood out for a long burn, the amount of heat delivered per hour will be much less than if you burn it quickly).

It'll be nice to be able to start your stove from coals without having to get up very early.

But come January/February, I doubt many are going to be shooting for long burn times

Here's some related links:
https://www.hearth.com/econtent/index.php/articles/burn_time_calculator

http://www.calculator.net/btu-calcu...=50&temperatureunit=f&calctype=heat&x=75&y=14

PS: Congratulations on the stove!

 

[Jerhurt]

I'm seeing the same results with my f55 also. It's a great heater going to be warm this winter