Tough to burn stuff: Is it consuming more heat than it's producing?

[theholycow]

I receive/have large quantities of newspaper, cardboard, etc. Of course, a little can be used to start a fire. One can go to lots of effort to make firelogs out of it. One can just bring it all to be recycled, as most people do.

However, if I put a rolled up newspaper or folded up non-corrugated carboard in my fire, I wonder...does it make more heat than it consumes? I know if I try to burn it alone it won't stay burning, most of it will be unburned. OTOH, if I have a decent fire going, it will burn to ashes (and lots of them!).

Does this mean it's consuming energy or is it still producing energy and just needs the constant fire or higher temperature around it to keep producing?

[jeep45238]

It just means that one way you have enough energy for a self-sustained reaction, and the other way you don't.

[maxxgraphix]

Shred it. Pack it into a small cardboard box. Dump some used motor oil in it. Then use this as a starter log. Does wonders. I also ad wood chips.

[JanGeo]

Paper has a lot of clay in it for it to hold ink for printing along with other components that give it strength and bind it together. Not the ideal burning material - however the old computer green bar paper really does burn nicely once you get the fire hot enough. The trick with paper is to have the air source blowing on the burning side of the paper stack so that it gets really hot and burns up the carbon well.

[theholycow]

Originally Posted by maxxgraphix

Shred it. Pack it into a small cardboard box. Dump some used motor oil in it. Then use this as a starter log. Does wonders. I also ad wood chips.

Now THERE is an interesting idea. Of course, the motor oil is the big concern...how much of it to use?
- Just enough to get a lot of the paper a little wet
- enough to soak most of the paper
- or barely any?
- Does the oil burn with a bad smell? I have a fireplace, not a wood stove...

I have a small collection of sawdust I've been waiting to use in something like this, so I could use that instead of chips. I probably also have a decent collection of appropriately sized boxen.

[JanGeo]

Don't burn the oil in a fire place it smokes and stinks like crazy. The paper will be well if rolled into a wet log and allowed to dry - done in the really old days - I think the wetting binds the pages together and help conduct the heat into the inner layers and makes it burn better - you have to let them dry out before burning however. Also crumpling them into a ball works well too but it makes the paper burn fast so watch out for flying balls of fire going up the chiminy.

[bobc455]

Originally Posted by theholycow

I receive/have large quantities of newspaper, cardboard, etc. Of course, a little can be used to start a fire. One can go to lots of effort to make firelogs out of it. One can just bring it all to be recycled, as most people do.

However, if I put a rolled up newspaper or folded up non-corrugated carboard in my fire, I wonder...does it make more heat than it consumes? I know if I try to burn it alone it won't stay burning, most of it will be unburned. OTOH, if I have a decent fire going, it will burn to ashes (and lots of them!).

Does this mean it's consuming energy or is it still producing energy and just needs the constant fire or higher temperature around it to keep producing?

In order for something to burn, it has to get hot. Since you put items in that are room temperature, heat has to be transferred into these items before they will ignite. So yes, everything consumes energy before it can release the energy.

The rate of heat transfer depends on the amount of surrounding heat (i.e. big hot fire vs. small cooler fire), surface area (sawdust vs. logs, shredded paper vs. rolled-up paper, etc.), mass, heat transfer coefficients, and so on.

If you were to put in wet paper instead of dry paper, it would consume more heat before it reached combustion temperatures - then the water would be given off as steam (without giving back any of the heat it consumed, except to the chimney) and then the paper would burn the same as if it were dry. (Did I explain that right?)

BTW very good use of the term "boxen"... LOL

-BC

[theholycow]

So, I think when it's all said and done, I don't waste any energy by burning the aforementioned difficult-to-burn stuff, and I most likely come out ahead at least by a little.

I had been messing with the term "boxen" for awhile (after all, the plural of 'ox' is 'oxen') when the computer store where I worked received a pallet of folded up boxes with the store name printed on the side. My best friend (who was working there too) jumped on it, grabbed the shipping strap, and made like a rodeo cowboy, and said "Yee-haw, a herd of wild boxen!". That incident forever cemented "boxen" in my brain...

[bobc455]

Right. So as long as it burn eventually, it's worth the energy consumed.

BTW I heard "boxen" from a comedian- YouTube doesn't work at the office, but I think this is the clip
http://www.youtube.com/watch?v=tt7btLu3JWs
or maybe it is http://www.youtube.com/watch?v=Y0A0UtolqsI
-BC

[itjstagame]

Yeah us nerds at the technical college all used boxen for multiple computer towers. Not sure where it first came from, but whenever I hear it I assume it refers to multiple computers.