Does more fire necessarily equal more heat?

[jcolgan]

It just started to get cold around here and while my wood stove was kicking butt on the low setting in the 50 degree weather, now that its in the 20s and 30s, the high setting doesnt seem to produce more heat, in fact...it seems as though the high setting produces more fire, but doesnt produce much more heat at all. I just got a new cord of wood and its solid dense ash from a local guy who is clearing about 30 acres, its only been cut down for 8 months, but it feels quite dry. Anyway, my stove is a quadra fire cumberland gap and Im using it to try to heat about 1000 sq ft of the first floor. Is it my imagination, or is it actually possible to produce more heat at the medium setting, even though there is less fire, than at the high setting? If not, then I must be doing something wrong.
I did have more seasoned wood previously (1 and 2 years since cut), but it felt much less dense and not any more dry than the ash, I cant imagine I was getting better heat from it. The ash is in a completely covered area, so its not getting wet (I heard it soaked up water very easily). The ash is not smoking like my old wood, it really burns nice...I just dont understand why I dont get a ton more heat from a lot more fire.

 

[dave11]

I don't know anything about your stove, so I can't comment on that, but I know most folks here will still tell you your wood isn't dry enough yet. Eight months doesn't cut it for most modern stoves. A moisture meter would settle the issue. Decent ones are about $100, but they'll last you.

I can comment though on the apparent lessening of heat from the stove since it got cold. Depending on how well your room/house is insulated, you're likely losing heat to the outdoors at double the rate you were when it was 40 F, and so perhaps it seems to you that the stove isn't putting out as much heat.

The colder it gets, the faster the rate of heat loss through walls and windows. You need to supply twice as much heat to the house at an outside temp of 20 F as you do at 40 F, assuming inside is around 60 F.

 

['bert]

To answer your question, with some stoves it is possible to get more heat with the stove set to medium. On high (air control wide open), often more heat is allowed to go up the chimney so less heat to the room. When you back the primary air down to medium, less of the heat goes up the chimney so effectively more heat is available for transfer to the room.

Get a hot fire going and back the air down and look for secondary combustion. That is when I find I get the most heat transferred to the room in my case YMMV.

 

[KeepItNatural]

"High" to me sounds more like a higher rate of burn, and not simply a high rate of heat output. I think that if you're getting more heat at a "lower" setting, than there's your answer right there.
+1 on the insulation idea.

 

[jcolgan]

Ok, I backed it down to medium and brought a thermometer down to my office where the wood stove is located and in about an hour the temperature went from 67 to 75, and the wood is burning much, much slower. The outside temperature has held steady at about 26 F. Thanks for the input!

 

['bert]

Good to hear. Just be sure to watch the stove temp now, as less heat is going up the chim. your stove temps will climb too. So this is where you can over heat your stove, which will lead to a whole new type of excitement.

 

[jcolgan]

Good to hear. Just be sure to watch the stove temp now, as less heat is going up the chim. your stove temps will climb too. So this is where you can over heat your stove, which will lead to a whole new type of excitement.

Do they sell some sort of thermometer for that? I have no idea how hot my stove gets.

 

[begreen]

Yes, pick up a stove thermometer at your local hardware store.

 

[firefighterjake]

'Berta Burner is spot on . . . and no, you're not going crazy or imagining things . . . with my stove with the air control all the way open I get lots of flames in the firebox and some heat . . . but when I start cutting back the air I get more heat in the firebox and less fire (although the secondaries will kick in and you'll start seeing the Northern Lights -- flickers of flames in the upper reaches of the firebox -- or the Bowels of Hell -- it will look like a portal to Hell has just opened up as the top 1/3 of your firebox will be belching out flames.)

To get even more heat and even better secondaries . . . once you've brought the stove top up to temp (it's a good idea to have a stove top thermometer and a flue thermometer to avoid overfiring -- you can pick these up at the local hardware store or on-line) . . . cut the air control back to nearly closed. If the wood is good and the air is good, you'll see the heat level increase even more and the secondaries will continue to amaze and delight the massive hordes of folks who will be gathered around the stove instead of the TV.

As 'BB mentioned, what is happening is less heat is going up and out your chimney, the secondary burning is happening resulting in more heat which you will feel radiating from the stove . . . even though the firebox may not be full of flames. This is the end goal -- more heat, longer burns.

As a side note, wood cut and split 8 months ago is typically not that great . . . this could be marginal . . . even with ash . . . as a result you may not be able to "close" down the air control all the way . . . if you close the air down to the 1/4 or "all closed" position and the fire begins to sputter out, open up the air a bit more . . . it may take a while for the wood to get to the point where you can do this. Incidentally, how "dry" the wood feels will not be all that helpful . . . short of buying a moisture meter, you can get an idea of how dry the wood is based on the sound it makes when hitting two pieces together, cracks in the wood . . . or a bit late . . . if you find the wood is sputtering, spitting and hissing out moisture once in the firebox.