Anyone else notice that cleaning out ash in Fireview results in noticeable efficiency improvement?

[sksmass]

And I mean like noticeable. Why would that be the case?

I admit to being pretty lazy about ashes. I try to minimize the frequency with which I clear out the ash in my stove. I routinely let the ash get as high as the base of the little andirons behind the window, and sometimes even a bit higher. Such was the case this weekend.

Then today I broke down and cleaned out the ashes, leaving just enough for a ~1" base. Tonight my fire has a noticeably bigger difference between the stovetop and flue temp than my weekend fires had.

To me the bigger delta between stovetop and flue temps indicates higher efficiency. The ONLY difference is the clean(er) box. But maybe I am just engaging in some wishful thinking.

But if this is real, and others have noticed it, then I guess I am going to have to stop being lazy about cleaning out the ashes.

 

[BrowningBAR]

When I have too much ash in any of my stoves, they burn differently. When the ash builds up too much on the Encore or the Defiant I notice burn times change and I see a difference as to how a reload takes off.

 

[Beau]

Ashes physically displace o2 volume?
The stove itself while being fed by air continuously still acts like a plenum, or a reservior that may improve the o2 to non oxidant gas ratio.

Just a guess.

Additionally perhaps it raises the fuel higher towards the secondaries, and the gases don't have as much time to heat up and re-ignite?

Those could be two primary factors.

 

[Backwoods Savage]

Naturally if the ashes get too high it will affect the fire. But at the highest burn rate which is usually in late January we empty ashes maybe every 4th day. In the fall I think we burned for about 6 weeks before emptying any ashes and no, we did not notice any difference in the burn.

In winter though when you want to fill that firebox before going to bed, you don't want the ashes too high so that you can put more wood in there.

 

[Flatbedford]

I'm with Dennis. All you did was make more room for more fuel.

 

[charly]

I have to agree with Dennis a well.

 

[fire_man]

I burned a Fireview in too-big of a house for the stove. Every inch of firebox space was necessary - I always felt like if I could just get one more split in there..... Excess ashes definitely hurt my heating abilities during cold spells. I got really good at loading the stove with the right shape splits to maximize the volume.

 

[greenbrierwv]

more room = more wood = more BTU's. a little ash doesnt hurt at all, might even help, but a lot reduces cu ft. unproven theory...no data that is.

 

[Beau]

Oh well, my hypothesis was based on a constant of = amounts of fuel... Obviously more fuel = more output!

 

[dafattkidd]

I burned a Fireview in too-big of a house for the stove. Every inch of firebox space was necessary - I always felt like if I could just get one more split in there..... Excess ashes definitely hurt my heating abilities during cold spells. I got really good at loading the stove with the right shape splits to maximize the volume.

Is the Progress giving you significantly more heat?

 

[fire_man]

The Progress is giving me TONS more heat. What amazes me (and others have agreed) is that with the same amount or less wood, the Progress heats noticeably better than the Fireview did. It's more efficient with the same amount of wood.

 

[wjb111]

I have the T5 insert and when the ashes start piling up after a couple days it does not generate as much heat. Usually have to let things burn out after 4 days to clean her out. After cleaning the ashes out, leaving an inch or less on the bottom the T5 generates WAY MORE heat than with an accumulation of ashes. All of what everybody else replied makes sense. I thinking the ashes also act as an insulator forcing more heat up the chimney and less in the stove/insert.
Just my thoughts & observations....

 

[charly]

The Progress is giving me TONS more heat. What amazes me (and others have agreed) is that with the same amount or less wood, the Progress heats noticeably better than the Fireview did. It's more efficient with the same amount of wood.

That's really nice to hear that about the Progress.. Everyone should be very happy with their new stoves . I know I'm very happy with my Fireview. I know I keep saying this,, but I can't believe how easy the stove is to run,,,set and forget, it's great!

 

[ddddddden]

Ashes physically displace o2 volume?
The stove itself while being fed by air continuously still acts like a plenum, or a reservior that may improve the o2 to non oxidant gas ratio.

Just a guess. . .

Oh well, my hypothesis was based on a constant of = amounts of fuel... Obviously more fuel = more output!

Yeah, what Sk may have simply been observing more heat from more fuel, but where's the fun in that analysis? To continue the investigation of the air space in the firebox affecting combustion. . .

another angle to ponder;


with a full load in the stove there is less available air space , but remember flue is pulling "X" air at a certain temp. filling up the firebox takes up a lot of space so more air is pulled through secondaries which do not get regulated in most cases the same way as the primaries, thus more air available for secondaries giving a more violent look due to the higher velocity and volume in the secondary air path.

another thing is that even without the secondaries, the primary air has a tighter path with the flue still pulling "X" through a smaller space so velocity (aka"turbulence") is higher

I think Master Holton is saying:
less empty space in the firebox = more turbulence in the air moving through the box = better burn.


So. . .if you were going to burn less than a full load, taking up space with ashes should be a good thing, but I've noticed something similar to what Sk is talking about. I think it's because there is less surface area of the wood exposed to air when the bottom splits are partially buried in ashes. Another thing to consider is that the Fireview has no doghouse air. I believe that the andiron plate deflects some of the airwash toward the back of the stove, after it travels down the glass. . .probably doesn't work as well with ashes piled in front of that plate.

I usually go 12+ hours between reloads, so I don't get the chunky kind of coals that will support the weight of several splits The small coals get pushed down into a deep ash bed, so I like to rake the coals to the middle and put a shorty N-S on either side to get the wood up out of the ashes and allow air to get to the coals and the bottom splits. Shorties aren't always available, so another way is to scoop out a wide N-S trench in a deep ash bed and put the coals in it. I was calling this the "tunnel of love," but I now know that there are important technical differences between this technique and the official Tunnel of Love.™ Perhaps I should call this technique the Love Nest®. . .

My hypothesis is that more ashes in the bottom makes for less lively combustion down there, unless you do something to provide for air flow to the bottom splits. Less heat, as observed by Sk, but longer burns when there are lots of ashes.

 

[jdonna]

I usually go 12+ hours between reloads, so I don't get the chunky kind of coals that will support the weight of several splits The small coals get pushed down into a deep ash bed, so I like to rake the coals to the middle and put a shorty N-S on either side to get the wood up out of the ashes and allow air to get to the coals and the bottom splits. Shorties aren't always available, so another way is to scoop out a wide N-S trench in a deep ash bed and put the coals in it. I was calling this the "tunnel of love," but I now know that there are important technical differences between this technique and the official Tunnel of Love.™ Perhaps I should call this technique the Love Nest®. . .

Good tip, I will have to try that. I do not mind several inches of ashes, does give a longer burn time if you are not around to feed the lion.

I agree with you guys in that a clean stove gives good air circulation under the splits, otherwise the air is partially blocked. Similar results are found if you put a round or split tight to the andiron plate, takes longer for the load to get going.