I have a furnace too powerful (wood stove Jotul F121)

[Alvin]

Hello everyone
my wood stove is basically 2x too powerful for my accommodation
it's a Jotul F121 and I only have 300m3 to heat!
So it always idles and it condenses a max in the chimney .......
it should be changed to a smaller one, but I don't have the means at the moment.
I therefore seek to improve the situation at a lower cost.
I have already lined the sides of the fireplace with firebricks
it already reduces the volume quite a lot, the result is positive but insufficient
I plan to limit the gas circulation paths in the stove, maybe with refractory cement .....
may also be to reduce the diameter of the outlet pipe

thank you in advance for your advice especially if they are positive. I know ..... it doesn't happen, it's dangerous ...... etc etc

[Alain G]

Hi alvin

The solution of refractory stones is a good solution to reduce the interior surface of the wood stove and it allows to make a reserve of heat.
You could try to place some above the part of the stove if possible.

You can actually decrease the diameter of the chimney to increase the speed of hot smoke, it will avoid condensation in the chimney. A chimney too big clogs more, I tried it.

[elephant]

I have a Don Bar that looks a bit like your stove. When I close the door, it closes, when I leave it open, it calms down. I can not say more, it is only used in the middle of winter.

[dedeleco]

Logically the combustion speed is fixed by the air inlets, their surface and the chimney draft !!

So it always idles and it condenses a max in the chimney ....

proves that you can reduce its power, and as the stove has a good heat exchanger with good surface area, the fumes come out cold, with condensation, and this stove has a very good efficiency of 99%, if everything burns without settling too much in the fireplace.
So instead of wanting to destroy the output, I would put a device to receive this condensation which flows into a good size pot, as with any condensing boiler. !!
We sell very expensive condensing boilers and stoves and you have it !!

To reduce deposits, you must re-burn the fumes with a deflector and a little air at this level.
Jotul F121 is marked with double combustion, good efficiency, and therefore little deposit, but condensation, if the chimney is long and poorly insulated (therefore not hot).
Any fairly long and cooled chimney and pipes will inevitably condense the smoke water vapors!
Instead of destroying the efficiency, it is better to collect the condensations with a large tank or insulate the chimney so that it stays hot !!
This stove from 9 to 6KW does not appear gigantic in power for 225m3 perfectly suited to your 300m3 !!
http://www.jotul.com/fr/wwwjotulfr/Main ... ul-FS-121/
Carefully read all the documentation on this stove on the jotul site, installation and use, you may have an installation error. .
In my opinion, you have a problem with your chimney too cold which inevitably condenses, either isolate, modify, shorten, or collect condensation at the bottom of the pipe !!

[dirk pitt]

you do well as you want but from an insurance point of view, I will refrain from modifying the stove by adding bricks or anything.
if unfortunately the chimney catches fire ....
sell this stove: jotul is a famous brand and at the start of winter, you will find takers.
and buy a smaller model.

[elephant]

Attention deledeco, apparently you confuse the FS-121 with the F-121, apparently older and 2 X more powerful

[dedeleco]

On the Jotul site the F 121 is not found !!

In any case, the condensation is a sign of very good performance, and of the pipe and chimney which are too cold and which refuse to heat !!

The easiest way is to collect condensations at the bottom of the chimney or pipe, especially if you do not have enough money to change the stove, and if it is able to operate at low speed!

If not, check that the chimney if cold, respects the standards as well as its insulation, if not, another stove will have the same problem !!

Any chimney or cold pipe and long enough will give condensation, whatever the stove, inevitably !!!!

Modifying the stove is dangerous, with bricks, or other, because it can make it inefficient and with excessive CO.
Important to have a CO detector with alarm, not expensive, especially at low speed and with exhaust and flared chimney !!

300 deaths per year with CO in France !!
http://spsm43.e-monsite.com/rubrique,in ... 17686.html
http://www.risquesetsavoirs.fr/spip.php?article5

Not to mention the insurance, which in the event of a serious accident, completely defile with incredible bad faith.

TO KNOW ABOUT CARBON OXIDE:

It is a colorless, odorless but deadly gas. Take the right steps to avoid suffocation. Carbon monoxide is responsible for 6000 poisonings and 300 deaths per year.

[Alvin]

Thank you for all the info
I'm going to try to mix it all up

indeed, do not confuse with the FS 121 which has nothing to do.
the F 121 is a very large closed stove and it is no longer in the Jotul catalog

reducing the volume of the fireplace with refractory brick can only be beneficial!

on the other hand, is the recovery of the bistre flow an advantage compared to my current assembly which brings everything back into the stove?

[dedeleco]

on the other hand, is the recovery of the bistre flow an advantage compared to my current assembly which brings everything back into the stove?

Brought back, the water in the hearth, re-evaporates again, in a cycle a priori almost endless, without leaving !!
The water vapor, produced by combustion inevitably, leaves the smoke, and must go outside, like the smoke, and so it's a bit like preventing some of the smoke from coming out !!

Or more roughly, as if you were swallowing your excrement!

reducing the volume of the fireplace with refractory brick can only be beneficial!

beneficial for what ??
Not proven, you reduce the exchange surface and the yield, and all the functioning is disturbed, so it is necessary to understand the physical phenomena of the stove, otherwise possible errors and more insurance !!

You do not answer my basic question on how is your chimney and the assembly of the stove, does it respect the rules, is it hot or cold (condensations then) ??
Fundamental because otherwise another stove will have this condensation and you will have spent money for nothing !!

You don't seem to be a stove and fireplace specialist !!
Mistakes are easy !!
Also, beware of CO !!
Buy a working emergency CO detector !!!
300 dead per year !!

[chatelot16]

putting brick around the fireplace does not hurt; we can make a fire smaller and as hot

it does not reduce the exchange surface above

I confirm that the chimney too cold is certainly the main problem

I confirm that letting the condensation fall back into the fireplace will be an endless problem! condensation absolutely has to come out elsewhere ... and the problem may be resolved without doing anything more