Secondary Burn DYI - HELP PLS

[carlo@ITALIA]

Hello I am running an old inset that is quite good BUT unless I have tryed to calm it down by closing as much as possible the intake air (it has only primary) ..at a certain point the draft is soi powerful that the wood will be exhausted very quickly. YOu can load a lot of wood but ..after max 1.5 H the fire is gone...then...coals are quite good in lasting for few hours....maybe 3-4.
My feeling is that lot of energy is going out from the chimeny and I get only a % in the house...
NOTE that I have also reduced at minimum the air needed to keep the glass clean but ...this only slightly changes the behaviour...may be only the coals are lasting more but not the fire....(good news is that the glass stay clean....).
Attached some pictures of my insert. It is a Montegrappa Compact 80.

NOW - I would like to improve the BURN TIME / EFFICIENCY.My idea is the following:1) find a way to better control the intake primary air and being able to "shut it down" to almost zero2) practicing some holes and being able to inject secondary air on the top of the box by tubes ...(interesting this box has got a kind of vermiculite on the top..that gets VERY HOT (it turns red...).To shut dow the primary air one very simple way is to "close" partially the grid where the has falls...
QUESTIONS.

- Any thoughts in general about how my insert currently works?
- Is my plan reasonable? ANy improvements drawbaks?

thanks a lot
carlo

 

[kennyp2339]

First clean and inspect the insert thoroughly, remove the cracked fire back and inspect for damage beyond that point, check the door glass & door gasket to make sure they are still functionable.
I'm fairly suspicious that you have something going on beyond a few simple tricks of the trade here, I'm making that judgement by seeing all the white ash and very clean door glass ( with exception of a possible air leak on the right side)

 

[SpaceBus]

Looks like the unit was overfired. Our stove was like this when we moved in. I use the stove as a yard ornament now.

 

[begreen]

The insert is not modern and lacks a secondary combustion system. It appears that draft is strong, perhaps due to a tall chimney?
We know nothing about this stove and how the air control is designed, but usually it is a very simple blade valve that covers the air intake.
What is right above the air control? Can air enter there? If so, try temporarily covering that entire area with metal tape.

 

[carlo@ITALIA]

Hi all and thanks a lot !!
Actually i don't think there is a major problem due to an overfire..the inner brics are broken because by accident i broke it it wood. I do not expect also to have problem with air leak...

I agree with Begreen that I have a huge draft due to around 4.5 MT x 20 CM diameter !! in fact when it reaches high temp it is literally not possible to lower it...I can delay the time it gets "Hot" ..but this means not a good burn..but then it starts and eat all the wood.

The primary air if feeded as follow:

- a square tube is positioned below the ash tray in a NORTH-SOUTH direction. One side is blind (into the stove) while the other exit the stove (acrually "protected by the front grill)....(see attached "schema")
- there is also a second way..it is the air that cleans the glass and is flowing directly from the top of the door...(here I am able to shut it down)..i found a way

Today I added a plate on top of the grill covering almost everything....this way less air is provided to the wood so it starts slowly...but, in any case, when it gets hot the fire lasts max 1.5 H.....this is not a good solution because I lose a lot of primary air control...would be better to find another way...that can be removing the grill in front of the insert and accessing directly the tube ..tring to shut it down...

VERY IMPORTANT - I do see a lot of secondary combustion in my insert BUT it is feeded only by primary air....(good thing is that this demonstrate that the insert is hot enough for it...)...this is why I would like to add tubes for secondary

THANKS A LOT

carlo