Post-Combustion & Secondary Combustion what is the difference

[Paramonte]

I am using a French made wood stoves model Itaya

http://www.invicta.fr/en/wood-stoves/chimney-stoves/itaya-chimney-stove
Specs:

• • In compliance with : EN 13240 standard - BImSchV
  • Reference : 6110-44
  • Heat output : 12 kW
    Efficiency : 76%
  • CO level : 0.1%
    Flamme verte : 6 stars
  • Performance rate : 0,7
    Post-combustion system
  • Continuous fire
    Airwash system
  • Fuel : Log 25, Log 33, Log 50
    Log length : 71 cm
  • Loading : Front loading
    Flue diameter : 180 mm
  • Flue location : top, rear
    Dimensions : H 846 x L 1051 x P 431 mm
  • Weight : 187 kg
    Heating volume : 160 to 480 m3
  • Heating surface : 64 to 192 m2
    Design : Contemporary
  • Finishing : Anthracite
    Warranty : 5 years

French made stoves are very popular round here (Portugal)

My question is: this wood burner is, according to the mentioned specifications Green (5 stars) and also is rated as Post-Combustion type. I thought it would imply an air intake from of the back of the burner which wood lead air to the top for the wood released gas and particles to be burned.

However there is no air intake from the back neither the usual device with many small holes that release the air to do the secondary combustion, inside.

This burner only has two air intakes: from the bottom close to the door (regulated) close to the ash tray and also close to the door up that the does airwash ventilation to keep the glass clear for a bit more.

I am attaching a file with the specifications, sorry it is in French, but there are schematics.

Could anybody explain me with this.
Many thanks for your time!!

 

[begreen]

Welcome. Nice looking stove. It looks like post-combustion here means secondary air injected from the back of the stove through 2 holes about mid-height. This happens when one adjusts the "réglage d’allure". Pushing this control in after the fire is burning well appears to feed the secondary air, though this is through fractured French translation and not having hands on the stove.
"Of burn setting adjuster : Located in the front , this register is used to modulate the shape of the device between " Rated power "
( 50% damper opening ) and "prolonged Combustion " ( damper closed ) ."
This diagram shows the post-combustion air injection.

 

[Dodgethis]

Let me help out with the french translation here . Réglage d'allure is the primary air. 50% open for maximum heat and closed for overnight burn. On this stove the secondary air can also be adjusted but it is more a one time adjustment (REgistre d'air secondaire). You adjust it base on the draft and dont play with it anymore after. You control the stove using the primary air like any EPA stove afterward. Well at least this is what the manual says.

 

[Paramonte]

Dear Begreen
Thank you for your welcome.
Many thanks for your reply and thank you for having pasted the relevant pictures in the reply.
I think I understood your explanations. The problem for me is that this burner does not have any holes in the back, contrary to the diagram that you selected from the pdf specification file. Those 4 holes seen in the figure 2 are just occupied by screws/bolt (sorry my lack of proper English terms).

So, I gather the first figure is just a generic diagram (as they mention), but I don't see any holes in the back of the burner which I think is a tell-tale for post-combustion (which the burner is advertised as having)

I believe that their claim of post-burning is based on the existence of the secondary air intake (on the top of the front door) which Dodgethis refers as the set-and-forget air regulator. This, I thought, would be the glass air-wash intake. May be do both roles: air-wash and post-combustion air intake???

Many thanks to Dodgethis for his accurate translation !! Made things clear!

 

[Dodgethis]

I might be mistaken but I don’t think the air wash and the secondary air intake are linked. Otherwise you will not be able to control the fire as the air wash is usually where the primary air is coming from along with the dog house. What you see marked as registre d'air secondaire at the top is not the intake but the adjustment. If you look closely you can see a + and – in figure 2.

 

[Paramonte]

Dear Dodgethis
The register "air secondaire" in Figure 2 with +/- is actually an air intake with a regulation. this is certain as I own this burner and used (sparsly) this regulation that is directly with a row of holes that adjust/mis-adjust as you regulate (this row is on the top of the burner) , I would think that both glass air-wash and Post-Combustion air should come from above, not below where the primary air intake is? Is this correct?
Many thanks

 

[Dodgethis]

Well normally the secondary air needs to be heated before entering the combustion chamber. So yes both the air wash and the secondary air enters from the top. The air from the air wash should be cold and should flow down in front of the glass. The secondary should be hot and stay at the top of the burn chamber igniting the smoke and wood gaz.

But this wood stove might be different.

 

[Paramonte]

Well normally the secondary air needs to be heated before entering the combustion chamber. So yes both the air wash and the secondary air enters from the top. The air from the air wash should be cold and should flow down in front of the glass. The secondary should be hot and stay at the top of the burn chamber igniting the smoke and wood gaz.

But this wood stove might be different.

Thank You!