Flue Cube - any thoughts or experiences of this??

[Stubby]

No, I wasn't being at all prescriptive just pointing out that your comments that the bricks were warming up and increasing efficiency of the fire was wrong. I like a good blaze in and open fire and if the wood is free...

 

Ok . Sorry was not having a go ! just wondering about how ineficient my open fire was as apposed to a qua lity stove >

[openspaceman]

Ok . Sorry was not having a go ! just wondering about how ineficient my open fire was as apposed to a qua lity stove >

 

It's hard to say but for a first approximation and ignoring the effect of ejecting hot air from the house and heat gain from the chimney then the open fire is limited to getting heat into the room by radiation, say 20% of the heat energy of the combustion. The best you can expect from a stove burning dry wood is probably 70%. Burning wet wood would impact on both methods so I don't thing the ratio would change much.

 

In broad terms with the 5kWhr(thermal) available per kg of dry wood perfectly combusted the highest temperature achievable is 1600C in the flame before any heat is lost to the surrounding. This heat is distributed to the whole massflow, double the massflow by adding extra air and the temperature is roughly inversely in proportion. So for a given temperature up the flue if you double the massflow you double the energy lost.

[Stubby]

It's hard to say but for a first approximation and ignoring the effect of ejecting hot air from the house and heat gain from the chimney then the open fire is limited to getting heat into the room by radiation, say 20% of the heat energy of the combustion. The best you can expect from a stove burning dry wood is probably 70%. Burning wet wood would impact on both methods so I don't thing the ratio would change much.

 

In broad terms with the 5kWhr(thermal) available per kg of dry wood perfectly combusted the highest temperature achievable is 1600C in the flame before any heat is lost to the surrounding. This heat is distributed to the whole massflow, double the massflow by adding extra air and the temperature is roughly inversely in proportion. So for a given temperature up the flue if you double the massflow you double the energy lost.

 

Mmmm. Thought it would be that . thanks .

[Goaty]

Bought a flue cube at the old price £166 +p&p.

My set up is not top notch, I have a budget stove/oven/boiler which is connected to central heating. The flue is not insulated, it is around 2.3m long.

 

We had trouble with air flow due to adjacent tree shelter belt, smoke blowing back into room when you open the stove door. Variable starting performance when lighting and filthy glass really quickly.

 

Also as we do firewood, we tend to burn the bits no body wants, large small non splittable pieces, leylandii etc. All seasoned though.

 

Lighting the fire is much improved.

 

The glass burns itself cleaner than before, but it still soots up and burns itself off.

 

I reckon it burns hotter. Hard to prove.

 

It has reduced blow back of smoke into the room, It could be partly stove design/setup.

 

Sorry this isn't convincingly dead certain but someone needs to test this product in a controlled scientific way.

[Paul Smith]

is 2.3m the total length of the flue?

[Goaty]

Aye it is.

[Paul Smith]

from the fire to the top cowl is 2.3m? Im sure the minimum allowed is something like 4.2m.

[Goaty]

Whoops I know a few of us in single storey dwellings with flues, I though the regs say a certain height above roof or ridge. In fact I've seen campervans with woodstoves and Flues through roof. Can't see the harm steam engines didn't go large on chimneys did they?

 

P.S Its not a thatched roof.

[WorcsWuss]

I'm sorely tempted by one of these, the flue off my Rayburn is a tortuous and we're in a hole sheltered by trees, when it's very cold and still there's no draw at all.

I think I'm going to have to bite the bullet and go for it, need to do something....

 

Anyone got a 'sweep code' for the 25% discount....?

[John Barleycorn]

Very skeptical. I suspect that a properly installed stove that has a correct flue, good air controll, a baffle plate & airwash on the door would do as well.