This chimney business [installation]

[LadyG]

My stove overheats if overloaded, the deck-head can get HOT.

I removed the metal ring at deck-head, drilled out fire cement [it had inclusions of grit], left an air gap, lightly stuffed same with glass fibre rope, bound the metal ring with glass fibre tape. I also insulated flue with glass fibre exhaust wrap] tape for eight inches from top. Overheating significantly reduced.

Question is: why has it worked?

Chimney [outside] is double insulated.

Same amount of heat, where did it all go?

Edited January 12, 2020 by LadyG

[blackrose]

3 minutes ago, LadyG said:

 

Question is: why has it worked?

 

 

Surely you must have intuitively thought it would work because that's what you did. Why do you think it's worked?

[LadyG]

6 minutes ago, blackrose said:

 

Surely you must have intuitively thought it would work because that's what you did. Why do you think it's worked?

I assumed the metal pipe and the solid cement at top of flue were good heat conductors.

I know an air gap is a bad conductor, not sure about glass fibre rope except it is non flammable and is a poor heat conductor.

Edited January 12, 2020 by LadyG

[blackrose]

4 minutes ago, LadyG said:

I assumed the metal pipe and the solid cement at top of flue were good heat conductors.

I think you are correct. Air is a better insulator than metal and cement.

 

Edit: You might want to waterproof the gap with some envirograf.

Edited January 12, 2020 by blackrose

[LadyG]

5 minutes ago, blackrose said:

I think you are correct. Air is a better insulator than metal and cement.

 

Edit: You might want to waterproof the gap with some envirograf.

Of course I am correct, I am a woman!

The outside roof has standard NB collar.

Edited January 12, 2020 by LadyG

[blackrose]

Glass rope is basically using the air between the fibres as the insulator. In most insulation (rockwool, sprayfoam, etc) it's actually air or some other gas in the case of foam, that's doing the insulating.

 

But big air gaps are poor insulators because convection can occur across the space, so the material creates small cells of air. In effect the material is just acting as the carrier. If you compress rockwool it will begin to lose its insulation properties because the density and proportion of glass fibres over a given volume will increase and the fibres are more conductive than air.

 

 

12 minutes ago, LadyG said:

Of course I am correct, I am a woman!

 

 

Of course you are a woman, you are sexist! ?

Edited January 12, 2020 by blackrose

[Sea Dog]

8 minutes ago, LadyG said:

Of course I am correct, I am a woman!

Whilst I have no issue with this sentiment, indeed I have been taught the value of agreeing, I'm not so sure it's a good basis on which to base how to do jobs which, done wrongly, might tend to promote fire, flood or pestilence. If this was the case, such things as the hetas and gas safe registers would be overwhelmingly populated by ladies without the requirement for any training.

 

[blackrose]

The main difference between sexism from men and women is that these days most men know that it's wrong. Women just seem to think it's ok. In truth most of them don't even realise they're doing it!

[The Welsh Cruiser]

A man might ovoid overloading his stove in the first place but who knows, he might be wrong to do so.

[Alan de Enfield]

1 hour ago, The Welsh Cruiser said:

A man might ovoid overloading his stove in the first place but who knows, he might be wrong to do so.

If he overloads his ovoids into his stove and is alone in the jungle with no women about is it still wrong ?