Thoughts on Internal flues, aesthetics and specifics on flue falls

[SweetWilliam]

HI,

Ideal Logic flue fall is 1.5 degree, as per manufacturers instructions.

Did you know that they have an allowance? The upper allowance is 2 degree, but this is not in the instructions. The question is if the flue fall is say 1.9 degree, does it comply with the manufacturers instructions or not? (and does it matter?)

Do you think that the flue fall should be considered over the entire length of the flue? For example, in once section it is 1.7, in another section it is 3.7 in another section it is 2.5. Given that the (apparent) tolerance, is the first section okay to leave as is or should each section be adjusted so that over all the flue is either 1.5 or within the 2 degree tolerance?

I would think that having a constant flue fall is best practice and looks better aesthetically, as the flue is internal and runs in a prominent position along the landing.

Also, another question, on a 6m flue length 1.5 degree is 156mm. What if the flue has two 90 degree bends, thereby reducing the actual length to 4m, is the flue fall still 156mm or 78mm?

What are your views of long internal flues, particularly ones on display and not boxed in?

 

[Basher]

"Also, another question, on a 6m flue length 1.5 degree is 156mm. What if the flue has two 90 degree bends, thereby reducing the actual length to 4m, is the flue fall still 156mm or 78mm?"

If you mean the point to point distance is 4m, but the total length of flue in circuit is still 6m from start to finish, then the fall (with the 90 deg bends) still has to be 156mm. Otherwise the bit between the bends would not have any fall!

 

[ShaunCorbs]

I would just make sure it has a fall on it over the entire length

 

[SweetWilliam]

Thank you. Makes sense.

The manufacturer has confirmed that the flue fall must be constant.