Wind, Stove Blow Back & CO

[WotEver]

4 minutes ago, Mike the Boilerman said:

Oh very scientific! 

I bet I could demonstrate otherwise.

This one reckons that the spinning creates a low pressure within the flue (bit like a centrifugal pump I guess). 

https://stovefanreviews.com/the-definitive-guide-to-chimney-cowls/

I have no idea myself. My dad fitted a simple rotating cowl (wind vane type thingy) on the chimney at home when I was a lad and that certainly worked. 

[MtB]

3 minutes ago, WotEver said:

This one reckons that the spinning creates a low pressure within the flue (bit like a centrifugal pump I guess). 

https://stovefanreviews.com/the-definitive-guide-to-chimney-cowls/

I have no idea myself. My dad fitted a simple rotating cowl (wind vane type thingy) on the chimney at home when I was a lad and that certainly worked. 

 

I reckon if I rigged up a fan at the base of a vertical flue, sucking downwards, a spinning cowl like that on the top would rotate as the air flowed through it and down the flue tube. 

 

[bizzard]

9 minutes ago, Mike the Boilerman said:

 

I reckon if I rigged up a fan at the base of a vertical flue, sucking downwards, a spinning cowl like that on the top would rotate as the air flowed through it and down the flue tube. 

 

We do the opposite with model coal fired steam loco's. When lighting up we place a little battery electric fan on the chimney top to suck air through the boiler tubes to draw the fire up. When there's about 10psi on the pressure gauge  the boilers own blower in the smoke box below the petticoat pipe takes over drawing the fire up, to about 90-100 psi.

[WotEver]

1 hour ago, Mike the Boilerman said:

I reckon if I rigged up a fan at the base of a vertical flue, sucking downwards, a spinning cowl like that on the top would rotate as the air flowed through it and down the flue tube. 

Yeah, but a fire doesn’t generally have negative pressure, it’s very mildly positive, so I don’t know what your fan is supposed to prove. 

[MtB]

2 hours ago, WotEver said:

Yeah, but a fire doesn’t generally have negative pressure, it’s very mildly positive, so I don’t know what your fan is supposed to prove. 

 

You really aren't paying attention are you!

See post 25.

[WotEver]

1 minute ago, Mike the Boilerman said:

 

You really aren't paying attention are you!

See post 25.

I did, and failed to see how the test outlined in post 27 was in any way relevant

[MtB]

1 minute ago, WotEver said:

I did, and failed to see how the test outlined in post 27 was in any way relevant

 

Jeez, I'm sure you can figure it out if you try. You're a clever bloke!

[WotEver]

5 minutes ago, Mike the Boilerman said:

Jeez, I'm sure you can figure it out if you try. You're a clever bloke!

Nope. You appear to agree that the rotation of the cowl will affect the flue pressure (downwards in your case, upwards in the web description) which supports their view