Why should I buy or not buy a pipe damper?

[Dune]

Pook, you are gone. If there was a vacuum, no air would be coming in to support combustion, therefoe the vacuum couldn't increase.

 

[Ratman]

Pook, you are gone. If there was a vacuum, no air would be coming in to support combustion, therefoe the vacuum couldn't increase.

try reading the post again......vacuum is impossible so a relative vacuum trying to become a vcuum from increasing temp will result in a downflow of air in the chimni as the hot air still rises= a loop
example is simplified by saying that the heat is applied externally to the sealed system= imagine the stove externally heated by a flamethrower

pook is your statement in reference to BEFORE the fire is started?
Are you stating that the damper, BEFORE the fire is started, would assist in controlling the loop you mentioned?
Once started wouldn't the upward flow override this?

I always thought the draft process was:
Before startup: The difference in the relative pressure of the colder outside air and the warmer inside air causes the initial draft.
After startup: Colder & denser air is pulled into fire from below and displacing the hotter more volitle air thus pushing it upward and creating a stronger draft flow.

 

[Ratman]

Perfect.
Thanks for your info pook.
I'm confused as far as if you are advising me to install a damper or not.
I remeasured and the 5" to 6" expander section goes up into the metalbestos pipe several inches so I should be able to install one just below which will give me clearance from the other screws.

 

[Dune]

Pook, you are gone. If there was a vacuum, no air would be coming in to support combustion, therefoe the vacuum couldn't increase.

try reading the post again......vacuum is impossible so a relative vacuum trying to become a vcuum from increasing temp will result in a downflow of air in the chimni as the hot air still rises= a loop
example is simplified by saying that the heat is applied externally to the sealed system= imagine the stove externally heated by a flamethrower

pook is your statement in reference to BEFORE the fire is started?
Are you stating that the damper, BEFORE the fire is started, would assist in controlling the loop you mentioned?
Once started wouldn't the upward flow override this?

I always thought the draft process was:
Before startup: The difference in the relative pressure of the colder outside air and the warmer inside air causes the initial draft.
After startup: Colder & denser air is pulled into fire from below and displacing the hotter more volitle air thus pushing it upward and creating a stronger draft flow.

example was set up with no fire but the stove heated externally with a flame thrower in order to understand how a chimni has a circular flow of air in it when system is airtight

When I start heating my house by heating my stove externaly with a flamethrower, I will be real worried about the "chmili loop affect". Till then, I will contiue to rely on physics. Sorry I ruffled your feather.