coalkirk wrote:Coalfire wrote:coalkirk wrote: Manual and barometric dampers BOTH are draft limiting devices. They do the same thing but they accomplish it differently. A baro limits draft by allowing room air to be drawn in the vent pipe. A manual damper limits draft by partially blocking the vent pipe. Both limit draft.
Actually a mpd does not limit draft. A measure of draft is with a manometer, when you close your mpd your draft does not drop manometer stays the same. same number means same draft, what you did limit was the volume that could ecscape.
With a baro when you push the flap open more the number on the manometer does go down, a lower number means the drafts has been limited.
Over fire draft, not chimney draft.
I will have to get a piece of brakeline and I will fish it in my secondary air and check the draft right above the the fire and compare to my manometer reading for my stove pipe(where the sampling port is between the mpd and the stove)
I will get a piece of line at work tomorrow and let you know the results.