avoiding/ minimizing barometric damper/ draft regulator parasitic losses

[pybyr]

For background, I "get" the conventional wisdom on avoiding barometric damper draft regulators on conventional wood appliances

I also "get" how they can be beneficial on wood gasifiers- by making sure that the fire does not get pulled through the heat exchanger before the maximum feasible heat can be extracted

so here's my question-

I have a chimney with three separate 8" round tile flues- one for the oil, one for the wood cookstove, and one for the wood boiler, all of which "draw" really well

they draw so well that, last night, as I was working a bit on my Econoburn install, I noticed that the "Field Controls" barometric damper on my oil unit was pegged nearly wide open, even though the oil unit had not run at all for the better part of 24 hours

when I put my hand near the opening of the damper, I could feel the draft-- and if that warm air is going up the chimney, I know that other cold air has to be coming in somewhere else to replace it.

I know that the baromtric damper on the oil unit is adjusted correctly, as I carefully set it up last fall using Bacharach pro instrumentation.

so- my question is- anyone have any ideas on how to maintain steady and efficient "overfire draft," while not having a lot of excess heat go up the flue during the much larger proportion of time that there isn't a fire burning?

thanks!

 

[antknee2]

One way is to tee off the back of your boiler and install about 2' of flue pipe and a another tee close to the floor , with your damper and clean out plug . This way you only suck out cool floor air and no back puffs from the wood boiler.
Anthony

 

[pybyr]

Thanks Anthony- only thing is, I am mainly aiming to try to prevent having household air goe up the flue at all, except when absolutely needed (during an actual burn)- because whatever air goes up the chimney has to be replaced by outdoor air that will leak in elsewhere.

anyone know of a motorized damper that could be put between the barometric damper and the main stack ?

 

[Blevesque]

I was just thinking about yesterday. It would be nice to maintain a constant draft. I found these but was scared to fing out the price. (broken link removed to http://www.preferredinstruments.com/boiler_monitoring_draft_control.html)

 

[flyingcow]

I looked at the link and if I read it right, the smallest damper was 12 inches. Plus I couldn't find a price, but i'll guess it's not cheap. I suppose if your around when the fires cooling down or out, you could cover the baro damper.

 

[flyingcow]

Whoops, I hit the send button before I was done. There must be something reasonably priced




pybyr-----Have you lit the Econoburn off yet?

 

[pybyr]

Whoops, I hit the send button before I was done. There must be something reasonably priced




pybyr-----Have you lit the Econoburn off yet?

I wish!

still dragging a lot of wood out of the woods, while plumbing and wiring... and heating the house with a wood cookstove...and working the day job... you can bet you'll hear about it here when I do light it off