How's Your Draft?

Im getting .15-.18 , but I have 3 90's ( bends) and in a river valley. Higher barometric pressure does affect my draft unless the high stack temp can make up for the low outside temp. I adjust my stove draft by my barometer.

My barometric damper is set to start breaking open at 0.05", and it has been spending a lot more time open than closed for the past few days.

I had to move everything 20' away from the baros so it didn't get sucked in...

That is enough to suck the coal out of the stove LOL[/quote]

Mike Sidell (TWC) could do a live weather report from your living room (he's used to bracing against winds pushing him sideways).

Ky Speedracer wrote:-12 degrees this morning and currentley 8 degrees outside now and mine will run between -.14 and -.20 and pull both baro dampers open. it will hold the baro for the Hotblast almost wide open and will pull the baro for the oil furnace open slightly and it will bounce every time the wind blows...

Oil furnace baro on the left and the Hotblast damper on the right...

Ky, your case is a perfect example for the nay sayers that claim baros cool the house by sucking warm air out and up the chimney.. If anyone was to have a problem with this effect it would be you with not one, but TWO baros wide open pullin .2 -.3... Most of us use one baro and only pull a FIFTH (or less) of that..

Yup... I dared to go there..

Yep.
Sometimes I stand there and look at those baros thinking to myself, where is all that air coming from?? So I walk around the basement feeling for drafts. I don't really notice anything that is obvious.
My house is what I would consider to be a typical "bungalow" type house' built in 1901. The basement entrance comes from a sun porch area on the back of the house. It was probably a cellar door entrance originally.the ceilings are 7' tall.
My basement is always warm. Depending on at what point of the burn cycle the stove is in. But I don't think it ever falls below 70.

I tried a MPD for a couple of weeks to see if I could get the draft down in the -.04 range like I hear most people keep theirs. The bit coal did did NOT like that thing at all. I could get it down to -.06 or so when the temp gets up in the thirties or higher and initial burn off of the voliatiles would try and back up in the stove and it always smelled like burning coal in the basement and had issues with it trying to puff back. Even with the MPDwide open at start up. Nothing ever registered on the CO detector. After about 8 or 10 days I couldn't get the mano gauge over -.05. The baros where still pulling open and smoke kept coming out of the load door every time I opened. Well you guessed it... The breech and every thing below the baro was damn near plugged with soot.
I uncapped the flue one night about 9:30pm and pulled that stupid MPD and pitched it. Then cleaned the flue pipe and it's running like a well tuned machine again. It seems to run best in the -.12 to -.15 range.
Maybe it burns more coal than it would if I lower the draft but I still get 10 to 12 hour burns. AND, no sooting issues. I quit sweating it and just enjoy the warm air...

If even you did tour the basement and find drafts, its not the blame of the baros. Cold air infiltration is gonna happen regardless due to stack effect in the house. Which is the whole point. The baro uses that cold air infiltration that is already happening naturally. Air that would be leaving the top of the house is being re routed thru the baro.

It's one of my hypotheses that can't really be proven but when looking at it from a pressure perspective, it's all crystal clear.

If you're selling it Lee, I'll buy it.

Yeah that actually makes a lot of sense.
My floors are actual old-school tung and groove hardwood. When you look up from the basement you see the actual bottom of the hard wood floors. There is no sub-floor. There are several areas when you're in the basement if you look up you can see light from the first floor. So there is certainly plenty of air being pulled down from the first and second floors.
The second floor is actually what use to be the attic and was finished out 60 years ago with the old school knotty-pine paneling. Even though we have added tons of additional insullation it's still nowhere close to air-tight. So pulling in outside air from the top of the house is very easy I'm sure.
Hot air naturally rises and cold air falls. I know there are other factors with regard to pressure but in a nutshell that seems to make sense.

Ky Speedracer wrote:Yeah that actually makes a lot of sense.
My floors are actual old-school tung and groove hardwood. When you look up from the basement you see the actual bottom of the hard wood floors. There is no sub-floor. There are several areas when you're in the basement if you look up you can see light from the first floor. So there is certainly plenty of air being pulled down from the first and second floors.
The second floor is actually what use to be the attic and was finished out 60 years ago with the old school knotty-pine paneling. Even though we have added tons of additional insullation it's still nowhere close to air-tight. So pulling in outside air from the top of the house is very easy I'm sure.
Hot air naturally rises and cold air falls. I know there are other factors with regard to pressure but in a nutshell that seems to make sense.

I know first hand how easy it is.

My FIL lived in a very old house with a coal furnace in the basement. He decided he was going to hook up cold air returns because he was told he could heat the house easier. Not so...........his house actually got colder. The longer the blower ran, the more cold air it was pulling from outside . And that's why I haven't hooked up cold air returns in my house yet.

As a bricklayer, I've built many a fireplace and many hearth setups for woodstoves and used outside air kits to bring the combustion air directly to or in closer proximity to the fire. Air is going up the chimney and it has to come in from somewhere.

I was also a oil burner tech for quite some time and have installed, repaired, calibrated and picked up off the basement floor many a barometric damper. I cannot imagine listening to the constant rattling of a baro in my living quarters. I believe this is my third year burning coal and I can think of only once where a barometric damper would have improved my situation, maybe, and that was just last week. The problem wasn't too much draft, the wind was driving the gasses back down my chimney. A baro wouldn't have done much to solve that.

tmbrddl wrote:As a bricklayer, I've built many a fireplace and many hearth setups for woodstoves and used outside air kits to bring the combustion air directly to or in closer proximity to the fire. Air is going up the chimney and it has to come in from somewhere.

I was also a oil burner tech for quite some time and have installed, repaired, calibrated and picked up off the basement floor many a barometric damper. I cannot imagine listening to the constant rattling of a baro in my living quarters. I believe this is my third year burning coal and I can think of only once where a barometric damper would have improved my situation, maybe, and that was just last week. The problem wasn't too much draft, the wind was driving the gasses back down my chimney. A baro wouldn't have done much to solve that.

I had that problem here but only when the wind came from due east. I made a cap for on my chimney, and although my draft does decrease significantly, the downdraft stopped.

SWPaDon wrote:I had that problem here but only when the wind came from due east. I made a cap for on my chimney, and although my draft does decrease significantly, the downdraft stopped.

Yours must be a brick chimney with the piers holding up a concrete cap? Mine is metalbestos and has a cap but it doesn't shield the wind, it only keeps out the rain. It set my carbon monoxide detectors off so I had to fiddle with some manual adjustments to compensate.

Mine is 8x8 red brick, but the previous owner had a 6 inch smooth wall stainless liner installed, and they put mortar around the outside of the liner clear to the basement. There was a small woodburner in the basement when I purchased the house, along with electric baseboard heat.

EDIT: My cap is a homemade sheet metal cap with 3 legs and a homemade band clamp holding it to the pipe.

"If even you did tour the basement and find drafts, its not the blame of the baros. Cold air infiltration is gonna happen regardless due to stack effect in the house. Which is the whole point. The baro uses that cold air infiltration that is already happening naturally. Air that would be leaving the top of the house is being re routed thru the baro. It's one of my hypotheses that can't really be proven but when looking at it from a pressure perspective, it's all crystal clear." (says Lee)

Except: The baros aren't consuming the cold, recently infiltrated outside air. They're sucking some of the warmest air in the house: in most cases, from very near and slightly above the heat source. And when drawing big numbers on the nano, wouldn't this also tend to establish air currents in the house TOWARDS the heat source (the opposite of the desired patterns)?

Disclaimer: I have a stove that benefits greatly from a baro, and one that does fine without one, so one vote cancels the other. And if anyone is throwing away MPD's, you can throw one my way.

Belgianburner wrote:Except: The baros aren't consuming the cold, recently infiltrated outside air. They're sucking some of the warmest air in the house: in most cases, from very near and slightly above the heat source. And when drawing big numbers on the nano, wouldn't this also tend to establish air currents in the house TOWARDS the heat source (the opposite of the desired patterns)?

As SB Woo my college physic teacher used to say with a heavy accent that took us 1/2 the semester to understand.....'consider your entire system'.....

regarding the baro taking in heated air... I've always thought it is better for it to take in and send 80* (or thereabouts) air than have the 500* air from the firebox going up the stack.

regarding the air currents heading back to the stove..... Although I'm not sure the baro is an efficient way to get air heading back to the stove for better heat distribution since the air may not be coming from the coolest room in the house; you do need the cooler air returning to the stove so the heated air can fill the space it vacates. There are many examples on the forum of improved performance when a basement door is opened or a duct from the most distant room improves temperature balance due to the air loop it creates. It's all about balance for the best flow, supply and return need to be equal same as in a water system.

The baro is not the answer in all situations, sometimes it may even hurt performance, sometimes an MPD will be better suited, sometimes neither.