Draft issues

[tupmoore]

I just installed a PSG Caddie add on, it works pretty well, it's hooked to 20 feet of triple wall, between the furnace and the triple wall is about six feet of single wall. My draft is still to hight even with a batametric damper installed, I can only get down to "0" from the manometer. What else can I do to lower my draft to the needed -0.04 to -0.06 range?

Jeff

 

[laynes69]

If that's galvanized pipe, I'd recommend removing it and putting stove pipe (black pipe) in it's place. Did you verify the draft before installing the barometric damper? If you have a 20' chimney, and a couple elbows, it reduces the overall chimney height. How are you verifying draft? Do you have a manometer? Having a reading of 0 means zero draft. The more the baro closes, the higher the draft will read. I have a 32' chimney and a baro keeps us between .04"-.06".

 

[tupmoore]

It is galvanized, I have a manometer, before installing the barometric it was "0.1" the triple wall has 2 15d elbows at the very top to get around a truss, i have 2 adjustable 90d elbows in the single wall which are spun around to be 45d or so.

Is it ok to come right of the furnace with a 90d elbow?

if I go higher it will draft more I think?

 

[Whitespider]

Sounds like your manometer ain't working, or it's installed incorrectly.
At "0" draft your house would fill with smoke in short order...

Keep in mind that you're measuring vacuum (or negative pressure)... meaning -o.01 is less draft than -o.02.
If your draft is indeed "0", it ain't too high... you need to increase it, not reduce it.

addendum; OK, ya' posted while I was... and that sheds a bit more light on it. When your manometer read o.1 (I'm assuming you read that as positive pressure) it was showing you the pressure differential between the room and the flue pipe... that meant you had -o.1 in the pipe (o.04 too much draft). After installing the damper the draft was reduced to "0"... meaning it's opening too easily and too far. You need to adjust the damper so it closes some... thereby increasing the pressure differential. Just forget about the "±" aspect of it and adjust the damper (closed direction) until your meter reads o.04 to o.06.

And the galvanized pipe is a serious safety/health hazard... it can give off poisonous gasses at flue temperatures.

 

[laynes69]

Two 45's will draft better than a 90. You want a strong draft. While .1" is high, it's not extreme. The baro should easily get you down in the range needed. The manual calls for .04"-.06". You need to remove that galvanized pipe, it's not meant for a solid fuel. When it's heated, it's coating can burn off which is poisonus.

 

[tupmoore]

That's all good news then can I use the barometric damper even though it is galvanized?

 

[laynes69]

They make barometric dampers that are specified for solid fuels that are not galvanized. If the baro is the only thing galvanized, I don't know if it poses a threat. I would just replace it and make it right.

 

[Whitespider]

I suppose you could put a short section of "black" pipe (like maybe 6-8 inches) between the tee and damper as an added measure to prevent it from getting too hot (likely it wouldn't anyway).
Me?? If I already had the galvanized damper?? That's what I would do... but that don't make it "right".
It's your house, your family... and your call.

 

[tupmoore]

I am going to replace it today, I am more the do it right and don't fix it later on.
Back to the draft though here is the part I do not get you are saying it needs to be a positive .04 a .06 attached it a copy of the manual. Why do they but the negatives in there. I do not mean to sound dumb just trying to learn and understand. These forums are great tools

If draft exceed –0.06 in. W.C a barometric damper should be installed on the smoke pipe. Never install a manual damper.

The barometric control must be adjusted so that the maximum draft measured at the furnace outlet does not exceed -0.06 in. w.c. Please note that a draft exceeding -0.06 in. w.c. will reduce the efficiency and could produce an uncontrollable fire. On the other hand, the minimum draft required is -0.04 in. w.c. in the evacuation pipe on the wood side, no matter what type of furnace (WOOD, WOOD / ELECTRIC OR WOOD / OIL).

 

[Whitespider]

Because when you are measuring the draft with a manometer it is showing you the pressure difference between the room and the inside of the flue. A reading of o.o6 means the room atmosphere pressure is o.06 higher than the flue atmosphere... which means you have o.06 inches water column vacuum in the flue (relative to room pressure)... which can be expressed as a negative number (-o.06)... a o.06 reading means the pressure difference is o.06, which is what you want. A reading of o.07 would be more draft (vacuum), o.06 would be less draft... and "0" means no draft. A positive reading on one side means the other side is negative by the exact same amount... your manometer is showing you the room side (positive pressure side), not the flue side (negative pressure side).

 

[brenndatomu]

Just out of curiosity, what brand/model manometer are you using? Also, you say that you can only get the draft down to 0,...from what? I think spidey is on the right track here, may just be reading things wrong. I have a Dwyer Mark II, if I hook the hose up to the wrong side, it will read backwards, the line hooked to the flue pipe needs to be hooked to the port marked "low pressure"

 

[stihly dan]

There are numbers on the damper weight, set the weight on .05 and you should be fine.

 

[Fyrebug]

Why do I need to answer when you guys have all the right answers!