Taller chimney vs draft inducer

[muleman51]

I just put up a new chimney, it draws between .04 and .05. I have 12' of insulated outside and 6' single wall inside. Should I add another 3' section of chimney outside or add an inducer inside, I feel I am just on the edge of having enough draft. I'd like between .06-.08 if possible.

 

[FatttFire]

How did you measure the draft?

 

[begreen]

Depends on the stove. Are you seeing issues so far? If not, I would try what you have for awhile. If it doesn't work, my preference would be to add the 3 ft.

 

[Metal]

Draft is dependent on more things than just chimney height. What is the weather like when you are testing it? As BeGreen stated, IF you have issues add another section first as it is the "cheapest" fix. I would guess if you checked at the right time when conditions are right you would measure higher draft, it's all about temperature and pressure.

 

[swestall]

I would also opt for adding a lenght of pipe. Not just because it is cheaper, it is also simple. I like the simpler soulutions being less complex they tend to last a long time with no problems.
Try a piece of inexpensive pipe up there to see if it makes the difference, if it works you can add SS.

 

[Metal]

On Class A (UL 103HT) vent you need to use the cap at all times (it is actually tested and increases the draft in windy conditions. I would not suggest putting a piece of single wall on top as it won't have the appropriate locks/attachments as the Class A so it could fall off and the cap probably won't fit on top as there is no outer wall. Also the single wall will cool easily and creosote could buildup very quickly. I wouldn't suggest this setup, even if temporary.

 

[muleman51]

This is for my boiler, I have had it plug up in the back and it's no fun cleaning it. If one piece of pipe fixes it then its cheaper but if it takes two its cheaper to go with the inducer,plus it doesn't get so high. I can try just putting up a piece of stove pipe on top. Does draft improve with outside temp rise or decrease or is it only dependent on exhaust temp (only around 300*). Also does a rain cap decrease draw? I measured the draft abou t inthe middle of a section 18" from outlet with a incline manometer when the boiler (Adobe gassification boiler) was up to temp (180* water temp).

 

[Metal]

The colder it is outside the better your draft should be (it is more the temperature differential). You may get some better advice in the Boiler Room on this one.

 

[slowzuki]

If its a Greenwood type boiler, I'd vote draft inducer because most like to run them while loading to reduce the face full of smoke issue.

 

[Gooserider]

I see someone already moved this to the Boiler Room, thanks... I would say that putting a length of stove pipe on the Class A is definitely not reccomended as a long term solution, however as a test, there is no problem with doing it - IMHO it is reasonable to spend $5-10 on a hunk of cheap pipe to see if it helps the draft before spending a whole bunch more on a length of Class A.

Rain caps are another issue with boilers... Seems there is more debate about whether they are needed / helpful on some boilers. According to another thread I just saw, the new Maine state regs on them actually prohibit the use of rain caps unless the manufacturer requires them... The concern seemed more with whether they made the smoke go sideways rather than the amount of obstruction, as one of the "problems" with outdoor boilers is that they tend to have short stacks that don't get the smoke up and out of the way as well as most stoves do.

Gooserider