Boiler exhaust

[nate379]

I am thinking of re-doing my boiler exhaust and wanted some ideas.

Right now it exits the back wall of my garage. The problem is that the exhaust can be pulled into the soffit vent and that isn't good for the house (will rot it out after a while).

I'm not sure why they didn't go up and out the roof, I guess maybe it was easier not to. Can anyone else thing of a reason?

In the pic, the vent is to the right of the people door on teh top. The bottom one is the intake (sealed combustion chamber boiler)

 

[kbs2244]

Is this one of the newer boilers that just use PVC for the exhaust?
If so, you can run it through the roof just like a plumbing vent.
I would put a wind cap on it so you don't get any blow down.

 

[tatra]

modifacation of the exhaust vent may void warranty.........that being said, the original installation may not be per manufacturers instructions in the first place.............buddy is in the hvac biz and is in charge of the crews doing the installs.........some interesting stories,,,,,,,,,,,,,

 

[nate379]

It's 3" stainless. I think it would get too hot for PVC. I haven't checked the temp but it gets hot enough that it burned my hand a while back. I would need to run double wall for sure.

I have the manual for the boiler and going straight up is ok per that. I think it was easier to run out to the back, I'm not sure?

I had gutters put up yesterday and they mentioned that it wasn't in the best place.

 

[redsky49]

Current location not per safety code. Can't be near any operable opening. The flue vent is emitting CO, an odorless invisible gas. You don't want any possibility of it entering the building. CO kills. Entering the soffit vents could also lead to infiltration of the building.

Relocate to roof per manufacturer's recommendations. Extend above roof per manufacturer and local requirements. (I have never done any projects in Alaska and don't know the roof snow load requirements. You want to have it high enough so that it isn't buried under the snow). Generally you extend 2 feet higher than the highest roof point within a 10 foot radius or some similar requirement.

Flue materials for boilers are typically galvanized or stainless. Flue temperatures for boilers are too hot for PVC.

Terminate flue with an approved vent cap, use the appropriate thru-roof thimble, etc., etc. Follow manufacturer's venting requirements.

As always, offered only as opinion

 

[nate379]

Building codes around here are fairly lax... it had to pass inspection, so it must be to code here. The house next door was done the same way.

Was thinking maybe moving the intake to teh roof as well. I'm going to have to look in teh book, but it would quiet the boiler down for sure. It's not super loud, but my bedroom is right near it, and it's annoying.

 

[walrus]

Its a power vent, isn't it?

 

[tcianci]

The only problem you have there is that it is not supposed to be that close to an operable opening. As far a rotting anything, it wont be a problem, exhaust from your boiler wont rot anything but it is slightly corrosive and the vent should be checked annually. BTW, carbon monoxide is heavier than air and it is obviously vented to the outdoors, don't worry about it. I have read lots of your posts and it seems like the last thing you need right now is another project. JMHO

 

[mikes334]

I say the more projects the better. I would look for a flue liner that is for a high efficiency unit. Maybe AL29-4C.