buderus g115ws direct vent exhaust routing

jeff121

hey guys, I recently purchased a g115ws with a riello bf3 direct vent burner kit. Ive been doing research and keep coming up with different opinions. Direct vent is not the same as power vent, right? The local hvac store says to "direct vent", it required the power vent fan to pull the exhaust out. Other sources Ive read it seems the pipe just runs out the side of the house and ends with a vent hood. (no power fan)

The boiler is on the south side of the house. the pipe will 90° up from the back of the boiler, go up 4-5' and then 90° out of the house. It will be going through drywall/wood/vinyl siding when exiting the home.

If anyone could point me in the right direction of what I actually need, I would greatly appreciate it.
Thank You!

clammy

if i where installing it i would use a tjerlunger SS1 i believe its been a while that i have done one .I like it better then the fields in any case make sure the power venter has a post and pre purge cycle .I personally like the SS1 you can adjust the draft easily and reduce the stack temp plus they fit in a 16 oc joist space and are zero clearance to combustable .You will still need to install a barometric damper .When they are set up and wiring and working as should be they have a decent lifespan i have one i did going over 16 years no issues .Off course they do like all things require maintance .peace and good luck clammy

jeff121

thanks for the info.
just to be clear, a direct vent does require a power vent?

STEVEusaPA

No, direct vent, more like balanced flue is a flue pipe and intake air extended thru the wall in the same location. Usually no draft regulator, and all seams sealed as the vent is under positive pressure produced by the burner motor..
Power vent, is power vent. Can be just a vent, or like mentioned above, a power vent with a fresh air intake (recommended).

Noel

That burner/boiler combination can be direct vented without a power venter. The length of pipe is limited to 6' of straight pipe with 2 90° elbows, maximum, using hard pipe.

HVACNUT

@jeff121.
Buderus defines what they spec for direct vent applications.
You can order it from your Buderus distributor.
Don't forget to install a barometric relief.
This brochure gives you the info.

kcopp

I would opt to build a chimney. A WHOLE lot less issues. Nothing to break

STEVEusaPA

You would build a chimney over direct vent (not power vent, direct vent)? Direct vent kinda has nothing to break at all. I mean the burner motor.

rick in Alaska

Buderus defines what they spec for direct vent applications.

You can order it from your Buderus distributor.

Don't forget to install a barometric relief.



Do NOT use a barometric damper if you are direct venting! The venting system is a positive pressure system, so if you put a barometric on, it will blow exhaust out of it.
This boiler and burner combination is definitely able to be direct vented, which means no power venter, just straight pipe out the wall.
Use a flexible exhaust system, ( can't remember what brand), or use solid pipe with the seams sealed with high temp rtv. With the solid pipe, you would have to have a thimble to go through the wall.
Be careful if you use the fields sidewall termination that has the air intake with it. The Riello has such a fast response to flame loss that if there is any wind blowing on it, it will bring exhaust back in to the air intake and the burner will recycle. You are better off with two pipes not being close together.
Rick

HVACNUT

> @rick in Alaska said:
> Buderus defines what they spec for direct vent applications.
>
> You can order it from your Buderus distributor.
>
> Don't forget to install a barometric relief.
>
>
>
> Do NOT use a barometric damper if you are direct venting! The venting system is a positive pressure system, so if you put a barometric on, it will blow exhaust out of it.
> This boiler and burner combination is definitely able to be direct vented, which means no power venter, just straight pipe out the wall.
> Use a flexible exhaust system, ( can't remember what brand), or use solid pipe with the seams sealed with high temp rtv. With the solid pipe, you would have to have a thimble to go through the wall.
> Be careful if you use the fields sidewall termination that has the air intake with it. The Riello has such a fast response to flame loss that if there is any wind blowing on it, it will bring exhaust back in to the air intake and the burner will recycle. You are better off with two pipes not being close together.
> Rick

Sorry I didn't specify.
The barometric relief is for the 4" combustion air, not exhaust.

kcopp

STEVEusaPA said:

You would build a chimney over direct vent (not power vent, direct vent)? Direct vent kinda has nothing to break at all. I mean the burner motor.

You Betcha! I have seen too many issue w/ direct vent set ups. Sooting. Lock outs. Too many pressures to deal with. Plus the really cold sub-zero winter air being sucked into the combustion chamber messing w/ the atomization of the oil. You can never really get the combustion set up properly.
No thanks.....

STEVEusaPA

@kcopp Thanks for your thoughts. You must be somewhere that gets very cold. In the Philly area, sometimes a couple days of single digits, never sub zero.
If the EK guys are lurking, I wonder how they make out with direct vent in their lab up in Fairbanks, Alaska.

Solid_Fuel_Man

I've had excellent luck with Toyotomi's oil miser boilers and heaters. The boilers and water heaters are conventional Delovan nozzled and I even had one in my own home when I had oil as backup heat. The concentric vent really helps with combustion air pre-heating. But their 3pass combustion fan moves a lot of air and it's a fire tube boiler.

kcopp

STEVEusaPA said:

@kcopp Thanks for your thoughts. You must be somewhere that gets very cold. In the Philly area, sometimes a couple days of single digits, never sub zero.
If the EK guys are lurking, I wonder how they make out with direct vent in their lab up in Fairbanks, Alaska.

@STEVEusaPA Yes sub zero here in New Hampshire is not unheard of.
I remember going to a install I did and the intake from outside was frosted on the outside of the pipe for about 2-3 feet into the home. Now granted it was -16F outside but you cant have the burner kicking off when you most need it.