Opinions wanted on oil boiler venting

Mark_25

I'm soliciting opinions on how best to pipe the venting for this oil boiler. I'd like to use L-vent, but am having a very very difficult time locating any in the area. I'm in the midwest, and nobody in the area carries or can get L-vent in less than 3-4 weeks. I have been checking the local supply houses, and nobody stocks it. So, I'm thinking I'll have to order some online or mail order or something. But the real question here, is how would you pipe the Vent? I had two ideas, one was to use Duravent DVL double walled stovepipe, and put the tee for the barometric damper right at the boiler breech, and use two 45's to get up to the straight section that runs to the Tjernlund SS1. The other, in the event I can't use DVL or equivalent, was to put the Tee in the main staight section, and the Barometric in the end of the tee, and use a 15 or 30 degree elbow straight into the breech. The benefit of doing the latter, is I can use Class-A chimney if I can't locate any L-vent anywhere. I've been trying to get either Selkirk or Security L-vent, but nobody seems to stock it, and I even had one supply house tell me that Security just went out of business. The only other option I can think of, is Zflex or something like that, but I'm not sure how I would handle the Barometric on Zflex. I don't have the 18" clearance for single wall pipe anywhere in the system. Any ideas or suggestions?

In case anyone needs it, I'm using a WGO-2 w/ 6" flue, top breech, and a powervent is the only option.

John@Reliable_6

What about moving the boiler or powervent?

Mark_25

There's really nowhere else to move it. Can't put it closer to the powervent, because that would put the boiler in an enclosed space, and I don't want to do that.

Patrick Powers

Clean Air Intake

What about moving the boiler like John@Reliable said and installing a clean air intake available from Field Controls.

John@Reliable_6

What type of building is it?

Mark_25

It's a pole barn. I can't install the boiler in the room with the power vent because that is going to be a bathroom. Not allowed. The boiler is also right next to the PEX, which will make a nice clean install. I can't move the powervent because that's the clsoest exterior wall. The wall the boiler is on is the back wall of a lean to/equipment shed. Can't vent into that.

Mark Wolff

Solutions

Single wall stove pipe is allowed to connect from the boiler breech to the powerventer IF you have at least 9" of clearance to a non-combustible, air separated surface.

We have to do this all the time so here goes.

First use DuraRock or some other brand of concrete board, cutting out a big enough square to cover any combustible surface within the 18" minimum. Using 1/2" copper couplings (or some equivalent to allow a 1" air gap between the combustible wall and the DuraRock, fasten the DuraRock to the wall with long sheetrock screws. It doesn't take much, usually 1 screw per corner and 1 every 24" around as needed.

This creates a sandwich effect of DuraRock, 1" air gap, combustible surface. If you look in the codebooks you find that the 18" clearance is halved to 9" if you follow this construction method.

nick z.

Thru the roof?

Anyway you can go up through the roof? Using double wall.

Mark_25

Don't have the 9 inches to the ceiling. Last I looked, you couldn't run single wall through a partition wall. That's why I was looking for Lvent, which you evidently can run through a partition wall.

Mark_25

I really can't run it through the roof.

Mark_25

does anyone know if you can put the barometric damper in the straight end of the tee? And let the appliance vent into the side leg? Like this:

------------ BD
|
Boiler

Seems like this would work, as it would essentially be a chimney laid horizontal. Draft would still flow from the powervent.

Mark_25

Ah, it didn't show it correctly.

_________________ BD
|
Boiler

Mark_25

Ah, it didn't show it correctly.

_________________ BD
*

Boiler

Mark_25

Ah, it didn't show it correctly.

PV T BD
Boiler

Mark_25

Ah, it didn't show it correctly.

Try this:

Jack_23

other L vent

What is your firing rate? If you are firing less than 168,000 BTU use the SSII. A better venter for less money. I represent Tjernlund, btw. The DVL and selkirk DS would be most easily found in the solid fuel distribution. Go to the wood stove guys. I sold DS, when I represented Selkirk, to Village Products (603 645-6060). Be aware that "pellet vent" is also L vent and approved for oil. Available in 4". Depending upon firing rate, it might work. What is the total run length? Do not install a barometric in the end of a Tee. You won't be happy! Insulvent by Z-flex is good too. Try to give yourself a bit of straight pipe on the inlet to the side shot. It gives a much better laminar gas flow into the SS. Also, be aware that the class A chimney is not approved for installation at more than 30degrees from vertical. And big bucks. L-Vent is the way to go with vent connectors.

Mark Wolff

No

The baro damper doesn't work correctly in that position. I've seen other contractors try it (against installation guidelines) and they blow out. The exhaust initially would rather go out the baro instead of up the chimney.

Mark_25

Really? Even with the powervent pulling negative pressure?

Mark_25

The firing rate is 0.75 GPH. About 85,000 BTU. I already installed the SS1. I could find absolutely NOBODY who could recommend one over the other when I was researching it. I found some info that Tjernlund was much better quality than Field, so that's the way I went. The minimum size Weil would recommend was 6", with the pellet vent is not available in, so I have to buy either Class A, expensive, or Type L, from Security or Selkirk. I can't find anyone selling Selkirk, so I am working with a local supplier to get Security SL vent. L is really the proper type to run, but it's just hard to find. The local retailers run Class A when they have to fix an oil furnace. NOBODY is installing oil around here anymore. But, I'm wierd, and I decided on oil for various reasons. Whatever, I'll get it sorted out, but it's sure slow going.

The run is a 90 at the breech, and an 8 foot straight shot right into the SS1. The flow should be very laminar, and should flow very well. Equivalent feet is about 18 ft. I decided to run a clearance reduction system right behind single wall from Breech to Tee, so I might be able to get a Barometric on the 18" from Breech to Tee. I bought a Field Controls 6" damper, it comes with a little ring to mount on a single wall pipe. Weil recommends a Barometric right above the breech for this model. I still don't believe that with a negative pressure in the vent, it would blow out the Barometric on the Tee end, especially if the burner is interlocked to the SS1 pressure switch, but I think I can figure out a way to get it down above the breech. Now I just have to wait for my supplier to get me parts if he can. He mentioned that Security was moving almost exclusively into Class A products, and that SL was getting hard to get. I have to believe that SOMEONE at least in the Northeast can still get and use L vent in larger sizes. Anyone got a good supplier of Selkirk or Security that will mail order?