Co-Axial DV question.

[FZB]

I have been looking at Jotul's "Gas Planning Guide" for the GF 500 DV Portland and it says; "A horizontal vent run made directly off the rear of the stove must terminate ONLY with a 36" Snorkel Cap." This got me wondering about what it takes to make a DV system work well as far as draft induction is concerned.

What's the advantage of a "snorkel" over a 90° elbow + an equivalent length of co-axial DV pipe? If someone wanted to horizontally vent this stove (or one like it) through the wall and and add an elbow and 36" vertical section of DV pipe outside the building, would the stove actually know any different?

If snorkels are really the only option for a horizontally vented stove, what is inside these silver boxes that makes them work better than standard co axial DV pip and what makes them cost so much? From what I've seen online, 36" snorkels are $600-$700.

 

[DAKSY]

If you were to run horizontally thru the wall, add a 90 degree elbow & then run DV pipe vertically, you would have to run all the way past the eaves in order to meet the clearances for the vertical cap above the roof line. 3 feet above any construction within 10 feet. It might cost less than a snorkel, but it wouldn't be aesthetically pleasing.

 

[FZB]

That's interesting that a vertical cap requires so much more clearance than a horizontal termination cap right next to the wall.

So what's in the snorkel that it can be right up against the building and terminate inches away from the siding? The only information I can find about DV snorkels is either retailers selling them or generic articles saying that snorkels exist and can be used on DV systems.

It might cost less than a snorkel, but it wouldn't be aesthetically pleasing.

I'm not sure I would call those snorkels aesthetically pleasing either LOL