Pacific Energy Spectrum installation.

[LLigetfa]

The bracing of long sections above the roof is a code requirement. Stay closer to the peak and avoid having to use bracing. Cheaper too and looks better.

What pitch is the roof? I'm guessing it's 6/12. If so, 4 or 5 feet off the peak would avoid bracing. What is the height of the peak AGL? You should be able to get by with going 2 feet higher than the peak on a straight up shot.

 

[begreen]

Bracing is not a big deal, we have one. It is required for every 5 ft of pipe sticking above the roof. So one Simpson brace would add $75, or if you are handy, you could make one out of 1/2" conduit and flat strapping for under $10. Maybe it's just me, but locating the stove so the shop is nicely functional seems more important because the shop is used year round.

 

[begreen]

Okay, here's the outside. And don't even get me all worked up on how much that pipe on the outside would cost. I was only posting the pic's for idea purposes. Looks like I would once again be better off going through the roof.

Yep, that is the idea and a whole lot safer than his stove install. Note there is no gable overhang on this house, but for parts, that is the general idea for the outside flue.

 

[whotheguy]

Bracing is not a big deal, we have one. It is required for every 5 ft of pipe sticking above the roof. So one Simpson brace would add $75, or if you are handy, you could make one out of 1/2" conduit and flat strapping for under $10. Maybe it's just me, but locating the stove so the shop is nicely functional seems more important because the shop is used year round.

I agree with you Begreen, function is important. Actually, the picture of the other persons stove install happens to be the same wall that my stove would be located at. It would be by the window you see in the pic of my house. This way it's on the other side of the shop that I don't use much. It would also be on the far side of my table saw out-feed table, but yet far enough so I didn't toast my buns should I bump into it should I be on that side of the table, which I rarely am. All my other machines are far from the stove so no worries of hitting it with any boards.

 

[begreen]

Got it. That makes things clearer. I'm just visually guestimating, but if it was adjacent to the window, or in front of one of the windows (with proper rear clearance from the stove), there might only be about 4' above the roofline and no brace required. If so, Ligfetta's suggestion is a good one and the stove is still out of the way.

 

[LLigetfa]

Maybe it's just me, but locating the stove so the shop is nicely functional seems more important because the shop is used year round.

Since whotheguy was going to exit via the window which is centred below the peak, taking a straight up flue nearer to as opposed to further from the peak seems to be in keeping with where he wants the stove. Going slightly off the peak gives him more flexibility in placement than being forced to centre it on a window.

Having more flue in the attic which appears not to be insulated could be a tad warmer than having the same amount of pipe outdoors.

Lastly is aesthetics. I see a lot of monstrosity shiny missles going up the side of houses and wonder what the owner was thinking. On my 12/12 roof, had I gone up the side not on a gable, I would have had 14 feet of outdoor chimney with two sets of braces. COming out near the peak left me with only 5 feet outside. Mind you, it is a tad short so the draft suffers but it would suffer much worse with more of the flue outside.

 

[whotheguy]

I don't know why I keep bringing this up expecting different results. Isn't that the definition of insanity....no comments please.


I just went and measured the outside of my garage wall. I put some yellow lines in the pic to show the distance....it's 13 feet.

Okay, let me have it, just be gentle... :bug:

 

[whotheguy]

And yes, the attic is just as cold as the garage, sometimes colder. With that being said, I can't see how I would have a gain by keeping the pipe within the confines of house expecting it to be warmer. Granted if the flue ran through the attic it would certainly put off some heat from the pipe.

 

[LLigetfa]

That is not enough length for a through-the-wall install. You lose 10 feet of effective height with the elbow/Tee and with all of the pipe out in the cold it will draw less. That length is just barely enough for a straight up shot through the ceiling.

 

[LLigetfa]

And yes, the attic is just as cold as the garage, sometimes colder. With that being said, I can't see how I would have a gain by keeping the pipe within the confines of house expecting it to be warmer. Granted if the flue ran through the attic it would certainly put off some heat from the pipe.

The pipe could be chased inside the attic to retain some of the heat if it was needed for draft. Since the attic is setup as storage, code might even require you to chase it. If you have draft to spare then yes, you can heat the attic with it by venting the chase rather than heat the neighborhood with an outside run.

 

[whotheguy]

And yes, the attic is just as cold as the garage, sometimes colder. With that being said, I can't see how I would have a gain by keeping the pipe within the confines of house expecting it to be warmer. Granted if the flue ran through the attic it would certainly put off some heat from the pipe.

The pipe could be chased inside the attic to retain some of the heat if it was needed for draft. Since the attic is setup as storage, code might even require you to chase it. If you have draft to spare then yes, you can heat the attic with it by venting the chase rather than heat the neighborhood with an outside run.

Geez o peet, something else I have to learn, what the heck is a "chase"? :sick: Okay, I figured out what a chase is....it's a damn box built around the flue After going through all what I have so far, I'm sure there is some scientific method to build one should I need it???

 

[whotheguy]

I just went and measured from the garage floor to the top of the stove=29 inches. I then measured from the garage floor to the middle of the window that's show in the pic above, it=7 feet. So subtracting the 29 inches from the 7 feet = roughly 4.5 feet. Now adding that 4.5 feet to the 13 feet I measured on the outside of the wall I have roughly 17.5 feet which doesn't include the 3 feet of pipe that would extend past the roof line. Adding the 3 would be around 20.5 feet.

 

[cycloxer]

Dude, keep it simple. Put the stove in the middle of the back garage wall and go straight out the top of the stove w/ as much black pipe as you can before you have to switch to stainless. You can offest the stove from the peak a few feet if you like to optimize its position. The advantages are numerous:

1.a. Cost. This will be your lowest cost option
1.b. Minimal external stainless chimney that looks like crap and just costs more $$$.
2.a. Heat. Centrally locate the stove in your garage for best heat transfer.
2.b. More heat from an internal chimney.
3.a. Draft. Straight up out the top of the stove drafts best.
3.b. Internal chimney drafts better too as it heats itself up.
4. Clearances. Straight up pipe will allow you to position the stove closer to the wall.
5. Cleaning. It's pretty easy to clean a chimney that is only a few feet off the peak.
6. Aesthetics. No braces or external stainless pipe that looks like crap and just costs more $$$.

If you want to put up a Rube Goldberg stainless chimney out the side of your garage and then have it extend 9 feet above your roofline, all the power to ya, but it is probably the most idiotic way to install your stove. It's your money. What's the gain?

 

[whotheguy]

I've already made up my mind, thanks to you all here, to run it inside the attic. I can't put it in the middle of the garage though, just too much stuff in the way and the room wouldn't "flow" from machine to machine as I am used to them doing. My only choice is under that window in the pic. I'll certainly keep my distances for the stove as stated in the instructions. With that also being said, is there certain distances to adhere to in regards to the pipe going through the attic? For example, not too close to trusses and such? I'm done beating the horse. I am however going to try and piece my pipe needs together using various "for sale" sites...craigslist and such.

Thanks all

Robert

 

[LLigetfa]

With a radiation shield, you can run the class A pipe between rafters that are on 16 inch centres. From the pics, I'd guess your rafters are on 24 inch centres so if your clearances work out well for placing the stove, I would roughly centre it between the rafters. Absolute minimum clearance to combustibles is 2 inches but if you have the space, use it. Don't forget to factor clearance to combustibles with your singlewall which will run on the same vertical plane. Of course radiation shield can be used if clearance is tight and is always a good idea anyway if aesthetics are not a big factor. Radiation shields help to convert some of the radiant heat into convective heat which is a good thing.

 

[cycloxer]

Yeah, you position the stove the best you can. You want a functional setup. It doesn't have to be absolutely smack dead center. Up against a wall center is good as it keeps it out of the way, but try not to wedge it in the corner. I would look up and center in between your rafters. It's the logical thing to do so that you don't need to use any elbows to jog the pipe. Measure your clearances. You may or may not need any shielding. Then look at where the exit would be in relation to the peak of your roof and you are good to go. You probably have a few workable options, so pick the setup that best fits your workflow. I understand that.

Stay away from the silver Nike missile look on the exterior of the house, I mean unless you dig that sort of thing ;-)

 

[begreen]

I've already made up my mind, thanks to you all here, to run it inside the attic. I can't put it in the middle of the garage though, just too much stuff in the way and the room wouldn't "flow" from machine to machine as I am used to them doing. My only choice is under that window in the pic. I'll certainly keep my distances for the stove as stated in the instructions. With that also being said, is there certain distances to adhere to in regards to the pipe going through the attic? For example, not too close to trusses and such? I'm done beating the horse. I am however going to try and piece my pipe needs together using various "for sale" sites...craigslist and such.

Thanks all

Robert

Download the installation manual for the pipe. (broken link removed to http://www.duravent.com/docs/instruct/L150_Sept09.pdf) It will show you the options.

The rules are pretty well defined. The main one to remember is that single wall pipe needs to stay 18" from any combustible. Double wall connector pipe or a heat shield on the single wall can reduce that clearance down to 6". Class A pipe needs to be a minimum of 2" away from the nearest combustible. As far as the exit from the roof, dead center flashings are rare and will require more roof surgery. I would offset from center at least 2 shingle courses below the roof cap. (Is that a cap vent on the ridge?) If the stove must sit under the window, then an offset with 2 - 45s in the single wall to align with the ceiling support box might be desirable.

 

[whotheguy]

BeGreen, that is a very good guide on installation, thank you. You mentioned that dead center flashing is rare. Well, since I have pre-fab'd trusses for the roof, shouldn't I have the same spacing up high as I do down low above the ceiling? I'm thinking if I split the difference of the joists on the bottom when cutting the hole in the ceiling, (24" on center), drop a plumb bob from the roof so I can get on target to the center of the hole I just cut. Now, I should have roughly the same amount of space in the roof rafters, (the ones that run at an angle from the eve to the peak)?

Now, cutting the hole in the roof, I realize class A pipe needs a minimum of 2" from combustables, I'm assuming this hole in the roof will be a bit larger, at least a minimum of 10" diameter? And the flashing will be several inches bigger than that to cover the hole?

And yes, it is a roof cap that you see.

My plan would be to center the stove to the wall, within reason, and measure to make sure I'm going through the center of the lower rafters AND be a little ways down from the peak, (a foot or so) as I don't want to cut into that.

How am I doing?

Robert

 

[begreen]

Sounds like you are grokking it well Robert. The hole in the roof will be oval as the perpendicular pipe will be going through a sloping roof surface. Once you have the roof flashing it will be apparent how large a hole you can cut. I like to drill a pilot hole in the approximate centerline of the flue system. Then take the flashing up on the roof, put it in position centered on the pilot hole, tucked under the upper course of shingles and pencil scribe the ID of the flashing cone to define my cut.

By dead center flashing I meant a roof peak flashing is a rarer animal, nothing to do with the truss spacing. That's why I suggested dropping a couple shingle courses down for the roof penetration. It doesn't have to be centered on the truss space. You can offset between the trusses and ceiling joists as long as things align from top to bottom and you are able to maintain at least 2" from combustibles for the class A pipe. Centering is good, but not mission critical.