| Author |
Message |
Bob Ayers (Califbob)
Registered Member
Username: Califbob
Post Number: 15
Registered: 8-2006
Posted From: 4.246.224.199
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, September 25, 2006 - 11:04 pm: | |
I'm running my generator exhaust behind some cabinets up through the roof.I got some imfo on EHP. They have a great product but it's real expensive. J.C.Whitney has some a lot cheaper. Does anyone have any suggestions as to what product to use that's not going to break me? |
Jim Stewart (H3jim)
Registered Member
Username: H3jim
Post Number: 269
Registered: 10-2004
Posted From: 68.7.236.108
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, September 25, 2006 - 11:44 pm: | |
HOw about 4" double wall galavnized flue pipe like they use to vent hot water heaters etc. Run the genset exhaust straight up through the middle. use 3 or 4 screws around a circle, through the vent pipe to keep the exhauset pipe centered in the vent pipe. |
Bob greenwood (Bob_greenwood)
Registered Member
Username: Bob_greenwood
Post Number: 163
Registered: 7-2006
Posted From: 4.227.117.245
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, September 26, 2006 - 5:26 am: | |
good idea ! |
George M. Todd (George_mc6)
Registered Member
Username: George_mc6
Post Number: 16
Registered: 8-2006
Posted From: 207.231.80.150
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, September 26, 2006 - 10:39 am: | |
Bob,
Double wall flue pipe, (technically known as Type B vent) has almost no insulating value. The installation Code requires a 1 inch clearance to combustible materials, AND air circulation in that 1 inch area! In other words, if you use 4 inch B vent, you MUST have a 6 inch circular opening TOP to BOTTOM, with that 1 inch clearance open into the generator compartment at the bottom, AND into the roof opening at the top. Go in a plumbing supply store and ask them to show you a "Code Cap, and a bucket." These are the upper and lower termination fittings for type B.
On a lighter note, WW Grainger sells hi temp insulation, also several diesel performance companies sell manifold and exhaust pipe insulation in rolls at reasonable prices.
George |
Bob greenwood (Bob_greenwood)
Registered Member
Username: Bob_greenwood
Post Number: 164
Registered: 7-2006
Posted From: 4.227.118.106
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, September 26, 2006 - 11:04 am: | |
I still would do it Stewarts way...if there were ever any leaks.they would want to follow either the first or second pipe wall OUT |
Ed Jewett (Kristinsgrandpa)
Registered Member
Username: Kristinsgrandpa
Post Number: 263
Registered: 2-2003
Posted From: 64.24.212.105
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, September 26, 2006 - 11:09 am: | |
George,I didn't know there was an installation Code for genset exhausts.
Where can I find more information on this code?
I'm about to start on mine and want to do it safely.
Ed |
Jim Stewart (H3jim)
Registered Member
Username: H3jim
Post Number: 270
Registered: 10-2004
Posted From: 68.7.236.108
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, September 26, 2006 - 11:44 am: | |
There is a code for houses, and George is correct if what you are running up the middle of the flue pipe is hot gases. By running pipe up the middle, the pipe will be much cooler than the gases, and by having the ends of the vent pipe open at both ends, you will get convection cooling. In essence, its triple wall pipe. I believe that run this way, you will be able to put your hands on the outside of the pipe even when the generator has been running a while. The critical issue is how hot the outside of the vent pipe will get, as you don't want it to start anything on fire.
I have a short length of double wall vent pipe where my generator exhaust pipe exits my sound box. I can touch it after an hour and its still not hot. |
George M. Todd (George_mc6)
Registered Member
Username: George_mc6
Post Number: 17
Registered: 8-2006
Posted From: 207.231.80.150
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, September 26, 2006 - 1:22 pm: | |
Ed,
There isn't a "code" for genset installation that I know of. What I was referring to is the Uniform Plumbing Code, which governs water heater venting, and the Uniform Mechanical Code, which governs furnace and boiler venting. Both codes are exactly the same, just in a different book for different trades. I am a licensed heating and air conditioning contractor, so I use the Mech. Code book.
The original suggestion made here was to use B vent for something is was not designed for, AND without complying with all of the installation requirements, eg. venting and clearances. Now, Jim is exactly correct, "the critical issue is how hot the outside of the vent pipe will get." Also, he says "open ends=convection cooling."
One last thing left out is that there is a draft diverter on ALL convection vented appliances which mixes cool air with the hot exhaust products BEFORE they enter the B vent, thereby reducing their temperature. My concern was not for leaks, I was ASSuming that it would be a solid piece of schedule 40 steel pipe in the middle, but Bob needs to read Jim's post about "screws on the outside to keep the pipe in the center" before saying that "if there were a leak, it would go up between the walls." Its going to go through one set of screw holes and not the other? That's an invitation to wake up dead?
My concern was, and still is heat, not CO.
Convection venting, which requires openings to outside at top and bottom was not mentioned in the original suggestion. The convection venting CAN'T start in the gen. compt. and end behind the cabinets either! The coach converters don't use B vent for a reason!
George |
Bob greenwood (Bob_greenwood)
Registered Member
Username: Bob_greenwood
Post Number: 166
Registered: 7-2006
Posted From: 4.227.118.121
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, September 26, 2006 - 2:09 pm: | |
I would not use the screws suggested,just run a pipe up the middle of the 3 or 4 inck double wall pipe |
Gus Causbie (Gusc)
Registered Member
Username: Gusc
Post Number: 194
Registered: 11-2005
Posted From: 63.97.117.52
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, September 26, 2006 - 2:20 pm: | |
I used EHP wet blankets on my gen exhaust and the difference was pretty amazing.
It may seem expensive but unless you have a pretty large exh pipe a little bit goes a long way. The peace of mind is worth a lot.
I'm going to use it on my new gen also, really great stuff and the customer support is first class.
I have no connection whatsoever with EHP, just a happy customer. |
Greg Peterson (Gpmci102)
Registered Member
Username: Gpmci102
Post Number: 26
Registered: 8-2006
Posted From: 76.16.217.92
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, September 26, 2006 - 8:23 pm: | |
I used the fiberglass wrap like J.C. Whitney sells on the exhaust pipe where it came out of the turbo and was close to a large wire harness. The stuff is available at speed shops because they use it to keep the exhaust gas hotter going into the turbo for more HP. It has stainless steel ties that you use to hold it in place. It worked great no problem with the vinyl wire insulation and it is not hot to the touch. You could double wrap it for even more insulation R-value. You can even get this stuff at NAPA. |
Marc Bourget
Unregistered guest
Posted From: 64.142.42.176
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, September 26, 2006 - 8:34 am: | |
If you position the exhaust pipe properly in the liner pipe, the exhaust gas pulses will serve to evacuate (cause air flow) the liner pipe helping keep things cool.
It's a little more technical than this, but, if you're curious, ask |
sylverstone (Sylverstone_pd4501864)
Registered Member
Username: Sylverstone_pd4501864
Post Number: 196
Registered: 7-2005
Posted From: 216.173.223.253
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, September 26, 2006 - 10:50 pm: | |
seems to me that all he needs to do is leave the bigger pipe open at both ends, and the fact that heat rises will do the rest.
i personally would, if at all possibe, plumb the gen exhaust into the bus exhaust right before the bus muffler.
if you can't do that, i'd vent it out the side.
if you absolutely *must* vent it through the roof, use the hot water heater pipe that jim suggested, run your exhaust pipe up the center, and seal the bottom end of the outside pipe to your gen bay, and the top to the roof.
the idea is like this
|1|2|1|
|1|2|1|
|1|2|1|
where 2 is the exhaust flow, 1 is the 1" or so air barrier around it, that will flow upwards as well once the air starts to heat up, pulling cold air into the bottom. (i'm making the assumption that your gen bay is not airtight)
you could even put a 4" elbow at the bottom with a hole in it the exhaust pipe goes through, like this:
|1|2|1|
|1|2|1|
|1|2|1|
\1|2|1\---
-\|2|11111
--|2|11111
--|2|\----
--|2|
and use dryer vent line to come from right behind your radiator fan the generator uses, causing permanent positive airflow.
make sure there's a 1/4" gap around the exhaust pipe where it enters the elbow at the bottom to keep it from heating up the outer pipe.
-dd |
Bob Ayers (Califbob)
Registered Member
Username: Califbob
Post Number: 16
Registered: 8-2006
Posted From: 4.246.229.87
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, September 26, 2006 - 11:51 pm: | |
Thanks a million for all the input.
I think I will go with the EHP stuph. I'll wrap it up like my favorite mummy and forget it. It's one of those deals that once it's in it's there for the duration. I'm going up through the roof strickle to be "camp ground friendly" even though I consider Wal-Mart my home park and maybe stay in a park once a year. I have had complaints about that "diesel smell" even though to me it's nose music. |
George M. Todd (George_mc6)
Registered Member
Username: George_mc6
Post Number: 18
Registered: 8-2006
Posted From: 207.231.80.150
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, September 26, 2006 - 11:51 pm: | |
Bob,
One last comment!
Type B vent pipe is neither air nor WATER tight. It is designed to convey flue gasses upward by their own temperature only. It is installed in one direction only, with the smaller end up, which fits inside the larger end, which is obviously down.
Sylverstone's method of connecting the generator compartment to the roof would PROBABLY work, except, #1 how are you going to hold the exhaust pipe in the B vent? #2, What is your rooftop going to look like, and what are you going to do with all the rainwater and washwater that runs down in in the gap all the way around the exhaust pipe? I guarantee it will also leak out around each joint!!! One more LITTLE thing, B vent is designed for STATIONARY applications. It is made with a flimsy at best inner pipe, with NO securements in the middle of the run. Talk about rattles that you can't find/fix?
Sylverstone hasn't sat next to a bus with a diesel generator exhausted at ground level either!
George |
David E Wilson (North_exp)
Registered Member
Username: North_exp
Post Number: 18
Registered: 8-2006
Posted From: 205.234.33.61
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, September 27, 2006 - 12:02 am: | |
The kabuta genset ive got will be plumped into bus exhaust that way would be the quitest and safest i think,the coolant lines also will be plumed together also so when the gen is running it will keep the engine warm enough to start,and when the engine is running it will keep the gen warm enough to start,just the way i am doing it. |
sylverstone (Sylverstone_pd4501864)
Registered Member
Username: Sylverstone_pd4501864
Post Number: 198
Registered: 7-2005
Posted From: 216.173.223.253
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, September 27, 2006 - 12:13 am: | |
>Sylverstone's method of connecting the generator
>compartment to the roof would PROBABLY work,
>except,
>#1 how are you going to hold the exhaust pipe in the B vent?
not sure what a "b vent" is, but i personally would tig weld it to the top of the outer tube.
or, alternatively, you can use bolts and spacers, because by then it's not hot.
>#2, What is your rooftop going to look like,
'56 scenicruiser... pretty distinctive. not sure what you're asking here?
>and what are you going to do with all the
>rainwater and washwater that runs down in
>in the gap all the way around the exhaust
>pipe?
*shrug* what do you do with the water that splashes into your generator bay?
or your engine bay?
>I guarantee it will also leak out around each
>joint!!!
umm. the tubing i am talking about for the outside tube is seamless, so i'd like to know how you think that's going to happen? maybe your seamless tubing leaks, but mine doesn't.
>One more LITTLE thing, B vent is designed for
>STATIONARY applications. It is made with a
>flimsy at best inner pipe, with NO securements
>in the middle of the run.
you're the only one here talking about b vent.
>Talk about rattles that you can't find/fix?
>Sylverstone hasn't sat next to a bus with a
>diesel generator exhausted at ground level
>either!
nice to see that you've so very knowledgeable about what i have and haven't done.
-dd |
Arnold J Molloy (Ayjay)
Registered Member
Username: Ayjay
Post Number: 39
Registered: 10-2005
Posted From: 141.154.252.117
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, September 27, 2006 - 8:29 am: | |
Hi:
Take a peek at, and maybe make yory copy of the "GEN-TURI" system,sold by many RV places.... Stainless pipe up the middle. polycarbonate on the outside supported by a few straps in between. cool enough to touch when running.
Works great, Been using one on the outside for about eight years.
AyJay |
Richard Bowyer (Drivingmisslazy)
Registered Member
Username: Drivingmisslazy
Post Number: 1684
Registered: 1-2001
Posted From: 75.108.82.163
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, September 27, 2006 - 9:29 am: | |
I second AyJays recommendation. The system he recommends is generally designed to route the exhaust from ground level up to the top of the bus to eliminate ground level fumes, but it does run cool to the touch at all times and would seem to be the perfect solution. I used one for many years also and if I was traveling I always left it installed.
Richard |
George M. Todd (George_mc6)
Registered Member
Username: George_mc6
Post Number: 19
Registered: 8-2006
Posted From: 207.231.80.150
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, September 27, 2006 - 11:45 am: | |
Dear Sylverstone,
I do not wish to get into a stinking contest with you, and make the rest of the members put up with it also, BUT. Please read SLOWLY AND CAREFULLY, Jim Stewart's 1st reply reading in part "DOUBLE WALL WATER HEATER FLUE PIPE"
Please then read my first post, apparently for the first time, also SLOWLY AND CAREFULLY, where I EXPLAIN: "Double wall water heater flue pipe, also known as TYPE B VENT!"
Please then read Jim Stewart's next post about "a code for houses, and George is correct if what you are running up the pipe is hot gasses..."
Now, on your 5th line down, you say "not sure what a 'b vent is, but i personally would tig weld it..."
Then you "say" "*shrug* what do you do with the water that splashes into your generator compartment...?"
Then "the tubing i am talking about is seamless..."
Lastly: "your'e the only one here talking about b vent."
Sylverstone, from your posts it is obvious that you have not read the previous posts with any understanding. Two of us have VERY CLEARLY explained in several posts that double wall water heater flue pipe is described as TYPE B VENT in both the Uniform Plumbing Code, AND the Uniform Mechanical Code. You then say that you don't know what it is, but yet you tell us how to weld it? Then you tell me that I am the only one here talking about type b vent? Sorry, but you're the only one here who doesn't know what it is, by your own admission in your post!
Now, I would like to ask you to CAREFULLY consider, before replying, what would happen if you were to put a 2 inch pipe inside a 4 inch pipe, leaving the space between the two pipes open to the roof, how much water will run down in between the two pipes. IF, we use your seamless pipe, all that water will run into your generator compartment!!! If we use B Vent, half of it will leak out behind the cabinets!
NO water splashes in my gen. compt. because it still has the bay door gaskets on it.
ALMOST all of us know what a generator exhausted out the bottom smells like, and ALMOST all of us would NEVER do that to our fellows.
I also suggest that you go down to your neighborhood Home Depot and look in the water heater aisle. There you will find a whole section with Type B vent. You will then notice that it is NOT seamless, and that its joints are neither air nor water tight.
I post only to the areas where I am qualified, (and licensed) which are electrical, and heating/air conditioning. I read prior posts CAREFULLY before offering advice, and I hereby suggest you do the same. Also, please consider the possible effect of using something outside of its rating, eg. fire or Carbon Monoxide poisoning?! That is the reason I do not post out of my area of expertise
My e-mail address is: toddelec@psyber.com and you are welcome to discuss this further with me at your convenience.
George MC-6#7827) |
sylverstone (Sylverstone_pd4501864)
Registered Member
Username: Sylverstone_pd4501864
Post Number: 199
Registered: 7-2005
Posted From: 216.173.223.253
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, September 27, 2006 - 5:30 pm: | |
>Please read SLOWLY AND CAREFULLY, Jim Stewart's
>1st reply reading in part "DOUBLE WALL WATER HEATER FLUE PIPE"
and that has *what* to do with my suggestion?
bob asked for a solution, i gave him the solution *i* would use.
>Please then read my first post, apparently for the first time,
>also SLOWLY AND CAREFULLY, where I EXPLAIN: "Double wall water
>heater flue pipe, also known as TYPE B VENT!"
yes, which apparrently works well for keeping noxious gases out of your home, but won't work to do the same thing in a bus, according to you.
>Please then read Jim Stewart's next post about "a code for houses,
>and George is correct if what you are running up the pipe is hot
>gasses..."
you mean the post where he says it will work, even though you say it won't?
>Now, on your 5th line down, you say "not sure what a 'b vent is,
>but i personally would tig weld it..."
way to quote out of context.
lets try this again.
you said:
"#1 how are you going to hold the exhaust pipe in the B vent?"
using logic that most of us were taught about the same time we learned to walk, it's obvious that you are making a reference to the problem of "how do i attach the exhaust pipe (smaller tube) that runs up the center of the vent (larger tube) that you seem to be convinced is called a b vent.
therefore, my response of "personally, i would tig weld it" is perfectly valid. if i have to go into more detail, i would suggest that he take the top of his exhaust pipe, and weld 3 (or 4 or 6 or however many he feels he needs) pieces of square stock to it in a radial manner, about 3" from the top end of his exhaust pipe.
he then slides it into the outer pipe. (you remember, the stuff you call b vent? but in this case i would use stainless because welding galvanized steel takes special equipment)
weld said fins to outer pipe.
>Then you "say" "*shrug* what do you do with the water that splashes
>into your generator compartment...?"
wow. you're sure good at this "out of context" thing.
lets try again shall we?
"and what are you going to do with all the rainwater and washwater that runs down in the gap all the way around the exhaust pipe?"
my reply was "*shrug* what do you do with the water that splashes into your generator bay? or your engine bay?"
i think it stands on it's own. how about i make it clearer.
"so what?"
but, since a simple generator bay drain is too complex for you, i took the liberty of designing one to go with this.
i'll scan the drawings when i get the chance.
at the bottom end of the pipe, put a t.
this t sits *below* where the exhaust pipe enters the vertical vent pipe.
the side entry is from your cooling airflow from your generaor fan, or an electric one, whatever. the bottom one you cap, drill a hole in it, screw in a tubing fitting, route tubing outside. done.
>Then "the tubing i am talking about is seamless..."
>Lastly: "your'e the only one here talking about b vent."
>Sylverstone, from your posts it is obvious that you have not read the
>previous posts with any understanding. Two of us have VERY CLEARLY
>explained in several posts that double wall water heater flue pipe
>is described as TYPE B VENT in both the Uniform Plumbing Code, AND
>the Uniform Mechanical Code. You then say that you don't know what
>it is, but yet you tell us how to weld it?
so apparrently *you* are incapable of making, building, or buying seamless b vent tubing.
you are also the same person who seems to think that it will leak water when it doesn't leak noxious fumes from gas appliances. it *might* if you don't install it upside down, which is logical in this instance, because a bit of warm fresh air in the cabin, should you get any (doubtful) isn't going to be a problem.
... if you're using b vent to begin with, which is not, and has not, been my suggestion.
>Then you tell me that I am the only one here talking about type b vent?
i'm talking about a solution to his problem. you are the one that's still stuck on b venting, even though you have already stated that it's unsuitable. (i personally agree, and would do it with that concept, but out of better materials)
>Sorry, but you're the only one here who doesn't know what it is,
>by your own admission in your post!
not by that name, no, why should i? i'm not in a field that uses it, however, i know what it is now, since i looked it up, and i have seen it and used it before. i'm sorry you can't grasp the difference between a specific product and a concept.
>Now, I would like to ask you to CAREFULLY consider, before replying,
>what would happen if you were to put a 2 inch pipe inside a 4 inch pipe,
>leaving the space between the two pipes open to the roof, how much water
>will run down in between the two pipes. IF, we use your seamless pipe,
>all that water will run into your generator compartment!!! If we use B
>Vent, half of it will leak out behind the cabinets!
so use stainless tubing. *shrug* you are radically overstating the amount of water in question, and you *are* allowed to put a cap on the stupid thing ya know? i would put a 90 degree elbow facing backwards myself, so if you are running your genset while moving it will in essence vacum out your generator bay for you (same way a small sailboat hull drain works)
on my bus i would use aluminum, and tig weld the tube to the roof and to the top of the generator bay, keeping all the water out of the bus under any circumstances. if getting a little water in your gen bay is a problem, go all the way through the floor with it, cap the bottom, and drill a small hole in it. the air your generator cooling system is putting into that vent (or your fan if you're using one) will slightly pressurize it if you have any kind of cap on it, forcing the water out the bottom.
>NO water splashes in my gen. compt. because it still has the bay door
>gaskets on it.
so how do you keep this generator cool?
no airflow in that compartment?
no way to put a water drain in?
>ALMOST all of us know what a generator exhausted out the bottom smells
>like, and ALMOST all of us would NEVER do that to our fellows.
*shrug* not all of us park right next to other people. it doesn't bother me, your mileage, (or generator quality) may vary.
>I also suggest that you go down to your neighborhood Home Depot and
>look in the water heater aisle. There you will find a whole section
>with Type B vent. You will then notice that it is NOT seamless, and
>that its joints are neither air nor water tight.
why? i didn't suggest use that material for the job.
>I post only to the areas where I am qualified, (and licensed) which
>are electrical, and heating/air conditioning.
of which this is neither.
>I read prior posts CAREFULLY before offering advice, and I hereby
>suggest you do the same.
pot kettle black.
>Also, please consider the possible effect of using something outside
>of its rating, eg. fire or Carbon Monoxide poisoning?!
>That is the reason I do not post out of my area of expertise
no, you just go off on a tangent.
-dd
(Message edited by sylverstone_pd4501864 on September 27, 2006) |
Bob greenwood (Bob_greenwood)
Registered Member
Username: Bob_greenwood
Post Number: 174
Registered: 7-2006
Posted From: 4.227.114.46
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, September 27, 2006 - 6:06 pm: | |
this is getting into a pissing contest...I still say 3 or 4 inch hot water heater vent will work for what the poor guy that started this thread,also they make rain caps for same,like silver says,it's made to vent gases out of your house,AND,we really arent useing it,cause there is the exhaust pipe running up the middle of it.. |
SkipEagle20
Unregistered guest
Posted From: 209.148.97.32
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, September 27, 2006 - 9:02 pm: | |
On the commercial/industrial construction jobs I
have been on the insulators used a heavy materal that was ridgid and preformed to a particular pipe size. It was 2" thick by 4 foot long and came in two halves which they would hold together with stainless steel straps. Also comes as corner elbo's. It could be cut with a hand wood saw. The thickness could be doubled by using a larger pipe size and wrapping over the first layer. At times they would do a finish wrap with an aluminum sheet material to make it purty. I have seen this used on high pressure steam pipes and huge generator exhaust stacks. Check with a shop that does this type of installation to see what they recommend. |
doug g
Unregistered guest
Posted From: 4.235.248.244
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, September 27, 2006 - 5:03 pm: | |
We had a Caterpillar exhaust that melted the radiator reservoir. I wrapped the exhaust pipe with the cloth exhaust wrap from Autozone. Works fine. |
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