Generator Exhaust - Running To the Roof

[Doug1968]

Fellows,

Here is my plan for exhausting my generator. I would appreciate your thoughts on this idea.

a) My diesel generator will be mounted in the first bay on the drivers side.
b) It will be mounted on a slide that will allow it to be pulled out for service. The exhaust will include a flex pipe to allow sliding the generator sideways as required to get it out of the coach. I am hoping this flex pipe allows moving the generator without the need to disconnect the exhaust?
c) The exhaust pipe, 1-1/4" will be run inside of a type B double wall gas vent pipe. The 1-1/4" pipe will have a series of spiders slid over it to assure that the pipe stays centered inside the type B vent pipe.
d) The exhaust system will exit the generator bay near the top of the bay ceiling and then run into bay number two. It will then make a 90 deg. turn and be routed through the cabin floor, up through the coach interior, and through the coach roof. The entire run will be through the type B vent pipe to assure that heat is not transferred to the coach floor or other structural members.
e) The vertical run through the coach interior will be placed inside of a chase designed next to a kitchen pantry cabinet and will be completely out of view.
f) If necessary, I could wrap the pipe with high heat insulation to assure a safe installation. I will also insulate well around the vertical run to minimize noise within the coach.
g) I am leaving the OTR heat/air system in place and will not plan on running the generator while driving.

Has any of you run your generator exhaust this way? Ideas and thoughts would be greatly appreciated.

Thanks,

Doug

[DMoedave]

The movable flex pipe will be a pain, but this could all work. The problem would be lots of $, time, and lost space on the interior. Not thrilled withthe safety factor either. Get to a rally and check out how people hang the up pipe. Some real nice,good looking installs around. Mine is not one of those i have 2 pieces of gutter pipe (white square type) that i slide together and hang. If your not using it while driving i would go the outside route. I have seen people run the exhaust inside tho. Good luck

[bevans6]

I've seen it done, a MC-5 at the SEBN rally in the spring had it done that way.  I think the challenge is the trim treatment on the roof of the bus. 

Brian

[luvrbus]

Doug the big boys use a swing joint not flex pipe for the generator with a slide I have no idea where you buy one maybe Newell. sevaral Eagles owners run through the roof they way you are doing if you need help ask Paul for Waynes number he is doing one now and use a stainless tip the chrome ones look tacky when they rust lol


good luck

[rusty]

Doug, I did it very similar to the way you described. I used 1 1/4 pipe inside of a double wall vent pipe and i wrapped the 1 1/4 pipe with insulation. I also ran the exhaust under the bus for about 12 feet with the muffler under the bus, that helps it cool before it enters the bus. You can but you hand on the vent pipe and it is no warmer than the surrounding air.

Good Luck Wayne

[Frank @ TX]

Hi Doug,
We ran the gen exhaust thru the bus an out the roof.
The gen is in the old AC condencer bay under the drivers area.
Flex pipe for about 2 feet to isolate the vibrations.
Then down thru the bay floor , 90 degree turn towards the rear into the muffler.
About 3 feet further ( according to the interior design ) the exhaust pipe turns up.
The exhaust pipe is in the middle of a 6" electrical conduit.
The conduit is bolted to the bay floor and the interior floor and the roof.
The exhause pipe just runs thru the middle of the conduit.
There is lots of room for air folw around the pipe to help it insulate the conduit.
If you're up on the roof you can look straight down thru the conduit to see the ground.
I had a muffler shop bend a tip to direct the exhaust 95 degrees to keep out the rain.
AND The exact same to the AquaHot exhaust on the pass side.
Both work great for 10 years now.
Lots of ways to do it.
Just make sure you don't have metal to metal contact , that noise will come thru to the interior.
Frank

[Fred Mc]

I went to an Indy race one time and saw how they did it with their million dollar buses so I did the same. Rant the exhaust from the generator to the side of the bus. When parked I slip a piece of flexible exhaust over the pipe and it connects to a 10 foot piece of 2 inch exhaust tubing. It is secured to the side of the bus with a couple of brackets that are invisible when the pipe is removed. I store the pipe UNDER the bus longitudinally when traveling. If you want to get fancy then have the stack chromed like the indy guys. I painted mine.

Fred Mc

[Greg Roberts]

I ran mine up through the double wall as you suggest. I wrapped with high temp header wrap and then covered that with metalized tape to hold all in place and used clamps on the end to also lock the wrap in place. In my design I leave the gen and flex to the muffler and then hard pipe from the muffler to below the coach. This pipe goes back to the next bay and passes through the double wall that runs from below the coach all the way through the roof. I have a strap support on the bottom that holds and centered the pipe. In my design I leave the bottom and the top of the double wall open so that any future gases escape to the outdoors rather than into the coach. I have also sealed all of the double wall seems and wrapped all joints with metalized tape. I did not need to wrap the external of the double wall with additional insulation as it is just warm to the touch. I am using 1 1/2" pipe on a 15kw unit and have no back pressure issues and no carbon build-up. I use a tractor flap on top of the exhaust pipe. I have 2 CO detectors installed for additional safety. Works like a charm and I get no complaints anywhere I go. That was my way.

[artvonne]

  Just remember that carbon monoxide is heavier than air. If you run it up to the roof, it can seep in where you live.

[Tenor]

Here is how I built mine.

http://www.busconversions.com/bbs/index.php?action=printpage;topic=12727.0

There used to be detailed pictures that went with this, but their gone now.  Moderators?  I will add, that the flagpole collapsed and I now have re-built it using metal.

Good luck!
Glenn

[Gary '79 5C]

Artvonne,

I was in your camp of thinking CO is heavier, however it is actually carbon monoxide is actually very close to the atmosphere's molecular weight and is neutral neither will it rise nor fall. I was installing CO detectors, previous security installation company work, and I wanted to get it correct. I checked this with several chemical engineers, and it is so. Many fire officials have different opinions than that of mole weight.

Have a great day.

Gary

[steve wardwell]

On our gen slide we have flex pipe running from the gen up to the top of the bay then down and out the bottom. The loop is such that it moves very little when sliding the gen back and forth...we have a muffler under then a turn towards the side of the bus. We don't have a stack yet but will eventually. For buses with the stacks running inside, the top fitting needed to shield the pipe opening is called a "Charlie Noble" in the boating world. Most are made of ss and have some have flanges to screw down to the roof... I have used these and are good quality and I thought looked  better than a truck type flapper.The boating industry also has pipe in pipe exhaust for just this app in ss meant to be exposed in the cabin.........s........

[Len Silva]

Here is how I built mine.

http://www.busconversions.com/bbs/index.php?action=printpage;topic=12727.0

There used to be detailed pictures that went with this, but their gone now.  Moderators?  I will add, that the flagpole collapsed and I now have re-built it using metal.

Good luck!
Glenn

Try this:
http://www.busconversions.com/bbs/index.php?topic=12727.5;

[FloridaCliff]

The exhaust will include a flex pipe to allow sliding the generator sideways as required to get it out of the coach. I am hoping this flex pipe allows moving the generator without the need to disconnect the exhaust?

I welded in a steel union on mine.

Makes for any easy disconnect when needed.

Cliff

[artvonne]

Artvonne,

I was in your camp of thinking CO is heavier, however it is actually carbon monoxide is actually very close to the atmosphere's molecular weight and is neutral neither will it rise nor fall. I was installing CO detectors, previous security installation company work, and I wanted to get it correct. I checked this with several chemical engineers, and it is so. Many fire officials have different opinions than that of mole weight.

Have a great day.

Gary

  We had an alignment mechanic that worked in a pit at the end of the shop. They brought several cars in one day and left them running. He ended up at the hospital from carbon monoxide poisoning. I cant argue how close its weight is, I dont really know, its just what ive been told and have read. But seeing as the only guy in the shop to get poisoned with carbon monoxide worked in a pit, its enough evidence for me.