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OT-- generator exhaust back pressure?

true temper

Stainless
Joined
Jun 19, 2006
Location
Kansas
I bought a new 3100 watt generator for my 5th wheel RV. I am making a place to mount it on the back bumper of the camper. Wife and I are VERY allergic to fumes off the engine. I would like to get some 1" flex pipe and some 1" EMT and make an exhaust stack and run up the ladder, above the roof line. The generator has a 3/4" hole coming out of the muffler. Do you guys see any problems with back pressure on the engine? Will it do it any harm?
I have a honda water pump with a long stack and its worked great for years.
 
You might want to remove the muffler. When I was in the generator business, it amazed me how much power the mufflers ate up. 3100 watt is not very big. If that's peak, it's about a 6hp motor. The portable generator builders face a challenge. Noise vs weight. The quieter they are, the more HP the muffler is eating up. So, bigger motor and more weight.
JR
 
JRIowa wrote "You might want to remove the muffler. "

Yeah, do that, and you won't have any problems with fumes. The other campers will bludgeon either you or the genny to death on the first night, so no fume worries at all!

Happy camping.

Chip
 
Chip,
Do you really think it would be that noisy after running through 8-10 ft of pipe? I don't really know, we never tried anything like that. I do know that adding any backpressure to a generator will kill performance.
JR
 
I have a 10 ft. pipe on a 6.5KW unit for home use.
It is quieter, I do not think a pipe added to the muffler adds much if any back pressure.
 
Can you convert it to run on propane (if it isn't already)

should be much less irritating fumes.
 
I'm of the school that making things louder in a campground is to be avoided.

Here's a store-bought option: http://www.campingworld.com/shopping/item/gen-turi-generator-exhaust-system/14041#readreviews

Most comments seem to be about fume improvement, rather than noise.


Some comments in this link below reinforce the backpressure=badness school of thought. Which is likely why the air-gap venturi-effect design is used in the above product.
http://www.rvforum.net/SMF_forum/index.php?topic=21854.0

It's focused on permanent-mount generators, though.

A couple genny points: In a previous decade, I had to work out of an mobile office trailer on-location at a video shoot locations fairly often, and fairly late in non-commercial areas. I ended up with a Honda Inverter Generator (EU-3000 IS) that is remarkably quiet, but dispenses exhaust thru a grill for dispersion, and doesn't lend itself to piping elsewhere. But it's got an effective muffler for sure.

During the research leading up to that purchase, I read many comments that the main source of noise from a standard generator (after exhaust) was the mechanical sound coming out of the engine (what with the explosions and all...) Worst offenders were Briggs 8-12 HP engines. No amount of muffler-foo is going to abate that. Placing them in a shallow dirt pit did, though. Not an optimal short-term solution.

Many, many folks ended up going with a pair of Honda (linkable) 2K inverter generators. Quiet as all get out, linkable for air-conditioner capability, or just use one if you're not using air. Most ended up leaving them in the bed of the pickup. But they're light enough to move where you're not, or place on the back of the trailer in a permanent (but vented) box. In that case, you could do an exhaust fan setup, with air in thru a grate in the bottom of the box, and power exhausted upwards. Would probably be good for fumes and stay cool too, if you did your math right.

If you really wanted them far away, you could put them in a box on the front of the truck, too. They're the size of small suitcases. Lots of choices...

Good luck.

Chip
 
I have done the two 2000 watt honda thing = pain in the butt, unload hook up parallel cables 2 units to fuel start and prevent theft.

Generator will not be used in a campground they have electrical hookups.

The genturi is an option, just wanted to keep it simple.

The new generator has fob remote start and stop.

Thanks for all the opinions much appreciated.

Guess I could do like this guy, quite entertaining read. http://bbs.homeshopmachinist.net/threads/34767-Generator-MOD?highlight=Geny
 
There is a device specifically for this... Its called a Gen-Turi

Because it flows into a bigger pipe with fresh air mix, it stays cool so it is not as dangerous. Many people (including me) have made one. Very easy and it works great

Google
 
Alpha you can shield with aluminum foil if you wanted to.


If you use EMT, just be aware that zinc is toxic when it burns, and EMT is meant to bend. If it catches the wind when driving it might fold over on you. Hard conduit might be a better choice. Its basically low pressure pipe, much more difficult to bend.
 








 
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