Looking for the Quietest Dual Fuel 9000w+ Generator?

[Supervstech]

That would be cool.

Part of this is defining exactly what one wants. This thread/discussion has helped clarify that what I actually want is low noise (<50db would be fantastic) *for my neighbors*.

And then to avoid the zombies of course - but this is secondary.

Ok, so, ya need to excavate a bunker below the bedrock, have a water table above it, isolate it from the gravity well of the planet, and engage the bergenholm to free the entire system.

Anybody on here an E.E. Doc Smith fan?

 

[OffGridInTheCity]

Exactly.
Some on here think the noise is from the exhaust, and most of the noise isnt...

Then again... some of us just like to argue.

I agree the 1.5" exhaust coming out the wall of the shed was LOUD! But I mitigated that with a 24" long baffle box with 2" rockwool (exhaust wen thru chambers with no direct path for sound). It took the sharp noise down but I was still left with significant deep throated noise and was annoying in it's own way. Overall, at the property line I still had 70db.

 

[DPC]

This not only reduces ground level fumes but it helps quiet things by directing the sound up

 

[DPC]

Not sure what you are suggesting here.

A car engine has a water jacket and a LOT of metal dampening mechanical noises.

An air cooled generator engine does not... the exhaust is a very small part of the noise.

Thats a point I was trying to make.
You explained it in greater detail.

Sometimes its just better to learn these things by taking your car apart and trying to hush your Chinese generator with all the bits and pieces

 

[DIYrich]

OK...

The build a generator quiet shed, it needs air intake and exhause with air sound dampers. The FLOOR needs to be lines with foam, or some sound absorbing surface, the 2x6 walls need dense pack fiberglass open face with sealed surface on the outside of the building. No sheetrock reflecting inside noise.

The generator needs to be mounted to the concrete with isolation mounts.

The exhaust needs to be double wall pipe, and have a thimble wall penetration.

Airflow is key to keeping a portable generator functional.

Zombie box might be easier.

 

[Supervstech]

Zombie box might be easier.

But where am i going to get the zombies to make the box out of?

 

[faccnator]

My Honda 7000iu something or other is so quiet you can’t hear it in the house

 

[Crowz]

My Honda 7000iu something or other is so quiet you can’t hear it in the house

My 12kw pulsar is so loud people in the next county can hear it in THEIR houses

 

[faccnator]

Haha I have other generators just like that

 

[robby]

Not every day - just as emergency backup. Part of this is I'm just annoyed at how bad noise mitigation turned out with shed! so I want to continue to experiment.

I'm going to try the dual GenMax 4600 wtih parallel kit. I can compare this with my existing Champion and report back eventually.

My new plan is to run the generator on the outside of the shed - you can see the Champion 8000w here - and measure dBA at the property lines and compare. One neighbor is behind the shed, the other neighbor is to the right ~10ft with fence.

You live in a situation that is much like mine, the neighbors are not that far away and you cannot put the Genny 200ft from your house.
I know you may not want to hear it but the only solution that works well in this situation is a Honda EU-7000 or get the EU-3000 and live with less charging capability.
I know it's a lot of money but it lasts for decades with just oil and filter changes.
The noise level will be so low that you won't be able to hear it in your house and you can run it without fear that the neighbors will come after you with pitch forks.
This is why so many people on here are letting you know that they own a Honda EU series generator, it is what you will end up with after trying 2-3 more cheaper generators. Trust me I know, I gave away the other one's to friends almost 19 years ago.

BTW is that not that a Honda EU-3000is in the picture taken after the fire?

 

[OffGridInTheCity]

You live in a situation that is much like mine, the neighbors are not that far away and you cannot put the Genny 200ft from your house.
I know you may not want to hear it but the only solution that works well in this situation is a Honda EU-7000 or get the EU-3000 and live with less charging capability.
I know it's a lot of money but it lasts for decades with just oil and filter changes.
The noise level will be so low that you won't be able to hear it in your house and you can run it without fear that the neighbors will come after you with pitch forks.
This is why so many people on here are letting you know that they own a Honda EU series generator, it is what you will end up with after trying 2-3 more cheaper generators. Trust me I know, I gave away the other one's to friends almost 19 years ago.

Agree - the message is getting clearer.
(And appreciated! as that's the purpose of starting this thread)

BTW is that not that a Honda EU-3000is in the picture taken after the fire?

Yes, I have a 23yr old Honda eu3000is that continues to run very well - including a propane conversion kit about 6 yrs ago.

 

[OffGridInTheCity]

Thanks for all the comments/inputs. Looked AGAIN at the Honda eu7000is (plus my personal experience with my eu3000is) and the dBA specs are just lower! I understand dBA to be to be algorithmic in noise as the metric increases - so the 50-60dBA range of the eu7000is is significantly quieter than the 60-70dBA range of all the others - ones listed in my 1st post.

Just made an order and found a $477 ebay propane conversion kit. @DavidPoz did an eu7000is -> Chargerverter and he got 90a @53.6v, and even 100a @ 53v - close enough. And I can always run a 2nd Chargeverter with my eu3000is to get 130-140a total.

Again, thanks for the discussion!

 

[faccnator]

You definitely will not be disappointed

 

[robby]

Honda makes really good generators. Both him and the neighbors will be happy with it.

 

[jimf909]

Thanks for all the comments/inputs. Looked AGAIN at the Honda eu7000is (plus my personal experience with my eu3000is) and the dBA specs are just lower! I understand dBA to be to be algorithmic in noise as the metric increases - so the 50-60dBA range of the eu7000is is significantly quieter than the 60-70dBA range of all the others - ones listed in my 1st post.

Just made an order and found a $477 ebay propane conversion kit. @DavidPoz did an eu7000is -> Chargerverter and he got 90a @53.6v, and even 100a @ 53v - close enough. And I can always run a 2nd Chargeverter with my eu3000is to get 130-140a total.

Again, thanks for the discussion!

Good luck and let us know how it works.

Your neighbor situation is just plain challenging. The max allowable mechanical noise at a residential property line in Seattle is 55dbA during the day and 45dbA between 10:00 p.m. and 7:00 a.m. Poorly installed water heater and furnace exhausts run above that and are terribly annoying even 20 feet away. Trying to keep a generator below that in a city will be tough.

 

[cpainter]

It is not exactly "off the shelf" but might be worth considering. The MEP-803A is a diesel generator, water cooled, skid mounted and enclosed, produces clean power, low fuel consumption at 80% load. Very conservatively rated at 10Kw. These units are military surplus and can be found in excellent condition if you look. I bought one with 29 original hours. The unit I bought was smaller at 5Kw and it cost $1,100. It had a couple of missing parts that were probably removed to keep another unit going. (A fuel pump and an oil pressure gauge both easily replaced). It even had new optima batteries in it. They run at a lower RPM (1800 IIRC) so they are not too noisy. I think the military calls them "tactically quiet".
You can buy them from a government contractor like GovPlanet, a division of Richie Brothers or you can find a vendor who has refurbished one and is offering it for sale if you don't want to do this yourself. These generators are quite reasonably priced for a generator that is reliable and built to last. They typically run about 10,000 hours and then are rebuilt. Try that with anything you find at a big box store. I don't think you are going to find anything in the 10Kw size class that is going to be truly quiet but this unit will probably be as quiet as any and it is affordable and is built to last.

I also opted for an MEP-802a. Diesel is far less flammable and is more efficient and easier to store. I got lucky and bought mine from a current military helicopter mechanic for under $2k. It was mounted on a military trailer (converted to 12V), serviced and ready to use. I like it portable in case I want to use it in a different location from time to time. For those wanting it stationary, they can buy one without the trailer and mount wherever they want.



I found this site to be a great source of information on these military units: https://www.steelsoldiers.com/forums/generators.55/

 

[ghostwriter66]

Exactly.
Some on here think the noise is from the exhaust, and most of the noise isnt...

Then again... some of us just like to argue.

Yep -- once they put an exhaust muffler on the end of the duromax's you could really just hear the engine clanking around ... sounded like a toolbox bouncing around on the back of a quiet truck ... but agree that about 85% of the NOISE is coming from the muffler ...

 

[Supervstech]

Yep -- once they put an exhaust muffler on the end of the duromax's you could really just hear the engine clanking around ... sounded like a toolbox bouncing around on the back of a quiet truck ... but agree that about 85% of the NOISE is coming from the muffler ...

This is a disagreement to my quoted post.
Not an agreement.

In water cooled engines, the majority of the noisr is out the tailpipe.

Air cooled, especially task motors like lawn mowers and generators, the noise is from the block itself...

 

[going_commando]

For the price of buying 2 inverter generators, a paralleling kit, and a chargeverter, you could probably by a Generac smaller unit and a 2 wire start kit from one of the online dealers. Might be something to consider.

To the people recommending older Onan, stop it! Don't raise the used price of the best generators ever made! My old man is a burgeoning Onan collector and has 6. I have a 5500w portable in my garage as my backup power that my grandpa bought in the early 90s and it still runs like a top, but it's a 3600rpm screamer.

 

[DPC]

Or for price of a generac you could buy a good generator like a used Kohler

 

[OffGridInTheCity]

The eu7000is arrived yesterday and did some sound tests today. Running the Honda at our deck in the open = 50-55'ish dBA at neighbor's property line. This meets what I was originally hoping for trying to run inside the shed. Fantastic - the neighbors can accommodate 55dBA at the fence line and I feel like I can run the generator without cringing!

Thanks for thread comments pushing me to buy the Honda! Plus it's just a fantastic little machine in terms of perceived quality up close.


The Details....
Here's a couple of pics to illustrate 2 locations to run the generator for the noise tests - in front of the shed and under the deck. I have wiring in place back to the Chargeverters at each location.


For the tests - powered the same Chargeverter set to 80a = 4800w, steady load at the current battery voltage.



Measured sound levels at various places around the yard. #1 thru #4 are at the neighbor property lines. #5 is near the street (no issue there) and #6 is up on the deck just outside our door - e.g. affects what we hear in the house.


Look at these Honda numbers at the neighbors - the green line. Only about 10dBA above the base noise level. The 70dBA outside our deck door is doable - especially for the sake of not worrying about the neighbors!

And then, look at the Champion Model 100297 8000w numbers at the front of the Shed - 10-15dBA increase - is on the order of twice as loud as I understand it.

 

[jimf909]

Wow! That must be a night and day improvement. Congrats and thanks for sharing the test results.

Have you tried it at 100 amps charging?

 

[OffGridInTheCity]

Wow! That must be a night and day improvement. Congrats and thanks for sharing the test results.

Have you tried it at 100 amps charging?

The Honda eu7000is is only rated for 5500w continuous and can't keep up as the battery voltage rises toward 57v (max the chargerverter can do). For example, at 56v battery * 100a Chargeverter = 5600w of charging and at 90% efficient the Chargeverter needs at least 6,200w continuous coming in.

@DavidPoz did a nice youtube on his eu7000is vs Chargverter - and at 9:10 you can see 100a but the battery is only 53.4v and the eu is at 5700w which it can't do continuously. Like David - I'm going with 80a as my default setting.

 

[DPC]

The Honda eu7000is is only rated for 5500w continuous and can't keep up as the battery voltage rises toward 57v (max the chargerverter can do). For example, at 56v battery * 100a Chargeverter = 5600w of charging and at 90% efficient the Chargeverter needs at least 6,200w continuous coming in.

You need an engine rated for 2 hp continuously for every kVA.
Very few modern generators advertise this...

As far as performance quality and quiet opperation.

Honda makes a quiet generator.
History:
In the late 60s Honda wanted into the small engine business but they were not willing to get into a slug fest with the likes of Briggs and Stratton.
The battle between Clinton, Briggs and Tecumseh was brutal.
It was a race to build the cheapest, lightest and do it in Volume.
Honda wanted no part of that so they went a different route .

They looked at Kohler and Wisconsin and Onan fighting for the quality market and they built an engione that good, but light small like the consumer end of the market.
They dominated this after a while.
The crushed it !

The cost of building a cheap engine started to look pretty bad on the consumer end of the market and people started to want the Honda products for home use too.
This scared the hell out of the remainers briggs tecumseh.
The response was commercial version of their cheap engines.

The G200 was still arguably a slightly better engine than 13 cubic inch Briggs for about the same price.
Tecumseh decided they would build ever cheaper engines and until they went out of business...

The GX series of Honda engines raised the bar again.
This put Briggs and Tecumseh into bankruptcy.

Then came the Chinese, and the clones and now you can buy a cheap version of a Honda and not see a significant difference in value.
And the parts are all the same so its cheap to repair.

Honda decided to fight the clones with a new cheap engine.
Beware of the cheap engines guys.
The GC series are not what they appear to be.
no corner was left uncut.
Yes they are clone fighters, the run pretty good but they are so cheap.

We are at a point where I would rather a clone than a Honda ( unless its the expensive commercial engines like the IGX )

 

[Brucey]

You need an engine rated for 2 hp continuously for every kVA.
Very few modern generators advertise this...

As far as performance quality and quiet opperation.

Honda makes a quiet generator.
History:
In the late 60s Honda wanted into the small engine business but they were not willing to get into a slug fest with the likes of Briggs and Stratton.
The battle between Clinton, Briggs and Tecumseh was brutal.
It was a race to build the cheapest, lightest and do it in Volume.
Honda wanted no part of that so they went a different route .

They looked at Kohler and Wisconsin and Onan fighting for the quality market and they built an engione that good, but light small like the consumer end of the market.
They dominated this after a while.
The crushed it !

The cost of building a cheap engine started to look pretty bad on the consumer end of the market and people started to want the Honda products for home use too.
This scared the hell out of the remainers briggs tecumseh.
The response was commercial version of their cheap engines.

The G200 was still arguably a slightly better engine than 13 cubic inch Briggs for about the same price.
Tecumseh decided they would build ever cheaper engines and until they went out of business...

The GX series of Honda engines raised the bar again.
This put Briggs and Tecumseh into bankruptcy.

Then came the Chinese, and the clones and now you can buy a cheap version of a Honda and not see a significant difference in value.
And the parts are all the same so its cheap to repair.

Honda decided to fight the clones with a new cheap engine.
Beware of the cheap engines guys.
The GC series are not what they appear to be.
no corner was left uncut.
Yes they are clone fighters, the run pretty good but they are so cheap.

We are at a point where I would rather a clone than a Honda ( unless its the expensive commercial engines like the IGX )

The Honda eu2200 uses a GXR120 I believe. Oversized for the rated capacity. Heritage is as rammer engine.

The GC line are only used in some of their lawnmowers?