Generator quieting

[AFHauler]

I have a Honda 3000 EM, I am looking for some ideas to quiet it down. Anyone had success with this, want to share some ideas?

[jjrbus]

Keeping the intake and exhaust air is the key, and makes a big difference. Like I said I can see from my tinkering how you would not experience any heat issues.

In my experiments without the fans my generator runs too hot. Air temp in the intake side looks reasonable but temps taken on the gen itself rise significantly. Putting a hand on the case and saying is warm to the touch is 105°! turning the fans off and it quickly goes to 120°

I don't know, maybe my fan is not performing up to par, possibly I am way off on my design. But I am not running this in the box without the fans and may even go for a larger one, I seem to be borderline now.
Many thanks Jim

[SoundGuy]

jjrbus wrote:
After a little bit of experimentation with cardboard and masking tape, I have used a roll of tape and all the cardboard in the neighborhood. the Jauguston design runs too hot for my comfort zone, unless his 2000° insulation is somehow dissipating heat in a way that I do not understand.

I can easily get an ambient air temp in the 90's in the gen box at the inlet side of the generator, the exhaust end at the separating wall, on the "cool" side of the wall will quickly rise to 120° (temp measured at base of handle on exhaust end) without the fan assist in any ducting resembling Jauguston's. The temp in that area will drop to a few degrees above ambient when genset is taken out of box.

Also in my tinkering if I route the engine exhaust separate from the cooling air the temp of the gen set goes up. That has me completely baffled??

After experimenting with this for a few hours it is obvious that your adaptation of this design does not have this issue. Your exhaust end will only be a few degrees warmer than the inlet temps as you are not restricting airflow. Any restriction to the exhaust airflow quickly raises the case temp of the genset. If you have the opportunity the temps on yours would interest me.

Unfortunately I wouldn't now be able to provide any temp measurements as I sold my EU2000i a few months ago and the purchaser was so impressed with the quiet box after I demoed it he bought it too. :B That said, jaguston built his EU1000i quiet box back in 2007 and as discussed in this thread he did take temp measurements and found no issues at all. I discoursed with him myself in early 2015 by which time he had used his quiet box countless times and had had no temperature issues with it at all. The key, as I've detailed previously, is to take advantage of Honda's EU generator design in which both hot exhaust gas and hot cooling air are exhausted together and are prevented from mixing with cool intake air. Jauguston's design achieves that goal by sealing tightly against the generator's plastic exhaust bezel, as he described (in part) to me in this PM ...

"I'll try to describe how it works. The EU series take in cooling air from several vents on the sides near the end the control panel is on. All the exhausted cooling air and the engine exhaust comes out through a grille on the opposite end. You may see the foam donut on the bulkhead near the back of the box with a hole in the bulkhead inside of the donut. The donut presses against the outlet end of the generator around the outlet grill. This arrangement prevents heated cooling air and engine exhaust from looping back to be taken back in to the cooling air intakes. This process is what makes the whole system work using only the generators cooling fan to keep it cool without additional fans. The outlet air/exhaust then goes through a three pass down/up/down then up again maze finally exiting the box vertically up. I placed a 6" square piece of high temperature pipe wrap on the bulkhead opposite the engine exhaust outlet just behind it to protect the 1/4" plywood divider from the heat of the exhaust.

There is a 4" X 4" hinged door to access the start cord and on/off switch and another to access the idle switch. I put a duplex 120v household electrical outlet on the end of the box the control panel is and put a short (12") cord with a plug to connect to the generator. I screwed some plastic things that are made to cap square steel tube to the bottom for the feet to fit in I found in a hardware store. The size that fit over the feet of the generator. They have sides maybe 1/4" high. Their purpose is to keep the generator against the foam seal. Most anything that keeps the generator firmly against the foam seal would work.

I lined the box with 1" sound deading material purchased from reddenmarine.com ... it is commonly used to line the inside of yacht engine rooms. The sheets are about $80.00 for a aprox 34X50 some inches. Its fairly heavy. The box weighs about 28#."

My design was simply a budget based interpretation of jaguston's design and like he I experienced no overheating issues.

[jjrbus]

Don't go to your room.

After a little bit of experimentation with cardboard and masking tape, I have used a roll of tape and all the cardboard in the neighborhood. the Jauguston design runs too hot for my comfort zone, unless his 2000° insulation is somehow dissipating heat in a way that I do not understand.

I can easily get an ambient air temp in the 90's in the gen box at the inlet side of the generator, the exhaust end at the separating wall, on the "cool" side of the wall will quickly rise to 120° (temp measured at base of handle on exhaust end) without the fan assist in any ducting resembling Jauguston's. The temp in that area will drop to a few degrees above ambient when genset is taken out of box.

Also in my tinkering if I route the engine exhaust separate from the cooling air the temp of the gen set goes up. That has me completely baffled??

After experimenting with this for a few hours it is obvious that your adaptation of this design does not have this issue. Your exhaust end will only be a few degrees warmer than the inlet temps as you are not restricting airflow. Any restriction to the exhaust airflow quickly raises the case temp of the genset.If you have the opportunity the temps on yours would interest me.

Then remember I started this going with a different design so have little room to change it, if I were to make any change it would be a more powerful fan, plus I need to get done and get out of town!

Also the noise barrier from West Marine is the same as Soundown It likely is Soundown with a different name, which can be bought online for $50 sheet less! I purchased mine from IBoat for $80 sheet including shipping. There are also more than 1 type of insulation's available. So needs some research.

Your input is greatly appreciated. I would not have thought of isolating the inlet end from the exhaust end which is a big improvement.

Finding hard ways to do simple things for 68 years. Jim

[SoundGuy]

jjrbus wrote:
I like the rubber cup idea but not entirely sold on it and still looking.

Interesting conversation but I still believe you're way overthinking this. :W Ditch the exhaust fans which aren't needed, add a fan if you must for intake, either go with a ready made exhaust bezel from Generator-Line or fashion your own as I did with a Home Depot heating duct, either of which will seal perfectly, line your box with the same noise barrier that jauguston did (available from West Marine), and use a simple wedge as I did to ensure the genset remains sitting tightly against the exhaust seal, which BTW is unnecessary if you use a Generator-Line replacement exhaust bezel.





OK OK ... I'll go to my room now. 😛

[ICamel]

Soundown Acoustical Open Cell Foam.
http://www.soundown.com/Section%202%20PDFs/2.1%20PDFs/Acoustic%20Absorp%20Foam.pdf

So far I have had no issues whatsoever with the plastic/rubber furniture feet not holding the genset in place. You could go with small wood blocks that are screwed to the bottom of the box and drilled with a wood bit to size for the generator feet.

[jjrbus]

ICamel wrote:

jjrbus wrote:
I refer back to your's and other's pictures as I work. I am making good progress on mine and at the point to add the foam for the generator seal at exhaust end on mine and realized you used the foam without the decoupler layer in it! It appears the foam I have will not make a good seal.
Jim

What foam are you using? If it is the Soundown and you are curving the 3/16" board that it is mounted to it should make a great seal. You will want to position the round furniture insets that the EU2000i feet set into so that the generator snugs up tight to the foam and will not slide away from it.

Soundown sells different foams. I did not pay close enough attention in my web wanderings.

I believe you have Soundown "acoustic" 1/2" $30 sheet. I bought Soundown insulation barrier, it is 2 pieces of foam with a loaded vinyl piece in the middle at $70 sheet, still 1/2".It is not as flexible as the acoustic. I believe "Jorgenson" used the insulation barrier.

I did use the 3/16" ply good idea, had to buy a 4X8 sheet to get 1 small piece, the rest will not go to waste.

I like the rubber cup idea but not entirely sold on it and still looking.

I am experimenting with different configurations on the exhaust ducting but not getting as low a temp on the genset as I would like even with the fans.
Thanks Jim

[ICamel]

jjrbus wrote:
I refer back to your's and other's pictures as I work. I am making good progress on mine and at the point to add the foam for the generator seal at exhaust end on mine and realized you used the foam without the decoupler layer in it! It appears the foam I have will not make a good seal.
Jim

What foam are you using? If it is the Soundown and you are curving the 3/16" board that it is mounted to it should make a great seal. You will want to position the round furniture insets that the EU2000i feet set into so that the generator snugs up tight to the foam and will not slide away from it.

[jjrbus]

I refer back to your's and other's pictures as I work. I am making good progress on mine and at the point to add the foam for the generator seal at exhaust end on mine and realized you used the foam without the decoupler layer in it! It appears the foam I have will not make a good seal.
Jim

[jjrbus]

ICamel wrote:

jjrbus wrote:
I have looked at your pictures several times and appreciate the temperatures you gave me in another thread.

I am experimenting with duct board doing this and it just about has me beat trying to shape it around the exhaust area and am thinking about Soundown for that area.

It appears that you put a 1/2 inch plywood divider there with the soundown facing the genset as a gasket, is that correct?
Thanks Jim

Jim:
The plywood is 3/16" which allows it to bend and conform to the curve on the exhaust outlet bezel.
Yes, the Soundown is what creates a gasket like seal between the plywood and exhaust end of the EU2000i.
Just got back from a dry camping trip and had the neighbor ask if he could take photos of my sound deadening box. He had a Honda Genset just like mine and you could hear his in my campsite louder than mine.

Thanks for the response, I misread your material list and came up with 1/2". When I look at pictures it is obviously not 1/2". The 3/16" is perfect for this application.

I gave up trying to form the duct board around the exhaust and ordered the 1/2" Soundown yesterday.

[Ron3rd]

Honda 3000 EM is a construction grade generator; basically as loud as a lawn mower. Not suitable for camping unfortunately.

[ICamel]

jjrbus wrote:
I have looked at your pictures several times and appreciate the temperatures you gave me in another thread.

I am experimenting with duct board doing this and it just about has me beat trying to shape it around the exhaust area and am thinking about Soundown for that area.

It appears that you put a 1/2 inch plywood divider there with the soundown facing the genset as a gasket, is that correct?
Thanks Jim

Jim:
The plywood is 3/16" which allows it to bend and conform to the curve on the exhaust outlet bezel.
Yes, the Soundown is what creates a gasket like seal between the plywood and exhaust end of the EU2000i.
Just got back from a dry camping trip and had the neighbor ask if he could take photos of my sound deadening box. He had a Honda Genset just like mine and you could hear his in my campsite louder than mine.

[jjrbus]

I have looked at your pictures several times and appreciate the temperatures you gave me in another thread.

I am experimenting with duct board doing this and it just about has me beat trying to shape it around the exhaust area and am thinking about Soundown for that area.

It appears that you put a 1/2 inch plywood divider there with the soundown facing the genset as a gasket, is that correct?
Thanks Jim

[ICamel]

I think the rivets give the box a cleaner look. They are much less expensive than SS hardware. If I have any rivets fail, my backup plan is to replace those with nuts, washers, and bolts.

profdant139 wrote:
(And now for a dumb and unimportant question -- why did you use rivets instead of screws or bolts?)

[profdant139]

Very well done! I would say that was well worth the money you've invested -- this box will make the difference between running the generator and not.

(And now for a dumb and unimportant question -- why did you use rivets instead of screws or bolts?)