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?

[ICamel]

Materials list:
Qty 4 sheets - 2' x 4' exterior grade 3/16" plywood purchased at Home Depot. This yielded the top, bottom, two sides, front and back ends and the two interior partitions.

Qty 2 sheets - 1/2" x 32" x 54" Soundown acoustic foam purchased from Amazon.com. You could get away with 1 sheet, but I opted to use more in places than Jim did.

Qty 1 package - Aluminum Pop Rivets, 3/16 x 1/4-Inch, 100 rivets.

Qty 1 package - Black Carbonized Fiber Welding Blanket, 18" x 18" purchased on Amazon.com.

Qty 1 - 2-Pack Power Cord 3 Feet Heavy Duty AC Power Extension Cord in 3 Feet purchased on Amazon.com.

Qty 6 - 3/4" x 1/16" x 36" aluminum angle bar.

Qty 1 - 24" Brass plated metal hinge(this was cut into two sections for the top).

Qty 1 - 12" Brass plated metal hinge(this was cut into two sections for the inlet end).

Qty 1 - 4 pack 1.75" round furniture cups.

Qty 1 - Brass plated lockable clasp and hinges for pull start door access.

Digital photos:
Left side
P1000073 by camelwhit, on Flickr

Air inlet end
P1000074 by camelwhit, on Flickr

Right side
P1000075 by camelwhit, on Flickr

Exhaust End
P1000076 by camelwhit, on Flickr

Top opened
P1000077 by camelwhit, on Flickr

Open top view
P1000078 by camelwhit, on Flickr

Air inlet open hinge for easier generator ingress/egress.
P1000081 by camelwhit, on Flickr

EU2000i in the Quiet Box
P1000083 by camelwhit, on Flickr

Close up view of how the generator snugs up to the partition between the exhaust side and the cool engine side.
P1000084 by camelwhit, on Flickr

My EU2000i is about 15 years old and still running strong!

[SoundGuy]

ICamel wrote:
With inspiration from jauguston I built a EU Quiet Box for our EU2000i.

It's hard to imagine anyone could complain about your EU2000i running ... great job! :B

[ependydad]

ICamel wrote:
With inspiration from jauguston I built a EU Quiet Box for our EU2000i.
I used the 1/2" Soundown material rather than the 1". Total cost was less than $125.
See and hear on my Flicker account. For some reason it won't play on Google Chrome(but will in "incognito window"), but will play on Mozilla Firefox and MS Internet Explorer.

EU2000i in the open.
http://www.flickr.com/photos/11322575@N07/26138226090/in/dateposted-family/

EU2000i in Quiet Box
http://www.flickr.com/photos/11322575@N07/26344709241/in/dateposted-family/

If it helps, they played fine in my Chrome browser.

The difference with load is astounding. You couldn't tell the heater was turned on with the box.

When I get my generator(s), this is absolutely on my "todo" list.

[ICamel]

With inspiration from jauguston I built a EU Quiet Box for our EU2000i.
I used the 1/2" Soundown material rather than the 1". Total cost was less than $125(NOT!). On Edit: Whoops!.....in the interest of full disclosure, after totaling up the individual costs it came to $182.01
See and hear on my Flicker account. For some reason it won't play on Google Chrome(but will in "incognito window"), but will play on Mozilla Firefox and MS Internet Explorer.

EU2000i in the open.
http://www.flickr.com/photos/11322575@N07/26138226090/in/dateposted-family/

EU2000i in Quiet Box
http://www.flickr.com/photos/11322575@N07/26344709241/in/dateposted-family/

SoundGuy wrote:

profdant139 wrote:
We have a Honda 2000 -- it is quiet but not silent. When we are boondocking, we add an extra extension cord so that the generator is as far from us as possible, preferably behind a big rock.

It's certainly possible to quiet an EU2000i to the point where it's barely audible 20' away. I based my own EU Quiet Box on one built for an EU1000i by rv.net forum member jauguston ... his pics are here for anyone interested. However, a major issue became abundantly clear in building my quiet box - "quiet" is directly related to how much you're willing to spend. :W After calculating I'd be in for hundreds $$$ to duplicate jauguston's box for my own EU2000i I looked for alternatives that wouldn't break the bank and although what I came up with certainly works quite well I have no doubt the results would have been even better had I been willing to spend more - lots more. I wasn't so it is what it is BUT with the box sitting the back of my Avalanche and the cargo lids in place my EU2000i running full tilt is barely audible 20' away. :B

[windviewer]

2oldman wrote:

SoundGuy wrote:
He can't. The OP's profile indicates he's here in Canada where Honda Canada offers the EU2000i without parallel capability ... there are ways around this of course

Yeah, using two extension cords. It's real simple, but I'm amazed at how many people go ahead and buy those expensive kits.

Now, if Honda removes the synching electronics for Canadian sales, that's quite different. I don't think they do that.

They haven't done it yet as the two EU2000i purchased in the last 6 months parallel just fine 🙂

[TheWB]

Most impressive job on that generator box SoundGuy. Amazing work.

SoundGuy wrote:

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

Here in Canada there are two Honda 3K models, one known as the EU3000iS which is the class leader in "quiet" inverter gensets and the EU3000iK (known as the Handi in the US) which isn't the same at all and is significantly noisier. If yours is the latter I can understand why you'd want to quiet it down, the former not so much. I built a Generator Quiet Box for my own EU2000i but for a 3K genset it would have to be quite a bit larger and I suspect a handful to move around. Although I fashioned my own exhaust bezel you'd certainly find it easier to design a box by first replacing the 3K's exhaust bezel with this one from Generator Line. For lining the interior of the box I used Reflectix for economic reasons but you'd achieve far better results using a noise control barrier such as this from West Marine. Done correctly, to achieve maximum results, this won't be inexpensive. 😉

[Ropdoc]

so there you have it.

[SoundGuy]

Ropdoc wrote:
youtube has interesting ideas. Just need to be carfeul of heat buildup. Genny needs to be cool.

Lots of terrible ideas as well, posted by those who clearly have no idea what they're doing :E ... FAR better examples are those shown in the link I provided earlier of Japanese designs which are based on sound engineering principles rather than uneducated guesswork. :R

[Ropdoc]

youtube has interesting ideas. Just need to be carfeul of heat buildup. Genny needs to be cool.

[2oldman]

profdant139 wrote:
That's the problem right there -- the cost/benefit ratio. That is probably why there are no commercially-available after-market generator boxes for the RV folks -- no one would pay more than about $200 (US or Canadian!) for that product.

..and why Honda doesn't have any worries about open frame gens in quiet boxes.

[profdant139]

That's the problem right there -- the cost/benefit ratio. That is probably why there are no commercially-available after-market generator boxes for the RV folks -- no one would pay more than about $200 (US or Canadian!) for that product.

[SoundGuy]

profdant139 wrote:
For the exhaust baffle, I think there is heat-proof insulation for home water heater chimneys -- it should not be too expensive. I should measure the temp of the exhaust area to see if there is a real fire danger.

Custom polycarbonate exhaust shrouds sold by Generator Line are rated to a moderate 250F so the 2000F batting I used is far beyond what is really required. Since I always use my quiet box in my Avalanche's rear cargo compartment I was thinking of dispensing with the plastic box entirely by simply enclosing the generator with a "box" formed with this West Marine Noise Control Barrier. Since it's a relatively stiff material I'd mount the same intake fan I'm currently using directly on the intake end wall, forget using an exhaust baffle, and instead exhaust directly out using a Generator Line exhaust shroud. If the foam needed any additional strengthening the outside of the foam enclosure could be reinforced with a lightweight plastic product such as Coroplast which is often used to enclose a trailer underbelly and which can be purchased at stores such as Home Depot. This design would certainly be lighter than any plastic or wood box lined with the same noise barrier and could probably just be set in place over the generator. The only reason I haven't proceeded with this idea is the significant cost of the noise barrier material and the Generator Line exhaust shroud which together could easily be $500 Cdn at the current exchange rate. :E

[profdant139]

For the exhaust baffle, I think there is heat-proof insulation for home water heater chimneys -- it should not be too expensive. I should measure the temp of the exhaust area to see if there is a real fire danger.

[SoundGuy]

profdant139 wrote:
As far as I can tell, the most cost-effective sound deadening material is called Homasote -- it is sold under a variety of names. Essentially, it comes in half inch thick sheets, 4 feet by 8 feet, and it is compressed cellulose.

Maybe there is a cost-effective way to waterproof the cellulose sheeting? And to use something else for the exhaust baffle.

I first tried a sheet product that sounds much like Homasote but it didn't work at all as it was way too heavy and crumbled easily. Any quiet box I've looked at online that's demonstrated excellent results has always used dense noise control barrier foam such as that product I link to earlier from West Marine. I have to admit I'm SO tempted to try it myself, except my wife would kill me if she knew I spent that much to buy a sheet of it. :E. As I mentioned earlier jauguston gifted me a piece of high temperature batting that I used for the exhaust box but had that not been available to me I think I'd have used Roxul stone wool, the only problem being I'd have had to pay for a whole bag of it when all I needed was a small piece.

[profdant139]

As far as I can tell, the most cost-effective sound deadening material is called Homasote -- it is sold under a variety of names. Essentially, it comes in half inch thick sheets, 4 feet by 8 feet, and it is compressed cellulose. It sells for about ten or eleven dollars a sheet. You could line the interior of a plastic box with this stuff, and it would not be too heavy, I think. (Obviously, there would have to be an air intake and an exhaust port, with baffles.)

The main problem with Homasote is that it is not weather-proof at all -- a little water and it turns to mush. The other concern is whether it is sufficiently heat resistant for the exhaust baffle -- I would guess it is not.

Maybe there is a cost-effective way to waterproof the cellulose sheeting? And to use something else for the exhaust baffle.

There are commercially available soundproofing materials available for exterior applications, but they are very expensive.