Deck Box as a Generator Quiet Box?

bgradert wrote:
I half tempted to order one from Amazon, assemble it, run the generator in it for a couple of minutes to see how it does.

SoundGuy wrote:
If you really want to control all the racket, which is particularly difficult with an open frame genset, you're going to have to spend some $$$, the most important expenditure being noise control barrier material such as this from West Marine.

Bumpyroad wrote:
I was wondering when somebody would recommend adding insulating material to the sides of the box.

This West Marine noise control barrier I linked to is far more than "insulating material" ...

"This flexible composite combines the sound-absorbing properties of open-cell polyurethane foam and the noise barrier capabilities of high-density PVC vinyl sheeting. The 3/32" flexible vinyl sheet is fused between two layers of foam an exterior ("decoupler") layer and an interior ("absorber") layer. The exterior layer is then covered with a thin film (2.5 mil) of mylar, reinforced with elastomer-coated fiberglass, for surface heat protection and enhanced sound absorption.

The overall effect is a dramatic noise reduction when compared with single-layer foam barriers."

Certainly, instead of a generator box one could line the cargo compartment of a truck with this sheeting but it sure would be costly, especially if the compartment had a lid like my Avalanche - that's a lot of square feet to fully cover and one would still need to provide an effective means of intaking cool fresh air and venting out hot cooling air & hot exhaust gas, just as I did with my own design.

I built a 1/2" plywood box for my Champion last year. I used a multi-input Fluke thermocouple meter to measure temperatures at many points inside the box.

Your enemy here is heat. I added some fans at various places on the enclosure and measured the temperatures. Without any fans, tempoeratures rose considerably. With fans, the temperatures dropped, but some localized spots actually got WORSE. Airflow control over a complex-shaped object such as a generator is a tricky subject at best. I ended up putting a duct booster fan inside a 6" duct section, then a 90 elbow into the intake side (sound loses intensity when bending 90 degrees). On the exhaust side, I had an open slot at the bottom of the enclosure and added pipe to the muffler exhaust to bring it outside the box.

After all that it was definitely quieter, but not nearly enough. This year I will experiment with added sound insulation.

Unless you are ready to spend hours and hours doing experimentation and measuring temperatures (and enjoy doing it like I did) forget about any quick solution.

In general, damping generator noise involves materials with high mass, which a deck box definitely is not. The box will probably vibrate with some resonant frequency and may actually be more annoying to hear. You will also probably raise temps in certain areas of the generator which will reduce lifespan of some parts (such as the voltage regulator, etc.). Raising the temp of the gas tank area might induce vapor lock.

This is just my observations after my efforts last year.

Steve

SoundGuy wrote:

bgradert wrote:
I half tempted to order one from Amazon, assemble it, run the generator in it for a couple of minutes to see how it does.

Your choice, but I already gave you the correct answer - "Any box on it's own will be shockingly ineffective at reducing genset noise." ;)

If you really want to control all the racket, which is particularly difficult with an open frame genset, you're going to have to spend some $$$, the most important expenditure being noise control barrier material such as this from West Marine.

Yes, you should have purchased a quieter inverter genset if your goal was to use it for camping ... but even so-called "quiet" inverter gensets still make a lot of racket, despite manufacturers' claims to the contrary. A properly designed quiet box can reduce that noise significantly - but doing so ain't exactly cheap. :E

There are no short steps around this - do it right or don't bother doing it at all. :W

I was wondering when somebody would recommend adding insulating material to the sides of the box.
bumpy

jamesroadking wrote:
A Honda 3000 watt generator list around $2299.00 The Yamaha one is something like $1800.00 or you can get the Champion 4000 watt one for about $250-$300.

Like I was saying, putting the generator on some carpeting in the inclosed bed of your truck puts the noise level probably the same as or Less than those Over Priced name brand generators.

"A fool and his money are soon parted"

Putting an open frame contractor generator on carpet in a truck bed would hardly get it to the noise level of a reasonably installed built-in Onan generator, much less a good inverter generator. The Onan would be at least as well enclosed and likely has a quieter engine to begin with (with a more sophisticated muffler arrangement).

I encountered one of the Honda 7000 watt inverter generators "in the wild" some time ago, powering a food truck in an amusement park (on what turned out to be a sort of food truck celebration day). I had to be within about ten or fifteen feet of it to be able to discern that it was running. I was quite impressed, even considering that it wasn't the quietest of areas to begin with and having no idea how much of a load it was operating under.

jamesroadking wrote:
Like I was saying, putting the generator on some carpeting in the inclosed bed of your truck puts the noise level probably the same as or Less than those Over Priced name brand generators.

And you have absolutely no documentation whatsoever to support this claim - correct? :W Truth is, doing so makes little difference at all ... and since these "overpriced name brand generators" still sell in volumes obviously many don't agree with your assessment. :W

A Honda 3000 watt generator list around $2299.00 The Yamaha one is something like $1800.00 or you can get the Champion 4000 watt one for about $250-$300.

Like I was saying, putting the generator on some carpeting in the inclosed bed of your truck puts the noise level probably the same as or Less than those Over Priced name brand generators.

"A fool and his money are soon parted"

My Honda 2 tousand is really quiet until you put a load on it. :)

Baffle box is in order. SoundGuy style.

bgradert wrote:
I half tempted to order one from Amazon, assemble it, run the generator in it for a couple of minutes to see how it does.

Your choice, but I already gave you the correct answer - "Any box on it's own will be shockingly ineffective at reducing genset noise." ;)

If you really want to control all the racket, which is particularly difficult with an open frame genset, you're going to have to spend some $$$, the most important expenditure being noise control barrier material such as this from West Marine.

Yes, you should have purchased a quieter inverter genset if your goal was to use it for camping ... but even so-called "quiet" inverter gensets still make a lot of racket, despite manufacturers' claims to the contrary. A properly designed quiet box can reduce that noise significantly - but doing so ain't exactly cheap. :E

There are no short steps around this - do it right or don't bother doing it at all. :W

Just a deck box? Probably not worth the effort/expense since it will need to be heavily modified to work.

If I wanted one, I'd build it of aluminum or plywood. All the sides would need to be treated with both mass loading and a sound-deadening material. Efforts to introduce air and provisions for the exhaust/engine temperature would be installed. There are plans out there on the Web. Soundguy's installation is very nice.

An alternative for the OP may be to sell the open-frame set he has and buy an inverter generator. The price difference may be lower in time/effort than trying to quiet his 3500W Champ.

Looking back I wish I would have saved and spent the money on an inverter generator. The one good thing about the Champion is it can power my fridge and other devices in my home if the power goes out. It was hard to drop $1k or more for something I may use once or twice a year.

My thoughts were to cut a hole for the exhaust to port through and some intake holes on the other wall of the deck box. The deck boxes I have owned prior assembled in a matter of minutes. I first would set the floor down, place the genset on the floor and build walls around it. I half tempted to order one from Amazon, assemble it, run the generator in it for a couple of minutes to see how it does.