Acoustics - 850 kva Generator

Marine acoustic engine compartment insulation applied to the walls and ceiling worked well not far from here.

Just keep in mind heat dissipation. OK, so you're set is now nice and quiet, but cooking it's self to death!

To be honest there are companies out there that will design and guarantee their work, give some of them a call.

There are electronic sound suppression devices that could be used. Some can be applied to the exhaust system.

http://en.wikipedia.org/wiki/Active_noise_control

http://www.osti.gov/bridge/servlets/purl/752962-YV4R2c/webviewable/752962.PDF

http://www.school-for-champions.com/science/noise_cancellation.htm

http://www.avlelec.com/?gclid=COnEzarT06oCFRd25QodnWW71g

What you use will depend on the environment of the room (humidity, etc.). Typically, these rooms are simply cement block rooms that amount to an echo chamber. You need to convert the acoustic sound to heat ultimately rather than have it bounce around until it escapes to the outside like it does now.

Many tricks can be used. One trick is to build an inner wall and ceiling inside the existing room to isolate the outer wall.

The wall should be isolated mechanically from the outer wall and fiberglass insulation batting placed between the two walls.

I would use drywall on the interior wall surface, possibly two layers (adding Green Glue between the drywall layers - more later).

If an interior wall is not possible, a second layer of drywall with a viscoelastic constrained layer of a product called Green Glue should be applied as per manufacture's direction. This will suppress a lot of noise.

Another product is Owens Corning 703 fiberglass panels. 4" thick panels will absorb sound very effectively. Optimum installation would be to suspend these panels away from the walls to act as a bass trap. The one issue is that these panels are also a potential mold trap if the room has moisture in it. [p[] Of course you can use a combination of the solutions I have cited to increase absorption.

You will also want to treat the inner surface of the room's door so it doesn't broadcast noise.

Lastly, a good muffler will quite the exhaust.

I used to work for a company that developed and built electronic mufflers. They work!

Active Exhaust Noise Cancellation - Clemson Vehicular Electronics ...

Start by mounting the genset on a vibration isolated (spring or cable type isolator with a low enough natural frequency so it won't go into amplification) subframe. a lot of low frequency energy will be conducted through the floor/foundation and low frequency will travel a really long distance and has a lot of power under that waveform curve. All the insulation on the walls in the world won't do jack to prevent conduction through the ground. You'll need to use a bellows on the exhaust piping probably to keep the genset movement on the isolators from busting the plumbing.

Hello, all hints given are correct. There are excellent mufflers available for the exhaust, there is sufficient damping of the engine noise inside the engine room.

But as the engine with 850 kVA will have an big air intake m3/h you will als need a noise suppression system in the air intake. Normally this are sheetmetal fabrications with many punched holes in the sheet metal and a filling of Glas fiber mats. Sorry I have no longer any info on producers of such kind of a system for Diesel engines but there is a link http://www.guh-schallschutz.de/de/schallschutz/produkte/schalldaempfer/lueftungsschalldaempfer.php?thisID=252 which shows large systems of such kind of noise suppressors. But the standard round mufflers (upper part of the web side) can be used too if you find the sufficient diameter for the motor's requirements.

In my case (20years ago) you had to wear "Micky Mouse ears" inside the engine room. But on the outside of the air intake noise suppressor there where measured 56 dbA in 1m distance - but you could see the running 650 kVA engine through the air intake noise suppressor! We did not have special means inside the engine room besides a heavy noise suppressing door - there were bare concrete walls only.

Do not forget bird protection nets and rain blocker or a 90deg down ward hood and design the air intake that way that the air speed at the required air volume is below 3m/sec other wise objects might be taken into the engine room.

The best products, that I have used, are made by Soundown who produce a wide variety of sound attenuation materials and acoustic isolators and dampers. (http://www.soundown.com/Section%201%20PDFs/Products.pdf) With their laminated barriers, vibration damping mounts, well designed muffler, and properly baffled air intake and ventilation ports you will be able to reduce noise to whatever level is required.

Get another geneator frst.