Best acoustic material for gen set

[jackfish]

I have room to add acoustical material around my Onan 3600 KY generator. The compartment and generator will accommodate 1/2" and 1" material, depending on location around the unit. Clearances and venting requirements per Onan installation manual will be observed. That said, what is the best acoustic material to use that has a 200 degree self-extinguishing rating. Rigid sheets are preferable. I found the appropriate adhesive. Thanks for your help.

[markopolo]

I bought some boat engine room sound proofing a few years ago that I wanted to try on a Class C but never got around to it. It was three layers, foam, a rubberized lead and foil. It was sold in 4'x4' sheet if I remember correctly and was very heavy. I bought it at a marine store.

The project never got started but the first problem was figuring out how to adhere the foam side to the walls of the generator compartment because I assumed the foil side should be exposed.

If I were to look into this again I'd check out Hushmat. Advanced RV is using it in their Class B's. Link: http://www.advanced-rv.com/hushmat-n...ction-testing/

[mlts22]

Dynamat or Dynamat Extreme? Supposedly is good for both acoustic dampening, vibrations, and dealing with heat. I'd definitely be getting this for a Ford E350/E350 doghouse. It may be expensive though.

[booster]

One thing to consider when choosing acoustic materials is the moisture absorption and breathability. Unfortunately, breathability and acoustic damping are contrary, so it can be a huge issue. I have seen a lot of capital machinery with rotted out areas due to sound insulation, with the moisture only coming from condensation that couldn't dry readily. The generator is underneath in most cases, will get wet when driving, and is in a prime place for condensation due to its close proximity to the ground, especially in areas of high humidity and cool night temps. What is good on an internal firewall, might be horrible under the van.