Generator Bay Insulation

[dougyes]

In your experience, what is the best stuff to insulate the generator bay from noise and heat? And where is the best place to buy it?

[Joe Camper]

Google a co called

Soundown

That is what we used everyone who sees it likes it

http://prevostmotorhomes.ning.com/forum/topics/a-generator-bay-rebuild

[Chaz]

Outstanding job, Joe. Absolutely outstanding!!!

[Joe Camper]

I do not think it is the quietest product for sure. The Mylar does not absorb sound as well as exposed foam egg create that is the quietest stuff IMO (if installed correctly).

We compromised for the ease of cleaning and the way the egg create style crumbles away as it ages making another real mess of another kind too.

It is still very very quiet in a bay, in a 3/4ply box lined with a sheet of lead layer of 5/8 drywall and then the 2in foam/composite sandwich from soundown.

Another big quiet factor is to put the radiator in a separate compartment and that way you do not exhaust the sound of the gen moving air over the radiator with the blower. This is why aircooled gas driven gens are hard to get ultraquiet. The cooling fan is exhausting as much engine noise as heat.

[artvonne]

Another big quiet factor is to put the radiator in a separate compartment and that way you do not exhaust the sound of the gen moving air over the radiator with the blower.

  Yet another plus to put in the "pro" column for deciding on tying the Gen cooling system into the Bus heating/cooling system. So far the only negative I can see is the possibility of needing to shut down the generator if you lose the engine cooling system. Gate valves to re-route coolant away from a damaged area while you seek repair could offer a work around solution.

[Joe Camper]

Another question is if you want the gen in there sideways or deep. Many reasons for doing it either way.

I cheeted and bought a converted one and did not go thru all that

[Seville]

Joe,
Very nice work ! It looks so clean.
I used Sonex, which is a sponge like matterial used for sound absortion in recording studios.
Its pretty quiet but gets very dirty!

[Joe Camper]

Ours is in there deep and very hard to clean around so I made the compramize and it's very nice to be able to give it a quick swipe with a paper towel and a little 409.

[Tenor]

I went on the cheap side.  I used 3/4 plywood for my box.  In the first build, I just lined it with 3/4 inch (approx) damaged fiberglass ceiling tiles from Menards.  Worked VERY well.  Then I took some advice from Ed Rolle.  He recommended using old truck mud flaps.  I smacked my forehead!  I had about 12 feet of old conveyor belt that I had left over from making a previous mud flap!  While I had the genset out for maintenane, I pulled the fiberglass, put in rubber, put in new fiberglass.  Almost can't hear it in the bus!  Outside, you hear the squirrel cage fan for the remote radiator and some exhaust before it hits the muffler.  Good luck!

Glenn

[artvonne]

  With the Gen in the forward AC condensor bay, I am considering running the exhaust down through a stainless flex coupling, and then alongside the frame rail to the rear axle bay, then into a muffler and out ahead of the rear wheels. My thinking is a Muffler inside the bay would radiate more heat and sound into the bay. By the time if gets to the muffler 20 feet away, there may not be much sound left to muffle. The only downside is I would not be able to slide the Gen out without disconnecting the exhaust.

  Lots of good thoughts here, and Joe, awesome job on yours.

[dougyes]

Glen Williams,
The fiberglass ceiling tiles you used are most likely "A" Fire Rated. I found a box of the ones that look like pressed fiber that said "fire repellent". I'm not sure how that compares to the A rating, but they said "reduces sound by 45%". Maybe I'll just put a torch on one to test its repellence before I use them. They were marked down from $57 to $5!

[Joe Camper]

Our exhaust runs tothe engine compartment before going up and out the roof but that is where the gen muffler is, situated directly over the bus muffler.

I put 5/8 drywall onto the inside of the 3/4 in ply box to cover to be a fire preventative.

[chev49]

How is the drywall holding up?

[gus]

Drywall is covered on both sides with paper?

[luvrbus]

Buy lead lined drywall works works like a charm a 4x12 sheet cost around 180 bucks for the 3 hr rated

good luck