Insulations suggestion for a genset quiet box

[Tedd]

I've installed a Coleman Powermate 6250 (5000 watt) Genset under the bus and would like to build a quiet box to help out a little with the noise.

The genset will be operated with its hatch door open to allow air in and heat out. I am also thinking I might leave the bottom open for the same reason.

The muffler will NOT be inside the quiet box. I have a bit of exhaust pipe that I can put on the muffler outlet when I run the generator. This will extend the exhaust beyond the side of the bus and will aim the exhaust down towards the ground.

On hand I have some pink stuff 1/2 thick foam insulation, some 3/8 plywood and some 22 gauge mild steel.

To insulate against heat and noise, my guess is to put the steel to the inside followed by the pink stuff and plywood on the outside.

[Twigg]

Originally Posted by Tedd

I've installed a Coleman Powermate 6250 (5000 watt) Genset under the bus and would like to build a quiet box to help out a little with the noise.

The genset will be operated with its hatch door open to allow air in and heat out. I am also thinking I might leave the bottom open for the same reason.

The muffler will NOT be inside the quiet box. I have a bit of exhaust pipe that I can put when I run the generator. This will extend the exhaust beyond the side of the bus and it will aim down towards the ground.

On hand I have some pink stuff 1/2 thick foam insulation, some 3/8 plywood and some 22 gauge mild steel.

To insulate against heat and noise, what order should the steel, the foam and the plywood be?

There are two types of noise ... internal and external.

To keep the interior of the bus quiet, locate the genset as far as possible from the area where noise would be intrusive. I'd build a steel box, line it with noise-deadening insulation (rockwool is good), then a plywood interior.

A good bit of the noise will be transmitted, not radiated, so if you could rubber-mount the box and/or the generator you would reduce the vibrations transmitted to the frame.

Exterior noise is a function of the exhaust AND the inlet. The induction noise of generators can be quite high. Quiet exhausts can be fitted, and that will help, but work needs doing on the air intake and that's not something I'm familiar with fixing.

[PNW_Steve]

Take a look at: https://acousticalsolutions.com/soun...-loud-widgets/

[Tedd]

Originally Posted by PNW_Steve

Take a look at: https://acousticalsolutions.com/soun...-loud-widgets/

That'll do it! I googled it but didn't come up with much.

Thank you.

[Daveyd007]

Look into replacing the Coleman Powermate with an inverter generator. Storm generators with Briggs & Stratton engines have thin-ribbed, air-cooled cylinder heads, as most of the rattling noise is coming from this section of the engine. Silencing this part of the motor by suffocating it with wool lining or the like, will just cause the motor to overheat and start a fire.
Besides, Powermates weren't designed to be encased in an aftermarket housing. Like Twigg mentioned, rubber is your best bet to isolate vibration.