Best DIY sound insulation for a generator box

[woodman-46]

Hello
I am making a weatherproof container for my smallish generator so that it can obviously be outside but protected from the elements. I have already planned in an inlet fan to supply plenty of air and an exhaust vent to clear that away.
I want to sound insulate it on the inside but wondered what would work as an inexpensive insulation in this case. It would not be right up against the generator but have several inches clearance all round
Any suggestions welcome
Thanks

 

[Deluks]

A box in a box, with dense rock wool in between the two.

 

[woodman-46]

Thanks.

 

[aveatry]

Yes with the rock wool but also need to separate the generator from the ground with rubber.

 

[freddiemercurystwin]

Rockwool RW5 or 6.

 

[jj4091]

Surely all the noise will escape through the exhaust won't it.

 

[Wayners]

Sounds travels through solids.
So something soil with the sound vibration getting absorb.Then something soft like rock wool. Then something solid..
Box in a box.

Even better if you use something like 4mm MDF then 6mm MDF as they catch different sound frequencies..
The rock wool allows them to vibrate.
Just make sure there is no continuous solid bridging inside and out for the sound.
Water is a solid. Sound travels 100s of miles in water

 

[Ivor Windybottom]

Check the specs for the generator. It will need ventilation - an air inlet at the very least but probably also limits on what you should put around it and whether it can be combustible material or not. You'll need to be really careful about putting anything around the exhaust - it will need fresh air clearance around it. e.g. look at tents with stoves - they have a big pipe around their exhaust to separate them.

As soon as you put an air inlet vent in then you'll defeat most of the sound proofing. Unless there's a direction that won't bother you or any neighbours.

 

[woodman-46]

Check the specs for the generator. It will need ventilation - an air inlet at the very least but probably also limits on what you should put around it and whether it can be combustible material or not. You'll need to be really careful about putting anything around the exhaust - it will need fresh air clearance around it. e.g. look at tents with stoves - they have a big pipe around their exhaust to separate them.

As soon as you put an air inlet vent in then you'll defeat most of the sound proofing. Unless there's a direction that won't bother you or any neighbours.

Hi thanks . All things taken into consideration already. As mentioned in my post there is a good air inlet fan and a good sized vent at the other end. The exhaust is going to go out via a flexible exhaust pipe. Just by surrounding the generator with five boards as an experiment cut the noise of the generator hugely . That is also taking into account the boards were not joined and had gaps. There will be plenty of space around the generator between it and any insulation.
Thanks

 

[Ivor Windybottom]

Are you off-grid or preparing for power cuts?

If you're on-grid ensure you're completely isolated (both L and N) from the grid before powering up your house.