generator baffle/silencer

[grandads_shed]

ok i have a 3kva honda generator, aircooled.
i was wondering if there is any way to make it qieter. i have thought of fitting a bigger exhaust from a car or somthing. as well as a different air filter system


anyone ever managed to make one more silent ??

 

[gavuk]

dig a hole in the garden ....earth is great for killing the noise,still have to make sure it can breathe though...failing that there have been some threads on compressor houses on here ,basically a box inside a box with soundproofing ...i'll have a look in a min

 

[grandads_shed]

cant m8 its in a garage. there is a row of them and no where to build a shed. it has to be in the garage, making an exhaust to go outside is no problem ,

 

[the snooper]

i made an exhaust for a 5 kva diesel from scratch and was shocked at my own results it worked far better then i had hoped for

 

[gavuk]

Got any Pics?.....do you need to retain their portability ,exhaust and inlet will def help ,but sound proof box,vented to outside would be the way i would go,,,,how about stacking them in soundproof boxes?.....with exhausts to outside....what size generators? and how many ?....

 

[the snooper]

how about stacking them in soundproof boxes

i think he is refering to the garages being in a row not that he has a row of generators

 

[gavuk]

Ha ha well spotted Snoop ...it is late

 

[grandads_shed]

one genny row of garages m8 ..

keeping it portable will be no problem, just need a clamp that will undo by hand for the exhaust to be released.

 

[the snooper]

the exhaust i made was made from 2mm steel plate, the idea is to get the exhaust to flow around as many corners as you can without causing any restrictions.
sound only travels in straight lines it can't go round corners it's only reflected.
it's the same principle if you make a sound proof box just make sure you have enough air flow so as not so seize or overheat the genny.
the silencer i made was on the principle of the picture below i made the box welded in all the dividers then when it came to putting the final plate on i drilled holes where the dividers was and plug welded them so that non of them would vibrate and cause noise.

 

[gavuk]

You could try local exhaust centre skip for parts........exhaust on a 3kw is quite small?....we used to pack bike exhausts with fibreglass insulation ,certainly made a difference to just having baffles,.....should be easy enough even in a "row of garages "

 

[shenion]

I was going to make a muffler out of some old 1lb propane canisters for a 11HP/5800VA. If not quiet enough would just make another and tack it on.

Would divide into two chambers 40/60% with a short pipe between. Having the chambers different sizes avoids resonances.

Never got around to it as I sold my gnerator.

 

[the snooper]

the exhaust i made was on a lombardini engine and was about 10 inch square by 3 or 4 deep and couldnt believe how well it worked

 

[gavuk]

Our diesel sprinkler pump at work is piped outside via an exhaust silencer and is still b****y noisy...........my 2.2kva is pretty quiet anyway ,at least the 3 times i've used it ....baffles and insulation works well ,don't forget to keep us posted (pics).......

 

[Cal]

generators run at constsnt speed, so you can tune the baffles to reflect and noise cancel each other keeping the exhaust compact, there will be a formula somewhere..

 

[Dr pepper]

I wanted to do this to a lawn mower engine that was to be part of a push trike trailer, the idea was to have the trike electric assisted by the engine, and when you parked up the engine ran till the batteries were full.
I never got around to it however I looked into a silent exhaust, basalt wool or fibre e-glass is used in car exhausts, as well as tubing with holes in (perf), I designed something up that used a car silencer, but had 20mm pipe rather than big stuff, the perf tube running the length of the silencer through the centre, and rather than have a single output pipe have loads of smaller holes drilled in the outside, the space between the perf and the outer silencer being filled with basalt.
Never tried it so might not work.