How to minimise noise from a generator?

stuffed, Feb 23, 3:11am
Am looking at getting a 6.8kVA generator for backup at home - have a downstairs veranda area with concrete block walls. I don't want to bolt it to the walls to mitigate sound and vibration. Anyone any good links or suggestions for placement?
Thanks

skin1235, Feb 23, 4:12am
noise is either engine induced vibration or caused by exhaust, if you can exclude those two the battle is won

I find they are quieter if out on soil, exhaust pointed way from reflecting surfaces
some of the larger ones with very loud exhausts do benefit from adding a length of pipe to that exhaust and directing it down a hole - lets the earth absorb all the sound effects

stuffed, Feb 24, 12:57am
Thanks for your input. Think after I get it will try out a few option before final instal.

mrploppy, Feb 25, 7:09am
Mount the generator on shock-proof mounts clear of any other surface. You could then cover the walls with sound-absorbing insulation panels.
http://www.ebay.com.au/itm/M10-40X-30-Rubber-Vibration-Mounts-80kg-Generator-Compressor-Air-Con-Machine-/281429237282?rmvSB=true&clk_rvr_id=786595696084

5425, Feb 25, 7:10am
Spend some real money and but a quite unit. less than 45 Db.

cantabman1, Feb 25, 7:49am
Ear pugs!

howgoodisit, Feb 25, 9:21am
Change the exhaust to a new bike exhaust.
Heaps of people change their original exhaust on bikes to sport exhausts to make them louder so there are plenty around.
https://www.bidbud.co.nz/852208771 https://www.bidbud.co.nz/852250278

richard112, Feb 25, 3:27pm
As above, anti vibe mounts (if you can't source anything suitable, mounting on wood rather than straight to concrete helps). Insulate, but make sure you don't compromise the cooling. Be careful what you do with the exhaust, especially if diesel. Constant speed diesels will build up soot in the exhaust if over restricted which can eventually burn. (Spectacular spark display)

iixii, Feb 26, 12:51am
A very cheap anti vibe base is to use an old truck tire. If the hole in the middle is to big it can be bridged with timber and have generator bolted to either the timber or tire.

annies3, Feb 26, 9:06am
We asked a coffee vendor how he had his generator running so quietly, his explanation was that he had cut the carb back as he was not using much power.

mechnificent, Feb 27, 2:00am
I'm with Skin. I'd keep it away and off the concrete. Put it on the ground, on a slab of wood or concrete sunk into the earth. The ground will absorb the vibration without transmitting it to the flat surfaces of your house. Aim the air intake and exhaust away from you, and down a hole in the ground if possible for the exhaust. Put walls betweem you and the generator to deflect the sound away if there are no neighbors, or enclose it with lined walls on all sides, Then make the cooling air holes in the shed face away.

gammelvind, Feb 27, 7:14am
Put it on rubber mounts, the larger the better, mount the machine in a box lined with that thick sound proofing foam used for lining boat engine rooms. I ran the exhurst through a muffler designed for a small truck, not much air flow restriction but heaps of sound deadening. The air intake was large designed like a dark room vent and lined with sound foam. Worked very well.

mechnificent, Feb 27, 9:58pm
You fellahs are starting to make it sound like a small power station.

If it's rural and only going to be used for a while and occasionally, then it may not need much at all. And if access and ventilation is going to be important then to have a stand alone enclosure is going to require quite a large construction. The costs soon escalate.

If they are rural, three walls might suffice.

stuffed, May 18, 7:42pm
This is the unit am looking at: https://www.tradetested.co.nz/browse/generators/6-8kva-digital-inverter-generator-with-remote.html
Will mount it outside on an 200mm concrete block boundary fence away from our living areas - holiday home next door. Have got a 700 x 500 x 40 piece of rubber from Para for a base and will build a wooden support frame.
Thanks for the great input.