How to make a generator quieter

I got a 9,500 / 7,500 watt generator in trade for some work I did a while back. It is a portable unit that you can roll around but it is big. It is virtually new. It works perfectly. I just did my spring service to all my power equipment so it is ready for huricane season and / or winter stormes.

The bad is it is really noisy. You can not talk to someone at all standing next to it when it is running and the constant drone when it is on is a bit annoying. Although not as bad as not having power. It is one of the off brand units but does have a briggs and stratton motor 15 hp I think?. The question is how to make this thing less noisy.

I was first thinking of seeing if there is some sort of changes to the exhaust I can make. Either replacing the current muffler completely or adding a second larger muffler to it that is possibly something that can be removed when transporting. The second option is to baffle it in some way. Obviously it needs air flow for cooling but there has to be a way to partially enclose some of it. using say foil faced insulation boards?

So what can I do? Anyone ever succeed at making one of these things quieter?

Since I got it in trade and it really is bigger than what I need (a 7500 / 6000 would work fine) I was thinking of selling it and looking for a used Honda or similarly smaller and quieter unit. BUT I know this unit. I have had it since new and having the extra power is nice. It will run my entire house with out any issues at all. With CFL's and LED's and having gas appliances and heat about the biggest power draw in the house is the microwave. (not including the tools in my shop)

It was SOOOOOOO nice having it when the power went out. Just plug it in and kill the main breaker and BAM!!!! I had power. My neighbor and I both have generators and we made a lot of "friends" during the last power outage. But making this thing quieter would make it that much nicer.

Intake can be noisy too.

Can't do much about the cooling fan.

Install a housing around it.

I have a big Rigid brand 9500/7500 that has the same problem. I took it camping in the paddock at Summit Point and was almost voted off the island for disturbing the peace. At a RACETRACK. When the power goes out at home - I park it outside and face the exhaust into the woods. It might piss off the deer but I can barely hear it inside.

I don't have an answer to this - but I noticed that the one on my buddies RV has a long exhaust pipe running under the truck. I think maybe a large round lawn tractor muffler (like John Deere has) with a detachable 6' long 1" diameter tube would go a long way to hushing it up.

I'm not sure if you can accomplish both quiet and cool. I don't think that it's all exhaust noise, though you could probably pick up somebody's stock Sportster muffler for cheap and try to do something with that.

An air cooled engine is going to be naturally noisy. A bigger muffler may help some. Be careful with baffling - you need to maintain plenty of air space, but some plywood walls braced up around it will help some as well.

Here's the safety sermon: you need a proper transfer switch or interlock with the main breaker.

The grow-op guys might have some tips on making a generator quiet. Just sayin'.

Put it in your neighbors garage and run a long cord to your house?

Flip a folding table on its side and position it between you and the generator. People on the other 3 sides will have to supply their own folding tables if they want peace.

stuart in mn wrote: Here's the safety sermon: you need a proper transfer switch or interlock with the main breaker.

For convince yes or if you need instructions to plug in a light bulb. Seriously through yes I here you and yes it is true it is the proper way to install one. One of my projects this summer is to properly wire in an exterior weather proof plug and have a transfer switch installed for it.

stuart in mn wrote: Here's the safety sermon: you need a proper transfer switch or interlock with the main breaker.

QFT! I work for Milbank, and we make automatic and manual transfer switches. Even if I didn't work for a company that made them, I would still recommend them. Not everyone in the house who could turn on a generator would know enough about electrical safety to shut off the main breaker.

I built a plywood box that had dual density foam (2 layers) glued on the inside and that helped a lot. I had a slip-over exhaust pipe with econo-car muffler. You'll probably need to have a fan built in to draw in cooling air.

If you do put a bigger muffler on it, pay attention to mounting, i.e. make sure the big shaking thing on the little die cast head is held by something besides aforementioned head. Lots of bracing. I've always wondered how well a typical car muffler would work. Mounting it to the engine/generator, or properly isolating it (some kind of flex pipe) if it's mounted to the frame, would be tricky, but you definitely wouldn't have any noise problems on the exhaust end.

On transfer boxes, backfeeding etc. Unless it's some life or death situation, never backfeed. A box of (properly sized!) extension cords and power strips to run to essential things is cheap relative to potential problems with a backfeed or the cost of having a transfer switch put in. If your furnace doesn't plug into an outlet, make it so or get one of the little furnace only transfer switches that can be installed a lot more easily than a whole house switch.

i saw a guy at a local camp ground, who took and built a wood box to cover most of the unit to quiet motor noise, then took exhaust pipe, bent it in a long sweeping S shape and add muffler at the end worked great and very little noise.

Call me crazy, but when I first read about your problem my first thought was plop it into this.

Maybe with a box fan in the doorway?

This is my next project.

http://www.homedepot.com/p/Reliance-Controls-200-Amp-Outdoor-Transfer-Panel-TWB2006DR/202216488#product_description

Mounting it outside the house adjacent to the main panel that is in the house. This also happens to be where I put the generator as there is a concrete walk that runs next to the house that is partially concealed from the street by a stone wall. I have for the last couple of years run the generator through two 30 amp fuzes and cut the main braker but I really like this option as it is neet and clean.

This will however require an electrician to move the mains to this box and then run leads to the main breaker box but once it is done it will make things really simple.

BAMF wrote:

stuart in mn wrote: Here's the safety sermon: you need a proper transfer switch or interlock with the main breaker.

QFT! I work for Milbank, and we make automatic and manual transfer switches. Even if I didn't work for a company that made them, I would still recommend them. Not everyone in the house who could turn on a generator would know enough about electrical safety to shut off the main breaker.

Ya I here you. People just don't know. Fortunately no on in my house would consider hooking up our generator as it has to be moved from the shed over to the house and plugged in. I don't think my wife and both kids could move it. LOL

Buy a Honda.

You can do what we did in the military. Dig a shallow hole for it, about half generator height then stack sand bags around it higher than the gen leaving a narrow pathway for access and air and finish off with plywood over the top with sand bags on top. Looks like a bunker but quiets it down a lot.

Tractor supply sells mufflers for old Ford tractors that have pretty small inlets and outlets.

In the ground idea is the best (quietest) answer.

I picture a 4' deep hole lined with four 4'x8' 5/8 PT plywood on end 4' above ground. If it's somewhat insulated all the better.

It's be easy to put a roof over it too. This will channel the sound up and away.

RV places sell an extension kit that uses a car type extra muffler and reducers to small pipe.

My lincon welder / gen is a noise thing but it only used for welding on the road or extream power outages. For house and race trailer we spent some $$ and got a Yamaha gen it will start my extra big A/C roof top and run everything in the trailer. its quiet too

When I built the header for my mini bike (Honda clone motor), I made an adapter and put the old muffler on my two stroke generator. Made a HUGE difference. A small car muffler will probably help your situation a lot.

Junkyard_Dog wrote: Call me crazy, but when I first read about your problem my first thought was plop it into this. Maybe with a box fan in the doorway?

Ding,ding,ding. We have a winner. Camping at my future brother in laws and he does just this with one of those plastic igloo dog houses. Floor removed so it's easy to flip off to get to the Gen to refuel.

You would need to brace it, but what about a long pipe that goes straight up - get the noise away from ears?

In reply to glueguy:

Feed it into the house chimney?