Generator Mufflers

Anyone know how to quieten a generator down a bit? My mother bought a dual fuel generator with plans to run it on propane. Apparently she didn't care for the two I have on my 12 acres when I offered to just bring one of them to the house. Anyways, it arrived, I set it up & got it running to break it in. I even bought plenty of maintenance supplies for it. However, she thinks its too loud. So, any one know how I can quieten it down? Better mufflers that will work, etc...???

 

A muffler won't do much good because most of the sound radiates from the engine block because they're so lightweight.
An enclosure with plenty of ventilation and a port for the exhaust would do more.
Keeping the generator cool while covered is the hard part because every hole you make in the enclosure to allow cooling air will also allow more noise to escape.
Consider these design criteria:
1. Sitting on earth or on a thick mat on earth is better than concrete.
2. Design baffles into the enclosure vents to trap more sound.
3. Use Rockwool or similar fireproof insulation.
4. Include a door and make the enclosure large enough to service the generator.

 

We don't know enough to give you good info. How big? Brand and model? Intended use (i.e., emergency or otherwise?)
The cheap way out is to move it further from the house, install a "dog house" over it with fiberglass insulation on the inside and lead the muffler out on the side away from the house.
Cheaper, if only for emergencies, is to live with the noise for the duration of the outage.

There are some more tricks, but money will be involved.

 

Portable, Champion Brand
https://www.amazon.com/gp/product/B00VFDJGCE/?tag=survivalmonke-20

 

Disconnect this first off....low oil shut-off sensor
Put it in a barn,shed etc,Run a longer cord.OR
Some just add a flex pipe on the exhaust,Dig a hole in the ground and stick it there...

 

I have not tried this but it makes sense. You bury a 55 gallon drum with some holes for condensate then hookup exhaust should make exhaust very quiet. Mine sits in garage hooked through a reverse flow car muffler then into the wood stove chimney. The engine is 18hp gas engine running 1800rpm. It belt drives a 5.5 kw generator using 1/4 to 1/3 gallon per hour.

 

Have to build a generator dog house or get a different generator.
There's youtube videos of a guy putting different mufflers on a generator to try and make it quieter. It didn't work. Not only did it not work it didn't even make a noticeable difference.

 

Stack some brick or block around it so it shields the house from the sound.

 

I did the same garage hook-up with my big gen unit - use boat tank fuel feed for long run >> plan on using salvaged bed mattresses for sound barrier during any necessary SHTF ...

 

Ear plugs

 

Its not the house. Its the neighbors & people driving by on the highway she don't want hearing it!

 

Buy a Honda inverter generator.

 

I saw a video where a guy leaned sheets of plywood against the gen. at an angle. It quieted down some.

 

A bit off-topic, but IMHO quite important.

This part could very easily kill you. Carbon monoxide is odorless and the molecules are actually small enough to pass through drywall. It is slightly lighter than air, but not enough to guarantee it will all go up the chimney.
A good CO monitor is a good idea if the genny is close to a house.

Anyhow....a vented, baffled, insulated enclosure is likely to be your best bet to cut noise down. Any muffler that quiets the engine significantly is likely to also interfere with the engine breathing...plus, as mentioned in another response, mechanical noise remains an issue.

 

Noise level goes down, price goes up.

 

Sounds like she wants solar panels, it is difficult to hide generator noise. You can't get too carried away because most portable generators are air cooled and the sound travels on air but I'm sure if you put a lot of time and effort into it you could setup some barriers that reflect and absorb sound. I put mine under some dense trees that would absorb sound and then reflected the sound coming out of the front back into the trees with some scrap steel beams I had. A pile of dirt in front of it would reflect the sound up into the atmosphere. A pile of dirt surrounding it would reflect the noise from all angles up into the atmosphere but is pretty much the definition of a pond unless you put a drain in the bottom.

 

With my setup it runs inside the garage but exhaust is routed outside through the chimney. While running you can't hear it at all 100ft away. The nice part is in cool/ cold weather it heats the garage very nicely. In hot or warm just leave a bay door open.

 

Not the same situation and this maybe worthless to you but......... I run generac gas 12,000 and 15,000 watt units for the food trailer and they are LOUD and the last thing you want at the end of a food trailer where yer trying to business is a generator drowning everything out. Tried all the muffler advice and at best got down to 3/4s as loud which is still to loud. So I did what some here have suggested and built a Gen house of sorts for them. That absorb some and direct the noise up instead of all around. A 2 inch thick kind of spongy rubber mat for it to sit on and put 3' side boards on the truck bed with the same rubber mats screwed on to the inside of the side boards. Can stand beside the truck with both generators running now and have a normal conversation without yelling. Go to the back of the truck and it is still VERY loud. 30 feet up at the Customer service end you can barely hear it. Just have to unhook the trailer and point the back of the truck in the least offensive direction. Cough and point the exhaust AWAY from the rubber mats........... It will catch them on fire and they make impressive black smoke

I have a 4,000watt Honda quiet run that will work for the small trailer but just does not make enough amps for anything big and with what those things cost more than one and lining them up ain't feasible. But to their credit when they are running you really don't even know they are there. But for a home back up generator it would cove the basics and Honda has proven to be very reliable in the realm of small gas generators.

Something else you may consider is a Propane or Natural gas fired generator. I got tired of dicking around with the big diesel generator on the farm and picked a 45kw propane job up and set a 2000pound tank for it. I had my electrician do the install to the breaker box out by the electric service. Have a big breaker box beside the meter with 50amp-200amp breaker that go to the different buildings and a 600amp service off the meter. Figured having him wire the generator cables in was better than me doing it since I was not 100% confident in myself fer this job, he charged $50 and a 20 pound ham as I had all the parts in my misc electric parts crate. Looks like a transfer switch, a disconnect box and then into the main breaker box. It runs relatively quiet and makes at least 200amps of power. Flip the disconnect off between meter and box and the Generator kicks on with about a 10-15 second interruption of power. Flip the disconnect back on and the generator shuts down with no power interruption. The old diesel generator I had to go manually start when the power went out. It won't power everything like the commercial kitchen gets right up to 200amps when everything is turned on and working. But it will keep the freezers freezing, the two cabins running lights, computers. TVs and all the stuff going. Friend has a 16KW for her place and I think she said hers cost $4000ish new and electrician charged her $550 for the install and parts. And another vendor has a 7500watt generac propane burner mounted on the front of his trailer on the tongue and runs it off of 20#-100# tanks It runs pretty quiet. I am debating getting one and mounting it in the box truck and using quick connect cables to run from a disconnect to the trailers main 50amp power plug in. Already carry 8 100# tanks and a dozen 20# anyway they run a lot more quiet than a gasoline job but not as quiet as a low rpm diesel. Running cost is looking to be considerably less on propane than gas or diesel.

Generac 45kW Generator—Protector Series NG/LP—Norwall PowerSystems