How to Quiet a Generator to Tolerable Sound Levels

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how to quiet a loud generatorMany people who go off the grid find themselves trying to learn how to make a generator quiet. The problem is that they don’t spend the time researching the right kind of generator to use and they end up trying to save a couple of bucks by buying an inexpensive generator.

Most of the people that I know who have done this end up looking for ways to make their generator quiet enough that it’s at least tolerable. I have to admit that we also fall into this category because when we first moved off the grid, we didn’t put a lot of thought into the type of generator that we should have and ended up going with a large generator that was very loud.

If you’d like to learn about the mistakes that we made while selecting our first few generators, you can read my articles called How To Choose a Generator That Will Be Perfect For Your Needs or What is The Quietest Generator For Camping?

How To Quiet A Portable Generator

The quietest generators are those that are designed to run quiet like our Honda EU2000i or some of the large backup generators for home use that are water cooled and encased in a sound dampening enclosure. If you end up doing like we did and making the mistake of buying an inexpensive generator and simply trying to make it quiet, you’re going to have your hands full because it’s not as easy as it might seem.

We’ve tried lots of things to quiet down our cheap 5500 watt unit and we were eventually able to come up with a solution that sort of worked for us but it may not be what you are hoping to hear. A lot of people want to hear that they can simply install a quieter muffler on their generator and that will magically transform the roaring beast into a purring kitten.

We purchased one of the quiet mufflers for generators but we ultimately weren’t very happy with the results. I can’t remember what brand we tried or where we bought it. We didn’t do any actual decibel testing but here’s a video that shows an example that was similar to the results that we got. In this video a man is demonstrating what you might expect if you install one of the super quiet mufflers for generators. His testing reflects the results that we got when we tried to do this although I’m not sure if the muffler he tested was the same one we tested.



In this video a special quiet generator muffler was installed on an 11 horsepower Briggs and Stratton engine that was powering a 6000 watt generator. He did three tests and in the first test he got a reading of 105 decibels without a muffler installed on the engine. When he installed the stock muffler he got a reading of 96 decibels. Lastly, he installed a muffler that he claimed to have paid $180 for and it only decreased the decibel readings from 96 to 90.

How Many Decibels Is a Quiet Generator

The generator in the video above was quieted by only 6 decibels after an ultra quiet generator muffler was installed. That is an improvement but in my opinion it’s still pretty loud when you compare it to a similarly sized Honda EU7000iS that is rated at 52 – 60 dB(A) (m.powerequipment.honda.com/generators/models/eu7000is) or a Yamaha EF6300iSDE that is rated at 58 – 64 dBA (www.yamahamotorsports.com/outdoor/products/modelspecs/622/0/specs.aspx)

Building A Quiet Box For a Generator

After experimenting with a couple different types of mufflers, including a homemade retrofitted automotive muffler, we realized that the most likely solution to the problem of how to keep a generator quiet was to build a sound dampening enclosure for our generator to run in.

WARNING: Never install or run a generator or any other internal combustion engine in an enclosure or building that will allow deadly exhaust fumes into a building that people or animals will occupy. Also, never stand in a building where a generator or internal combustion engine is running. Doing so could result in death! Additionally, you should never install a generator in close proximity to combustible materials to prevent the risk of fire.

What we did was make a cinder block sound dampening room for our generator. We built this enclosure about 150 feet from our house to help with the noise level. We also oriented our makeshift “generator dog house” so that the door was facing away from our home. We unfortunately didn’t build it very well so it didn’t last very long but it did quiet the generator down to some degree. It did, however, last long enough for us to finally save up enough money to buy a genset that was actually designed to run quiet.

I should point out that we also added an inlet vent that we inserted an electric fan in to blow fresh air over the generator to help prevent it from overheating. We also installed and outlet vent for the exhaust to vent out of which we think helped provide good airflow across the engine.

Generator Sound Room

This is a diagram showing the top view of the generator sound dampening room that we made.


Tips For Quieting A Noisy Generator

Here are a few tips to keep in mind if you are concerned about the noise of your generator at your off the grid home.

  • Don’t install your generator near your home. The farther the generator is from your living quarters, the quieter your noisy generator will actually seem. This is probably the least expensive and one of the most effective ways to deal with the noise level of a loud generator.
  • Construct some type of a sound enclosure or at least a “sound deflector” for your generator. When we were trying to find out how to quiet down a generator, we tried an experiment where we simply placed a large piece of plywood between our cabin and the generator. Believe it or not, just deflecting the sound away from the home made a significant difference in the perceived noise level.
  • Don’t install your generator on a wood floor. Our initial attempt to build a sound dampening enclosure was a colossal failure. We simply built a small add-on which was about the size of an outhouse to the outside of my husband’s tool shed and placed the generator in that little room. This actually amplified the sound! It amplified sound just like a hollow body guitar amplifies sound. The wood box acted as a resonator that made the generator seem much louder than it actually was.
  • Orient the generator so that the exhaust is not pointing towards your home. We learned that simply turning the generator around so that the exhaust was pointing away from the house made a bit of a difference in how loud the generator seemed to be.

The Best Advice I Have Is To Buy A Quiet Generator

We learned the hard way that it’s much better to save up and buy a really nice generator that is designed to run quietly than it is to try to figure out ways to make a cheap generator quiet. Not only will these nicer generators run quieter, they are usually engineered better which means that they will probably be more fuel efficient and last longer.



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2 Responses to “How to Quiet a Generator to Tolerable Sound Levels”

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  1. ashland fadeley says:

    I have a number of generators. The Onan generator runs at half the speed of the cheaper (about 1,700 hundred revs a minute) models and is much quieter.

  2. Joe Tacker says:

    I am not the owner of this generator. It belongs to the water company that is directly behind our home. It sounds like a jet plane and last for at least a half hour… it is unacceptable. PLEASE HELP US FIND A SOLUTION!!!!