Soundproofing Generators: 9 Tips to Reduce Noise

Soundproofing a generator

Last updated: April 15, 2022 at 7:53 am

Generators are a great source of power for remote areas or for situations when the power goes out. The only thing about generators is that they can be noisy, which can make it difficult to sleep or converse with others during use.

In this article:

We’ll cover some of the main points on soundproofing generators and why they’re noisy in the first place.

Why Are Generators Noisy?

Generators can be loud, especially those that are inexpensive. The engine size, muffler, fuel tank capacity, and the number of outlets will all affect the noise level. The more powerful units are generally louder than smaller ones that have less power output. There are a few key reasons for this.

First is the engine that powers the generator. Generators create electrical energy through an engine, which can make a lot of noise even inexpensive models. To mitigate this, manufacturers usually include a muffler and other sound-absorbing materials like foam and rubber to muffle the noise. More expensive generators have more effective mufflers and sound-absorbing materials, so they are quieter.

Another reason generators are noisy is because they often must deal with wind noise and air resistance as they run. If your generator is in an open space or it’s windy outside, this can cause them to be louder than usual. This is unavoidable for the most part and is only helped by higher-quality mufflers and sound-absorbing materials built into the machine.

Here are some other reasons why generators are noisy:

  • The generator is not placed on a flat surface: if you have a portable generator, you must place it on a flat surface to avoid noise. If you place it on an uneven surface, the engine will struggle to keep running, causing it to make more noises than usual.
  • The oil level is low: keeping your oil at the right level will help your generator run better. If your oil level drops below what it should be, your engine will heat up and cause your generator to make more noise as well.
  • The air filter is dirty: this will cause your engine to work harder and make more noise.
  • The spark plug is bad: if your spark plug has become dirty or damaged, it will cause problems when starting up and during operation. You need to replace it with a new one for the best results.
  • The generator has loose components: having loose or worn-out components like nuts and bolts can lead to excessive vibration.

9 Ways to Soundproof a Generator

Generator noise can be very loud and tends to disturb neighbours. Here are a few ways to make generators quieter:

1. Build a Quiet Box

Building a box around your noisy generator is one of the easiest ways to quieten it down. You can build it from plywood or any other solid material, but make sure to use materials that are lightweight and easy to work with.

The box aims to contain the sound and make the generator quieter. The material you use will determine how effective the box will be in this regard. The generator box also doubles as an added layer of protection for the machine from being exposed to outdoor elements such as rain, snow, dust, and debris that could potentially damage the engine.

generator quiet box

You can also build a smaller enclosure around the exhaust pipe. This will help shield some of its noise as well.

Make sure you leave enough space around your generator so that it is not too cramped inside the box, as this would generate more heat when running and could lead to problems like rusting and component failure.

2. Place on Soft Ground

Having a generator on concrete is a recipe for disaster. When a generator is placed on a hard surface, such as concrete or asphalt, the vibrations travel easily through the surface and create a lot of noise.

You will need to place your generator on a soft surface where there will be less noise and vibrations. If you have someplace in your house or property that could be considered soft ground, use it.

If your generator has wheels, simply move it to an area that is not concrete. Some generators have rubber mounts that dampen the noise and vibrations. If you can get one of these, you are more than likely to have a quieter generator.

You should also place the generator away from any walls or fences as these can make the noise worse and increase the echo.

3. Use Only the Engine Size You Need

Most times, a big generator size makes more noise. So, you must go for an engine size that’s just enough to supply the electrical load required by your household appliances or business equipment.

This will not only reduce the amount of fuel used by your machine but will also help minimize the noise level produced by it.
You can also get a dual fuel generator with which you can switch to gas (propane) for quieter operation.

If you go for propane or natural gas generators, make sure to check the runtimes of the model. Although they’re quieter than gasoline versions, they may not last as long on a full tank of fuel.

4. Deflect the Sound

One of the simplest and most effective ways to reduce the noise level of your generator is to add some sound deflectors. To make your deflector, you can use any material that will deflect the sound waves down towards the ground.

When building your sound deflector, place pieces of wood around the generator at an angle but leave room for airflow while deflecting the sound waves down into the earth.

Make sure there is enough space in between the wood and generator so heat can escape. If you use cardboard instead of wood, it will not last as long, but you can still get good results.

Another option for sound deflection is using sound blankets made from fiberglass insulation or special acoustic foam.

5. Invest in a Zombie Box

zombie box

Zombie Box is a portable, weatherproof, noise-reducing enclosure for portable or standby generators.

The Zombie Box has been tested to reduce sound pressure levels by up to 10 decibels using only acoustic foam inside the box. The Box is fully customizable with additional sound dampening material added if required.

Here are some benefits of using a Zombie Box:

  • Noise reduction up to 90%
  • Weatherproof design
  • Fast, easy installation
  • Adjustable size to fit any generator up to 7000 watts
  • Constructed of durable, rust-free materials
  • Fully ventilated sides and top allow air circulation and cooling of the generator

6. Replace Your Generator’s Muffler

The theory is that since the larger muffler has more space, it will absorb more sound.

However, it’s important to note that there are many different types of mufflers out there. Just because one type of muffler reduces noise on one model, doesn’t mean that another type will work on another model.

If replacing mufflers doesn’t sound like fun, there’s always investing in a quiet generator.

7. Install Sound Deadening Material Inside the Generator

Another strategy for quieting an existing generator is to install sound deadening material inside the generator. This is usually done by drilling small holes in the enclosure and inserting felt pads or other types of sound deadening material inside the enclosure.

This can be somewhat effective but depending on how much material you use; it can also negatively affect airflow inside the enclosure which could cause overheating problems and premature failure of your generator.

8. Add Vibration Pads or Rubber Feet

Vibration pads or feet are rubber products designed to absorb vibration and reduce noise. They are commonly used in the construction industry to keep generators from sliding around on concrete floors. But they also work well to separate the generator from the ground and reduce noise.

Depending on what you want to do with your generator, you can either buy pre-made ones online or make some yourself. This is done by cutting off a piece of rubber matting (like what is used in gyms) or buying some sheets of rubber at a hardware store.

All you need to do is place them under the four corners of your generator and that’s it, your generator is now a lot less noisy.

In addition to lowering the noise levels, these pads will also help protect the surface that you are placing your generator on from any damage.

9. Use an Exhaust Extension

For outdoor generators, an exhaust extension may help to quiet the unit down by directing the sound away from people who are nearby.

Some generators have an exhaust system that can be extended straight up into the air to direct the sound upward and away from people on the ground below. Others have curved exhaust extensions that allow you to direct it downward toward the ground.

Conclusion

If you have a generator, then treating it well and servicing it regularly are important tips to follow. But if you have a noisy generator, there are things that you can do to quieten it down.

The information above should help you get your generator back under control, so it’s no longer too loud for you or your neighbours!

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About the Author: AJ

AJ is a self-confessed soundproofing nut. He has written full-time on Quiet Living for the past 3 years, and has a wealth of knowledge about living a quieter life, soundproofing and fixing loud noises.

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