How to Quiet a Generator: A Guide to Making Generators Less Noisy

Generators provide excellent backup power and are great for outdoor use in non-electrified locations. Although they have significant drawbacks, one of the most annoying and most consistently complained about is the jarring noise they make.

Thankfully, you don’t need to continue putting up with the excessive noise level and you can focus your mental energy on your tasks instead of trying to block out the noise.

This guide is going to explore why generators are so loud in the first place, and more importantly, we’ll give you tips and tricks about how to quiet a generator and lessen noise pollution. We even teach you how to build a soundproof box! So, let’s dig in.

How is Generator Noise Level Measured?

Generators are mechanical equipment with motors that drive their functioning. Hence, the noise.

An appropriate sound level, like any other sound, is a subjective assessment. The design of the generator and the cost of the unit dictate the varied degrees of loudness.

Decibels (dB) are the unit of measurement for sound and a decibel level describes the relative difference in sound volume.

The decibel scale is logarithmic, which implies that when the sound rating is dropped by three units, the noise is reduced by half. As a result, a generator with a decibel rating of 75 is half as loud as one with a decibel rating of 78.

Why do Generators Make Noise?

There’s a variety of reasons why a generator may produce more noise than is acceptable:

Power Capacity

Mobile generators push electricity through an engine which could be noisy. The loudness of the engine is dependent on the amount of power it produces. So, a generator which generates a lot of energy is generally going to be noisier than one which produces less.

Quality

Often, a generator may still produce less noise than a generator with less power-generating capacity. This usually happens when there’s a big quality difference in the generators.

Some generators come with robust pipe casings and rubber tires, which offer better insulation against noise and vibration. However, generators of this caliber are often more pricey.

Wear-Out and Damage

The older a generator gets, the worn out it is. Worn-out generator engines are likely to become damaged and in need of repairs.

Damaged or worn-out generators are bound to produce more noise. They could also cause more problems aside from noise. They may begin emitting smoke, for instance, or may become difficult to start up. If you notice your generator doing any of that, take it in for repairs.

Proximity to Living Quarters

Another reason why a generator may be noisy is because of how close it is to your house or living premises. This doesn’t mean that the generator is producing a greater output in decibels; it’s just that the sound is closer to you.

Vibration on Hard Surfaces

A generator is very likely to make a lot of noise if it’s placed on a hard surface such as concrete or wood. The vibrations of the generator combined with the hard surface is bound to produce more sound waves than if it were placed on a softer surface, which absorbs some of the sound.

Why You Should Learn How to Quiet a Generator That’s Noisy

Putting up with the loud sounds of generators is a bad idea. Noise is a form of pollution that’s a minor irritation at best, and a health risk at worst:

• The loud noise produced by generators can negatively affect mental health and increase stress levels.
• Long and continuous exposure to loud noises may build up to gradual damage of the eardrums and lead to progressive hearing loss.
• Sleep deprivation may occur as a result of the irritation caused by generator noises.

Summary of Noise Reduction and Prevention Techniques

For a quick overview, just scan the following steps to learn how to quiet your generator:

1. Position the exhaust pipe away from your home
2. Reduce noise by mounting the generator on a soft pad or use anti-vibration mounts
3. Reduce noise by ensuring there’s an air gap
4. Change the generator’s location
5. Add a noise muffler
6. Use water as a muffler
7. Use sound deflectors
8. Reduce vibration in the engine housing
9. Build a soundproof box
10. Build a sound attenuation enclosure
11. Buy generators that don’t produce much power (unless you really need it)
12. Buy high-quality generators
13. Keep your generator in good condition
14. Don’t let your generator run for too long during low throttle operations
15. Change the air filter regularly
16. Use the right fuel
17. Turn the generator off when not in use

Tips on How to Quiet a Generator

There are several ways to reduce the noise a generator emits. The right approach is largely dependent on which of the factors mentioned above is the cause of the noise.

Position the Exhaust Pipe Away From Your Home

The best position for a generator exhaust pipe is away from your home. This will ensure that the noise produced by the exhaust dissipates before it reaches you.

While doing this, remember to be considerate towards neighbors. So, don’t put it where the noise will carry into other people’s homes or establishments.

A common solution is to simply direct the exhaust pipe toward the sky. It’s important to mention that this method only reduces the noise produced by exhaust and not by an engine. So, if it was your engine that was producing the noise, positioning the exhaust somewhere else won’t solve the problem.

Mount the Generator on a Soft Pad or Use Anti-Vibration Mounts

Vibrations play a huge role in causing noises and a significant part of the vibrations produced boils down to how you set up your generator in the first place.

If possible, place your generator on something soft such as rubber tires, rather than hard surfaces like concrete floors, which amplify vibrations even more. 

You can also consider sliding a separate board underneath where you intend to place your generator. Or place the surface of the generator onto a rubber mat or even plywood that has been covered with rubber sheets.

This will reduce how much vibration gets transferred from the engine to the floor surface and thus cut down how noisy it becomes.

Think about investing in some specially tailored anti-vibration mounts that are made of neoprene, spring mounts, or dampers mounts. They can be made as thick as needed to reduce the vibration and subsequent noise emanating from your generator.

Reduce the Noise by Ensuring There’s An Air Gap

An air gap refers to how much physical space is between the generator and where it’s placed. A larger distance reduces how loud vibrations from the engine can be heard as there isn’t a direct transfer of sound through solid materials like walls, floors, or metal surfaces.

If you’re inside your home, for example, then putting objects between yourself and a loud generator is an effective way at reducing how noisy it becomes when running.

Change the Generator’s Location

When possible, move your generator to a more convenient place. This way, generators will not be directly next to areas such as bedrooms or living rooms, which are more sensitive or vulnerable to loud engine noise. 

You can consider installing a decibel meter in your home just so you can see how loud the generator is running at certain times.

Add a Noise Muffler

A muffler is equipment that’s placed onto the end of an exhaust pipe to reduce how much noise it produces. Commonly, several generators come equipped with mufflers. If yours doesn’t, or it is damaged, you can get a new one.

The generator muffler’s holes and channels eliminate the pressure of the exhausts emitted from the machine. The muffler is designed not just to reduce noise but to combine sound waves and cancel them out.

How effective these devices make generators run depends on how well they were installed in the first place. If possible, try contacting professionals or car mechanics for installation.

Use Water as a Muffler

One clever way you can reduce the noise coming from a generator is by using water as a muffler. Water is a well-known sound muffler, and the method is also known as the “Water Bucket Trick”

The trick essentially involves putting a hose over the exhaust pipe and channeling it into a bucket of water. The hose shouldn’t be rubber or any material that can be affected by heat. Also, make sure that you connect the hose to the exhaust pipe only when the generator isn’t running.

After connecting the hose to the exhaust, get a bucket filled with at least 5 gallons of water. Then, place a hole few centimeters away from where the hose enters the bucket. This is to ensure that by no means would water be carried all the way back to the generator’s exhaust — this could lead to serious problems. After all, water and voltage are a dangerous mixture.

Now that the hose has been fitted into both ends, you can flip on the generator. The hose carries the noise from the exhaust into the bucket of water, which muffles the sound. There should be a continuous bubbling of the water in the bucket due to the sound force, and is an indicator that you’ve done things correctly.

Note that this trick only quiets the noise emitted by the exhaust, and not the generator’s engine itself.

Also, in order to further eliminate the risk of water being carried back to the exhaust, in addition to creating a hole at the opening where the hole is thrust into the bucket, you can also place the bucket far away from and at a lower level than the generator.

Use Sound Deflectors

 A sound deflector is also an effective method to keep down noise levels.

The most effective item used for building sound deflectors is plywood. Plywood surfaces often reduce noise transmission by reflecting sound waves, so find some plywood boards and lean them against your generator sides in a box shape.

Don’t place sheets of plywood at the side containing the exhaust, though, because plywood  isn’t fire-retardant unless specially treated.

This method works by deflecting the sound downward toward the ground, resulting in a much more manageable noise level.

Note that the plywood method has its downsides: it doesn’t completely eliminate noise, but it does have the advantage of being easy to set up and take down.

Reduce Vibration in the Engine Housing

If a generator’s engine is not fitted with a vibration damper, then it will vibrate and transmit noise. Reducing the vibrations of the engine can help reduce how noisy it gets.

This method somewhat dampens the sound levels by reducing any rattling or shaking that may be present in your generator during use.

Excessive vibrations may be caused by loose parts in the engine or absence of rubber washers under screws. If any part is loose in the engine, you should fasten it back and ensure everything is fastened tightly together before starting up your generator again.

Also, you can place rubber washers under screws or replace old or worn ones. This goes a long way in dampening the sound that emanates from the engine.

Build a Soundproof Box

A sound proof box is another great alternative for reducing generator noise. This is more convenient when the generator is stationary and not being moved from place to place as soundproof boxes and generators can be a heavy combination.

You can purchase soundproof boxes, or you can just build one for yourself with the guide below.

Items You’ll Need:

• Closed-cell vinyl or foam matting
• Saw
• Measuring Tape
• Soundproof sheets or Medium Density Fiberboard (MDF)
• Acoustic caulk
• Mass Loaded Vinyl (MLV) sheet
• Handle
• Nails or screws 
• Metal venting ducts    
• Insect-proof mesh

Steps

1. Use tape to measure your generator’s size and leave about three inches on every side for ventilation and insulation.
2. Cut out five sheets of MDFs or soundproof sheets according to the measurement.
3. Measure the size of the ventilation ducts you bought and also the width of the exhaust. Now cut these out from the wood.
4. To suit each side of the box, cut off five sheets of Mass Loaded Vinyl. This will obstruct sound even more. Glue all four sides together. Seal gaps and seams with acoustic caulk around the edges.
5. Cut out five sheets of foam matting or closed-cell vinyl or to the MLV layer. Thankfully, several foam mattings are self-adhesive, so it should make the process simpler. Seal gaps and seams with acoustic caulk once more.
6. After nailing or screwing the four walls together, add the top.
7. Attach the handle for simple removal.
8. Plug the gaps in the wood with venting ducts. Make certain they have some bends. Sound waves are normally straight, but when they’re bent, the sound is disrupted. To seal the interior edges, wrap acoustic caulk around them.
9. Attach the insect-proof mesh to the interior of the vent openings to keep pests out.

Build a Sound Attenuation Enclosure

Steel enclosures with sound absorption can also be used to quiet your generator.

The enclosures are built with perforated sheet metal and have a high-density rock known as a splitter contained within. The perforated sheet metal allows for plenty of air to pass through while absorbing the sound and reducing sound wavelengths.

Attenuators are created depending on your generator’s size and your specific sound attenuation requirements.

Tips and Tricks on How to Prevent Noise from Generators

This section is more to give you sound advice (pun intended) on how to prevent inordinate noise being emitted by your generator.

Buy Generators That Don’t Generate Much Power Unless You Really Need It

If you’re not using a generator for power hungry appliances, consider buying one with less wattage.

Inverter technology is used in the quietest generators on the market. They have an average sound volume of roughly 50 decibels, which is comparable to the sound of normal conversation (usually 50–60 decibels).

Inverter generators are smaller and less powerful than traditional generators. You won’t be able to power too many heavy items depending on the size and brand, but you should be able to cover your basic electricity needs.

Conventional generators, on the other hand, maintain a higher intensity to provide for their increased energy output. And, as you may have guessed, this leads to greater noise.

Buy High-Quality Generators

This is probably one of the most effective ways to get rid of generator noise. It comes at a cost, but you’ll be able to invest in generators that are much quieter than ever before and maintain their quality for longer periods of time.

When buying generators, shop for one with low decibels. Also ensure that they have anti-vibration mountings, such as robust pipe casings and rubber tires, which offer better insulation against noise and vibrations.

It’s also helpful if the generator is composed of corrosion-resistant materials, like aluminium or steel.

Keep Your Generator in Good Condition

If your generator isn’t looked after, it can get rusty or very dirty, which will cause more sounds and vibrations while running. If you take good care of your generator engine by making sure everything is clean and oiled regularly, you’ll reduce how noisy it gets.

To keep your generator performing at its best and as quietly as possible, consider having it serviced regularly by a certified professional.

If you find that the engine is making big noises during operation on full throttle, this might be an indication of something wrong with the machine and may need repairing or replacing.

Don’t Let Your Generator Run for Too Long During Low Throttle Operations

Low throttling can also create some noise, but not nearly as much as when running generators on high RPMs. To avoid unnecessary noise, don’t run the generator constantly at low speeds, unless necessary for longer periods of time, such as overnight.

Change Your Air Filter Regularly

Filters prevent dust from entering the engine’s air vents, which contribute to additional noise, such as rattling. Cleaning or changing your air filter should help reduce this.

Use the Right Fuel

If you really do need a generator that packs a greater punch than inverter generators, then make sure you use generators that use the right fuel.

Contemporary diesel engines emit significantly less noise than older diesel engines and even newer gasoline engines. Why? Because newer diesel motors require less energy and so operate significantly quieter than gasoline generators due to their superior efficiency.

Gas engines make more noise than diesel engines when they’re going at full power as they require greater Revolutions Per Minute (RPMs) than diesel engines to create enough power. The most common RPM for tiny gasoline generators is 3,600, and newer diesel engines typically spin around 1,800 RPM.

Don’t allow constant generator noise to bother you and give yourself some peace by using newer models of diesel engines.

Turn the Generator off When Not in Use

When generators are kept on continuously, they can begin to produce loud noises even when they’re not in use. If generators are switched off after each usage, this extends how often their engines run continuously.

This small but significant act ensures that there’s less risk of them breaking down or wearing out quickly, ultimately reducing noise risk.

Take Away

Hopefully, you’ve gotten some useful advice about how to quiet a generator. Just remember that it’s a good idea to determine the root cause of the noise before deciding what method you should apply.Keep reading to learn What type of Led Lantern is best when there is a power outage, or learn How to survive an EMP attack.