How to Make a Silencer for a Generator

Updated On: May 8, 2021

Making a silencer for your generator is a difficult task to take upon yourself. It should be said that buying a silencer or a muffler is more cost-efficient. It also requires less hassle and physical activity. You might not be making a silencer for being cost-efficient, or a minimalist, rather because you like to experiment, and your inner engineer has taken control of your psyche. Jokes aside, let’s get into the guide to make a generator silencer/muffler at home.

Making a Generator Muffler

First, you should go online and look at some cutaways of different muffler designs. You will notice that some design has delta plates. The idea is that the sound waves and exhaust will enter the muffler through the chamber and they will reach the delta plates where the sound will be split, splitting the sound wave, makes the sound bounce around the chamber through different plates, and in theory, the sound is supposed to be quieter when it comes out of the muffler.

Silencer for a generator
  • A typical muffler design follows these steps. An inlet and outlet for sound waves and exhaust to come in and out of the muffler
  • Points of stagnation like the delta plates, where the sound is divided, it passes around bouncing into the delta plates, lowering the trajectory of the sound as it goes through the chambers. The velocity increases near the outlet because of the delta plates and their positioning; the result is a quieter sound.

With bigger mufflers, the procedure is pretty much the same; there will be points with higher restrictions and stagnations, velocity modifiers, and delta plates. Most generator mufflers and silencers used as a plugin to the exhaust follow these methodologies through different executions. Velocity and pressure measurement will be an essential part of the process, having to design and measure the muffler and its integral components will require some additional skills. If you want to make a good enough silencer by yourself, know that you have to be able to work with high adaptability. You will have to improvise along the way and make adjustments and decisions that suit your situation best. 

Other kinds of mufflers utilize a different design, but the idea is pretty much the same. They usually have many holes dug into them where the sound passes through, much like a gun silencer, and then there are layers of shielding with foams to dampen the overall sound.

Having a 3D printer will aid you a long way. You can make your measurements and input them in the software. There are different ways to operate a 3D printer, which depends on the model you own. If you don’t own one, you might have to take extra steps to gather and assemble the required pieces for your muffler. 

There are many great free tutorials online on 3D printers and how to operate them. You can likewise find people who already own a 3D printer to help you out with the job. Measure the exhaust of your generator, where the muffler will be plugged in. Make sure the muffler is made in accordance with the diameter of the generator’s exhaust pipe. 

A professionally built muffler considers various things like the size of each chamber and the positioning of each plate. The trajectory and velocity modifiers, as well as the stress level of the muffler. 

What you can use is a 3D modeling software. There are free ones and many paid ones that you can utilize first to create a digital model of your muffler and then test the trajectory of the exhaust and sound waves as well as the pressure in each chamber. What you ought to do is check things like these before you make a muffler as you will be able to change the design and go through various iteration of the design until you find the best one that pleases you with its performance. This can work very well with a 3D printer, and if you don’t have a 3D printer, you can simply visit a mechanic, show him your designs and the dimensions of the pieces, and have it made for you. What we are shooting for, is optimized flow, reduced pressure, and lower sound levels.

Other DIY generator silencing methods

If you are simply looking to find a way to make your generator quieter without having to go through the various strenuous methods mentioned above, you can simply use some cheaper techniques that will cost you less to no money and also requires much less work. You don’t always need a muffler or a silencer to quiet a generator. You can utilize generator boxes, generator deflectors, and other soundproofing methods. Below are some of the ways to go about silencing your generator with low effort and money. 

Rubber feet

Generators like the compact portable generators usually create a lot of vibration. Vibration, as you know, is the cause of creating sound waves. If somehow you can lessen the vibration, the noise that is produced will also decrease. It would help if you did not put the generator on wooden surfaces as it protrudes more sound because of the increase in vibration. Putting it in hard surfaces also does somewhat the same. You can use a rubber surface that’s relatively rigid for a generator to stand, or you can use a foam pad to put under the generator that will reduce the vibration. In essence, this will reduce the commotion raised by generators. This works great for portable generators or compact generators. Inverter generators are also compatible with this method since they also vibrate a lot. Even though inverter generators produce less noise, you can make it even quieter with a rubber-feet or a foam pad underneath the generator. 

Using water for noise suppression

This method is much more accessible and should be one of the easiest. A water container, a hose, and a clip are all you need to utilize this silencing method. The generator has to be placed higher than the water container, and using a hose; you basically clip it to the exhaust pipe of the generator. The other end of the hose will be dipped into the water. There are various safety procedures that you must follow to avoid accidents. An extensive article about generator safety tips has been published recently. Read that before you attempt any of the DIY methods. The water suppressor technique has been described neatly in the article “How to Quiet a Generator.” 

Making a Soundproof Box

A soundproof box will help neutralize a lot of the noise that a generator produces. It is much more relevant for portable generators, and you should be very careful of CO poisoning. The right amount of ventilation has to be ensured. You also need to make sure that the box has the correct measurements and placed at a reasonable distance from the living area. When you open the soundproof box to maintain the generator, let it stay open for a good while before you go near it, as the CO buildup can be very high, making you faint without you noticing. There should be warning signs near the box, and the user has to be always aware that CO accumulation is typical near the soundproof box, so caution is advised. Despite the risks, if you are wary of the small factors, a generator box can be a very effective method do reduce generator noise. It also saves the generator from other external harm. Harm from things like weather changes, pests, insects, and animals can be negated with a soundproof box. It can likewise help you ensure that no harm comes to pet animals from the generator. 

If you are interested in making a soundproof box to silence your generator, then read up the comprehensive guide on how to make a soundproof box for your portable generator here.

Final Words

If you want a muffler for your generator, it’s better to buy one than make one. It’s more cost-effective and convenient. If you’re going to make a muffler for reasons other than cost and efficiency, then be prepared to go through a steep learning process. Some of the processes require a preset of acquired skills. However, if your focus is to silence somehow the noise that is produced by your portable generator with less to no money, then you can try the other DIY methods that we mentioned. It’s crucial to understand and avoid the risks that come with DIY plans in relation to portable generators, so be cautious and mindful about any approach that you may take.

About Steven Smith

For the last 20 years, I have been working as a professional contractor in many construction projects. From my childhood, I love to work with different kinds of power tools. In my spare time, I love to do a different kind of DIY project. It gives me a kind of inner satisfaction.

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