Generator Baffle Box: How To Build a Soundproof Generator Box For Home and RV needs in 8 Easy Steps [+ Guide To Soundproof the Existing Generator Quiet Box]

Having a Generator in our backyard has become a new norm considering the unreliable power supply due to natural disasters. We all want them in our backyard but no one wants to hear that ear tearing noise. Do you?

Well, I guess no. It doesn’t matter if it is a portable generator, gas generator, or even an inverter generator, you will have to bear with the noise. So, how can we tackle it? Here’s why I bring a definitive guide to build a quiet generator baffle box for RV and home needs. And if you have an existing box, don’t worry! I have something for you too????

Do you know: Few laws in the United States require you to cut your generator noise below 65 dBA for daytime (7:00 a.m. to 10:00 p.m.) use and 50 dBA for nighttime (10:00 p.m. to 7:00 a.m.) use as measured from complaints’ property line. Violating these limits can result in fines up to $2000 for residents and $3000 for businesses.

Everyone wants power for their various needs, starting from a portable generator for your RV and camping power supply or it can be a generator permanently installed at your home for your needs during power outages.

“The noise ????” is what everyone hates about a generator whatever maybe your needs. If you’re looking to soundproof your installed generator then I wrote the guide for silencing your generator at home for you. I’ve listed 13 ways to Silence your generator.

But those hacks won’t work if you’re willing to shift your generator more often than not or using a portable generator for your RV and camping needs. If you want to hit the quiet noise level in one go, then this guide is for you.

Building your own soundproof box for your generator is much easy than those YouTube video tutorials suggest to you. Trust me! If you’re willing to put your hands on, then this is no big task.

How to build a Soundproof Generator Baffle Box

Remember that it is practically impossible to completely mute your generator. Your generator needs sufficient air and vents to keep the generator from overheating. And those holes make space for the noise of a generator to get out.

Things You’ll be needing:

Note: I’ve included links to these products to buy in case you don’t have any of them

  • Medium Density Fiberboard: This will be our main building material for the box.
  • MLV – Mass Loaded Vinyl: This will be the first layer of soundproofing for our generator box.
  • Foam moats: This will serve as an additional soundproofing layer for our quiet box.
  • Green Glue: A brilliant Soundproofing material used to glue the edges and second layer.
  • Ventilation Duct: Used to create a proper air supply for the generator box.
  • A measuring tape
  • Hammer and Screwdriver
  • Right angular ruler
  • Some pen and paper: For noting down the measurements
  • Screw and nails
  • Cutting Saw: Can be circular or table

Measure the dimensions of your generator

While building a quiet generator baffle box, you need to know that not all generators will be of the same size, so do those soundproof boxes enclosing them. So, it’s pretty obvious that you’ll need to measure the dimensions.

Measure the length, width, and height of the generator as accurately as possible. There’s a carpenter’s proverb that says: “Measure twice, cut once”. If you mess up those measurements here, then you might not have spaces for your generator to breathe or even it can’t fit in the silent box.

Considering the additional soundproof layers to be added inside the box and the air supply requirement, it’s always better to add 4 inches to all the sides from the original measurement.

Cut the MDF Boards

After having noted down the measurements now it’s time to cut the fiberboard accordingly. And by the way, if you have any plywood pieces left in your garage, they can do the job. Certainly, you’re not restricted to the one I recommended, but for sure it helps. In case you want the best soundproof wood comparison and find out which type of wood does the best job, I’ve got that covered too.

If you don’t have any, then I’ve done the research for the best sound deadening fiberboard and I’d suggest this. These medium dense fiberboards will surely make the difference by themselves.

Coming to the cutting part, using the right angle ruler and a pencil, mark the generator measurements on the board. Mark the pieces with a pencil so you won’t get confused after cutting. Using a cutting saw or a table saw, cut the boards according to the measurements as precisely as possible.

I’d warmly recommend using Medium Dense Fiberboard as the Main material

Make Some Holes for Ventilation

The working of generators makes it essential to have ventilation holes for its enclosure. As generators are gas-powered, they need to exhaust the fumes out. Also, those powerful gas engines need to have good airflow to avoid overheating.

Assuming you have got that Ventilation Duct I’ve advised in your hand, measure its diameter. Now you’ve to mark two circles of that diameter.

  • Drill the first hole on the top piece of fiberboard near one of its sides.
  • Make the second hole on one of the side pieces(which should be used as a wall) and that piece should be placed in the opposite direction to that of the hole in the top piece.

Hot air in the generator rises, so the higher the ventilation holes, the better. When you’re done with marking everything and cutting, now it’s time to layout the side pieces inside up. As the top will be sitting on the side pieces and be screwed down, you need to draw a perimeter line around the top piece to fit in with the side pieces, inner soundproof layers, and of course your generator for which we’re building a quiet box.

Install MLV – Mass Loaded Vinyl Insulation

There’s a zeroth rule of soundproofing which says “more the number of layers, the better noise reduction”. Layers of materials, layers of free space, layers of anything is all that matters. The air gap between the generator and the walls will make the noise scatter.

Do you know: Mass Loaded Vinyl is one of the backbone material for soundproofing. Whether it may be soundproofing your room, door, or even wall. We’ll need it to be there.

And this will be the first layer that you’ll want to add to your quiet box for noisy generator. Now roll the Mass Loaded Vinyl across the fiberboard pieces and mark the perimeter of the fiberboard pieces on it.

Mark the Mass Loaded Vinyl pieces according to the labels of fiberboard pieces, cut them accordingly, and paste it to the inside walls of your fiberboard pieces.

I’d warmly recommend using Mass Loaded Vinyl as the first layer for your Silent Generator box

Caulk the MLV layer using Green Glue

Gluing the Mass Loaded Vinyl layer to the fiberboard applying a regular glue is a good task generally. Except pasting those edges can be a little tricky with normal glue.

Using a good Caulk like this Green Glue can make this job easier. It’s totally okay if you want to use any other caulk, but just to mention, the one I just suggested has acoustic properties too! So, two birds at one shot, right!

Install the acoustic foam mats On

Well, it’s all about layers, right? More the number of layers, the better the soundproofing.

And yet, Acoustic foam is right behind the Mass Loaded Vinyl in the list of must-haves for soundproofing anything under the roof of the sun.

Having a cheap acoustic foam mat in your soundproof box will drastically reduce the noise from the generator. You will be installing them inside the quiet box.

Acoustic Foam mats are soft, little fluffy mats that will absorb the sound vibrations within themselves and make it hard for sound to travel across them. Yet, remember nothing can mute the noise completely

Firstly spread the foam mat across the fiberboard pieces just like you did for MLV. Mark them, label them, cut them accordingly, and finally glue them to the MLV layer itself. And here again, if you’re finding it difficult to glue the edges, then the Green Glue will be of good use for you.

I’d highly recommend using these cheap Acoustic Foam mats as an additional layer

It’s time to Assemble the Quiet Generator baffle box

Make sure you give enough time for green glue to dry up. After that, attach the fiberboard pieces that will work as side walls to the one which serves as the top using screws.

While joining together make sure each piece is in its place. Take care of the positions of ventilation holes. You may have to use green glue to seal the gaps between your fiberboard which will itself serve as sound deadening material.

You can put hinges on one of the sides of the quiet box so that you can have access to the generator. In that case, you will have to do readjust the vent hose accordingly as the hose will be present as an obstacle.

Design for installing Ventilation Ducts while building Quiet Generator Enclosure

Installing Ventilation Ducts

As discussed earlier, your generator needs to “breathe”. On your way to soundproofing it you cannot afford to suffocate your savior. Generators run on gas and work on the principle of combustion. If you don’t give enough air supply your savior can turn into a potential catastrophe by itself.

Your generator needs good airflow to let out exhaust fumes and avoid overheating. To do that, we’ll have to put Ventilation Duct into the ventilation holes we have made earlier.

Pro Tip: Sound reduction happens least when it travels in a straight direction with the least turn and thus minimizes the soundproofing capabilities of our quiet generator quiet box. So, it’s best to create the most bends, turns possible when installing a ventilation duct to maximize sound reduction.

So, we can say that the longer the ventilation duct, the better soundproofing we can achieve.

Once done, placing a little vent on the top of the openings in the box will give the final touch

I’d highly recommend using a Ventilation duct for proper air supply for your soundproof generator box

On Building a Quiet/Soundproof box for your Generator

It wasn’t that tough, right? Purchasing a commercial soundproof generator enclosure is quite expensive whereas building one by ourselves is far more affordable.

Hence, by removing the downside of our only savior during power outrages, we can happily enjoy on-demand power supply and sleep peacefully.

How To Soundproof Your Existing Generator Baffle Box

If you have an existing RV Generator Box or a normal one, for which you wish to soundproof, I’ve solutions for soundproofing almost every type of box you could have. Generally, people would think covering the generator box completely can make it quiet, which can go terribly wrong. Your Generator needs to “breathe”. It is a combustion engine, it needs to exhaust fumes, it needs airflow to avoid overheating.

So, what can you do to your existing Generator box?

Depending upon the type/situation your generator quiet box is in, I’ve corresponding solutions.

1. What material is used in making your Generator baffle box?

If it’s metal:

If it’s concrete:

  • Separate your generator from the floor using anti-vibration pads.
  • Mass Loaded Vinyl is not required.
  • Sound absorption material should be included as shown in the above process of building a quiet box for the generator

If it’s plastic:

  • Use Mass Loaded Vinyl.
  • Separate your generator from the floor using anti-vibration pads.
  • Use vibration damping material.

If it’s Wood:

  • Mass Loaded Vinyl will increase the wall density significantly
  • Separate your generator from the floor using anti-vibration pads.
  • Sound absorption material can help.

2. Does your generator quiet box has big air gaps?

It’s the trickiest problem you’ll face while soundproofing your box. Soundproofing needs air gaps to be closed. On the other hand, generators need a good air supply. How can we meet both ends?

Well, planning properly will solve both problems. Using Ventilation Duct with multiple twists and turns can dampen the noise to a good extent. Also, pointing the vent in the opposite direction of your home can make it much less audible.

Also, building an external structure using bricks or something that can control the noise. You’ll have to be careful doing that cause it might cause overheating. You need to constantly check the temperature inside for testing.

3. Attach sound absorption material inside walls

As most of the walls are hard and hard surfaces are good sound reflectors. This is not helpful if you’re willing to soundproof the box. Fixing some sound absorption materials to the walls will lessen those reverberations and can cut down the noise by 5-7 decibels.

Real quick tips to Make Your Generator quieter

Place your generator away

Placing it nearer might seem convenient considering the cables connected, but it will sound too loud to you. You should place it as far as possible no matter if you’re using it for home purposes or camping purposes.

Ideally, the recommended distance is 20 feet away from you. Even the branded generators can’t help in this. All they’ll advertise is “our generator is no louder than 60 decibels” and still include a mark saying “7m” meaning that sound reading is taken at that distance. This obviously means you’ll have to place your generator at least 20 feet.

So, I’d suggest you invest in extra-long extension cords so that you can place your generator at the farthest point. And even if you want to quiet your generator for camping, the better place the generator on another side of the van.

Point the exhaust pipes vertically

Just like you put the noisy things away, you will have to adjust the noisy parts of your generator away. Sounds cool, right?

The noisy parts? The exhaust system is the loudest part of an engine running on fuel.

Usually, most generators have their exhaust pipe aiming horizontally. They will shoot smoke and noise in that direction. What can you do? If possible bend the exhaust pipes vertically so that the noise will dissipate into open air without any echos. If it’s not possible, point then in the opposite direction to that of your living space.

Get the generator of the right size

You know the equation. Higher the power of your generator, the more noise it will produce. So, assess the power needs of your home/camp and buy the one which fits your needs as precisely as possible. Not only will it increase fuel efficiency by not burning fuel for excess power, but it will also lower the noise of your generator.

Put the rubber feet

Sound generates when two hard surfaces vibrate when in contact. And we don’t want that to happen between our generator and the hard surface beneath. Unless you have a soft surface underneath your generator, it’s important to put something soft to cushion those vibrations.

What can you do? You can put your generator on the grass or dirt to cushion the reverberations. If you’re unable to find such an area, you can use rubber mats you have or even these cheap anti-vibration pads will do the job for you.

Tips for Proper maintenance

  • Run your gen for at least half an hour every three months to keep it in good health.
  • Never refill the generator when running, or hot. Let it cool down.
  • Never let your generator to run out of fuel. It can cost you serious money.
  • Never put your generator on an ununiform surface. Your generator built requires it to be on the uniform level.
  • Replace the oil for every 50-hour running time.
  • Always lock your generator.
  • Never run your generator in rain. Put at least any kind of shield with enough ventilation.


Can you put a generator in a box?

Yes, absolutely you can put your generator in a box. Just that you need to make sure the sufficient air supply is provided to make sure your generator can “breathe” and avoid overheating. Apart from that, you will have to put a ventilation duct to make a way for exhaust fumes. You can also put a cheap and tiny fan to your generator baffle box it makes “breathing easy”.

How much airflow does a generator need?

The formula is 65 cubic feet per minute(CFM) per 1000 watts. For household generators of not more than 10000 watts requires 650 CFM. You can make that airflow happen by putting at least three ventilation systems. One for the exhaust fumes outlet, the second one for cooling the generator, and the third one for air intake.

Can you enclose a portable generator?

Yes, you can put your portable generator inside the enclosure. Just that you need to provide proper airflow for exhaust fumes, air intake, and generator cooling. Those enclosures not only will protect you from the weather but also from thieves and reduces the noise a little bit.

How far does a portable generator need to be from the house?

Make sure you place your generator at least 20 feet or 7 meters away from your living area. Also, point the exhaust pipe away.

Do you need to cover a generator in the rain?

Yes, you should cover your portable generator in the rain. Instructions from the generator manufacturer warn you not to run your generator in rain. Put at least a cover or shield with enough ventilation for exhaust fumes, air intake, and cooling.

Warning: Never operate a generator or any other internal combustion engine inside enclosed space or indoors. Neither you should enter such a building having one. It can be extremely hazardous. More than 900 people died of carbon monoxide, thousands injured while using generators. So, be careful.

Wrapping up on Generator Quiet box For Home and RV needs

Building your own Quiet box for a generator isn’t tough, right? And converting the existing one into a Soundproof box is easy too! The generator comes in handy for all homeowners, campers, RVers, contractors, particularly during power outages. Hopefully, the guide, those quick tips helps you designing your own soundproof box.

Did I leave anything? or have any suggestions? What hacks have worked and not worked for your generators? Feel free to put down in the comment section. I’ll be glad to answer you.

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