Generators are extremely useful in a multitude of applications from having power on long camping trips deep in the wilderness to powering your tools on an off-grid job site. If you are plagued by regular power cuts, then a generator will help you stay connected.
But, one glaring problem with a generator is the noise that it produces. This can become incredibly irritating to both you and everyone within earshot of it.
If you are looking for a solution on how to make a portable generator quieter then please read on for some quick and cheap solutions on how to do so.
How to Soundproof a Generator (Portable or Fixed)
Portable generator sound can be reduced by damping the low frequencies as this is predominantly what a generator produces. Low frequency sound waves can travel long distances and are rather annoying to anyone in your immediate neighborhood.
What you need to do is use dense materials for soundproofing as these are best suited for damping these low frequency sound waves.
The Project: Building a Generator Quiet Box
What we will be doing here, is building a soundproofed enclosure, also known as a generator quiet box. This can be made of wood, steel or brick and mortar depending on your budget. It’s ideal to use a dense heavy material where possible as this will resist the transfer of vibrations caused by low frequency pressure waves.
It must be noted that this container cannot be completely sealed as the generator produces fumes that will build up in the housing. The generator also needs to be cooled down to prevent it from shutting off.
I would personally recommend using wood for the enclosure as it’s easy to work with, its cheap and you will be adding sound proofing to the inside of the enclosure anyway.
Step 1: Build and Clad the Frame
Build a wooden frame by using 2×2″ square timber or similar.
The frame must be assembled to resemble a cube like structure. This frame should easily cover the generator with some space around the generator, as you do not want the generator to touch the enclosure.
Next you need to cut out some plywood to cover all 6 sides of the frame.
Be sure to apply some green glue (see on Amazon) to the frame before screwing the plywood onto the frame using wood screws.
Do not fix the front panel onto the frame. This will be the door and you will need two hinges (my Amazon hinge recommendation) to let you open and shut it, plus a latch (Amazon latch).
Once all the panes have been fixed, give the entire enclosure a few coats of water resistant varnish to protect it from the elements.
Step 2: Cut Ventilation Holes
The generator also needs an air vent from outside to ensure that the engine gets enough fresh air. You will need to create some airflow through your enclosure and this can be accomplished by adding an industrial cooling fan to the side of your enclosure near your generators air intake and having an air vent on the opposite side of your enclosure
I would use this air vent on Amazon to do this.
It is important to add ducting to these openings. If there is a clear line of sight between the generator and the outside of the enclosure the sound will escape, and your soundproofing will be useless.
You can add a baffle that forces the sound to change direction before exiting the enclosure. Remember to create openings for the power cable and exhaust.
Step 3: Add Sound Insulation
Once all the plywood is secured, you will need to isolate your generator from the ground by adding a thick rubber mat underneath the generator, two layers of 1/8 inch rubber will do the trick – use this rubber matting. Green glue can be used to glue the sheets to the floor of the enclosure.
Next you can add some sound insulation. I will recommend using mass loaded vinyl (MLV) sheets as this material is perfect for reducing the low frequency sounds of the generator.
The best mass loaded vinyl for soundproofing a portable generator is this stuff, called TMS – view Amazon prices.
Cut the sheets out so that they fit snugly into the enclosure. Any gap will reduce the overall effectiveness of the soundproofing.
You should add the sheeting onto the front door is such a way as to ensure a snug fit when the door is closed. This can be done by placing the hinges and lock in such a way as to squeeze the sheet when the door is closed.
Final Thoughts
In conclusion, you will only reduce the sound down to the atmospheric level, completely removing the sound will not be 100% possible, but by making an enclosure using the materials I recommend you could get some great results.
A simple enclosure using the correct materials will make a huge difference to the sound levels of your generator. Be careful not to place your generators exhaust too close to your home as carbon monoxide is lethal.
Generators make a heck of a lot of noise and you can significantly make your generator quieter using the method laid out above. Good luck with your project!
