How to Reduce the Noise of a Portable Generator

A yellow portable power generator.
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What You'll Need
Sound dampening, waffle-shaped rubber tiles
10 three-inch bolts with nuts
20 two-inch washers
10 one-inch rubber washers (about one-inch thick that your bolt will fit through)
Thermocole padding
Cinder blocks

A power generator can really help you when disaster strikes or when there are other emergencies, but the constant noise can be detrimental to your health. Studies have shown that loud, sustained noises increase your risk of heart attack, destroy concentration, and make quality sleep impossible.

The noise from a generator comes from two places: the exhaust system and vibrations in the engine housing. You can change the exhaust to make it more efficient and create an enclosure around the generator that will allow it to “breathe” for air cooling purposes, while restricting noise. Each of the following steps will reduce the noise in different ways; if you do all of them, your portable generator will be significantly quieter during use.

Step 1 - Add Padding

Decide where you want the generator to rest. Place it as far as possible from the structure you are trying to power, such as the house or recreation vehicle, to reduce the noise you'll hear. Then, lay the rubber waffle pads on the ground and place the generator on top of them.

Step 2 - Install Exhaust

A motorcycle exhaust is recommended for changing the exhaust on your generator. You can find these easily at a local motorcycle custom shop for a small amount as most cyclists prefer custom exhausts. You will need to create a custom pipe system to attach it, and the exhaust must be vertical to the generator.

Step 3 - Add Anti-vibration to the Engine Housing

To get the maximum reduction in motor noise, you will need to use a sound and vibration dampening material on the engine block. The stock screws will usually have a rubber gasket already attached for noise reduction, but you can double that by adding another rubber washer and longer bolts. If you look at the frame around the engine, you will see where the screws secure it. Attach the rubber washers here to reduce the vibrations and thus the noise.

You will need to unscrew one stock bolt, replace it with a new bolt, and add a rubber washer to the outside of the metal washer, allowing the frame to be sandwiched between rubber. From left to right it will be bolt head, metal washer, rubber washer, frame, rubber washer, metal washer, and bolt. Repeat this for all of the frame bolts and tighten securely.

Step 4 - Create Enclosure

Next, you will need to build an enclosure around the generator. Walls should be on three sides of the generator with the switches and connections on the open side for easy access. Cinder block is the best wall material as it does not need to be sealed. Keep it stacked to a height of one foot taller than the generator and leave a breathing space of six inches to one foot between the generator and the wall.

Test your generator by turning it on while you're monitoring inside your house to see how much the sound still carries. If you're still unsatisfied with the result, add a little more insulation to the cinder block walls to see if it improves.