How to Make your Generator Run Quietly
By Emily Hutchison
Generators are a major asset when the power goes out. A generator acts as a backup power supply. Most are gas powered and come in a wide variety of shapes, sizes, and prices. Many generators can be very loud which can make using them a pain. Here are a few simple tips to make your generator run smoothly and quietly.
The Muffler Myth
Mufflers work on the principle of deflection. The sound is bounced around back and forth inside the muffler and should come out the other end much quieter. Adding a muffler can reduce the sound 1 or 2 decibels. Not a huge difference. A muffler will change the frequency or pitch. A loud low hum might be more appealing than a high pitched squeal. A large muffler may a make the generator run less efficiently. Try adjusting the jetting to make up for the added exhaust.
There are mufflers that absorb the sound instead of deflecting it. This works much better at the overall sound reduction. Absorption mufflers do best with lower horsepower equipment such as a small generator, not a car. An absorption muffler shouldn’t affect the generator’s efficiency.
DIY Portable Generator Noise Shield
Reduce the generator sound output by up to 10 decibels. For this, you’ll need several small sheets of plywood or OSB. The OSB seems to do a bit better than plywood. Place them around the generator on an angle. The sound will be deflected down towards the ground where it is absorbed, while still allowing plenty of airflow to the generator motor. The generator should now sound 4 times quieter.
Build a Permanent Quite Box
Measure the generator and build a frame out of 2×4’s. Screw the plywood or OSB board to the frame. Use L brackets to strengthen the corners. Add quiet boards to the inside of the box to absorb more of the sound. For a lighter weight box use installation instead of heavy boards. Use spray foam to seal the gaps, this will help keep the sound from escaping. Note the box will need a hole or fan to allow for air flow. Spray paint and add a handle on top to finish the product.
Plywood or OSB
Quiet boards or installation boards
Spray foam to close the gaps
Spray paint if desired
Handle for easy lifting