Most air compressors have one thing in common, they’re noisy and loud. Higher horsepower and budget priced compressors seem to sound the loudest.
While the easiest solution would be to just go out and buy one of the new ultra-quiet air compressor models that are specifically designed for quieter operation, some may want a DIY solution to quiet down their existing compressor.
We’ll discuss methods used by low noise compressor manufacturers to suppress the sound produced by their machines and see if we can retrofit any of the design features to help reduce the noise of the compressor we already own.
Combine these methods with the additional, general air compressor sound reduction tips that you’ll learn, and you should be able to modify your obnoxiously loud noise maker into something that is quite a bit easier on the ears. A seemingly minor noise reduction of even a few decibels can make a substantial difference, risk of hearing loss is reduced, it is easier to talk with others, and most importantly that annoying compressor noise is quieter.
While researching sound dampening methods to quiet an air compressor, I discovered some pretty solid tips and videos. I also found a few unique out of the box, or should I say in the DIY soundproof box ideas.
Most common small compressors of 1 HP or less have noise levels around 80 to 90 dB or more, while comparable quiet compressor models range from 40 to 79 db. To get an idea of the difference in sound, an 80-dB compressor is twice as loud as a 70-dB model and a full four times louder than a 60-dB compressor.
OSHA says extended exposure to sound levels above 85 dB can cause permanent hearing loss, so you’ll want to quiet that noise down to acceptable safe levels or wear hearing protection to protect your ears.
Manufacturers of the quietest air compressor models use various methods to reduce noise levels produced by their machines including:
1.) Install an Intake Silencer - A significant amount of the annoying high frequency pulsating noise produced by air compressors comes from the air intake. As the compressor rotates inrushing air is drawn past a reed or flapper valve which rattles and vibrates on each pulse.
Intake muffling devices are usually constructed as a combination air filter and silencing device. Intake air is baffled through tubes or sound deadening materials that dampen the sound produced by the incoming air rush through the filter while keeping the air compressor’s air intake flow restriction to a minimum.
By installing an input silencer or intake muffler such as the one of the Solberg silencer models that we reviewed here you can typically reduce the pulsating noise that the air intake system creates.
To purchase an air intake filter replacement, you’ll need to know the pipe thread size on the intake head of your compressor. The intake silencers come in standard MPT male pipe thread sizes such as ¼”, ⅜”, ½”, ¾”, 1”, etc. You can always use a bell reducer and short pipe nipple to install a larger filter/silencer than required, however you would never want to use an undersized intake filter that restricts the intake air flow to your air compressor.
Some users have reported quieter results by installing the silencing filter on one or two 90-degree street elbows. Here your mileage will vary, you’ll need to experiment with a few different configurations to determine which setup quiets the compressor more.Another option is to plumb the air intake to a remote filter box or even through an outside wall which will further reduce the noise produced by the air compressor.
Here is a good YouTube video of a homemade air compressor intake silencer that worked pretty well to make this compressor quieter.
2.) Isolate the Compressor from Everything -You don’t want any rigid connections to the compressor that can radiate noise. If you have a stationary air compressor, use rubber isolation mounts to anchor it to the floor. If you use rigid plumbing, install a short flexible air hose between the compressor and the plumbing. Use flexible conduit or rubber cord for the power connections, no rigid conduit directly connected to the compressor.
Depending on what type of compressor you have, users have even mounted the compressor and or pump on rubber grommets to cut down the noise.
These sound reducing rubber and EVA pads are inexpensive and can be installed under stationary compressors
3.) Use Compressor Sound Deadening Materials - Compressor noises are reflected off solid objects such as walls. If your compressor is located near a wall or in a corner the walls act like a loudspeaker reflecting the compressor noise back into the work area. You can reduce reflected noise by covering any walls near the compressor with sound absorbing blankets or acoustical materials.
4.) Put Distance Between You and the Compressor Noise - dB levels drop significantly as you move greater distances from the source of the sound. Move your compressor as far away as you can from your location (preferably in another room or outside) and put as many walls as possible between you and the air compressor. This will make a dramatic difference in the audible noise level. This tip can be easily accomplished by simply purchasing a longer air hose to reach your work area, while keeping the compressor some distance away. The increased distance alone can reduce compressor noise by as much as 25%.
5.) Build a Soundproof Air Compressor Box - Constructing a DIY soundproof box or sound dampening enclosure to encapsulate the entire compressor is typically a very effective solution to muffle the noise produced by a loud electric powered air compressor. You can build a soundproof enclosure for your compressor to absorb some of the noise by installing sound absorbing material on the all the walls, top and floor. For a tight budget you can use suspended ceiling acoustical tiles to absorb the noise.
Your soundproof cabinet can be simple or elaborate, take a look at this soundproof enclosure constructed of solid concrete. Concrete blocks with the voids filled with sand are very effective for blocking sound. You can find a plethora of different quiet compressor box ideas on the Internet, everything from complete compressor rooms with framing, multiple layers of drywall, and sound deadening insulation batts to plywood boxes, old freezers and even cardboard boxes. However, If I were designing a soundproof compressor box I would use fire resistant materials for safety such as gypsum board or concrete block, cardboard would definitely be out.
Whatever you choose to do, make sure not to restrict the airflow around the compressor, or it will overheat and possibly cause burn out or catch fire. You’ll will need to provide adequate ventilation by installing an exhaust fan or other means to pull in cooler air and exhaust the heat produced by the compressor. Also, do not put any insulating materials directly on the compressor’s air tank. The tank helps to condense the moisture in the heated compressed air produced by the pump and needs to be uninsulated to function efficiently.
Homemade Soundproof Box for Air Compressor Video
Here is one of dozens of homemade air compressor sound reduction box videos that you can find on YouTube.
6.) Wear Hearing Protection - If your compressor is still loud or it is not feasible to use any of the compressor quieting tips above, you should use PPE (personal protective equipment). Extended exposure to loud noise can cause permanent hearing loss. Get some ear plugs or muffs and use them whenever you are exposed to loud noises for extended periods. Hearing protection can’t quiet the air compressor down, but it will reduce the noise that you hear to safe levels .
Remember, whenever making any modifications to quiet your air compressor, safety should be your first priority. Compressed air can be very dangerous if unsafe modifications are made to your equipment.
If you want to know how to quiet down a noisy air compressor, then the 6 tips found above should certainly help. However, don't expect your loud compressor to magically become silent. All compressors produce noise, and the 50 dB to 60 dB models are either small super quiet compressors that have low CFM capacities or cost several thousand dollars. It's really a trade-off, how much money do you want to spend to either buy a quieter compressor or modify your existing compressor to lower the noise level that it emits.