How to Make an Air Compressor Quiet? (10 Effective Ways)

Let’s face it: air compressors are loud, and they can get even noisier with the passing of time. However, there are many things you can do to make your air compressor quieter.

Let’s see some tips that will help you to improve your workspace.

Why Is My Air Compressor Making Noise?

Before starting, I would like to go over some facts that make compressors noisy. It’s important to identify which noises are caused by the compressor’s mechanics and design and which are caused by wear, maintenance problems, etc.

Principal Noise Sources

We already know that compressors are really loud, but what makes them so loud?

Friction: The main reason for the noise from compressors is friction. DC or gas-powered compressors have lots of metal moving parts sliding inside one or more cylinders to compress the air. Besides, despite compressors using lubricants, it’s not enough to reduce metal-to-metal friction.

Vibration: To make things worse, the pistons’ bore is relatively small, and the strokes are short compared, for example, to a car engine. This makes the piston/s travel at high speeds (RPM), creating lots of vibration. At the same time, vibration loosens parts of the compressor, adding more noise to its operation.

Inlet and Outlet: Air compressors have one or more intakes that suck air from the atmosphere (intake) and release compressed air to the tank (exhaust). The problem is that most compressors don’t have mufflers or any kind of noise reduction elements. The combination of all these results in noisy machines.

Type of Compressor: Last but not least, the type of compressor you own also determines the noise levels. Reciprocating compressors are louder than rotary screw versions. Some tips in this article are useful for rotary screw compressors, but we will focus mainly on reciprocating compressors, which are the most popular and troublesome.

10 Ways to Quiet an Air Compressor

Below you will find some ideas to make your air compressor quiet.

1. Sound Reduction Box

If installing the compressor away or in a separate area is not an option, you can buy or build a sound reduction box. There are several ways of insulating them and suppressing the compressor’s annoying sound. Remember that compressors need air to do their job, and they also need it to keep their working temperature at optimum levels. Depending on your budget and materials, the compressor’s noise can be reduced to an insignificant buzz.

You can build a soundproof enclosure by yourself. Here is a video that explains how to build a DIY box, step-by-step.

2. Install Sound Dampening Material in the compressor room

If you have enough space to install your compressor in a compressor room, you can install sound-dampening materials. You can cover the walls and ceiling with sound blankets, acoustic panels, or foamboards to soundproof the room. Cork is also a good and cheap insulator.

Just remember to use fireproof materials and keep the room properly ventilated, as compressors dissipate a lot of heat.

3. Cover the Compressor with Sound Blankets

This is another solution when you can’t install your compressor in a separate room. Sound blankets are not as effective as a sound reduction box, but they can help to make your compressor much quieter and more bearable. Depending on your compressor’s model and make, some blankets are like a sheath; they are tailored made for your compressor and come with holes and ventilation at the right places.

If you don’t find a blanket specially made for your compressor, you can cover it with standard sound blankets like the ones used in small or home music production studios.

Try to cover the motor, which is the noisiest part of the compressor, and remember to leave openings for the hoses, ventilation, and the hose. This may not look as tidy as a box, but if it’s well done, you can reduce the noise by up to 30 to 50%.

4. Intake Silencer (Put a Muffler)

Compressors’ intake is probably one of their loudest sources of noise. Most annoying high-pitched pulsating noises escape from the intake or multiple intakes depending on the number of cylinders the compressor has.

Installing a muffler (you can use a simple car exhaust muffler) is one of the cheapest ways of reducing noise.

DIY Air Compressor Silencer

Here’s a video that explains how to build an inexpensive silencer that really works.

Some companies sell special mufflers for compressors, but they are expensive. Mufflers are connected to the intake port by a hose and can provide a noticeable noise suppression of up to 50% as it filters a lot of the higher-pitched noises.

5. Place the Air Intake Away

You can do this by installing an external filter box. This will allow you to move the air intake away from the compressor and help you to isolate noise better.

It can also allow you to install a bigger filter box that works as an intake silencer and removes most of the resonance coming from it. Installing a bigger air filter will help you extend the air filter changing intervals, saving you time and money in the long run.

Besides, you will be able to remove the individual air filters from the top of the cylinders reducing vibration sounds.

6. Install the Compressor on a Rubber Pad

Vibrations coming from the piston/s or rotors operation are transferred to the floor, and some of the compressor’s noise travels through the floor, expanding it to the rest of the place. You can install anti-vibration rubber mats under the compressor to absorb vibrations and some noise as well.

Anti-vibration pads can also be made of cork or plastic, but the best isolator is the industrial rubber mat, which is made specifically for dampening the vibrations of industrial machinery.

7. Lubricate the air compressor

Lubrication is key for keeping machinery working smoothly and soundly. Compressors are not an exception; if your compressor is noisier than usual, maybe it’s time to check the lubrication level. Oil reduces friction between the pistons, bearings, joints, and all the compressor’s moving parts. Minimizing friction helps the parts to move freely and smoothly, which translates into a more effective and silent compressor.

Proper lubrication prevents the metals from excessive wear and tear and keeps corrosion away. Checking a compressor’s oil is easy; they usually have site glasses where you can see the fluid level. In the worst case, they have accessible dipsticks. Lubricating your compressor frequently and changing the oil once a year will help you to keep it functional and quiet.

This tip may not be applicable if you own an oil-free air compressor.

8. Replace Filters

Dirty air filters clog, making the compressor operate inefficiently. It will need to work harder to provide the same output. The harder the motor works, the noisier it gets.

If you haven’t replaced your compressor’s air filter/s in the last few months and you feel your compressor louder than ever, check the air filters; they might need to be replaced.

9. Preventive Maintenance

This task is key for extending your compressor’s lifespan, preventing breakdowns and premature wear and tear, and also helps to keep the noise down. As the moving parts wear, the noise increases, so it’s best to perform good preventive maintenance to keep the compressor working at full capacity at all times. It’s a good idea to keep your compressor always well-lubed, replace the air filter/s before they clog, and have it examined by a professional from time to time.

If you own a belt-driven compressor, take proper care of the drive belts and pulleys, which can become noisy and make grinding and/or pitching noises when they are not in good shape. Worn-out drive belts may slip, causing even more noise and forcing the compressor’s motor to work harder to compensate for the pressure drop generated by the defective belt.

Loose parts can be the source of extra noise. When doing preventive maintenance, check for parts that may be loose because of the compressor’s operating vibration. Extra noises fix most of the time by just tightening some loose parts.

10. Check for unusual noises

If you hear bubbling or hissing noises coming from your compressor, you should check for leaks in the air pipes. If you hear banging noises, it’s time to have your compressor checked by an expert.

It can be a serious problem, such as a faulty piston or a connecting rod. It can also be a head gasket problem.
In both cases, we are talking of a serious repair. Fixing these problems will end the excessive noise.

Type of Compressor and Noise Levels

Two of the most popular types of air compressors are,

1. Reciprocating compressor and
2. Rotary Screw Compressor

Reciprocating Air Compressor

Compressors used at paint shops, car repair garages, small to medium businesses and industries, and homes, among others, are generally of the reciprocating variety. Whether electric or gas-powered, these compressors use pistons to suck the air up, compress it, and send it to the air tank.

Reciprocating compressors can be loud up to 85 dB or even more when they are not working well.

Direct Drive v. Belt Driven Air Compressors

There are two types of reciprocating compressors. One type is not better than the other, but depending on the intended use and other issues beyond the scope of this article, people tend to prefer one or another.

• Direct Drive: In these compressors, the motor is connected directly to the rotor. This reduces the number of moving parts in the units, which should make them quieter. It’s a big “should” because noise also depends on the quality of the product, so buying a direct-drive compressor it’s not a guarantee that it will be quieter than a higher-quality belt-driven compressor.
• Belt Driven: As their name suggests, belt-driven compressors use a drive belt to transfer the rotation from the motor to the air pump. While everything is working properly, the pulleys, drive belt, and cover should be as quiet as a direct-drive unit. However, when they are not properly maintained, pulleys can make noise, whine and emit sounds that, added to the sound of the pistons, make them noisier than direct drive compressors.

Rotary Screw Compressors

These compressors are more efficient than their reciprocating counterparts and quieter. The noise level from this type of compressor is in the range of 70 to 75 decibels.

Also, many rotary screw compressors come with enclosures, and the resulting noise can be as low as 65 dBA.

However, these compressors are far more expensive to purchase and maintain. If you have the budget, consider getting a rotary screw compressor.

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