If you own or rent home improvement devices like grinders, sanders, jackhammers, nail guns, and spray painters, then you’re using some form of air compressor. These range in size from tiny pancake compressors to huge units that are going to be appropriately noisy.
How do you make an air compressor quieter? By wrapping the motor, covering the intake with a muffler, encapsulating/blocking off the compressor, or moving the intake, you should have a less noisy air compressor. You can also put rubber grommets around the device’s motor or buy a new air compressor altogether.
No matter which of these options sounds most appealing to you, I recommend you read on. I’ll go into much more detail about all the methods for silencing your air compressor. Also, I’ll cover air compressor anatomy and provide some pointers for getting a new one.
Understanding Your Air Compressor
Before I get into how to make your air compressor quieter, I thought it’d be best to discuss the various types of air compressors out there. There are eight types, and they are:
- Centrifugal compressors: Also referred to as radial compressors, centrifugal air compressors are commonly used for turbomachinery jobs. With an impeller (rotor), fluid passes through the compressor. This creates velocity that boosts pressure within the device.
- Turbo compressors: Whether you call them gas, axial, or turbo compressors, this unit uses an airfoil to create gas pressure via rotation.
- Scroll compressors: As the name tells you, spiral or scroll compressors move in a circular motion. They’re often part of an air conditioning system as they can move refrigerant and air.
- Rotary vane compressors: Rotary vane compressors include vanes that allow the rotor to move within its own cavity.
- Rotary screw compressors: This air or gas compressor is a positive-displacement unit (more on this later) that can achieve very high air pressure volume. If you use an impact wrench or a jackhammer, it’s a rotary screw air compressor.
- Compound compressors: Several cylinders arranged in stages comprise compound compressors. The air goes into the first cylinder, gets compressed, and then cools down. Next, it moves to another cylinder and gets compressed further.
- Single-stage reciprocating compressors: If air gets compressed just one time, then it’s considered a single-stage reciprocating compressor.
- Two-stage reciprocating compressors: Likewise, if the air gets compressed, goes through an intercooler, and then gets compressed even further, the unit used is a two-stage reciprocating compressor.
No matter which of the eight types of air compressor you use, each one has several terms associated with it. These are as follows:
- CFM: Cubic feet per minute or CFM is the measurement of the delivery of air from the compressor.
- SCFM: SCFM refers to standard cubic feet per minute. This is just the CFM but standard. You’ll see CFM on air compressor packaging far more often than SCFM.
- HP: HP or horsepower is the amount of power the compressor’s motor has. Most motors are 1.5 HP at the lowest and 6.5 HP at the highest. You can expect higher HP compressors to be noisier.
- PSI: There’s also pounds per square inch or PSI. This is the air pressure rating of the compressor. PSI can influence the CFM, making it higher or lower.
All air compressors can be placed into three broad categories. The first of these is high-pressure air compressors or HPACs. These exceed 1,000 PSI for their discharge pressure.
Medium-pressure compressors have a more variable discharge pressure. It may be 151 PSI through 1,000 PSI. Lastly, there are low-pressure air compressors, also called LPACs. These have the lowest discharge pressure, 150 PSI and under.
Finally, let’s talk about displacement, shall we? Air compressors have dynamic or positive displacement. With dynamic displacement, kinetic energy becomes pressure energy via moving parts. An example of a compressor with dynamic displacement is a centrifugal compressor.
Positive displacement compressors will take air, transport it to a chamber, and then compress it back to a certain pressure. The air then moves out of the chamber and into an outlet. Examples include vane compressors, rotary screw compressors, and two-stage reciprocating compressors.
How Loud Are Air Compressors, Anyway?
To power the devices they do, air compressors are by no means quiet. If you’re lucky, your compressor might be 40 decibels. Bigger, heavier units can be more than 90 decibels.
For your reference, most conversations you have are on average 55 to 65 decibels, so a 40-decibel air compressor is pretty darn quiet. Even a vacuum cleaner is anywhere from 60 to 85 decibels.
Most lawn mowers are 90 decibels, while an airplane lifting off from the ground and taking flight is about 140 decibels. It’s at that volume that hearing damage becomes a risk. Still, even the prolonged use of items that are between 80 and 90 decibels could eventually lead to hearing damage. It won’t happen overnight, but if you run your air compressor often enough, you could lose your hearing early.
Why are air compressors so loud? It has to do with a couple of things. The first of these is the location. If your air compressor is in the same room as you, you’re going to bear the full brunt of its volume. Even if it’s in the same building, sometimes you still hear more of it than you wish you would. The further away your air compressor is from you, then, the better.
You also have to take the power source into consideration when it comes to the volume of your air compressor. If you have a gas-powered compressor, it’s going to make so much more noise
than an electric compressor would. That’s due to all the hard work the gas-powered compressor’s engine has to do as it starts up and chugs along.
Friction is another component in determining compressor noise levels. Dynamic displacement air compressors, with all their moving parts, have a lot more friction. Positive displacement compressors, which tend to have fewer moving components, are less friction-heavy. That would make them quieter than dynamic displacement compressors.
Finally, the capacity and size of your air compressor make a difference if you want less noise. Low-capacity inflators use a piston that moves very, very quickly. That heats up the inside of the compressor just as rapidly. You’ll certainly hear all those parts as they move.
How to Make an Air Compressor Quieter
Okay, all that explanation about air compressors and how they work is out of the way. Now it’s time to expand on the methods I outlined in the intro on how to silence your compressor.
Wrap up Your Compressor Motor
If you’ve ever covered a hot water heater with sound deadening materials and noticed it ran more quietly, the same principle applies to your air compressor. A sound deadening mat is a safe bet since it’s designed to reduce sound.
If you don’t mind spending a bit more money, this mat from Noico Solutions on Amazon is highly-rated. It uses foil and automotive butyl to cover 36 square feet. You get nine sheets in a pack, so you should have enough to cover your entire air compressor motor. For less than $70, this isn’t a bad solution to your noise problem.
Noico also has a cheaper version of their sound deadening mat for less than $20. You only get 10 square feet of coverage but 10 sheets in all. This is better for smaller motors.
Cover the Intake with a Muffler
Another option you can try is covering your air compressor intake with a muffler. Welded mufflers are best for this job, such as the Thrush 17658 welded muffler on Amazon. This is one of the highest-rated mufflers of its kind, and it costs less than $50, too. It’s 19 inches, made of polished 304 stainless steel, and has an outlet and inlet opening of 2.25 inches each. Inside, the muffler boasts dual chambers.
Okay, so now you’ve got your muffler. What do you do with it? Good question! First, you want to find your air compressor’s intake. Plug in a two-sided air hose so one end is on your muffler and the other is on your intake. The first hose should be connected to the other one.
While it’s a somewhat complicated job, it’s possible to slice four decibels off your air compressor noise levels. Not too shabby!
Move the Air Intake
The air intake is a crucial part of the air compressor. This is where the air enters the unit. If you want, you can move the intake somewhere where its noise won’t bother you nearly as much.
Some air compressor owners have tried garden sheds, basements, or garages. The problem with the basement or the garage is that these rooms are still attached to your house. While the air compressor will be quieter than if it was in close proximity to you, you’d definitely still hear it down your basement or in your garage.
That’s why some people have opted to transport the intake outdoors. The wide openness of a backyard or a side yard means the compressor makes less noise. It’d also be further away from your house, so you’d hear even less of your air compressor.
With a bracket and a rubber hose, you can do this job yourself. To start, take your rubber garden hose and place it in the air intake. Don’t force it in there or you could break the intake. A bracket placed loosely yet firmly will keep the hose in place as the air compressor moves and works.
The other end of your hose should be buried a few inches underground if possible. Grommets or brackets can be used to adhere this end of the hose exactly where you want it to be. The more secure the hose is, the less noise the whole setup should make.
Encapsulate or Box It up
Encapsulating your air compressor will, of course, make it sound quieter to you. When I say box it up, I mean it quite literally. You’d make a spare room outdoors in which to house your air compressor. By using soundproofing materials on the walls, such as acoustic foam, you could ensure that you almost never hear the air compressor again.
Going this route is going to be costly since you’re erecting a small building from scratch. You’d also have to make sure the room is big enough for the compressor and has adequate ventilation. Otherwise, as the air compressor warms up, it’ll overheat and fail, cause a fire, or explode.
Check out the article on how to build a generator silent box since that type of soundproof enclosure could be used to keep an air compressor quiet.
Put Rubber Grommets Around the Motor
If you want to cut back on the volume of noise from your air compressor, use rubber. Its sound-absorbing qualities make it efficient to quieten loud units. For this project, it’s better to have grommets made of rubber. These should be fitted so they can go over your air compressor’s motor.
Rubber grommets are a basic tool and are thus inexpensive. You can find a set of 180 pieces for less than $10 on Amazon. With such a big set, no matter the size of your engine, you can be sure you have a rubber grommet that fits.
Tips for Shopping for a Quieter Air Compressor
Your last option for silencing your air compressor is to replace your current loud, clunky unit with a smaller, sleeker, quieter one. This is a good idea not only for your sanity but for your hearing, too. As you remember, earlier in this article I mentioned that prolonged noise from an air compressor that’s 80 or 90 decibels can cause hearing loss.
Here are some of my favorite quieter air compressor picks, all from Amazon.
California Air Tools 8010 Ultra Quiet, Oil-Free Air Compressor
This eight-gallon air compressor from California Air Tools is as it says: oil-free and quiet. It’s made of steel and runs at 120 PSI max. Its cubic feet per minute is between 2.20 CFM at 90 PSI or 3.00 CFM at 40 PSI.
Since it doesn’t use oil, you shouldn’t have to do as much maintenance. This saves you money and time. It takes only 165 seconds for the tank to fill all the way. The air compressor’s low-amp draw contributes to its quieter operation. By the way, the sound rating for the California Air Tools 8010 is 60 decibels.
Senco PC1010 One-Horsepower, One-Gallon Air Compressor
Another very highly-rated pick comes from Senco. This air compressor is intended for crafting, hobbies, home improvement, and renovation purposes. It has a capacity of one gallon and a low peak horsepower. It’s a lot lighter than most air compressors, enough that it’s considered portable.
Makita MAC700 Big Bore 2.0 HP Air Compressor
My final pick for quiet air compressors is the Makita Big Bore. While a little more expensive, you get tons of features that make this unit worth owning. These include oil lubrication for less wear and tear and a pump that keeps going longer at a cooler temperature. There’s also less risk of motor failure from voltage drops as well as tripped breakers. This is all due to the Big Bore’s low amp draw.
With fewer revolutions per minute (RPM), you won’t hear the Big Bore nearly as much as you would other air compressors. Its cast-iron pump is built for durability, too. The Big Bore operates at between 68 and 70 decibels.
Air compressors are handy for home improvement and renovation tasks, but they can be incredibly noisy. Not only are the loud sounds annoying, but they can possibly damage your hearing if you use your air compressor often enough.
By tinkering with the intake, wrapping the engine, or even enclosing your air compressor, you can cut down on the high levels of noise these units make. Buying a new, quieter air compressor might also be in the cards for you.