Best Air Compressor Water Separator For 2021







Best Air Compressor Water Separator For 2021 1


Campbell Hausfeld Air Cleaner and Dryer


Best Air Compressor Water Separator For 2021 2

Neiko 30252A Water and Oil Separator for Air Line


Best Air Compressor Water Separator For 2021 3

NANPU NPT Compressed Combo Water/Oil Trap Separator


Best Air Compressor Water Separator For 2021 4

THB Heavy Duty High Flow Particulate Filter


Best Air Compressor Water Separator For 2021 5

Campbell Hausfeld Air Filter Quick Release Bowl

A water separator for your air compressor will help to remove water, solid particles, and oil from the machine.

This enables you to ensure that only clean, pure air will get to your pneumatic tools. While you might not think this is a big deal, you’re wrong. 

How can your air tools be damaged by unclean air?

Even a bit of moisture can cause problems. It cleans the air tools’ oil and this can lead to wear and tear, as well as other issues.  

So, with that in mind, let’s check out the best air compressor water separator for 2021.

By reading this buying guide you’ll be able to choose the most effective air compressor water separator on the market to keep your air tools functioning well and reduce your expenses! 

Best Overall Winner: Campbell Hausfeld Air Cleaner and Dryer

Campbell Hausfeld Air Cleaner and Dryer

This air tool cleaner hits all the right notes to keep your tools in mint condition and save you money. Here’s why it’s an Amazon’s Choice product and the best water separator for air compressor units on our list.    

Featured specs

  • Desiccant system 
  • Outlet screen 
  • Quick-release bowl 


  • This air compressor water separator filter works to remove oil and will effectively eliminate 99.9 percent of all oil aerosols. 
  • It contains a desiccant system that eliminates water vapor so no moisture will be able to get into and damage your air tools. 
  • This air dryer is really easy to use – the desiccant system actually changes color when it needs to be recharged or changed. This ensures you’ll always be reminded to do it.  
  • This air dryer contains an outlet screen to prevent any desiccant particles from entering it. 
  • The system makes use of a quick-release bowl so you can see the fluid level. This is a user-friendly feature that’s great for beginners and experienced users alike. 
  • It’s protected against damage by having metal guards, so it’s built to last. 


  • Some people who have purchased this air dryer have reported that it has some plastic parts, such as the drain valve. 
  • Others have reported that it didn’t come with any connectors. 
  • To mount it onto the wall, you’ll have to use a U-bracket which is sold separately. 

Extra Features

  • This air dryer has a quarter-turn drain so it’s easier to maintain.
  • It only weighs 4.9 pounds, so it’s both compact and small. 

Buying Advice

This air dryer by Campbell Hausfeld is user-friendly, even if you’ve never worked with an air dryer before. Since it’s built to last, with features that make using it more comfortable, it’s clear why this air dryer is the best one on the market. 

Runner Up: Neiko 30252A Water and Oil Separator for Air Line

Neiko 30252A Water and Oil Separator for Air Line

This air dryer will remove particles, oil, dust, and water from your air compressor with ease. You’ll also find it easy to maintain, which is a bonus. Here’s what to know about it. 

Featured specs

  • Twist-on tool application 
  • Clear housing
  • Release valve 


  • This air dryer has a universal ¼-inch NPT inlet and an outlet design that ensures the air line can connect to your air tools. The inlet is airtight so that you don’t have to worry about leaks. 
  • It can be easily attached to your air tools – simply twist it on and you’re good to go! 
  • It’s built with aluminum and brass to keep it durable and strong. The aluminum is also resistant to rust. 
  • This air dryer has clear housing so you can check how much debris is caught in it and this makes it easy to know when you should change the filter. Fantastic. 
  • It couldn’t be easier to clean – just press the release valve and all the dirt that’s been collected inside the air dryer will be released. 


  • Despite its promise to prevent leaks, some people who have purchased this air dryer have reported that it did leak. 
  • It has plastic parts that can crack or break. 

Extra Features

  • It’s really light – it only weighs 3.52 ounces – so you won’t have to worry about working with bulky equipment. 
  • It’s really cost-effective. 

Buying Advice 

This is the best air water separator for compressor units because it helps to eliminate a variety of materials, such as water and debris, before they can damage your air tools. Best of all, it’s really easy on your budget.

Alternative: NANPU NPT Compressed Combo Water/Oil Trap Separator

NANPU NPT Compressed Combo Water/Oil Trap Separator

This isn’t just an air dryer – it’s a complete kit that you’ll love using with your air compressor and air tools. Let’s see what it has to offer and why it should be in your workshop. 

Featured specs

  • 5-micron brass filter
  • Pressure regulator 
  • Wall mount 


  • This air dryer has a 5-micron brass filter to remove a variety of particles that could damage your tools. 
  • It has many accessories that come with it – these include a semi-auto drain, a polycarbonate bowl with a metal guard, a 0-150 gauge and bracket, an air coupler pair and plug kit, two 3/8-inch NPT fittings, and a thread seal tape. 
  • This water separator for air compressor makes use of a self-relieving pressure regulator so that outlet pressure is monitored.


  • One of the drawbacks of this air dryer is that it comes with plastic fittings. Some people who have purchased this product have reported that these don’t work well with metal fittings.
  • Other people have reported that the dial on this air dryer is very small, which could be difficult to read, especially in poor lighting conditions. 
  • Other people reported that they didn’t receive instructions with their air dryer. This could be problematic if you’ve never worked with a water separator before.  

Extra Features

  • This air dryer comes with a wall mount for the ultimate convenience in how you choose to store it in your garage workshop.  

Buying Advice 

You want an air dryer that’s built with user-friendliness in mind and makes your work go smoother. That’s why you should consider purchasing this air dryer from NANPU. It’s a complete kit with all the accessories you need, so it’s worth it. 

Alternative: THB Heavy Duty High Flow Particulate Filter

THB Heavy Duty High Flow Particulate Filter

If you’re looking for a heavy-duty air dryer, this one is worth checking out. Here’s everything you need to know about it.

Featured specs

  • Sight glass 
  • Replacement filters available
  • Compatible with various systems


  • This water separator can be used with both low- and high-pressure systems. 
  • It comes with a wall-mounting bracket for greater convenience. 
  • You can easily tell what the moisture level is like, thanks to the sight glass that’s provided on the metal bowl. 
  • This best air compressor water separator automatically removes particles and moisture from its metal bowl with ease. 


  • Some people have reported that they had problems with the product’s automatic air drain. 

Extra Features

  • When you need to replace this air dryer’s filter, you’ll be glad to know that you can easily find replacements on Amazon. 
  • People have reported that it was really easy to install and use. 
  • Others have said that this air dryer works really well to remove moisture. 

Buying Advice 

This industrial air dryer is a no-frills product that gets the job done and makes your life easier. 

Alternative: Campbell Hausfeld Air Filter Quick Release Bowl

Campbell Hausfeld Air Filter Quick Release Bowl

Looking for an air dryer that costs less than competing products but gives you value for money?

This one by Campbell Hausfeld is worth checking out. 

Featured specs

  • Quick-release bowl
  • Desiccant system 
  • Brass filter 


  • This is an air dryer that’s perfect for when you need oil-free and moisture-free air, such as when spray painting. 
  • It has a quick-release bowl. This makes it easy to see the fluid level. 
  • Its oil-removal filter is effective at capturing and eliminating 99.9 percent of oil aerosols, which makes this dryer the best water separator trap filter for air compressor products.
  • It has a desiccant system to eliminate water vapor and maintain the integrity of your tools. 
  • It comes with an outlet screen so that particles can’t get into the airstream. 
  • It has a sintered brass filter element. This is important because it captures particles that are as small as five microns in size. 


  • Some people have reported dissatisfaction with the fact that the valve is made of plastic. 
  • This air dryer doesn’t come with a mounting bracket, so you’ll have to purchase that separately. 

Extra Features 

  • This air dryer contains a quarter-turn drain so it’s easy to maintain. 

Buying Advice 

This best oil water separator for mobile air compressor is a solid and well-made air dryer that you’ll be glad you purchased for your home workshop.

While it doesn’t come with extra accessories such as mounting brackets, it’s a solid product for when you need to use your air tools. 

Air Compressor Water Separator FAQ 

Now that we’ve looked at five of the best air compressor water separators for your DIY projects, let’s check out some common questions pertaining to these products and air compressors in general. 

Does my air compressor need a water separator?


You might not think you need a water separator but this is essential for your air compressor.

If moisture can get into your air tools, this will cause them to experience wear and tear prematurely. You will end up feeling like you spent so much money on those tools only for it to go to waste. 

Another important thing to bear in mind is that sooner or later water will end up in your air compressor.

When it does, it will cause damage to the internal parts of the compressor, such as by making them rusty. This, in turn, makes it even more difficult for lubricants to reach these parts, which can harm the entire system. 

Ultimately, it’s important to remember that just one cubic foot of compressed air can contain millions of particles and considerable amounts of water (via Air Best Practices).

If these are not eliminated with the use of a filter, they can cause the system components of the air compressor to not function properly. There are many negative consequences that can result from water accumulating inside your air compressor, besides for rust. These include: 

  • Water interfering with the compressor’s lubrication, which causes wear and tear of the compressor’s moving parts. 
  • Inability of the compressor to work properly. An example can be found with spray paint application. If water gets into the system, it can result in a lack of uniform color, not giving you the spray paint results you want.
  • Ice being formed. Alarmingly, the accumulation of water can lead to ice being formed in the system’s control lines. This can cause the system to not work properly, as its essential controls can experience malfunctions.

When you use your air compressor, its tank pressure tends to fluctuate. The air gets pushed down the connection hose all the way to your air tools. Now, the problem with this is that the air will accumulate water vapor and bring it to your tools.

By making use of a water separator, you can keep water away from your tools so that they can’t become damaged, and this product is easily attached to your water compressor so it will maintain the compressor’s quality and lifespan, too. 

Now, what about when you use compressed air to inflate your car’s tires?

You might not think you need a water separator for regular, small tasks such as these, but you do! Water and moisture can cause tires to deteriorate and rust, decreasing their quality and making their lifespan much shorter. 

It’s clear to see that no matter what you are using your air compressor for, you need to ensure that you have an air dryer handy with which to use it. 

Why is moisture removed from compressed air?

While you might think that compressed air won’t contain moisture, this is actually not the case – and this, in turn, is why there are air dryers on the market for use with air compressors. 

The truth is that water accumulation is a natural occurrence whenever air is compressed. How much water is produced will be dependent on various factors, such as the quality of the inlet as well as the quality of the air in the environment.

If you have humid and hot air in your environment, it will have a higher amount of moisture as compared to cold, dry air. This will also affect the air in your compressor.

It’s also worth knowing that when air gets compressed, it will be cooled down and when this happens it actually condenses into water.

Now, your air compressor needs dry air, so this is quite a complicated situation and it’s clear to see that it could cause you problems! That’s why you need to make use of an air dryer to ensure that the air your compressor gets is completely dry and as pure as possible. 

How does a water separator for air compressor work?

A water separator for your air compressor works by removing condensation, and it’s usually designed in one of two ways in order to achieve this goal: centrifugal design and coalescing design. Let’s take a look at how these designs vary. 

  • Centrifugal design: In this design, a motion is produced in the air so that particles that are in it can move faster in an outward pattern. When they reach the outer limits, they are drained into the bowl of the water separator. This system works well to remove water droplets, as well as debris and dust that are larger than five microns. As we’ve seen in our air compressor water separator reviews, many of the products make use of a bowl design. 
  • Coalescing design: In this system, the separator makes the air flow from the inside to the outside of the separator’s filter element. These filters require regular replacing so that they can work at their peak, which does make them a little more high-maintenance. 

Why does my air compressor make so much water?

Now, maybe you’ve found that your air compressor is producing a lot of water and it just doesn’t feel right. What is causing this? Is the air compressor faulty, or is something else at play? 

If your air compressor is producing lots of water, this could be as a result of the receiver tank needing to be drained. This is something you should actually do on a regular basis to prevent condensation from accumulating.

This is regardless of the type of drain that your air compressor contains. You can drain the tank very easily. Here’s how to do it: 

  • First, find the tank’s drain valve. You’ll find it’s usually located near the tank’s lowest port. 
  • If you are working with a compressor that has a manual valve, you’ll have to rotate the handle so that a blend of compressed air and water will be released from the tank. You might see a large amount of water come out if your tank hasn’t been drained for some time. Then you should hear the compressed air expand. 
  • If your air compressor is operated by a timer, you should press the “push to test” button (you’ll find it on the control faceplate). This enables you to manually override the sensing circuit to open the valve. You’ll hear air hiss and burst. 
  • Hold down the button to open the valve so that you can release any moisture that’s inside the tank. Then, simply let go of the button to close the valve once you’re done. 

It’s worth bearing in mind that a common reason why your air compressor will contain water is as a result of how the compressor motor and pump become very hot during use.

This hot air is humid, so it’s full of water, and it will be pushed into the compressor’s tank, which contains a cooler temperature.

The water vapor will condense into water and start to drip down into the tank. If your compressor tank runs for a long period of time at once, this will further increase the level of humidity that’s being produced inside the tank, resulting in lots of water accumulating in it.

Ensuring that you regularly drain the compressor tank and connect a water separator to it to prevent moisture from entering the air compressor and your air tools will keep them all in great condition.  


You’ve spent a lot of money on your air tools and air compressor, so the last thing you need is water to get into your compressor and damage it or your air tools. It’s time to eliminate water, particles, and oil from causing damage to your workshop equipment. 

To achieve that goal, and have a less stressful experience when working on projects at home, you need to purchase a water separator. In this buying guide, we’ve featured reviews of the best air compressor water separator on the market.

We’ve also answered questions pertaining to air compressors and water separators to help you use them in the best way and see their value.

Best Air Compressor Water Separator For 2021 6

Nathan Bradley

Nathan Bradley spent most of his time with his father in the garage. Bonding over woodworking, mechanical repair, and organizing the tool wall for his dad (because it was always a mess), Nathan became a professional garage renovator. From detached garages turned into inlaw suites, outdated garages into music studios, and everything in between, he’s seen a thousand ways to flip a garage, organize it, and put it to good use.