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Maybe you’re a dive shop on the hunt for the latest and greatest air compressor technology. Or, maybe you’ve just moved onto a boat and want to have a way to fill your tank without the hassle of going into a dive center. In this guide, we’ll reveal the best air compressors for scuba diving tanks.
In this article we’ll cover:
The best air compressors for scuba diving tanks, including our top picks
Normal air compressors vs scuba air compressors
How scuba air compressors work
Things to consider when choosing the right air compressor for you
Table of Contents
The Best Scuba Compressors: In Depth
Max-Air 35 – Our Top Pick
Best portable scuba tank compressor
With a dimension of 71 x 33 x 38 centimeters and weighing only only 38 kilograms (85 pounds), the Max-Air 35 one of the most popular another popular portable scuba compressor with a higher charging capacity. Rated at 4.2 cfm, this compressor can either be powered by a gasoline motor, a single-phase electric motor, or a three-phase electric motor. Regardless of what motor you choose, this compressor can fill a scuba tank in 22 minutes.
Aside from the standard features of a scuba compressor like the oil/water separating chambers and pressure relief valves, this compressor has a built-in upgraded feature like the digital hour or tachometer (available in gasoline powered units only) which helps you in monitoring and maintenance purposes. It also has an optional automatic pressure shut off switch when it reaches a full charge pressure. The downside of this air compressor is that it chews through filters pretty quickly, you’ll need to change it roughly every 15 tank fills.
Weighing only 46 kg (101 lb) with a dimension of 78 × 34 × 42 centimeters, the Bauer Junior II is one of the smallest and lightweight scuba compressors. It is preferred for boat use and in remote locations.
This compressor is powered by a gasoline motor (options are available for electric motor) and has a capacity of 3.5 cfm. It has a single filling hose and can fill a standard 80 cubic feet tank from 0 to 3,000psi in 24 minutes. The compressor block can work efficiently for decades with minimal required maintenance.
The Bauer Oceanus is classified as a portable yet high performance scuba compressor. Weighing 52 kilograms (115 pounds) with a dimension of 79 × 35 × 42 centimeters which is a typical size for portable units, this compressor has a higher capacity at 4.9cfm. Powered either by a gasoline or electric motor, this compressor can fill a tank from 0 to 3,000psi in only 17 minutes.
While it has all the qualities typical to a Bauer compressor, this compressor stands out among the portable units. It has a 2 filling hose that can simultaneously fill 2 tanks at the same time, thereby saving time and energy.
Another compact and lightweight scuba compressor is the Coltri MCH-6 that has a dimension of only 75 x 35 x 39 centimeters. It has a charging capacity of 3.5 cfm that can be powered by several motor options. If you choose the petrol motor, it can fill a tank in 20 minutes while the single phase electric motor can fill in 25 minutes and the three phase electric motor in 20 minutes.
The good thing with the Coltri MCH-6 is that it has several upgrades that would help you in a relaxing and comfortable tank filling. You can opt for the automatic condensate drain upgrade which frees you up in manually doing it and the engine auto stop option when it reaches the maximum charging pressure at 3,000psi or 205 bar.
If you want a fast charging compressor that can fill multiple tanks at the same time, then take a look at the Bauer Mariner. This is a mid-sized compressor that weighs 115 kilograms (253 pounds) with a dimension of 130 × 64 × 70 centimeters.
Ideal as a stationary unit, this compressor comes in 3 different versions. The Mariner 200 is rated at 7cfm and can fill a tank in 12 minutes while the Mariner 250 is rated at 8.8 cfm and can fill a tank in 9 minutes. Its biggest version, the Mariner 320, is rated at 11.3 cfm and can fill a tank in 7 minutes. All units have a 2 filling hose configuration, except for the Mariner 320 where it has a 4-filling hose configuration.
Another mid-sized scuba compressor ideal for stationary operation is the Max-Air 90. Weighing 125 kilograms (276 pounds) and measuring 106 x 51 cm x 73 centimeters, this compressor has a rating of 10.8cfm. Powered either by a petrol or electric motor, it can fill a tank in 7 to 8 minutes.
The Max-Air 90 is mounted on a thick steel frame that is powder coated to withstand the elements like salt corrosion. This air-cooled scuba compressor has a manual condensate valve, a pressure maintaining valve for optimum air processing, intake filter and pressure relief valves on all stages. It comes with 2 filling hoses that can simultaneously charge 2 tanks at the same time.
Scuba tanks are filled using an air compressor and not with an oxygen compressor. Oxygen is only a component of air, and pure oxygen is not used in recreational scuba diving as it is toxic at certain depths.
The air inside the scuba tank is the same with the air we breath. It is just compressed. To put things into perspective, just imagine the air inside a large room being sucked, filtered, cleaned and compressed into that small scuba tank. Scuba air compressors ensure that the air is suitable for breathing, making it different than an air compressor made for other purposes, like tire inflation.
How does a scuba compressor work?
To simplify, a scuba compressor works by sucking in air from the surroundings and processes it using a 4-stage compression before it is released out going to the tank as compressed air. When you turn on the compressor, air is sucked in via the intake pipe, or in some instances, an intake hose that is elevated to get fresh air and avoid the fumes produced by the motor.
As air is processed inside the compressor, the air is compressed stage by stage where the pressure of air increases as it passes on to the next compression stage. Before it is released out of the filling valve, it passes through a filtration system where water and oil is separated forming a condensate. This condensate is then released out of the compressor through the water and oil drain valve using a predetermined time interval. The final filtered and compressed air is then released out through a filling valve which is attached to your tank.
Things to consider when buying a scuba compressor
Motor: petrol or electric
All scuba compressors are powered by a motor which either runs on petrol or electricity. Choosing the type of motor will greatly aid you in preparing your scuba tanks, and of course, your mobility. For compressors that are powered by electric motors, they are great for stationary operation or in areas with electricity. For compressors that are powered by a petrol motor, they are great for mobility where you can take them anywhere, even in areas with no electricity.
Size and capacity
There are a variety of sizes for scuba compressors, ranging from the small compact units to the large and heavy systems. While ideal for the frequent traveller or boarding it on a boat, small and compact scuba compressors may take time to fully fill a tank. On the other hand, while large compressors may take less time to fill a tank, they are usually heavy and may take up space making them ideal only for stationary operation.
When it comes to the charging capacity of scuba compressors, it is either expressed in liters per minute (lpm) or cubic feet per minute (cfm). Compact portable compressors have a low charging capacity (3 – 4 cfm) while large compressors have higher charging capacity that can go way up to 20 cfm. This simply means that the higher the charging capacity, the faster it can fill a tank.
Single or multiple hose
A typical scuba compressor usually has a single hose to fill one tank at a time. However, there are configurations that allow your scuba compressor unit to the installed with 2 or more hoses. This is particularly true if you have a large scuba compressor which can fill multiple tanks at the same time.
At the end of the day, having your own personal scuba compressor comes with a price since they are expensive. If you new to the sport of scuba diving, having a scuba compressor may not be recommended as having your tanks filled in a dive shop is more convenient and cheap. But if you are really into this sport, then a scuba compressor should be in your bucket list as it gives you the freedom to enjoy diving without going to the dive shop multiple times just to have your tanks filled. And lastly, scuba compressors can cater to other sports that need compressed air as it can also be used in filling up tanks for paintball and air guns.