Compressed air is commonly used as an effective medium for transferring energy in both home and industrial processes. This air is used as stored compressed air in air tanks or directly produced with air compressors. Depending on your use of compressed air, a key question people often ask is about the difference between air tanks and air compressors.
Compressed air tanks (or air receivers) are primarily compressed air storage containers that deliver compressed air to an application when needed. On the other hand, air compressors convert air pressure into compressed air to run applications or for storage in air tanks.
This article gives you a comprehensive comparison of air tanks and air compressor uses, sizes, and costs. Knowing the differences between them will help you decide which you should choose for your compressed air needs.
Air Tanks and Air Compressors: Operation and Functions
The function of air tanks and air compressors is the same when it comes to the transfer of energy through compressed air.
However, air tanks and air compressors differ in how they operate when transferring compressed air energy.
Air Tank Operation and Functions
Air tanks are portable compressed air storage vessels that you can easily carry around for simple applications.
They are common in workshops and garages, and vehicle owners use them for their tire-inflating needs.
To use an air tank, you fill it with compressed air from an air compressor or a garage near you. Then, when the need arises, you draw the compressed air from air tanks using the blow-off valve or pressure release system and use it in applications.
The uses of compressed air tanks include:
- Compressed air storage
- Inflating tires and other inflatables like air beds and balloons
- Supporting air compressors so compressor controls can provide a consistent air signal
- Supporting operation in secondary equipment (equipment that regulates, protects, monitors, and controls primary equipment)
Unlike air compressors, ordinary small-sized air tanks can only run a few simple operations before you have to refill them.
Air Compressor Operation and Functions
An air compressor compresses air and converts air pressure into usable energy. That way, it supplies airflow to equipment or an application.
They are commonly used in larger machines like refrigerators and industrial applications because they can compress large amounts of air and supply it to an application.
That does not mean you cannot use an air compressor for a simple task like inflating a tire. But air compressors are more cumbersome and difficult to move. As such, an air compressor will be heavier than an air tank of the same tank capacity. Air compressors also require a source of energy to run.
Some air compressors have an attached air tank. A good example is the California Air Tools 8010A Air Compressor which you can purchase from Amazon.com. The tool has a:
- Large 8-gallon aluminum tank
- Quick universal connector
- Wheel kit for easy transportation
To use an air compressor, open the air inlet to allow air to pass into the cylinder. Once in the cylinder, the air is pressurized and forced through the outlet valve into an air tank, through an air tool, or an application.
Specific uses of air compressors include:
- Inflating tires and other inflatables
- Chilling air in air conditioners, freezers, and refrigerators
- Pumping water at high pressure in water blasters and pressure cleaners
- Supporting breathing underwater for scuba divers
- Powering airbrushes during spray painting
- Powering industrial processes such as packaging and transportation, sanding, positioning, and cutting
- Powering workshop equipment like impact wrenches, nail guns, sanders, grinders, and drills
- Controlling heating and cooling in vehicle engines, train and truck breaks, and park rides
- Powering construction machinery, including hammers, drills, and compactors
- Controlling water and water displays in water fountains
- Powering hospital equipment in dentistry, sanitization, and oxygen delivery processes
- Firing ammunition in paintball and air guns
- Powering agricultural equipment like sprayers
Integrated Use of Air Tanks in Air Compressor Systems
People often pair air tanks with air compressors in large industrial applications as part of a compressed air system.
Combining an air tank with an air compressor helps in:
- Creating temporary storage and a supplemental source of compressed air, ensuring there’s sufficient air when the demand for compressed air in an application increases.
- Retaining constant pressure and a stable flow of compressed air.
- Stabilizing compressor demand for air, allowing it to keep up with air demand, and preventing extensive motor wear due to overworking.
- Trapping and draining condensation from the compressing process.
Overall, you could think of combining air tanks and air compressors as a mode of optimizing efficiency in an industrial plant.
However, air tanks used in air compressing systems are much larger than the small portable air tanks used by car owners or small size workshops.
Air Tanks vs. Air Compressors Size Differences
Considering that air tanks and air compressors work differently, it’s evident that their sizes also vary.
Size differences between air tanks and air compressors are marked by their tank volume capacity (in gallons), the amount of compressed air they can store/produce, and the pressure capacity (in PSI).
For air compressors, the airflow rate and the horsepower also differ from one air compressor to another.
Air Tank Sizes
Compressed air tanks come in different sizes, measured in gallons of compressed air. Standard air tank sizes include:
- Five gallons (18.9 L)
- Seven gallons (26.5 L)
- Nine gallons (34 L)
- Ten gallons (37.8 L)
- 11 gallons (41.6 L)
A ten-gallon (37.8 L) air tank is likely to be more useful for a few applications, while a small five or seven-gallon (18.9 or 26.5 L) tank is only suitable for small applications, even though it’s lightweight and easy to carry.
Air tanks used in large operations and those integrated into industrial air compressor systems can be thousands of gallons. In other words, the size of an air tank will depend on the type and the application.
For example, if you need an air tank to inflate the flat tire of a small car, you should go for one with a capacity greater than 7.5 gallons (28.4 L) for two reasons:
- First, a small car tire has a volume of one cubic foot, which is equivalent to 7.5 gallons (28.4 L).
- Second, heat increases air pressure. As such, you should not fill an air tank as it can explode with increased air pressure.
In addition to their volume capacity, the size of air tanks is also measured by their pressure rating.
Air tanks have a maximum pressure rating, which is the maximum air pressure that the air tank can handle without posing any risks.
Air tanks’ maximum air pressure is measured in pounds per square inch (PSI), and most air tanks are rated between 125 and 175 PSI (861.8 kPa and 1206.6 kPa).
Air Compressor Sizes
Even though you can consider the physical size of your air compressor for practical portability and usage reasons, you shouldn’t determine air compressor size solely on its physical size or gallon capacity.
Instead, consider these three measurements for a more accurate sizing:
Air Compressor PSI (Pounds per Square Inch)
An air compressor’s PSI is its pressure capacity or the amount of force with which it can deliver compressed air.
Air compressors used for pneumatic tools are usually rated at 70-90 PSI (482.6-620.5 kPa). Other high-pressure air compressors are rated at 135 PSI (930.8 kPa).
Air Pressure CFM (Cubic Feet per Minute)
An air compressor’s CFM is its airflow rate or the amount of compressed air it can produce at a specific pressure level.
Compressors with higher CFM ratings can produce more compressed air, making them ideal for larger operations.
Air Compressor HP (Horsepower)
An air compressor’s HP is its horsepower or the motor’s work capacity. Typically, air compressor HP is rated between 1.5 and 6.5. Larger industrial air compressors can have up to 15 HP.
When considering an air compressor, its HP rating is not as crucial as its CFM and PSI ratings because more horsepower does not necessarily mean better air compressing.
Besides, today’s cutting-edge air compressor models can do more with less HP, which means less energy consumption, greater efficiency, and longer life.
Air Tanks and Air Compressors Costs
Comparing the cost of air tanks and air compressors can be tricky. This is because both are primarily created and used in different applications.
Different air tanks have specific uses. Some are for:
- Powering air tools
- Paintball firing
Air compressors have more features than air tanks, which can mean increased costs. Besides, some air compressors complete smaller amounts of work and others larger amounts of work.
In comparison, you’ll pay more for an air compressor than an air tank, even when the volume capacity of an air compressor is lower than that of an air tank.
For example, the price of a 6-gallon air compressor can be somewhere between $100 and $200. However, you can easily find a 10-gallon tire inflator air tank for about half that price.
Air Tank or Air Compressor: Which Should You Get?
You should get an air tank or air compressor based on the kind of work you intend to do with either equipment. Get an air tank if you need compressed air for smaller applications and get an air compressor for larger operations.
To break it down for you, if you need compressed air for inflatables, a simple air tank will do the job for you.
However, air tools like wrenches, nail guns, sanders, grinders, and drills and high-energy operations like cutting, positioning, and packaging in large industries will require you to have an air compressor.
If you have a high-energy tool, consider combining an air compressor with an air tank to improve efficiency.
Choosing between an air tank and an air compressor will also depend on your budget. As established earlier, air compressors will cost a lot more than air tanks.
But the cost should not surpass purpose and function when deciding whether you should go for an air tank or an air compressor.
- The Spruce: How to Use a Portable Compressed Air Tank
- Air Compressor Help: Difference between an Air Compressor and An Air Tank
- Quincy Compressor: Why Is a Tank Important When Using an Air Compressor?
- The Compressed Air Blog: PSI, CFM, and HP: Understanding Air Compressor Measurements
- VMAC Air Innovated: What Size Air Compressor Do I Need For Air Tools?
- Coates: 13 USES FOR AIR COMPRESSORS
- Quora: How does a compressor work?
- Frauenthal Airtank: Air Tank Functions