What Is Compressed Air & Where Is It Used?

Whether you realise it or not, compressed air is likely involved in most aspects of your life. It plays an important role in many industries - which is why here at The Hosemaster we offer a huge range of compressed air parts and components. To find out more about compressed air and where it’s used, keep reading…

What is compressed air? 

Let’s kick things off with a definition; what exactly is compressed air? 

Put simply, air is the mixture of invisible gases that surround us all everyday. Composed of a mixture of gases, air is made up of approximately 78% nitrogen, 21% oxygen, and a smaller percentage of other gases such as carbon dioxide, hydrogen, and neon. 

It’s important to note that air isn’t merely made up of gases. It also consists of small particles that are known as aerosols. These include things like dust and pollen. These aerosols can be either naturally occurring or anthropogenic - and with too many aerosols in the air, it can cause breathing problems for animals and humans alike. 

Okay, so far so good - we have a definition for ‘air’. 

So, what is compressed air? 

Again, without going into too much detail, compressed air is air which has been forced into a small, confined space - thus pushing the molecules of the gases closer together.

Bear in mind that the process of compressing air results in the temperature of the air increasing. This is because the act of compression makes the molecules within the air move more rapidly, resulting in an increase in temperature. As scientists would say; ‘the temperature of the air is directly proportional to the kinetic energy of the molecules’.

This process does require energy - which is why air compressors require an energy supply (typically a mains electricity supply or via a diesel or petrol powered motor). Whilst some of this energy is recouped when the pressurised air is released, a great deal is often lost in the form of heat. 

It’s for this reason that it’s worth investing in the latest compressor technology, high-quality compressed air hoses, and other associated components and parts; the more you can reduce inefficiencies, the lower your energy bills will be when using compressed air.

We admit that this is a rather simplistic explanation of the process of creating compressed air, but we hope it does at least provide an overview of the fundamental operating principles of modern air compressors. 

To put it another way, air compressors take the ambient air that surrounds them, force the air into a container, pressurising it in the process. This air is then stored in a pressurised tank (usually via an intercooler which cools the compressed air closer to the ambient room temperature) whereby it is either stored for later use or used straight away for a range of applications that require pressurised air.

Which of course leads us on to our next question…

What is compressed air used for? 

The use of compressed air dates back to the late eighteenth century when the first motorised air compressor system was invented by Englishman George Medhurst. 

Since then, the use of compressed air has increased enormously, finding a broad range of applications. 

The primary reason for the popularity of compressed air is that it is an excellent medium for the storage and transmission of energy. This benefit becomes especially apparent when you consider other forms of energy transmission and storage. 

For example, the use of batteries for the storage and transmission of energy is expensive and cumbersome (batteries are both large and heavy). The use of steam for energy storage and transmission is also expensive and is less user-friendly (steam being a potential safety hazard). 

Today, then, compressed air has found widespread applications. These applications can be divided into two main categories: 

• Energy air. 
• Active air. 

Below, we’ve detailed what each of these terms means. 

Energy air

Energy air refers to applications in which compressed air is used to power mechanical work. 

That is, air compressors are used to power equipment such as impact wrenches, nail guns, drills, jack hammers, buffers and more. 

Active air

Active air refers to applications in which the air plays an active role in the process.

To put this another way, the compressed air actively comes into contact with the subject of the process. For example, compressed air, via a tool such as an air gun, is used to clean a component or part, or is used to clean a surface and remove dust and detritus.

It’s this latter application of compressed air that is perhaps the most recognisable to the public at large. 

Where is compressed air used? 

In both its active and energy forms, compressed air is used in an exceptionally wide array of industries. 

Some of the industries in which you’ll find compressed air used, include (but are not limited to): 

• Automotive. 
• Construction. 
• Mining. 
• Pharmaceuticals. 
• Agriculture. 
• Semiconductor and electronics production.

These are just a few examples of the diverse industries in which compressed air is put to use. 

Fun fact - did you know that compressed air is so widely used that it is considered to be the ‘fourth utility’ after water, electricity, and gas?

What types of air compressors are there? 

Given that compressed air is so widely used in so many different applications, it’s no surprise to discover that there are a number of different types of air compressor available. 

However, in a broader sense, you can group air compressor into two main categories: 

• Positive displacement compressors. 
• Dynamic compressors. 

Positive displacement compressors

Positive displacement compressors work on the following basis; the compressor has a cavity that allows a volume of air (or gas) to enter at atmospheric pressure. The size of the chamber is then deliberately decreased - typically using a piston or rotary screw - which then increases the pressure of the air/gas. 

The most common types of positive displacement compressors are; piston compressors (also known as reciprocating compressors), scroll compressors (also known as double rotor compressors), and rotary screw compressors (also known as single rotor compressors). 

Dynamic compressors

Dynamic compressors create compressed air by using an impeller to accelerate air within a confined space. Once the air has been accelerated, it is then slowed down via a diffuser and volute to transfer the kinetic energy into pressure. 

Common types of dynamic compressors include centrifugal and turbo compressors which are typically used in industries such as the chemical and petrochemical industry, steel manufacturing, and fertiliser production. 

What types of compressed air tools are there? 

As we mentioned earlier, there is a dizzying array of compressed air tools in use today. One of the most popular uses for compressed air is in the ‘active air’ fashion, using it to clean objects or clear surfaces. 

Here at The Hosemaster, we stock a wide range of blowguns that are ideal for using active air.

Our air blowgun range includes: 

• Flexible nozzle blowguns. 
• Rubber tipped angle nozzle blowguns. 
• Extension nozzle blowguns.
• Safety curtain blowguns.
• Pistol grip blowguns. 

And, that’s just the tip of the iceberg! If you want to see what else we have to offer, explore our complete range of blowguns.

What other components do you need to use compressed air? 

Aside from a suitable compressor and a compressed air tool, there are a few other essential components you should consider. 

Pneumatic tubing

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In any use of compressed air, it’s necessary to convey the compressed air from the compressor to its end use point (e.g. blowgun). 

To do this, you’re going to need appropriate lengths of suitable pneumatic tubing. 

The majority of pneumatic tubing is designed to work within specified pressure ranges. For example, here at The Hosemaster, we stock pneumatic tubing that can be used up to 300 psi (20bar). 

Other important factors to consider when choosing pneumatic tubing include: 

• Diameter - this will affect which tools and items of equipment you can use the tubing with (unless you have converters). 
• Length - you’ll want to ensure that you don’t have to stretch your tubing. Likewise, if it’s too long, it can become a trip hazard. So, ensure you select the correct length. 
• Material - different materials are more or less suited to certain settings. For example, industrial nylon is ideal for environments in which the tubing is likely to be stepped on or rubbed up against things. 

Push in fittings

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If you intend to regularly connect and disconnect tools and other components from your compressed air system, then it’s vital you use push in fittings. 

Push in fittings - also known as push-to-connect fittings - provide a way of quickly and easily disconnecting and connecting parts from a compressed air system. They also do this without air escaping from the system. 

Push in fittings can have several ports, allowing for multiple items to be connected/disconnected. Here at The Hosemaster, we have a frankly enormous range of push in fittings for pneumatic applications. Our range includes fittings of different shapes (e.g. elbows, tees, 45º). We also stock push in fittings of differing diameters as well as reducers - allowing pneumatic tubing of different diameters to be connected together. 

Air filters and regulators

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Air filters and regulators are another recommended component to incorporate into your compressed air system. 

As we’ve previously written, there are a number of different types of filters and regulators that tend to be used in compressed air systems: 

• Air filter units - for improving the quality of the air within compressed air systems (which is particularly important for active air applications). 
• Air regulator units - which allow the user to adjust the flow of air from the compressor. 
• Air lubricator units - these help to reduce friction and wear and tear on air tools connected to pressurised air systems. 

Whilst the above are often stand-alone items, it’s also possible to buy single units that combine air filters, regulators and lubricators together. 

Other compressed air components

Aside from the above items and parts, you may also want to consider the following parts (depending on what you’re doing with your compressed air): 

• Hose assemblies. 
• Quick release air couplers and adapters. 
• Hose reels. 
• Recoil airlines.
• Silencers and accessories.

Looking for compressed air parts and accessories? 

Then you’re in the right place. Here at The Hosemaster, we pride ourselves on offering one of the largest ranges of pneumatic parts and accessories on the internet. 

Shop pneumatic parts and accessories at The Hosemaster now

For more buying guides, advice and information, read The Hosemaster blog…

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