A Guide to Air Compressors

Reviewed by Osman Hafeji, Technical Support Engineer (January 2025)

Welcome to our in-depth guide on air compressors. Whether you are a professional tradesperson or a DIY enthusiast, gaining a solid understanding of air compressors can be highly advantageous. This guide will cover everything you need to know about air compressors, including their definition, applications, how to choose the right one, and a glossary of essential terms.

Air compressors are versatile tools that cater to various applications, from powering air tools to inflating tyres. By providing a continuous supply of compressed air, these machines make numerous tasks easier and more efficient. Let’s delve into the fascinating world of air compressors!

Air compressors are highly versatile and find applications across various industries and sectors. Here are some common uses:

Air compressors are frequently used to inflate tyres, sports balls, and inflatable toys. With the appropriate attachment, you can easily fill your car or bicycle tyres, ensuring optimal pressure for safe and efficient driving.

In the automotive and manufacturing industries, air compressors are widely used for spray painting. They provide a consistent stream of compressed air, allowing for a smooth and even application of paint on surfaces.

Air compressors are integral to pneumatic systems, which use compressed air to power pumps, actuators, and other components. These systems are commonly found in manufacturing plants, automation systems, and industrial machinery.

Air compressors are essential for operating air tools such as pneumatic drills, impact wrenches, and nail guns. These tools require a constant supply of compressed air to deliver high power and efficiency.

Selecting the right air compressor for your needs involves understanding the different types available and their key properties. This knowledge will help you make an informed decision and ensure you choose the best air compressor for your specific requirements.

There are a variety of air compressors on the market, each with unique characteristics:

• Piston Compressors: These compressors use a piston to compress air and are versatile, making them suitable for a wide range of applications.
• Rotary Screw Compressors: These compressors utilise two interlocking screws to compress air. They boast high efficiency and continuous operation.
• Scroll Compressors: Scroll compressors have two spiral-shaped scrolls to compress air. They are ideal for small-scale applications as they’re both compact and quiet.

When choosing an air compressor, consider the following properties:

• Air Pressure: This refers to the force the compressor can generate, typically measured in pounds per square inch (PSI).
• Air Flow: Also known as volume flow rate, it indicates the amount of air the compressor can deliver per unit of time, measured in cubic feet per minute (CFM).
• Tank Capacity: Some air compressors come with a storage tank to hold compressed air. The tank capacity determines how much compressed air can be stored at a given time.
• Power Source: Air compressors can be powered by electricity, petrol, or diesel. Consider the availability of power sources and choose the one that suits your needs.

Whether you are a seasoned professional or just starting, understanding the terminology used in the world of air compressors is crucial. In this glossary, we will explain some key terms and concepts related to air compressors, helping you make informed decisions when purchasing and using these powerful machines.

1. CFM: Cubic Feet per Minute, a measurement of the airflow capacity of an air compressor. It indicates how much air the compressor can deliver in a minute and is an important factor when selecting a compressor for specific applications. Another common measurement for air flow used in the UK is litres per minute (l/m).

2. PSI: Pounds per Square Inch, a unit of pressure measurement. It represents the force exerted by the compressed air. Bar is also a common unit of pressure measurement in the UK, where 1 bar is equivalent to 14.504 PSI. Most tools and equipment have a recommended PSI range for optimal performance. 

3. Tank Capacity: The volume of compressed air that an air compressor can store, measured in gallons or litres. It determines how long the compressor can run before needing to refill. 

4. Oil-Free: An oil-free air compressor is designed to operate without the need for oil lubrication. It is suitable for applications where oil contamination is a concern, such as in food processing or medical environments.

5. Single-Stage vs. Two-Stage: These terms refer to the number of compression stages in an air compressor. Single-stage compressors have one piston that compresses the air to the desired pressure, while two-stage compressors have two pistons for higher pressure output.

6. Portable: Portable air compressors are compact and lightweight, making them easy to transport and use in different locations. They are ideal for DIY projects, small workshops, and construction sites.

7. Industrial: Industrial air compressors are heavy-duty machines designed for continuous operation in demanding environments. They can deliver high volumes of compressed air for industrial applications.

8. Air Compressor Hoses: Essential accessories that connect air compressors to air tools and other equipment, ensuring a reliable flow of compressed air.

Now that you are familiar with some of the key terms, you will be better equipped to choose the right air compressor for your needs. Browse our wide range of air compressors and accessories to find the perfect solution for your projects!