Contents 

• What is compressed air and how is it made?  
• Why is compressed air important?  
• Where is compressed air used?  
• Types of compressed air systems  
• Electric and diesel air compressors  
• Environmental and efficiency considerations  
• Choosing the right compressed air solution  

Compressed air is one of the most widely used sources of power across modern industry. 

Often described as the “fourth utility” alongside electricity, water and gas, it supports processes across manufacturing, construction, food production, healthcare, energy and many other sectors. 

An industrial air compressor can provide a reliable source of power for pneumatic equipment, automated machinery and production processes. Depending on the application, compressed air can also be stored, distributed through pipework and treated to meet specific air quality requirements.

So, what is compressed air, how is it produced and where is it used? 

 

What is compressed air and how is it made? 

Compressed air is ordinary atmospheric air that has been pressurised and stored at a pressure higher than the surrounding atmosphere. 

The process starts with an air compressor drawing air in from the surrounding environment.  The air compressor increases the pressure of the air to store its energy to be released as required. 

The principle is similar to inflating a balloon. Energy is used to force air into a confined space, then released when the air is allowed to escape. 

Different types of industrial air compressors use different methods of compression, including: 

• Rotary screw compression  
• Reciprocating piston compression  
• Centrifugal compression  

Compressors can also be powered in different ways. Electric compressors use an electric motor, while a diesel air compressor uses a diesel engine to drive the compression system. 

The result is a controllable supply of compressed air that can be used to power everything from compressed air tools UK businesses rely on to large-scale industrial equipment.

 

Why is compressed air important? 

Compressed air is widely used because it provides a flexible and reliable source of power for industrial equipment. 

It can be distributed through pipework across a facility or stored in air receivers for use when demand increases. Pneumatic equipment can also be used in environments where electrical equipment may not be suitable. 

Key benefits include: 

• Reliable operation for demanding industrial applications  
• Flexible distribution through compressed air networks  
• Instant availability when equipment needs to operate  
• Suitable for hazardous environments where electrical equipment may present additional risks*  
• Controlled air quality when the system includes appropriate filtration and drying equipment  

 

*Working in ATEX zones may need additional non-standard features. 

The quality of the compressed air can also be tailored to the application. An oil-free air compressor, for example, can provide air where contamination needs to be tightly controlled, while a compressed air dryer can remove moisture from the system. 

For businesses that rely on pneumatic equipment or production processes, having a dependable supply of compressed air is often essential to keeping operations running. 

 

 

Where is compressed air used? 

Compressed air is used across a wide range of industries. Its flexibility makes it suitable for powering equipment, controlling processes and supporting production where a dependable source of compressed air is required. 

Applications vary considerably depending on the sector. 

Industries where compressed air plays an important role include: 

• Construction and infrastructure, where mobile air compressors and towable compressors can power breakers, drills, pumps and other pneumatic equipment 
• Manufacturing and automotive, where industrial compressors support assembly lines, automation, production equipment and pneumatic tools 
• Food and beverage, where oil-free compressors and air treatment equipment can provide clean air for processing and packaging 
• Pharmaceuticals, where controlled air quality is required for sensitive processes 
• Healthcare and precision engineering, where clean, dry compressed air can be essential  
• Energy, marine and heavy industry, where high-capacity compressors support maintenance, equipment and process operations 

Compressed air is used for a huge variety of tasks. Pneumatic tools can include drills, impact wrenches, breakers and grinders, while larger systems can power automated machinery, valves, conveyors and production equipment. 

The right compressor depends on factors such as the required pressure and flow rate, air quality, operating environment and how long the equipment needs to run. 

 

 

Types of compressed air systems 

There are several different types of compressed air systems, with the right choice depending on the application and operating conditions. 

 Oil-flooded compressors 

Oil-flooded compressors use oil to lubricate and cool components inside the compression system. 

They are widely used across general industrial applications where the compressed air does not need to meet the strictest purity requirements. 

Common applications include: 

• Construction 
• Engineering workshops 
• General manufacturing 
• Heavy industry 

Oil-flooded compressors can provide efficient and reliable operation for demanding applications. Filtration and air treatment equipment can also be added where the application requires cleaner air. 

Oil-free compressors 

An oil-free air compressor is designed so that oil does not come into contact with the compressed air during the compression process. 

This makes oil-free air compressors particularly important in industries where contamination could affect products, equipment or processes. 

Typical applications include: 

• Food and beverage production  
• Pharmaceuticals  
• Electronics manufacturing  
• Healthcare  
• Precision engineering  
• Other applications requiring high air purity  

Depending on the specification, oil-free systems can produce Class 0 compressed air, making them suitable for applications where oil contamination needs to be avoided. 

GenAir supplies a wide range of electric, hybrid and diesel oil-free air compressors, including centrifugal models available since our acquisition of Dutch-based specialists, RTC Group. 

 

Electric and diesel air compressors 

The choice between an electric compressor and a diesel compressor depends largely on the working environment, available power supply and the demands of the application. 

Electric compressors are well suited to locations with a reliable mains electricity supply. They are commonly used in manufacturing facilities, workshops and indoor environments, as well as projects where reducing on-site emissions is a priority. 

A diesel air compressor has its own engine, so it does not depend on a mains electrical connection. This makes diesel compressors particularly useful for construction sites, infrastructure projects and remote locations where a suitable power supply is unavailable. 

Diesel compressors are also available in oil-free configurations, providing high-quality compressed air for applications where mains electricity is unavailable. 

Key considerations include: 

• Electric compressors are suitable for sites with access to mains electricity and applications where on-site emissions and noise need to be limited
• Diesel compressors provide greater flexibility for remote or temporary applications where mains power is unavailable  
• High-capacity compressors can provide the air volumes required for large industrial processes and demanding applications  
• Mobile and towable compressors can be transported between locations as project requirements change  

Some businesses use both electric and diesel equipment depending on the application. A compressor rental provider can assess factors such as air demand, pressure, location and operating conditions to identify suitable equipment. 

 

Environmental and efficiency considerations 

Compressed air is an essential part of many industrial operations, but producing it requires energy. The way a compressed air system is designed, maintained and operated can therefore have a significant effect on efficiency and running costs. 

Energy consumption 

Compressing air requires a considerable amount of energy. Poorly maintained equipment, incorrect sizing and air leaks often waste 20-30% of output. 

The Carbon Trust also finds that compressed air uses around 10% of UK industrial electricity. 

Common causes include: 

• Leaking pipework or connections 
• Incorrect compressor sizing  
• Poor maintenance  
• Running equipment when it is not required  
• Pressure settings that are higher than necessary  

Regular maintenance and leak detection can reduce unnecessary energy consumption. Selecting an industrial air compressor that matches the actual demand of the application can also prevent equipment from working harder than necessary. 

Emissions and sustainability 

The environmental impact of a compressor depends partly on how it is powered. 

Diesel compressors produce exhaust emissions because they use an internal combustion engine. 

Electric compressors have no combustion emissions at the point of use, although their overall environmental impact depends on the source of the electricity. 

For businesses looking to reduce emissions, options can include: 

• Electric compressors 
• More energy-efficient compressor systems 
• Variable speed drives 
• Renewable electricity 
• Alternative fuels such as HVO, where suitable 

GenAir also supplies equipment designed for applications where reducing emissions is a priority, including HVO-compatible compressor solutions. 

Our hybrid models can deliver in emergencies, running on diesel and then switching to the grid at the earliest opportunity. 

Plus, our Stage V diesel compressors offer significantly reduced emissions, HVO compatibility and regulatory compliance. 

This is especially beneficial in sectors like construction, infrastructure, utilities and petrochemical, providing you with compliance, power and clean performance all in one product. 

Noise reduction 

Compressors can generate significant noise, particularly in industrial environments and when large equipment is operating under high demand. 

Noise levels can be managed through appropriate equipment selection, acoustic enclosures, sound insulation and careful positioning of compressors. 

Electric compressors can also be suitable for applications where reducing noise is a consideration, particularly indoors or close to occupied areas. 

Air quality management 

Compressed air quality is critical for many applications. 

Moisture, oil and particulates can affect equipment, production processes and product quality. Air treatment equipment is therefore often used alongside the compressor. 

Depending on the application, this can include: 

• Refrigerant air dryers 
• Desiccant air dryers 
• Filtration systems 
• Oil separation equipment 

The required level of air treatment depends on how the compressed air will be used. Food production, pharmaceuticals and other sensitive industries may require highly controlled air quality, while less demanding applications may have different requirements. 

For example, UK food sites often work to the BCAS Food Grade Compressed Air Best Practice Guideline 102. For direct contact with food, it calls for ISO 8573-1 Class 1 for oil, Class 2 for particulates and Class 2 for water (a -40°C pressure dew point). 

 

Choosing the right compressed air solution 

Compressed air systems come in a wide range of sizes and configurations, so choosing the right equipment starts with understanding the application. 

Factors to consider include: 

• Required air pressure and flow  
• Air quality requirements
• Compressor capacity  
• Operating environment 
• Available power supply  
• Duration of use  
• Space and access restrictions  
• Environmental requirements  

For temporary requirements, air compressor hire can provide access to the equipment needed without purchasing a permanent system. This can be particularly useful during planned maintenance, emergency cover, production peaks or major projects. 

A compressor for hire may also be appropriate when additional capacity is required for a limited period. Depending on the application, this could mean a mobile air compressor for a construction project or a large industrial compressor for a high-volume production process. 

GenAir provides air compressor rental solutions across the UK, with a fleet of oil-free, oil-flooded, electric and diesel-driven compressors. 

With equipment available for a wide range of applications, GenAir can provide compressor hire for businesses that need reliable compressed air without the commitment of purchasing additional equipment.