Air compressors are used throughout industry to turn electrical or diesel power into compressed air. The compressed air can then be used to function power tools or paint spray guns as well as CNC machinery. For such a vital piece of kit, pivotal to the success of businesses and projects the humble air compressor is often overlooked. For many the reality of just how vital it is only comes when they are without one, to avoid this situation care must be taken to select the air compressor that’s right for you and fit for purpose. With such a diverse market there’s an air compressor suitable for every situation, whether it’s a large scale industrial project or a much smaller commercial build, however before we go into too much detail lets cover the basics.
Air compressor design
The purpose of an air compressor is simple: To convert air at atmospheric pressure into compressed air to be used to power an array of different tools. From reciprocating to rotary screw the way that each compressor works differs, but the general principle remains the same. The commonly used Piston powered air compressor serves as a great example, in basic terms the side mounted motor powers a drive shaft which in turn powers a piston. As the piston is at its lowest point the inlet valve allows air into the free space above the piston. As the piston moves up and the inlet valve closes the air is compressed and exits via the discharge valve into the tank. With every intake of air the tank is filled until the amount of air within the tank builds up to an acceptable pressure (psi). It’s this compressed air which is then used to power the tool in question, or in some cases inflate an item, this can include (but is not limited to) the following:
Air compressed tools
Using compressed air to power a tool offers users an increased level of power, perfect for heavy duty projects. It’s not surprising then that there’s a wide array of tools that use compressed air to function. There’s the obvious tools like nail guns or pneumatic drills and impact wrenches, all of which not only deliver a better power output but also act as a timesaver over the more conventional means. Then there’s the tools are generally recognised as battery or hand powered only, such as drills, grinders, sanders and saws in fact there’s an air powered appliance for the majority of tools!
Air compressed spray guns – The spray gun is used by both professional and hobbyists to spray paint under pressure. Using a spray gun is the industry standard for applying paints to any surface, due to its speed and the excellent coverage and finish it gives.
Air compressor inflatable
This can cover anything! A great feature of an air compressor is its adaptability, all will come with a maximum output, but within this output it’s possible to select the PSI of your choice through a pressure regulator. This means that whether you’re inflating a football or the tyres on your car an air compressor will do the job, offering a versatile all-in-one solution.
Air compressor types
There are numerous ways in which an Air compressor can differ, from shape to functionality, one of the most important areas to focus on though is the ‘type’ of air compressor. This generally consists of the following two varieties; Piston powered reciprocating air compressor, Rotary screw compressor and the centrifugal compressor. As explained above, the reciprocating air compressor is the smallest and the more common of the two, the remaining Rotary screw compressor functions as follows:
Rotary Screw Compressor
Powered by a motor that drives a timing belt which in turn enables two large diameter screws to revolve in perfect alignment, this compressor can create a much higher output than the reciprocating air compressor with some models able to apply pressure (psi) into the thousands. The motion in which the rotary screws operate allows for a near constant and smooth supply of compressed air, perfect for heavy duty machinery that requires a stronger power source. However it’s the increased efficiency that most buyers are interested in, the way in which it functions generates more power whilst using less energy to do so.
Although air compressors come in many different shapes and sizes from squat ‘pancake’ shaped to horizontal or vertical cylindrical tanks, they mainly operate on one of the two above principles. Moving onto the compressed air tank, it pays to take note of the shape and size of this feature as it’s the capacity within this tank that dictates when the motor will start up and begin pumping more compressed air. Repeat this stop/start cycle too often and the result could potentially be a worn out motor, if the air compressor will be under heavy use then it’s advisable to go big with the tank.
Air compressor features
The above information is all well and good at providing an insight into the inner workings of an air compressor, however before deciding upon which ones right for you, there are some other very important factors to consider.
Will you have access to a stable electrical source to power your air compressor? If not a diesel or gas powered may be a better alternative.
If opting for a diesel or gas powered machine then a well-ventilated area is a must, likewise if there’s a restriction to the amount of noise that can be made (i.e. a built up residential area) then it’s worth considering a quiet air compressor such as the Clarke Shhh.
Dependant on the specific use you have in mind, portability plays a key role in the practicality of using an air compressor. For example if working on a build with several floors or even just around your home for multiple uses. Many of the larger models are freestanding and as such are much more cumbersome to move around. If you have no single use in mind then going with a portable model will only add an extra degree of flexibility and may pay dividends in the long run.
Air Compressors for Industrial use
For starters there are the large scale projects with heavy pneumatic machinery like jackhammers where a continuous flow of high psi compressed air is required. The best option is of course a rotary screw compressor; its quickness and efficiency make it the ideal choice. For heavy use its worth taking into account the extra capacity that a 2 cylinder air compressor will give you, double the compressed air, double the potential output!
At the other end of the industrial spectrum there are the smaller jobs that still require an air compressor although not one so powerful, the nail gun standing out as a perfect example. Although it depends on the thickness of the substrate and subsequently the size of the nail, the compressor needed to power a nail gun is typically a smaller model with a maximum PSI of no more than 100. The reciprocating air compressor is the obvious choice, as the nail gun only fires one nail at a time it’s never in constant use and even under moderate to heavy use the compressed air it produces will still be sufficient.
Needless to say portability is also an essential aspect to consider, the more compact the better, allowing users to travel around the site as and when required. By popular demand manufacturers usually include a carry handle or in some cases even wheels, ensuring a convenient method of transportation.
Air Compressors for Business use
There are many businesses that benefit from the use of an air compressor, whether it’s to speed up there operation or to achieve a superior level of craftsmanship. A prime example of this can be seen at your local garage. From the pneumatic impact wrenches which take the nuts of the wheels to the spray guns that apply the paint and primer to car panels, without the advantages that using compressed air gives them it would be impossible to compete within their market sector. For something that requires a consistent flow of compressed air such as an industrial grade spray gun a rotary screw air compressor is certainly the best option, when it comes to the impact wrench although the same job could be done with a reciprocating air compressor, with the adjustable pressure switch on the rotary screw it can provide enough power for both.
Air Compressors for Home use
For the DIY enthusiast or small home business an air compressor can be an invaluable piece of equipment. Asides from the obvious edge an air compressor gives the average hobbyist over hand tools, there are a number of other useful reasons to own one. Using it to power a blowgun can come in handy when removing sawdust or metal fibres from projects, whilst it can also be put to good use as a tyre inflator. Ensuring vehicle tyres are at the correct psi will pay off in the long run, leading to a better fuel consumption and subsequently a saving on fuel bills.
For small home businesses when time literally is money the efficiency that can be achieved with an air compressor is priceless. Put simply anything that previously had to be done by hand can now be done via compressed air, what’s more unlike an electric hand tool the power on an air compressor is fully adjustable so only one tool is required to do the job.
Selecting the right air compressor specification
Once an Air Compressor type has been selected, there’s still the matter of choosing the correct model from the technical specification, which highlights the differences in areas like power output and capacity. All of the information presented is relevant; however some are more important than others:
Air Displacement (CFM) – Standing for cubic feet per minute, this measures the airflow relative to the PSI. It’s worthwhile checking the manufacturer’s specification of your air powered tools first and try to match the CFM needed to operate them.
Air Receiver (Litre) – The air receiver is the tank and its capacity, which is measured in litres. The larger it is the more it stores, however it’s worth noting that as the tank bigger it will take longer initially to fill to the required PSI.
Motor (Watt) & Input (Valve) – This refers to the power of the motor, the higher the rating the more powerful the motor that powers the piston or screws. This is only to be used as a secondary deciding factor after the CFM.
Air Compressor brands
Being the indispensable tool that it is, the market is saturated with air compressor brands, so how do you know which ones right for you? Well, using the above information is a good place to start but it doesn’t answer the question of quality or reliability, for that you need to invest in a renowned brand. To help you out we’ve handpicked a selection of highly regarded brands that offer some of the best air compressors on the market:
Atlas Copco are one of the largest manufacturers of industrial air compressors. Their GA range is the industry standard for electrically powered rotary screw compressors. Atlas Copco also control a number of smaller brands such as:
- Chicago Pneumatic
HPC are known for their high quality air compressors and bright yellow cabinets. One thing of note is that on some of the three phase models you have to pressurise the oil separator tank to remove or change the lubricant. Needless to say this should only be undertaken by a compressed air engineer.
Regarded as one of the largest suppliers of tools and machinery for all trade industries. Offering quality British built air compressors for a variety of end uses, if Clarke doesn’t supply it you’re not going to find it elsewhere!
– As one of largest names in automotive tools, Sealey offers a wide range of quality air compressors, from low noise screw compressors to large freestanding piston driven compressors.
SIP Airmate – Looking for something at the higher end of the market? No expense is spared with SIP Airmate’s great range of industrial grade compressors. British built with some sporting genuine Honda motors, the SIP Airmate is a force to be reckoned with!
Air Compressor maintenance
Purchasing your air compressor is just the beginning, like every machine it requires maintenance and the motor servicing. Before the first use each day a quick inspection for any leaks or holes should be undertaken, if everything appears as it should and the oil levels are sufficiently topped up then your machine can be started up. Asides from this daily routine it’s also prudent to check the filters, valves, belts and any nuts and bolts that may have loosened due to vibration.
Air Compressor parts
Even a regularly maintained machine will need spare parts at some point, in fact buying and replacing old parts with new is all part of the maintenance. It’s the motor that commonly needs replacement parts, just as over time any motor will, whether its electric, diesel or gas powered. As with all motors there are parts that have a shorter lifespan than others, namely the air and the oil filters. Through extensive use and general wear and tear, it’s also possible that other key components may need replacing too; the good news is that spare parts are not hard to come by. To ensure you that the part you need is correct in terms of make and model its always best to deal direct with the professionals, we aim to provide our customers with the very best technical support enabling you to get back up and running in no time!