An air compressor is essential for certain professions like mechanics or painters, but it can also be essential for heavy jobs in a house, or just to help you inflate the tires on your car. From the portable model to the twin-cylinder machine , there is something for all tastes and uses . Follow our buying guide to choose the right air compressor for your needs .
THE DIFFERENT COMPONENTS OF THE COMPRESSOR
The principle of an air compressor is simple: the engine drives a compression cylinder whose job is to compress the air in the tank to the desired pressure . Once it is reached, the engine stops. You can then use your machine for your jobs, whether it’s inflating tires or painting a wall. When the pressure drops below a certain level, the engine will restart and the cycle will resume.
The safety elements of your compressor
To prevent overpressure and control said pressure, your air compressor is equipped with several control and safety elements :
- The manometer shows you, using a needle or a digital screen, the pressure inside the tank.
- The pressure regulator , often installed next to the manometer, allows you to tell the engine the pressure to reach in the tank and prevents it from rising higher. It is most often a simple graduated wheel.
- The pressure switch enables the motor to be restarted automatically when the pressure in the tank is too low. You can change it on some models, although the factory setting (6 bar most often) is usually sufficient. It is fitted as standard on all recent compressors.
- The safety valve is a safety device enabling the pressure inside the tank to be rapidly reduced in the event of a fault with the regulator or the pressure switch.
THE DIFFERENT TYPES OF AIR COMPRESSORS
There are different types of air compressors, as well as a wide variety of uses.
The coaxial compressor
In a coaxial air compressor , the compression head , which compresses the air in the vessel, is driven directly by the motor , without the use of a belt. This method of compression produces compressed air much faster, requires little maintenance and is more economical. It is therefore better suited for occasional and short-term use.
The belt compressor
Unlike the previous one, a belt-driven air compressor , the most widely used model, is made up of a transmission belt between the engine and the compression head . This technology is easier to repair and offers much higher durability. Indeed, the parts heat much less since they are not directly in contact, and therefore run less risk of breaking.
The portable compressor
For small jobs like inflating tires, stapling, or air cleaning, a portable compressor is ideal. As the name suggests, you can carry it by hand wherever you go thanks to a tiny tub and compact motor . Some models even run on battery or plug into a cigarette lighter, allowing you to use them in all conditions.
The oil-free compressor
An oil-free air compressor is made up of naturally lubricated Teflon parts , including the compression head, which saves you the hassle of regularly filling it with engine oil to keep it running smoothly. Most often portable, it is especially indicated for occasional and non-prolonged use.
The vertical compressor
The main advantage of the vertical air compressor is that it saves you space in your garage or garden shed. As the name suggests, its tank is vertical, not horizontal, and the motor and control elements are positioned above. This model, coming in all sizes, is suitable if you have limited storage space.
The screw compressor
The screw compression system is made up of two parts rotating in opposite directions against each other , compressing the air in the tank. The most common model is said to be liquid injection : a coolant, most often oil, circulates in the compression chamber in which it is mixed with air. A separator allows the air to be released and injected into the tank, while preventing any return to the outside.
IN WHAT SITUATION TO USE AN AIR COMPRESSOR?
Inflating and blowing
To inflate your car’s tires or use a blow gun , a small portable compressor like this model from the Prodif brand will be more than enough. Equipped with a 6 liter tank, a 1.5 HP motor and a pressure of 8 bars, it will allow you to easily carry out all kinds of small occasional jobs.
Stapling and nailing
The stapling and nailing require a more powerful model that can operate over a longer period. This Prodif single-cylinder coaxial compressor will allow you to easily carry out this kind of work with its 50-liter tank, its 2-horsepower engine and its pressure of 8 bars. It will give you sufficient breath to carry out all your renovation tasks.
Large area painting
The air compressor can make your life much easier if you have to paint large areas , such as an apartment or a house. This, however, will require a machine that is powerful and can operate for long periods of time without a problem. You will then need a tank of about 100 to 150 liters, like this model from the manufacturer Proffer . Its size and 3 horsepower engine allow it to deliver an air flow of nearly 310 liters / minute at a pressure of 9 bars . You can also move it easily thanks to its wheels.
To clean or strip large areas , nothing beats sandblasting . This technique will require the use of an air compressor to power your sandblaster, and it will have to be powerful. A tank of at least 150 liters and an engine of more than 3 horsepower will be needed, and a stage compressor will be preferable, as in this model from Profor , to provide you with continuous airflow.
WHAT TYPE OF COMPRESSOR FOR WHAT SITUATION?
Compressor for occasional use
If you only need an air compressor for occasional uses , like inflating your tires or using a paint gun, a portable model will be enough for you. With a tank of about 20 liters and a 1.5 HP motor delivering an average pressure of 8 bars, you will be able to accomplish all these jobs without any problem. You can also invest in an oil-free model , which is more expensive but requires much less maintenance.
Compressor for regular use
For more regular work and longer , if you are building or renovating your home, for example, you’ll need an air compressor with a tank of greater capacity and a large air flow allowing you to work quickly and effectively. A 3-horsepower single-cylinder engine and a tank of about 150 liters delivering a flow rate of 230 to 310 L / min will suit you perfectly. Finally, a compressor coupled with an automatic wall hose reel will save you space in your workshop.
Compressor for professional use
Are you a mechanic, painter or any other profession requiring an air compressor? You would do well to invest in a powerful model that can withstand long periods of use on a regular basis . It must first have a large tank, at least 200 liters, to have sufficient reserve, aided by a twin-cylinder engine of at least 5 horsepower , to deliver a minimum air flow of 400 L / min , allowing a efficient work. Finally, prefer a multi-stage compression unit , guaranteeing you a continuous flow whatever the intensity of use.
PROFOR 200L 5.5HP THREE-CYLINDER BELT COMPRESSOR
THE DIFFERENT CRITERIA FOR CHOOSING YOUR AIR COMPRESSOR
Expressed in bars, the pressure designates the force supplied by the air leaving the compressor. Each of the tools you can attach to it requires minimum pressure to be maintained to function properly. Add two or three bars when you choose your machine, in order to be comfortable and to be able to connect a secondary tool if necessary.
The air flow is probably the most important factor to consider when choosing a compressor. Expressed in liters per minute or in m³ per hour , it is quite simply the volume of air that the machine will release over a given period. It is directly correlated with engine power and tank size. The more intense the work you will have to undertake, the greater the air flow must be. Check the prerequisites of the accessories you wish to acquire before choosing your compressor.
Expressed in horsepower, the engine power is less important, but to be taken into consideration all the same. The more powerful your compressor has, the faster its tank will be filled, and the longer it can be used continuously.
Depending on the supply voltage available and the desired application, you will choose a compressor with a single-phase or a three-phase motor . The single-phase motor, suitable for home or DIY use, is recommended for a voltage of 230V. Beyond that, opt for the three-phase motor which tolerates a supply voltage of up to 600V, most often delivered in an industrial environment and suitable for intensive use and for applications requiring higher power.
Comfort and ergonomics
When you are doing any work or repairs in your home, the last thing you want is to fight with your compressor to get it running. So choose a model that is easy to use , but also take its dimensions into account, so that you don’t have to build your own shelter outside. If you have little room to store it, opt for a vertical, more compact model.
The compressors equipped with wheels can be of any size, be it a small device with a 20 liter tank or a behemoth of 200 liters. These models allow you to work anywhere , as long as you have a power supply nearby. Be careful, however: the maneuverability of your compressor will be inversely proportional to the size of its tank, even with the help of the wheels. If you only need it for very occasional use, you can opt for a portable model without a tank, which is much more practical.
Fixed models are recommended if you want to install a pneumatic circuit in your workshop.
The sound level
Most compressor models today are fitted with silencers to reduce the noise level . Those equipped with a heat engine will however be noisy, no matter what. So remember to protect yourself with noise-canceling headphones when you use it, and also remember to warn those around you.
The size of the tank
The size of the tank of your compressor will depend on the intensity of its use . If you just want to inflate your car’s tires, a simple portable model under 10L will be more than enough. The more time and longer the work is required to perform the work, the greater the volume of the tank will have to be, to provide you with adequate air flow and to prevent the motor from tiring when running continuously.
HOW TO MAINTAIN YOUR AIR COMPRESSOR?
Change compressor oil
Unless you have an oil-free model, you will drain that your compressor at least once a year. Also check its cold level before each use, and add more if necessary. Remember to choose the right oil for your compressor .
Change the compressor air filter
The air filter prevents the entry of impurities into the tank which could block the system entirely. Clean it regularly with a vacuum cleaner, and change it every year or so, for effective filtration.
Empty the water tank
When the air is compressed in the tank, condensation forms and settles at the bottom of the latter. To maintain optimum power and prevent rust formation, it is necessary to drain the compressor tank regularly. For daily use, it is recommended to perform this purge every 6 months and annually for regular use. For this, the compressor is equipped with a valve or purge tap, generally placed at the rear.
When buying an air compressor, you need to think about its long-term maintenance, especially if one or more parts break. Make sure your dealer guarantees the supply of spare parts for at least 5 to 10 years after purchase .
THE DIFFERENT ACCESSORIES FOR AIR COMPRESSORS
Compressor accessories kit
To get started with your compressor, we recommend that you purchase an accessory kit . Most often including a hose, an inflation handle and a blower, it is ideal for small maintenance work on your home and your car.
The stapler nailer
For larger jobs, you will need a stapler nail gun like this model from the manufacturer Rapid . Connected to your compressor via a pneumatic hose, it allows you to fix both nails and staples thanks to its versatile charger . In addition, you can direct the air exhaust to prevent dust rising.
The impact wrench
The impact wrench , also called wrench , lets apply and release bolts. The pneumatic version , used with an air compressor, makes it possible to attach or remove a car wheel effortlessly and in record time.
The ratchet wrench
Close to the impact wrench, the pneumatic ratchet wrench allows you to screw and unscrew nuts in any position effortlessly.
The chisel hammer
As the name suggests, the chisel hammer lets you chisel in any material , whether it’s leveling a surface or removing tough plaster from a wall. Its pneumatic version delivers much more power than electric models, and this over a much longer period.
The inflation handle
A very simple but essential accessory, the inflation handle plugs directly into your compressor and allows you to easily inflate all types of tires (car, bike, etc.) or structures (swimming pool, bouncy castle, etc.). Equipped with a separate pressure gauge, it allows you to precisely control the pressure.
The paint gun
Nothing beats an air compressor for painting large areas in record time. But for this you will need a paint gun . It is simply a handle equipped with a reservoir filled with the paint of your choice . You just need to pull the trigger and it will be sprayed on the target. It can be either gravity (the tank is above) or suction (the tank is below).
Compressed air hose reel
In order not to encumber yourself and risk an accident with pipes running everywhere under your feet, you can opt for a reel , equipped with two outlets: you connect the first to your compressor, and the second to your tool. You just need to pull lightly to unwind the hose, which will automatically rewind after use.
The compressed air hose
There are several types of compressed air hoses to choose from to use your pneumatic tools . The spiral polyurethane pipes are ideal for short occasional use. Their internal diameter should be similar to that of the compressor air outlet to optimize air flow.
For more intensive or even professional uses, you need a PVC pipe with exterior reinforcement . It adapts to larger compressors and withstands a much higher pressure, of the order of 20 bars.
REELS AND PNEUMATIC HOSES
Not all of your tools will likely have the correct threads to connect to your compressor, or the PVC pipe you purchased does not contain screws. You will then need to buy a fitting to connect everything. Some models even offer you two or three outputs, in order to connect several tools and thus save time.