Air compressors come in a wide variety of sizes depending on the primary function they perform. They can use a little force as ramming a nail into floorboards or as high as acting as a hammer. Most air compressors that we talk about here range from 1 CFM to over 60 CFM. So all you need to do is pick the right compressor for your project needs. You might ask what size air compressor do I need? They come in different sizes and you need to pick the proper size based on your application. Read on to know its basics along with detailed buying guide.
What is an Air Compressor?
An air compressor acts as a pump that takes fuel or chemical energy and converts it into compressed air. Using various techniques, an air compressor takes in air and stores it within a storage mechanism while applying pressure. The compressor automatically shuts off when this pressure is at the maximum limit. This compress continues being stored in the tank until used for some purpose. When all the air is released out of the tank, it undergoes depressurization. An air compressor should not be mistaken for an air pump.
Types of Air Compressors
Air compressors can be put into different categories depending upon the type of pressure levels that they function on.
- Low-pressure air compressors deliver the lowest air pressure out of all the variants. These usually function at around 10 bars of pressure per square inch.
- Medium pressure air compressors: They work in the mid-range for pressure. These deliver anywhere from 10.4 to 68.9 bars of pressure per square inch.
- High-pressure air compressors can provide over 69 bars of pressure per square inch.
Different Kinds of Compressors Depending on Chamber Specifications
Air compressors can also be divided into two main categories depending on how the storage chamber creates the air pressure.
- Positive Displacement Compressors: These work by taking in air that is pushed in from outside into the main chamber. This works by reducing the volume of the chamber, which in turn induces high pressure into the system.
- Roto Dynamic Compressors: These comprise a centrifugal system within the chamber that helps to compress the air inside. A spinning component is used to induce the pressure in the chamber.
Features of Air Compressors
Most of the air compressors used for smaller everyday applications tend to be fueled using gas or diesel. One can measure the power that their air compressor provides by comparing the values in either horsepower or cubic feet per minute. The air compressors that utilize them give out toxic fumes, which require an exhaust chamber. Most of these smaller air compressors function at about 120 and 240 Volts of electricity. Tank shapes come in a variety of arrays such as “twin tank,” “pancake,” “horizontal,” and “vertical.”
How to Maintain Air Compressors?
- One must go through the user manual to completely understand the air compressor working.
- Air compressors with age tend to loosen the fastest. It is sometimes necessary to tighten these to avoid losing air from the chamber.
- Make sure the intake valve is clear of any debris. This can change the airflow within the machine.
- The hoses can get bendy and folded inwards due to long use. It is necessary to keep changing out the hoses at regular intervals.
- Make sure that the filter is always clean. A dirty filter makes the air compressor struggle more when taking in the air. This, in turn, reduces the working life of the machine.
- If the compressor is being used in humid climates, water is getting collected in the vents. Draining this water ensures that the machine lasts for longer.
- The fuel tank is also prone to get clogged with use. If the compressor works on gas, this is a more frequently occurring problem due to suspended particles clogging up the valves. It is recommended to clean it at regular intervals of time.
- The safety system may sometimes stop working as well. This can prove an issue as the machine tends to get quite hot or cold. The manual gives a good idea of how to operate the machine.
- The compressor oil also needs to be changed. After quite a prolonged use, it is recommended that the oil be changed.
- The air compressor needs to be taken care of after frequent use. These generally get sprayed by oil during use, which can create a buildup in the compressor.
What is CFM?
CFM stands for cubic feet per minute. It is a measure of the rate at which air is coming out. It acts as an indicator for gauging air velocity. CFM is an important measure of understanding how much pressure you need for carrying out a particular task. An air compressor would require different ranges of CFM for a wide array of tasks. It is generally tabulated that a 1 Hp sized motor in an air compressor can generate about 3-4 units of CFM. An acceptable range of CFM for air compressors for everyday use would be between 0.1-5 units.
What Size Air Compressor Do I Need?
Check the common applications below and find out how big of an air compressor do you need
1. Nail Gun
For air pressured nail guns, the ideal pressure is targeted to be around 90 PSI. However, the minimum pressure should be at least 70 PSI. The more heavy-duty work your nail gun will partake, the greater the power used will be. For common nail guns that work on 16-gauge nails, a 4.5 CFM should suffice for the task at hand.
2. Air Guns
Air guns are designed to have smaller air chambers responsible for dealing with quite high ranges of air pressure. Most gun barrels are small enough to not worry about contracting the volume, but getting a high enough compression value is of main concern here. Regular ranges of air pressure that work for other tools will not cut it in this case. Most air guns are equipped with compressors that can provide up to 4500 PSI and more.
3. Air Hammer
An air hammer comprises a system of pistons that move when high enough air pressure is applied. These are generally attached to a tank or barrel using hoses. High-velocity air is pumped through this to get the hammer going. The amount of pressure being applied will again depend on the specifications and make of the tool. A commonly accepted range for air pressure is about 90-100 PSI.
4. Air Impact Wrench
Air wrenches carry out a wide range of heavy-duty tasks. Most basic models use about 90-100 PSI of air to function. The smallest available model in the market, which operates using a 3/8-inch diameter, needs 3 CFM to run. A slightly bigger model at ½-inch would require greater power at 4 CFM. ¾-inch air wrenches work the best using an air compressor that can provide 7 CFM or more power.
5. Air Ratchets
Most air ratchets function the best by using around 90-100 PSI worth of pressure. Air ratchets are designed in such a way that the volume of the barrel does not provide any issues. The smaller air ratchets sized at around ¼, and ½ inches can function off 3 CFM. The greater the size of the air ratchet being used, the more power that needs to be supplied.
6. Brad Nailers
These do not require much air pressure to work with. Most commercially available models can function using 1 CFM at 90 PSI. Some smaller models can be run at pressures as low as 60 PSI.
Tires have valves inbuilt into them and generally do not need high air compression values. Most of these can function effectively with 4 CFM air compressor. Cars that are utilized daily can use 32-35 PSI.
8. Plasma Cutter
Plasma cutters vary greatly depending on their size and applicability. A cutter at 6 CFM with 90 PSI worth of pressure should be able to undertake a variety of cutting tasks.
9. Sand Blasters
These operate under high-pressure conditions and need a lot of force to run. These would require at least 70 CFM at 90 PSI.
Tips to Keep in Mind While Choosing an Air Compressor
If you are confused about how to choose an air compressor, follow the below buying guide and tips to choose the best one that suits your requirement.
- Depending on the type and nature of work that you plan on carrying out, the power of the machine plays an important role. Horsepower is a good indicator of the machine’s capacity to function.
- Air compressors require an amount of electricity to function. Identifying the wiring and phase system in your surroundings will give you a good idea of where to start.
- The nature of work dictates the amount of air pressure required as well. Tasks that require a lot of impacts will require greater air pressure.
- The amount of free air within the compressor is also important to remember while purchasing a compressor. Calculating the total amount of air you need for your project at peak capacity can provide sufficient ideas.
- You can opt for either fixed-speed or variable-speed air compressors, depending on your requirements.
- Understanding the amount of time your compressor can run before getting heated up is important during use. These can also be taken into consideration while considering the safety requirements.
- Air quality can often dictate how long your compressor can run. The poorer the air quality, the quicker the machine will deteriorate as floating bodies in the air often clog up the compressor.
- Environmental factors like moisture content and humidity need to be considered when purchasing a compressor. The greater the humidity, the more water buildup you will see in your machine.
- Temperature determines the amount of time you can use an air compressor without having the risk of overheating and potentially acting as a safety hazard.
The next time you plan on purchasing tools, consider getting yourself an air compressor to up the ante. Air compressors can not only add the much-needed force but ensure that it is comfortable to use. While investing in an air compressor may seem expensive, these are a great investment and generally last for quite a long amount of time. Air compressors keep getting better and more portable and can now be used for a wide range of applications for household use. Think no further if purchasing an air compressor is up on your list of things to do.