When you purchase an air compressor, you must understand the difference between horsepower and cubic feet per minute (CFM). Although horsepower is a critical specification of the air compressor, it only determine the strength of the motor. The horsepower of an air compressor will determine how quickly the motor can pump air back into the air compressor’s tank after it has been used.
However, CFM will tell you how many cubic feet of air can be released from an air compressor every minute. CFM is the measurement of the volume of air that your pneumatic tools require to function. If the air compressor that you purchase does not have an appropriate CFM compared to the requirement of the tool, the tool will not function correct.
How to Choose an Air Compressor
Another critical factor to consider when purchasing an air compressor is the relationship between pressure and the volume of air that can be released from an air compressor. These two variable are represented as PSI and CFM, respectively. As the PSI of an air compressor increases, the CFM output of the air compressor will decrease.
This is because the air compressor will have to squeeze the air into a smaller area of the air compressor tank. Therefore, the CFM rating of your air compressor will have to match the PSI and CFM requirements of your tool. For example, if your tool requires 90 PSI to function correctly, then the air compressor will also have to output the necessary CFM at 90 PSI.
Using the air compressor for tasks at a different PSI may damage the motor of the air compressor over time. Different tools require different amount of air volume. As such, it is critical that you purchase an air compressor that will match these requirements.
Light tools, such as air ratchets, will require a smaller CFM of air then heavy-duty tools like HVLP spray guns. Therefore, there is a difference in the amount of CFM that a small tool will require as opposed to a large tool. Using a tool that requires a high CFM with an air compressor that cannot supply that much CFM will cause the tool to not function correct.
The type of air compressor that you purchase will also depend on the type of environment in which you will be using your air compressor. For example, pancake air compressors are small and portable. They are most appropriate for small tasks in a garage.
Twin stack and rotary screw air compressors are much larger and more powerful than pancake air compressors. These tools are appropriate for use in industrial shops where air is required in large volumes. In order to determine the amount of air compressor that you need for your workshop, you can make a calculation of the CFM requirements of your tools.
You can find the CFM requirements for each of your tools in the tool manuals. Add 20% to the total CFM requirement of your tools to allow for the reduction of air volume caused by the air hoses and air filters. Once you have calculated the total CFM that you require, purchase an air compressor that can supply that amount of air at the required PSI for your tools.
Furthermore, the size of the air tank for the air compressor is important. A larger air compressor tank will allow the air compressor to work for longer periods without the motor having to turn on again to refill the tank. Additionally, a larger air tank will reduce the amount of time the motor of the air compressor has to turn on and off; this will prevent the motor from overheating.
In order to avoid common mistakes with your air compressor, follow a few rules. One of them is to not use the horsepower of the air compressor to determine whether the air volume for your tool is sufficient. Another rule is to avoid using thin air hoses for your tools, as this will reduce the amount of CFM that is supplied to the tool.
Additionally, you should drain the moisture from the air compressor tank every day. Without draining the tank, the moisture will lead to the formation of rust inside the air compressor tank. Another rule is to avoid using very long air hoses for your air tools.
Using very long air hoses will cause the PSI of the air to drop along the length of the air hose. Furthermore, make sure that you use the correct voltage for your air compressor. Using a very long extension cord for your air compressor will reduce the voltage of the air compressor and make it less efficient.
Another important factor is the duty cycle for the air compressor. The duty cycle will determine how much time your air compressor will have to work before it need to rest. Most air compressors will have a duty cycle of 50%, although professional air compressors can have a 100% duty cycle.
This means that the air compressor will not have to rest during its point of operation; it will remain in operation. Select an air compressor with the appropriate duty cycle and air tank size for your needs in order to ensure that your air compressor will remain in good working order.
