About the Differences in Air Compressors

Air compressors are very useful in different types of applications. Different types of projects may require a different type of air compressor each. Smaller tools that require smaller amount of air pressure may only need smaller types of air compressors. Some applications may need to use air compressors that run continuously and some that do not. It is important to know the differences in each type of air compressor in order to make the right choice of what to use for each specific project.

Function

Some of the differences in air compressors show in the different ways people use them. There are air compressors for different kinds of projects and needs. There are compressors used for pumping air into tires and inflate balloons. In a hospital setting, air compressors help provide oxygen to patients. Scuba divers also benefit from using a different kind of compressor to supply their oxygen under water. An air conditioner makes use of an air conditioning compressor as a source of energy to help produce cold air. A lot of home improvement projects make use of air compressors, such as powering pneumatic nail guns, staplers, grinders, power washers and sprayers used to apply paint or wall textures.

Features

Some features differ among different air compressors. They vary in their motors, pressure settings, amp draws, cylinders and vacuum pumps. The motor or engine powers the process of air production. When combined with the compressor pump, a motor produces the air needed. They differ in HP (horsepower), ranging from 1/2HP to 4HP. Different compressors also vary in the types of voltage used. Most compressors run on 110-volt circuits; however, some have dual-voltage option, which lets the users switch the voltage from the standard 110-volt to 220-volt and vice-versa. This is advantageous for those who travel to different job sites that may have differences in voltage units available for use. Some jobs require more air which a 220-volt motor can help produce; therefore, if there are dual-voltage sites, the operator can switch to the higher voltage to perform this function much better. Some stationary compressors have 208v, 230v or 460v that can be hard-wired into the power supply. Air compressors differ in the PSI (pounds per square inch) and CFM (cubic feet per minute). Some tools, such as pneumatic nail guns and staplers, can consume less air than other tools, such as grinders and sprayers. The smaller tools require less CFM consumption along with the recommended PSI compared to bigger tools.

Types

The most common types of compressors used today are the reciprocating or piston compressors, rotary screw compressors, rotary sliding vane compressors and centrifugal compressors. The reciprocating or piston compressor provides back and forth movement of a piston located inside the compression chamber. During operation, a reciprocating air compressor compresses a fixed amount of free air using a specific amount of pressure. A rotary screw compressor compresses air using two rotating inter-meshed rotors while the rotary sliding vane compressor compresses air between the casing and the rotating rotor by making use of its movable rotor blade. The centrifugal compressor uses an impeller mounted on a shaft. When the rotation of the impeller increases, it produces a faster moving air at a high pressure. The diffuser found around the impeller then converts the kinetic air energy at a high-pressure level into a potential energy.

Size

The sizes of air compressors also differ. A larger tank can hold a larger amount of air. It also means that with a bigger tank of compressed air, the consumption takes much longer. This would also mean that it would take longer to refill a larger tank once the compressed air fully depletes. For smaller tools that require less air compression, one can choose air compressors with smaller tanks. Some of the smaller models are portable, while others need a forklift or wheeled cart to move to different locations.

Considerations

Before tackling a project, you must find out your tool's air requirements. Find out if you would need a large amount of air or only a small amount of air. Choose between a stop-start and a constant-run motor type of air compressors. A stop-start uses a pressure switch that automatically turns on and off the compressor unit. This type of compressor build up the air pressure at a predetermined level measured in PSI. After reaching the desired pressure level, the machine turns off automatically. The machine turns on automatically again once the pressure lowers. A constant-run type of air compressor means that the motor is running continuously to turn the pump. A pilot unloader valve opens up automatically to allow it to run even when the tank reaches a high-pressure level. The constant-run is preferable in bigger projects that need uninterrupted constant airflow, such as those using sprayers and grinders.

Resources

• About Air Compressors
• Types of Air Compressors