Gas Vs. Electric Air Compressors

Air compressor can run off of electricity or gasoline.

Air compressors are handy machines used in auto body shops, industrial settings and home improvement projects. Their mechanical design works to convert energy produced by pressurized air into a kinetic form that can be used to power tools and other machines. When deciding on whether to use a gas- or electric-powered compressor, the type of job involved may point to which one will work best.

Identification

An air compressor is made up of a piston compressor, a crankshaft, a cylinder, a valve head and a connecting rod and piston. These parts work together to gather and compress air so the energy generated can be used as a power source for tools like sanders, grinders and lifts, according to Popular Mechanics. Most larger-sized compressors come with an air tank, which is designed to hold a certain quantity of air within certain pressure levels. Both gas- and electric-powered versions are capable of handling any number of tasks; however, certain circumstances may warrant using one over the other.

Function

While some air compressors may use a rotating impeller vane to generate air pressure, the most commonly used models have a piston/cylinder mechanism that does the compressing, according to Popular Mechanics. This method is called positive displacement and is based on the reciprocating action of the piston. As the piston moves up and down inside the cylinder, it creates varying degrees of pressure that work to suction air in, compress it and convert the resulting energy into a power source.

Electric Powered

If an electrical hookup is within reach, an electric-powered air compressor can be more convenient and less expensive than gas-powered versions, according to ToolBarn.com, a tools and repair resource site. These are the most commonly used compressors and generally cost less than gas types. Electric air compressors come in portable styles, as well as permanent-mount options. Most electric-powered versions come with an automatic "stop-start" switch that turns the compressor on when tank pressure levels are low, and turns it off when pressure levels are high. This switch also works to stop the compressor motor when no tools are in use.

Gas Powered

Gas powered air compressors can provide the same amount of pressure as electric-powered versions, so there's little difference in performance ability. When there's no electrical hookup available or the hookup is a great distance away, gas-powered compressors only require gasoline to run. One main difference between gas and electric versions is the automatic "stop-start" mechanism, as gas compressors have no way of turning themselves on and off, according to ToolBarn.com. Instead, a pilot unloader valve opens and closes to regulate the pressure level in the tank. This "constant-run" mechanism might work best for tools that require a constant flow of high pressure air, like sanders, grinders and sprayers.

Considerations

Air compressors can vary in their capacities to power one or more tools at the same time. Jobs requiring large amounts of pressurized work best with a multistage compressor capable of storing air at high pressures, according to ToolBarn.com. A single stage version is more suited for a home improvement-time job where 120 psi or less is needed. In terms of "stop-start" switches, if the compressor is shutting off and on more than 20 times an hour, a constant-running compressor may be needed. Constant-run versions are available in both gas- and electric-powered models.

References

• Popular Mechanics: How It Works -- Air Compressors
• ToolBarn.com: Air Compressor Buyer's Guide

Resources

• Help in Understanding and Using Air Compressed Air