Important Factors to Consider When Choosing an Air Compressor

An air compressor is a straightforward machine. It consists of a motor that

compresses air into a storage tank. The air can be released at a chosen

pressure when required to power a pneumatic tool. There are 10 main

things to consider when choosing one of these machines.

DIY users

Domestic users need small hand held compressors to inflate tyres, toys and

power DIY tools.

Builders and contractors

Building contractors need a tough compressor that can be hand held,

wheeled or connected to a van or other vehicle to power tools ranging from

nail guns to heavy pneumatic drills.

Commercial users

Commercial users need high performance air compressors to power

manufacturing processes and equipment. These can be conveyor belts or

offshore drilling equipment.

Power source

Domestic compressors usually run on standard household voltage from a

mains power socket. Building contractors and commercial users can use gas

or diesel powered compressors outdoors or electrical powered compressors

indoors. Large commercial users usually have their own generators for

powering compressors.

Performance

The compressor must match the tools it will power. This is the amount of air

it will deliver in standard cubic feet per minute (SCFM). DIY tools usually

needs up to 5 SCFM while larger tools need 10 SCFM and above. A standard

rule is to choose a compressor that delivers 1.5 times the maximum air

requirement of the tool.

Tank size

Air powered hand held tools need a tank size between 2 and 6 gallons. You

also need to decide between vertical tanks that take up less space than

horizontal tanks but usually are at the low performance end. Horizontal

tanks are best suited for high performance needs.

Pump

A single stage compressor has one or more cylinders each producing

compressed air at the same output pressures. These are suitable for tools

used over a short period. Two stage air compressors have two or more

cylinders. The first cylinder feeds compressed air to the second cylinder for

further compression and so on to the next cylinder. The air is stored in tanks

of the same size. This pump type suits high demand and high performance

work and to power tools that run continuously.

Lubrication

An oil lubricated compressor is heavier and larger than an oil free version. It

also requires an oil monitoring device to ensure oil levels do not fall to low.

Oil free versions are good for portable compressors.

Air hose length

Extension leads should be avoided on air compressors. If the compressor

has to stand at a distance from the tool, ensure that the air hose is long

enough for the job.

Control system

Start / stop control systems suit DIY purposes and those that do not need

continuous air flow over a long period. Use a constant speed control if the

compressor stops and starts over six times during one hour. A dual control

system allows the operator to choose between start/stop and constant

speed.