Air Compressor Basics: What You Need to Know

Air compressors power pneumatic tools, inflate tyres, and run spray equipment. Choosing the right one means understanding a few key specifications.

Key Specifications

CFM (Cubic Feet per Minute)

Airflow rate - how much air the compressor delivers. This is the crucial specification for tool operation. Each tool requires a certain CFM to work properly.

PSI (Pounds per Square Inch)

Pressure the compressor generates. Most tools need 90 PSI. Most compressors exceed this, so PSI is rarely the limiting factor.

Tank Size (Litres/Gallons)

Air storage capacity. Larger tanks mean tools can run longer before the compressor needs to cycle. Smaller tanks are more portable.

HP (Horsepower)

Motor power. Generally correlates with CFM output but not directly. CFM is more important than HP when choosing.

Matching Compressor to Tools

Check Tool Requirements

Each air tool lists CFM requirement (usually at 90 PSI). Your compressor needs to exceed this - ideally by 25-50% for comfortable operation.

Common Tool CFM Requirements

• Tyre inflator: 1-2 CFM
• Brad nailer: 0.5-1 CFM
• Framing nailer: 2-3 CFM
• Impact wrench: 4-6 CFM
• Die grinder: 4-6 CFM
• Spray gun: 8-12 CFM
• Sander: 8-12 CFM

Continuous vs Intermittent Use

Nailers use air in short bursts - a smaller compressor with recovery time works. Sanders and spray guns use air continuously - need compressor CFM that matches or exceeds tool requirement.

Types of Compressor

Pancake/Portable

Small tank (6-12L), light, easy to carry. Good for nailers and tyre inflation. Limited CFM.

Hotdog/Sausage

Horizontal tank, slightly larger. More CFM than pancake. Still relatively portable.

Twin Stack

Two tanks for more capacity. Intermediate size and capability.

Upright

Vertical tank, workshop-based. Larger capacity, higher CFM. Less portable.

Stationary

Large horizontal tank, high CFM output. Professional workshops. 150L+ tanks.

Oil vs Oil-Free

Oil-Free

Lower maintenance, lighter, no risk of oil in air line. Typically louder, shorter lifespan, lower CFM ratings. Fine for occasional use and nailers.

Oil-Lubricated

Quieter, longer-lasting, higher CFM capability. Need oil changes and maintenance. Better for regular heavy use.

Choosing the Right Size

For Nailers Only

6-12L portable compressor is sufficient. Pancake or similar. 2-3 CFM.

For General Workshop

50L tank, 8-10 CFM. Handles most tools except high-demand continuous use.

For Professional Spray/Sanding

100L+ tank, 12+ CFM. Consider oil-lubricated for durability.

Additional Features

• Regulator - Adjusts output pressure. Essential.
• Water trap/filter - Removes moisture from air. Important for spray guns.
• Multiple outlets - Run more than one tool line.
• Wheels and handle - For portable units.
• Auto shutoff - Stops motor when tank full.

Maintenance

• Drain tank after each use (moisture collects)
• Check/change oil (oil-lubricated models)
• Clean/replace air filters
• Check hoses and connections
• Safety valve function check

Browse workshop equipment in our workshop collection.