Air compressor buying guide

The most important factor to consider when choosing an air compressor is what tools and tasks you will use it for. That will then determine the CFM (cubic feet per minute) requirement to power the tools (see more detail in the next section).

You’ll also need to consider how frequently and how long you’ll use it to determine what air storage tank capacity you need. For example, you’ll only need a small tank for occasional DIY use, but a large tank will be better for professional or prolonged use.

Other considerations include whether it needs to be portable, and therefore whether you need a corded or cordless model, and if you need a brushed or brushless motor or an oiled or oil-less model.

• Corded or cordless?
  Corded air compressors are plugged into the electricity to supply power to the motor, which means they must be used near a power socket. For this reason, corded air compressors are best suited for use in factories and workshops where portability isn’t required.
  On the other hand, cordless air compressors are powered by petrol or diesel. The absence of a cord means they can be used anywhere and are much easier to move around.  
• Brushed or brushless?
  Brushed air compressors have a motor that’s driven by small metal brushes. Whereas brushless air compressors have a motor with an electronic circuit board and sensor. The absence of brushes on a brushless motor means reduced friction and heat build-up and, therefore, less wear and tear, which gives them a long lifespan. Brushless motors are also more efficient to run than brushed motors.
• Oiled or oil-less?
  As explained in the section above, an oiled air compressor has moving parts that are lubricated by oil. In contrast, an oil-less air compressor’s components have a special self-lubricating coating. Choosing between the types can be decided by considering how much the air compressor will be used and whether non-contamination of the air is important. For example, if the air compressor will be used for long hours daily in a factory, an oiled model will be best. Whereas an oil-less model is better for infrequent or DIY use. And if the air compressor will be used for spray painting or in a clinical setting, an oil-less model will supply non-contaminated air. 
• Tank capacity
  Air compressors come in various tank sizes, measured in litres, ranging from 4L to 100L. Generally, the larger the tank, the longer you can run the air compressor at a consistent power. However, the tank size you need will also depend on the tool you plan to use it with. All tools require a minimum airflow, measured in cubic feet per minute (CFM). To determine what tank capacity you need for a tool, multiply the tool’s standard cubic feet per minute (SCFM) by 6.