Portable air compressors are the work-horse of building and construction sites. They supply compressed air, and lots of it, to power all kinds of heavy tools.Portable air compressors come in all kinds and sizes..Portable compressors are driven by a big diesel engine. The size of the engine and the compressor depends on the air flow that is required and the air pressure. Portable air compressors can usually deliver from 7 to 12 bars.The amount of air they can product per minute (the air flow) vary between types. What size of compressor you need depends on the air-tools you use. Do they require a lot of air, do they require high pressure? Most air tools in construction and general use require around 7 bar, but the air flow varies greatly. A portable air compressor is used to supply compressed air on construction sites, road works, or whenever people need compressed air where a stationary compressor is not suitable.They are also used as (emergency) backup compressors for factories, for example when their stationary compressor needs maintenance or stopped working. They are powered by diesel engines, so they don’t need electricity.