Though the amount of air produced by the compressor is the most important factor, the air tank also plays a role in the proper operation of air tools. Small air tanks are better for portability, but larger tanks tend to be more durable over time.
Air Tank Size
Larger tanks will operate tools longer without needing the compressor to run. For frequent use of tools that require a lot of air, such as spray guns, wrenches, and grinders, a small tank will require more cycling from the compressor to keep the tank filled.
This increases wear on the compressor.
Buyers should consider where the air compressor will be used. Those using the air compressor in the garage can have a large tank with little problem, while roofers and others who need a portable tank will do best with a smaller one.
The cost of compressors increases quickly as the size of the tank increases. However with heavy use, smaller tanks and smaller-output compressors can be expected to have a short life.
The initial purchase cost of a compressor with a larger tank may be offset by a longer usable life.