# Air Receiving Sizing

This calculation uses the air consumption rate of the instruments and determines the size of an air receiver based on the time required to meet a minimum pressure. The minimum pressure is generally the low pressure set point of a compressor. The initial pressure is the design pressure the receiver. The calculation is displayed symbolically as:

\(Size_{gallons} = \frac{Pressure_{Atmospheric}\times Time (Flow_{out} - Flow_{in})} {Pressure_{Initial} - Pressure_{Final}}\)

If the compressor only runs when the low level pressure is met, then the Flow_{in} would equal zero.

Tags: Equations for Air