Horsepower required to Compress Air

Online air compressor horsepower calculator

The horsepower required to adiabatic compression of air can be calculated with the calculator below:

N - number of stages

V - volume flow of compressed air at atmospheric pressure (cfm, ft3/min)

k - adiabatic expansion coefficient

P2 - absolute final pressure (psi)

Theoretical horsepower required to compress one cubic foot of free air (atmospheric pressure) for single-staged, two-staged and three-staged compressors are indicated in the diagram below. In general - plus 15-20%  friction.

horsepower required to compress air

  • 1 cfm (ft3/min) = 1.7 m3/h = 0.47 l/s
  • 1 psi (lb/in2) = 6894.8 Pa (N/m2) =  6.895 10-2 bar
  • 1 hp = 745.7 W

The power required to adiabatic (process without transfer of heat) compression of air can be expressed as

HP = [144 N P1 V k / (33000 (k - 1))] [(P2 / P1)(k - 1)/N k - 1]                                (1)


HP = horsepower

N = number of compression stages

k = 1.41 = adiabatic expansion coefficient

P1 = absolute initial atmospheric pressure (psi) (14.7 psi at sea level)

P2 = absolute final pressure after compression (psi)

V = volume flow of compressed air at atmospheric pressure (cfm, ft3/min)

  • adiabatic compression (or expansion) takes place without transmission of heat

Related Topics

Related Documents

Tag Search

  • en: horsepower compressed air online calculator
  • es: caballos de fuerza calculadora en lĂ­nea de aire comprimido
  • de: PS Druckluft Online-Rechner

Search the Engineering ToolBox

- "the most efficient way to navigate!"

Engineering ToolBox - SketchUp Extension - Online 3D modeling!

3D Engineering ToolBox Extension to SketchUp - add parametric components to your SketchUp model

Add standard and customized parametric components - like flange beams, lumbers, piping, stairs and more - to your SketchUp model with the Engineering ToolBox - SketchUp Extension/Plugin - enabled for use with the amazing, fun and free SketchUp Make and SketchUp Pro . Add the Engineering ToolBox extension to your SketchUp from the Sketchup Extension Warehouse!

Translate the Engineering ToolBox!
About the Engineering ToolBox!