To calculate vacuum pump capacity using an Excel spreadsheet, you must account for system volume, target pressure, and external factors like leakage and pipe conductance
Several technical platforms provide pre-configured Excel tools for these calculations:
This calculates how long it takes to pull a vacuum on a specific volume. vacuum pump capacity calculation xls
cap S equals the fraction with numerator cap V and denominator t end-fraction cross l n open paren the fraction with numerator cap P sub 1 and denominator cap P sub 2 end-fraction close paren : Required pumping speed (typically in cap C cap F cap M : Total system volume (chamber + piping). : Desired evacuation time. cap P sub 1 : Initial pressure (usually atmospheric, cap P sub 2 : Final target pressure. 1. Structure Your Excel Sheet
Lucas added a multiplier. "If we assume peak vapor load during the first few minutes doubles the gas volume, the pump might stall." To calculate vacuum pump capacity using an Excel
For a rotary vane pump: 70 / 0.95 = 73.7 m³/h → choose 80 m³/h model.
Where C is the conductance of the piping system, which can be estimated using Excel calculators for conductance. Steps to Build Your Vacuum XLS Input Section: Create cells for Initial Pressure ( P1cap P sub 1 ), Final Pressure ( P2cap P sub 2 ), Volume ( ), and Time ( : Desired evacuation time
Given chosen pump speed S_pump and S_eff:
[
t_actual = \fracVS_eff \times \ln\left(\fracP_start - Q_total/S_effP_target - Q_total/S_eff\right)
]
Understanding Vacuum Pump Capacity