Purge Time (Contaminant Removal)

Purge Time (Contaminant Removal)

VE-15
ASPCSPAdvanced

Formula
ln(C₂/C₁) = −(Q'/V) × (t₂−t₁)
When to Use

Calculate time required to reduce contaminant concentration from C₁ to C₂ once generation has stopped.

Symbol Legend
SymbolMeaningUnitNote
C₁Initial contaminant concentrationppm
C₂Desired final concentrationppm
Q'Effective dilution ventilation ratecfm
VRoom volumeft³
t₂−t₁Time intervalminutes

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