Work out air change for contaminant control instantly with clear inputs, formula shown and shareable results.
Dilution ventilation airflow is the contaminant generation rate divided by the acceptable concentration, multiplied by a mixing factor because real rooms never mix perfectly. K ranges from about 1.5 for good mixing with the source far from workers, to 10 for poor mixing with the source in the breathing zone.
Dilution airflow
Q = G x K / C
Preliminary estimate only. Ventilation for contaminant control must be designed by a qualified engineer or occupational hygienist to a recognised industrial ventilation standard.
Q = G x K / C. Dilution ventilation airflow is the contaminant generation rate divided by the acceptable concentration, multiplied by a mixing factor because real rooms never mix perfectly.
For highly toxic materials, high generation rates, or where the source is close to the worker. In those cases local exhaust at the source is the only reliable control.
This calculator takes 4 inputs: Contaminant generation rate, Target airborne concentration, Mixing factor K, Room volume. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.