ToolnozaFormula and method
Measured Q = area × mean velocity. Personnel Q = people × factor. Diesel Q = operating kW × factor. Upstream Q = selected requirement / (1 − leakage fraction).
Worked example
12 m² × 2 m/s = 24 m³/s = 1,440 m³/min. A selected requirement of 20 m³/s with 10% leakage needs 22.22 m³/s upstream.
Limits and assumptions
Preliminary comparison, not a ventilation design or compliance check. Illustrative coefficients are not legal minima. Gas, dust, DPM, heat, blasting fumes, network losses and fan pressure are excluded. Validate with measurements, equipment approvals and a qualified ventilation engineer.
Frequently asked questions
How is the result calculated?
Measured Q = area × mean velocity. Personnel Q = people × factor. Diesel Q = operating kW × factor. Upstream Q = selected requirement / (1 − leakage fraction).
What should I check before using it?
Preliminary comparison, not a ventilation design or compliance check. Illustrative coefficients are not legal minima. Gas, dust, DPM, heat, blasting fumes, network losses and fan pressure are excluded. Validate with measurements, equipment approvals and a qualified ventilation engineer.
Sources
NIOSH — Air Quantity Estimator
The source describes a separate DPM estimator. This tool uses only the displayed formulas and does not reproduce the NIOSH model.