Fan Engineering — Auxiliary Duct Sizing
Auxiliary Duct Sizing for mine and tunnel fan systems.
Duct diameter is the fourth-power lever (friction ∝ 1/D⁵ for constant Q): stepping from 800 to 1,000 mm cuts pressure to a third. The mine-wide habit of 'whatever duct is in the yard' costs more fan power than any other single decision in auxiliary ventilation.
Formula
Note: Mine ventilation is statutory and life-safety territory: airflow quantities, gas limits and re-entry times must be set by the registered ventilation engineer/manager under your jurisdiction's mining regulations — this calculator is a planning and training aid.
Auxiliary Duct Sizing for mine and tunnel fan systems. A free mine ventilation & air quality tool — no sign-up, no upload, instant results in your browser.
About Fan Engineering — Auxiliary Duct Sizing
Fan Engineering — Auxiliary Duct Sizing computes the governing relationship A = Q/v · D = 2√(A/π) live as you type. Duct diameter is the fourth-power lever (friction ∝ 1/D⁵ for constant Q): stepping from 800 to 1,000 mm cuts pressure to a third. The mine-wide habit of 'whatever duct is in the yard' costs more fan power than any other single decision in auxiliary ventilation. Defaults are pre-filled with realistic values for this exact scenario, and the worked example substitutes your numbers step by step so the math is never a black box.
How to use Fan Engineering — Auxiliary Duct Sizing
- 1Enter your values — Face quantity required, Duct velocity target (sensible defaults are pre-filled).
- 2Read the live results: Duct area needed, Round duct diameter.
- 3Check the "with your numbers" line to see A = Q/v · D = 2√(A/π) substituted step by step.
- 4Adjust inputs until the scenario matches yours, then copy or share the result.
Why use Fan Engineering — Auxiliary Duct Sizing?
- ✓Instant, free and private — every calculation runs client-side in your browser; nothing is uploaded
- ✓Built on the stated formula A = Q/v · D = 2√(A/π) with authoritative sources cited on the page (McPherson, M.J., Subsurface Ventilation and Environmental Engineering; Hartman et al., Mine Ventilation and Air Conditioning, 3rd ed.)
- ✓Duct diameter is the fourth-power lever (friction ∝ 1/D⁵ for constant Q): stepping from 800 to 1,000 mm cuts pressure to a third.
- ✓SI ⇄ Imperial toggle converts your inputs in place, so you can work in the units your drawings use
Frequently asked questions
What formula does the fan engineering — auxiliary duct sizing use?+
It evaluates A = Q/v · D = 2√(A/π), exactly as published. Sources: McPherson, M.J., Subsurface Ventilation and Environmental Engineering; Hartman et al., Mine Ventilation and Air Conditioning, 3rd ed.. The substituted worked example on the page lets you verify every step against the textbook.
How should I read the result — and how far can I trust it?+
Duct diameter is the fourth-power lever (friction ∝ 1/D⁵ for constant Q): stepping from 800 to 1,000 mm cuts pressure to a third. Mine ventilation is statutory and life-safety territory: airflow quantities, gas limits and re-entry times must be set by the registered ventilation engineer/manager under your jurisdiction's mining regulations — this calculator is a planning and training aid.
When is this calculator the right tool for the job?+
Auxiliary Duct Sizing for mine and tunnel fan systems. A free mine ventilation & air quality tool. The mine-wide habit of 'whatever duct is in the yard' costs more fan power than any other single decision in auxiliary ventilation. For neighbouring scenarios, the related tools below cover the same engine with different presets.
Does it support both metric and imperial units?+
Yes — the SI ⇄ Imperial toggle converts the values already in the fields, preserving the physical quantity, so you can flip mid-calculation without re-entering anything.
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