Fan Engineering — Fans in Parallel
Fans in Parallel for mine and tunnel fan systems.
Two fans never deliver twice the air: the extra quantity drives the square-law system curve up and steals part of the gain — on steep circuits a second fan can add only 25–40%. Parallel pairs also risk one fan stalling while its twin hogs the duty; matched curves and surge margin checks are mandatory.
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.
Fans in Parallel 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 — Fans in Parallel
Fan Engineering — Fans in Parallel computes the governing relationship Q_combined ≈ n·Q₁ × (1 − system penalty) — exact answer needs the curve intersection live as you type. Two fans never deliver twice the air: the extra quantity drives the square-law system curve up and steals part of the gain — on steep circuits a second fan can add only 25–40%. Parallel pairs also risk one fan stalling while its twin hogs the duty; matched curves and surge margin checks are mandatory. 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 — Fans in Parallel
- 1Enter your values — Single-fan quantity at p, Fans in parallel, System-curve penalty (sensible defaults are pre-filled).
- 2Read the live results: Combined quantity (est.).
- 3Check the "with your numbers" line to see Q_combined ≈ n·Q₁ × (1 − system penalty) — exact answer needs the curve intersection substituted step by step.
- 4Adjust inputs until the scenario matches yours, then copy or share the result.
Why use Fan Engineering — Fans in Parallel?
- ✓Instant, free and private — every calculation runs client-side in your browser; nothing is uploaded
- ✓Built on the stated formula Q_combined ≈ n·Q₁ × (1 − system penalty) — exact answer needs the curve intersection 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.)
- ✓Two fans never deliver twice the air: the extra quantity drives the square-law system curve up and steals part of the gain — on steep circuits a second fan can add only 25–40%.
- ✓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 — fans in parallel use?+
It evaluates Q_combined ≈ n·Q₁ × (1 − system penalty) — exact answer needs the curve intersection, 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?+
Two fans never deliver twice the air: the extra quantity drives the square-law system curve up and steals part of the gain — on steep circuits a second fan can add only 25–40%. 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?+
Fans in Parallel for mine and tunnel fan systems. A free mine ventilation & air quality tool. Parallel pairs also risk one fan stalling while its twin hogs the duty; matched curves and surge margin checks are mandatory. 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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