Place fans and GPUs on the case. Intake against exhaust with filter and radiator losses, worst-case pressure balance, case air heating. Lock the fans that must run and solve for the lowest speed of the rest. Save configurations as load cases and export them.
No fans placed.
Click a fan mount on the case.
Click a GPU bay on the case.
Each fan contributes CFMmax · derate · rpm/rpmmax. Catalog CFM is a
free-air figure. The derate depends on the mounting and on the fan: pressure-optimized blades lose about
20 % at a mesh filter, weak airflow blades up to 40 %.
| Mounting | Derate | Band | Pressure-opt. |
|---|---|---|---|
| Open grille | 0.88 | 0.80–0.95 | — |
| Dust filter | 0.70 | 0.60–0.80 | 0.78 |
| Floor + filter | 0.64 | 0.52–0.74 | 0.72 |
| Radiator 27 mm | 0.62 | 0.50–0.75 | 0.72 |
| Solid or glass front | 0.50 | 0.40–0.62 | 0.58 |
| …38 mm / 60 mm | ×0.90 / ×0.76 | thicker fins cost flow | |
| …push-pull pair | ×1.12 | series adds pressure, not parallel flow — one entry covers both fans | |
Worst case sums intake at the low end of each band and exhaust at the high end. Positive there means positive regardless of how the estimates fall.
Case air heating: ΔT = 3.1 · W / throughput (m³/h). Heat sources: open-cooler GPUs at full board power, blowers at about 15 %, radiators mounted as intake at the loop heat you enter, an air-cooled CPU at its package power, plus board, RAM and drives. Exhaust radiators and the PSU are not counted; their heat leaves directly.
Solve: locked fans keep their speed. Unlocked exhaust fans drop to their minimum rpm (off if none is given). Unlocked intake fans run at one common fraction of their maximum, the lowest at which the worst-case balance is still at or above the margin. Fans below their minimum rpm are held at it. This is the quietest arrangement under the n⁵ law when the fans are of similar size.
Sanity check: a paper strip at the rear grille pulled inward means negative pressure.
The export lists all components, then the current state and each saved configuration as a load case with fan rpm, balance and case heating. Saved in this browser.