Datasheet figures next to each other, and the airflow balance, pressure verdict and case air heating that the fans in each box compute to behind that case's own front. Calculated with the CaseFlow model, not measured.
| Antec NX420 | BitFenix Fang | |
|---|---|---|
| Form | Mid Tower | ATX mid tower |
| Volume | 42.6 L | 42.4 L |
| Dimensions | 416 × 221 × 463 mm | 421 × 210 × 480 mm |
| Front | mesh dust filter | mesh dust filter |
| Fan mounts | front 3 × 120/140, top 2 × 120/140, rear 1 × 120/140 | front 3 × 120/140, top 2 × 120/140, rear 1 × 120 |
| Radiator support | front 360 mm, top 240 mm, rear 120 mm | front 360 mm, top 280 mm, rear 120 mm |
| Dust filters | top, bottom | front |
| GPU length | 330 mm | 360 mm |
| Cooler height | 175 mm | 163 mm |
| Stock fans | 1 × fan (rear) | none |
| Stock airflow, max rpm | – | – |
| Stock pressure verdict | stock fans named but no datasheet - nothing computed | ships without fans |
| Case air at 290 W | – | – |
| Stock fan noise | – | – |
| All mounts, reference fans | 176 in / 198 out CFM 3 / 3 mounts | 176 in / 185 out CFM 3 / 3 mounts |
With a reference pressure-optimized fan on every mount the NX420 moves more air. The Fang ships without fans, so only the mount capacity row compares. The stock fans of the NX420 are named without figures behind them, so its stock columns stay empty. The pressure verdict describes the stock fan set, not the case: stronger or extra intake fans in the free mounts, or slower exhaust fans, turn a negative balance positive.
Neither ships with fans the model knows, so there is nothing to plot. Open them in CaseFlow and add fans.
Each stock fan contributes CFMmax · derate · rpm/rpmmax behind its wall's mounting class: filtered mesh
front and side mounts as dust filter, bottom as floor + filter, top and rear as open grille, solid and glass fronts as side-slit intake at
roughly half of a mesh front. Front, bottom and side blow in; top and rear blow out.
| Mounting | Airflow blades | Pressure-optimized |
|---|---|---|
| Open grille | 0.88 (0.80–0.95) | 0.88 (0.80–0.95) |
| Dust filter | 0.70 (0.60–0.80) | 0.78 (0.70–0.86) |
| Floor + filter | 0.64 (0.52–0.74) | 0.72 (0.62–0.80) |
| Solid or glass front | 0.50 (0.40–0.62) | 0.58 (0.48–0.68) |
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: ΔT = 3.1 · W / throughput (m³/h), with an open-cooler GPU putting its full board power into the case air plus board, RAM and drives. Capacity puts a reference pressure-optimized fan on every mount at max rpm — 120 mm 60 CFM, 140 mm 75 CFM — a generic good fan, not a product.
Mount counts, radiator support and clearances are datasheet figures. Nothing here is measured; the same model runs in CaseFlow.