CaseCalc › Fan curves › Light Wings White 120mm PWM high-speed

be quiet! Light Wings White 120mm PWM high-speedcomputed

Airflow the Light Wings White 120mm PWM high-speed delivers behind a dust filter and on a radiator, and its noise, over the whole rpm range. Every curve on this page is calculated from the manufacturer's free-air rating with the CaseCalc derate model. Nothing is measured; the shaded bands show the spread to expect.

Datasheet figures and what arrives

Frame120 mmpressure-optimized blades
Free air, datasheet52.3 CFM89 m³/h
rpm range? – 2500
Noise at max, datasheet31.0 dB(A)
Static pressure, datasheet2.60 mmH₂O
Behind dust filter, max rpm41 CFM37–45 · computed
On 30 mm radiator, max rpm37 CFM30–43 · computed

Delivered airflow over rpm — computed

0 10 20 30 40 0 500 1000 1500 2000 2500 rpm open grille dust filter radiator 30 mm CFM delivered
rpmOpen grille CFMDust filter CFMRadiator 30 mm CFMShut-off mmH₂OdB(A)
75013.812.211.00.23<15
100018.416.314.60.42<15
125023.020.418.30.6516.4
150027.624.521.90.9420.1
175032.228.625.61.2723.3
200036.832.629.21.6626.2
225041.436.732.92.1128.7
250046.040.836.52.6031.0

Model values; the band is drawn in the charts above. Multiply CFM by 1.699 for m³/h. The minimum controllable rpm is not published for this fan; rows start at 30 %.

Static pressure against airflow — computed

0 0.5 1 1.5 2 0 10 20 30 40 53 CFM free delivery 100 % · 2500 rpm 75 % · 1875 rpm 50 % · 1250 rpm mmH₂O static

From the datasheet's 2.60 mmH₂O shut-off pressure and 52.3 CFM free delivery at 2500 rpm, scaled by the fan laws (flow ∝ rpm, pressure ∝ rpm²) on a parabolic curve. Real axial fans have a dip in the middle of the curve that this shape does not show; the end points are the datasheet's.

Noise over rpm — computed

below room noise 0 5 10 15 20 25 30 35 0 500 1000 1500 2000 2500 rpm dB(A)

From the datasheet's 31.0 dB(A) at 2500 rpm. At half speed (1250 rpm) the model gives 16.4 dB(A). Below about 15 dB(A) a fan is inaudible in a quiet room.

Use this fan in the calculators

Compared with other 120 mm fans

How these numbers are computed

Delivered airflow is CFMfree air · derate · rpm/rpmmax. The free-air figure is the manufacturer's. The derate is the share of it that survives the mounting; it does not depend on rpm because fan pressure and flow resistance both scale with rpm². Airflow is therefore linear in rpm.

MountingAirflow bladesPressure-optimized blades
Open grille0.88 (0.80–0.95)0.88 (0.80–0.95)
Dust filter0.70 (0.60–0.80)0.78 (0.70–0.86)
Radiator 30 mm0.60 (0.47–0.76)0.70 (0.58–0.83)
Solid or glass front (side slits)0.50 (0.40–0.62)0.58 (0.48–0.68)

The bands are the plausible spread of filter mesh density, radiator fin density and grille geometry. They are not statistical confidence intervals from measurements; they are the range the same fan lands in across typical cases.

Noise is the aerodynamic term Lmax + 50 · log₁₀(rpm/rpmmax) added on an energy basis to a constant 6 dB(A) motor and bearing floor, so the curve flattens at low rpm instead of running to zero. The band uses slopes of 40 and 60 dB per decade, ±1.5 dB on the rating and a 3 to 9 dB(A) floor. Manufacturer dB(A) figures are not measured the same way across brands; differences under 3 dB between brands mean nothing.

Static pressure, where the datasheet gives it, is drawn as a parabola from the shut-off pressure to free delivery and scaled by the fan laws: flow ∝ rpm, pressure ∝ rpm². It is a shape between two datasheet points, not a measured curve; real axial fans dip in the middle.

Nothing here is measured. The values are what the fan laws and typical case resistances predict from the datasheet. Use them to compare and to size; expect a real build to land inside the band, not on the line.