CaseCalc › AIODatabase › Silent Loop 3 420mm

be quiet! Silent Loop 3 420mmcomputed

Coolant temperature this AIO settles at over fan rpm, its dissipation in W/K, and the noise of its 3 stock fans. Calculated from the radiator size and thickness and the stock fan's datasheet with the RadiatorTemp model. Not measured; the bands show the spread.

Datasheet figures and what they compute to

Radiator420 mm52 mm core
Stock fans3 × Silent Wings 4 140 mm PWM51.3 CFM · ?–1100 rpm · 13.6 dB(A)
Pump3500 rpm max
Dissipation at max rpm24.2 W/K20.5–27.8 · computed
Coolant, 250 W, 30 °C intake40.3 °Cat max fan rpm · computed
45 °C at 250 Wneeds 590 rpm (54 %), <15 dB(A)

Coolant above intake air over fan rpm — computed

0 5 10 15 20 25 30 35 0 250 500 750 1100 fan rpm 350 W 250 W 150 W K coolant above intake air
fan rpmCFM through coreW/KCoolant above intake, 250 WCoolant at 30 °C intakedB(A), 3 fans
3303311.7+21.351.3 °C<15
4404513.9+17.947.9 °C<15
5505615.9+15.745.7 °C<15
6606717.8+14.144.1 °C<15
7707819.5+12.842.8 °C<15
8808921.1+11.841.8 °C15.4
99010022.7+11.041.0 °C17.2
110011124.2+10.340.3 °C19.1

Model values; the ±15 % band is drawn in the charts above. Change heat load, intake and target in the database view.

Dissipation over fan rpm

0 5 10 15 20 25 0 250 500 750 1100 fan rpm W/K W/K dissipation

Noise, 3 fans

below room noise 0 5 10 15 20 25 0 250 500 750 1100 fan rpm 3 × dB(A)

Use it

Other AIOs

How these numbers are computed

A radiator moves heat in proportion to the difference between coolant and incoming air: Q = q · (Tcoolant − Tair). q depends on the air actually passing through the core. Airflow per fan is CFMmax · derate · rpm/rpmmax with the radiator derate (0.62, or 0.72 for pressure-optimized blades) times the core-thickness factor. Per 120 mm segment at 27 mm: q = 8.5 W/K · (airflow / 45 CFM)0.6; heat transfer over fins scales with roughly the 0.6 power of velocity.

CoreAirflow factorFin area factor
27 mm1.001.00
30 mm0.971.09
38 mm0.901.15
45 mm0.841.22

Thick cores gain fin area but lose airflow; at low rpm the net is close to zero. With fans off, natural convection is taken as 1 W/K per segment. The band is ±15 % on q: fin density, coolant flow and preheated case air. Pump speed matters little above roughly 1 l/min. Noise is the stock fan's curve plus 10 · log₁₀(fan count).

Air entering the radiator is case air, usually 5 to 10 K above room. Die temperatures sit above the coolant by the block and TIM delta, typically 25 to 45 K under load. Nothing here is measured; the same model runs in RadiatorTemp.