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Heatsink with forced circulation for electronics.

Heatsink with integrated ventilation.

Knowing the thermal resistance in free air of an heatsink and the air velocity which flows the heatsink surface itself is possible to calculate the thermal resistance and the maximum dissipate power with forced air circulation.

Input dati
Maximum expected air temperature (ambient temperature).


Maximum working temperature of the heatsink.


Air velocity that flows the heatsink.


Help for the definition of the air flow.

Distance between the baffles or width of the surface for passage of air.

Distance between the baffles


Height of the baffle or height of the surface for passage of air.

Fin height


Number of slits for the air passage (n.1 in case of one only surface).

Quantity of slits


Some examples of air flows

Fan typeW x H (mm)m3/h
Axial40 x 409.7
60 x 6021
80 x 8050
92 x 9280
119 x 119130
127 x 127250
172 x 172305
Centrifugal15 x 519.6
33 x 9356
127 x 11780
115 x 159200
253 x 83115
329 x 83173
395 x 83200
Calculates and sets velocity.

Air flow


Waiting speed calculation.

Thermal resistance in free air of the heat sink

°C/W, K/W

This value can be obtained from the catalog of the producer or calculated with the available application in this section of the website.

Wait calculate
Thermal resistance of the heat sink
(forced ventilation)
Maximum power dissipable W

Important: give the thermal resistance of the heatsink in free air considering the only surfaces touched by the air circulation.

Real example of heatsink with forced ventilation. In the picture on the left you can see an example of a special heatsink normally functioning with natural air circulation, by necessity, a fan pressurize the internal of the case and a series of slit canalizing the air into the external baffle.
This solution allows the cooling of the inner components and the fins of power limiting accretion of dust and noisiness, the external fin is able to assolve its function without the fan for the 90% of the hours of functioning.
Only in summer or with sun exposition come into action the forced ventilation for keep the temperature into the project limits.

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Applications for thermal dissipation.

Heatsink in free air
Heatsinks on PCB
Heatsink with forced circulation
Dissipation for cabinets
Forced ventilation
for cabinets