Thermal Resistance Tool for Bonded Fins

Aavid Thermalloy offers 42 different base profiles to which fins with heights from 25mm to 140mm (1.0 inch to 5.5 inches) can be attached. Performance datasheets can be generated for any combination of base profile, fin height, and length.

Predicting Thermal Performance

Use the following steps to determine thermal resistance (°C/W) for various bonded fin lengths at different air velocities.

Step 1
Select a base profile, length and an air velocity.

Step 2
Enter the values for each of the parameters listed and press the Calculate button.
Clicking Calculate with no inputs will load the example below.

Step 3
Read the calculated thermal resistance* in °C/W.

Parameter Units
Length inch mm
Base Width inch mm
Fin Height inch mm
Air Velocity LFM m/s
# of Fins    
Thermal Resistance °C/W

*Actual thermal performance will vary with the amount and position of the heat input(s). Values determined by this calculation can be used for comparisons between various Aavid Thermalloy bonded fin heat sinks. Thermal resistance = 0.295 °C/W (approximately*)

Example To calculate the thermal resistance of a 5.0" long by 2.40" wide bonded fin base #66825 with 16 fins at 2.0" high with air velocity of 500 LFM, enter the values in the text boxes and click the calculate button.

Related Factors Fan manufacturers rate their fans by volume of output. In order to use this tool correctly, volume must be converted to velocity by using Airflow Volume to Velocity Conversion Chart. Remember to derate for static pressure head.