Does a Case fan and heatsink cool down a Raspberry PI?

With a heatsink, case fan and open case:

With a load averages of:

load average: 0.26, 0.12, 0.20

Load average is the average cpu load over 1 minute, 5 minute and 15 minutes

The temperature was:

vcgencmd measure_temp
temp=33.6'C

and

cat /sys/class/thermal/thermal_zone0/temp
34076 # 34.07'C

With a heatsink and open case (No case fan):

With a load averages of:

load average: 0.01, 0.10, 0.14

The temperature was:

vcgencmd measure_temp
temp=58.9'C

and

cat /sys/class/thermal/thermal_zone0/temp
59400 # 59.4'C

Conclusion

Case fan

Yes, a case fan does cool down a Raspberry pi significantly. In the case under test the case fan decreased the temperature by around 24’C, a 40% decrease.

Images of the set up:

It is an important performance consideration.

Once it gets 80°C, the CPU starts to throttle.[1] It’s the same case with the GPU once the temperature rises to 85°C. Thermal throttling significantly affects the Pi’s performance; dropping the CPU’s clock speed to as low as 750MHz from 1.5GHz slows down the processing time.

There is another verdict that states the Raspberry PI needs a fan.

With a heatsink, case fan and open case:

With a heatsink and open case (No case fan):

Conclusion

Case fan

Source