Passive cooling Raspberry Pi 4 B

I've got a GeekWorm Aluminum Case.

Room Temp 23 C Ri Pi Temp 60 C Case External Temp 43 C

The quoted Pi throttle temp is 85 C

Pi workload = top reporting %Cpu(s): 55.0%, (viewing CCTV camera).

So I reckon it could take and extra 12C room temp.

I also have a little, 8cm, USB desk fan, I use for shifting heat from my compute cupboard on a hot day. If I'm worried, I can put the case in front of that. Today, within 5 minutes, fan on slow, it dropped the cpu temp 15 to 45C.

Sure, I have the passive Flirc full body aluminum case, it works wonderfully with the 4B, usually the temperature is below 60°C.

While I haven't had 35°C in my living room because I leave the sliding door into the garden open at night, so max. was ~27°C on the hottest days around here I wouldn't expect the 4B to overheat at 35°C, especially since it goes into throttling only at around 90°C, which I am quite sure will never be reached with this case.

-jw-

Am 15.08.2023 um 16:01:53 Uhr schrieb Jan Panteltje:

What happens if you stress the CPU?

In my case, stress-ng --cpu 8 took the cpu temp up to a max of 70C after

That was without putting the case in an external airflow. With the case in a strong external airflow, the cpu temp went down to 50C, after just

I assume you don't live at 35C without some kind of fan?

Marco,

I have a number of RPi 4 and not had a problem with them, but my maximum room temperature has been just 29°C. None are being stress with CPU load. Keep them out of the sun!

The best "housing" I've fund so far has been the Raspberry Pi 400 - the RPi built into a keyboard.

My experience with cooling electronics is that as long as air can get in and out, and the air isn't much above 40°C and your kit can handle internal temps of 100°C, you just need a ventilated housing. Or some big fins and a heatsink.

Fans enable you to get about 3-5 times the cooling that convection alone will net you. But take power and make noise.

Experience shows that it is extremely difficult to predict thermal performance theoretically, as how the equipment is installed plays a huge part. My advice is suck it and see. If your CPU cores are over 100°C, then its time to probably do something.

Am 16.08.2023 um 00:21:08 Uhr schrieb Pancho:

True, but I will ask that to have a buffer.

I will look for a metal housing that has a connection to the CPU, so the heat can spread to the entire housing.

I also have a Flirc, in a 2 m2 closet. it never reaches above 55 degrees summer or winter

This is what the Flirc case has, the entire case gets kind of lukewarm when the Pi has to do some work.

-jw-

That works, but beware, still put vents in it for hot air to leak out

That is not possible, since the case is full body aluminum, there is simply not a space for more than the RPi4, and, as the others who have the same or a similar case stated, it is not necessary.

-jw-