For Raspberry Pi4 continuous selfhosted server operations: with and without case fan. This graph show a 20°C decrease, with a slow rpm fan.
The metal case has thermal stickers to reach for main components on both sides, and the fan is what I have in scrap parts, totally not for that case but pushes a lot of air with low noise compared to screaming mini cpu fans.
I’ve kept a raspberry pi 4b that’s given a mild OC to 1900Mhz in my boiler cupboard for a year and all its needed to keep it below 50 is: