If you have the original case for your Raspberry Pi 5 B and use the active cooler, the cooling will not be efficient unless you remove the top. This is because the hot air will be circulated inside the case.

To get cool air in, you need a plate and fan shroud that allows the fan to draw in air from the top. Since the active cooler is based on a different cooling principle (relying a lot on passive cooling with the big heatsink) the fan is smaller and pushes less air through compared to the fan that originally comes with the case. To help the fan cool more efficiently, I designed a clip-on exhaust port, allowing heat from the heatsink and hot air to be pushed out the back of the case.

It will of course cool much better with the top cover off too, as additional air can escape through the GPIO pin cut-out.

Designed with Shapr3D.