Review on Waveshare Raspberry Pi PoE+ HAT Compatible With Raspberry Pi 3B+/4B 802 by Hesham Peltier

Installed on 3B+ without heatsink. As others have said, the hat profile will get in the way of a tall heatsink, and the 3b+ has a different die coating that dissipates heat better than previous versions. I also use mine in a C4labs case/chassis so my fan runs more frequently and after looking at some chip temperature logs I found that the fan kicks on at around 50C which is GOOD for the chip's operating temperature . I believe the speed will be throttled at 80C. Anything between 50C-75C is still good for the chipset. The next step is to determine if the fan can run continuously but at a lower speed to ensure motor longevity and overall board temperature. I can't imagine that constantly cycling the fan motor on and off will help control the fan in the long run. For me, the fan turns on every 2-3 minutes. I use my PI to power my LAN controller and Pi Hole. I am not overclocked. Hardware is included and POE works fine once you plug in the ethernet cable.