CPU Cooler fan direction
CPU Cooler fan direction
Two fans are available for your CPU cooler, with one notably more powerful. The stronger fan should blow air away from the heatsink toward its rear, not toward it.
The CPU cooler must always direct air towards the heat sink for best performance. The same applies to GPU coolers. Only fans that should expel air are those on the case and PSU, while watercoolers require airflow toward the radiator. Hope this clarifies.