Which way does fan blow air PC? Look for the arrow
Some case fans (but not all) have an arrow showing the direction of airflow. Some fans have a small arrow on the casing that indicate the direction of airflow. Whichever way the arrow points, that’s the side that air will blow from.
Which way are PC fans supposed to face? When mounting case fans, air flows across the open side towards the side with the protective grille, like so: So the open side of the fan should face outside the case for intake fans on the front or the bottom, and it should face inside the case for fans on the rear or top.
Should top PC fans be intake or exhaust? If your case has vents at the top, they should be placed as exhaust fans because hot air will rise. Side-mounted fans should be used for intake, though they often don’t have air filters.
Should CPU cooler intake or exhaust? Intake is better for the thing that is being cooled by the AIO. Not for the system. CPU performance doesn’t degrade if it’s 2-3C higher (intake vs exhaust), as long as it’s below the throttling range.