Gamecube, PS2, Xbox 360 (original model), and I'm sure other consoles used a design that creates negative pressure by having only exhaust fans. Gamecube is probably the most similar as it has a direct air flow from one side of the case to the other. 360 pulled air in along the side vents and out the back, PS2 had mostly a long front vent and blew air out the back, but the airflow was less directed. As a person who refurbs consoles for a living, Gamecubes are usually cleaner inside than most other systems. PS4's (original models), despite their recency, are some of the worst. The intake vents are bigger than the width between the heatsink fins, so stuff gets pulled in from the side vents and can't pass through the heatsink, clogging the airflow with a wall of fur. And if it's a smoker's household, or they use a lot of aerosol air fresheners, that fur wall becomes a thick paper mache like blockage.This would be a bad idea (IMO) unless the intake vents aren't on the bottom. With the fan on top, that would create negative air pressure which would draw in air from every opening (like the optical drive). An intake fan at the bottom ensures all the air going in is from that area creating positive pressure inside. I suppose the biggest advantage of the latter would be if MS bother to put in any sort of dust filter as it would virtually eliminate most dust from getting into the enclosure, whereas with the former (fan on top) it would be almost impossible to prevent dust from getting in.
Regards,
SB
As long as it's a straight line from intake to exhaust, and the intake is filtered to be at least less granular than the heatsink or exhaust, it will be fine.