Solved

whats best wat to have a fan blowing in the bottom of ur case

anyone know this as zalman recomend it blowing out yet others say it blowing in so confused lol
2 answers Last reply Best Answer
More about whats wat fan blowing bottom case
  1. Best answer
    Generally, you intake from the bottom/front and vent from the top/rear, so the answer would be have the fan blowing "in".

    The idea is not to fight convection; hot air wants to rise, so don't fight it and try and push hot air down out of your case. Instead, pull cold air up, and sent it up and out once its been heated.

    The issue is, of course, the bottom of the case is more prone to dust. A good case will have a good dust filter on the intake at the bottom - make sure you keep it clean (and be happy any accumulated dust on the filter is ON THE FILTER vs in your computer).
  2. Enthusiast Builder said:
    Generally, you intake from the bottom/front and vent from the top/rear, so the answer would be have the fan blowing "in".

    The idea is not to fight convection; hot air wants to rise, so don't fight it and try and push hot air down out of your case. Instead, pull cold air up, and sent it up and out once its been heated.

    The issue is, of course, the bottom of the case is more prone to dust. A good case will have a good dust filter on the intake at the bottom - make sure you keep it clean (and be happy any accumulated dust on the filter is ON THE FILTER vs in your computer).



    Convection forces are not in play in this environment. Compared to the forces applied by the fans, and for that matter the emission of heat by components, convection is treated as "0". "Heat rising" in a computer case is a myth. (I mean, technically, yeah it rises, but the actual values are so small they can be entirely ignored)

    The distances involved aren't big enough, and the heat differentials inside the case aren't big enough, and are mixed by forces much larger, to involve convection forces in the equation. The air is essentially uniform inside the case.

    There are three things which matter in terms of answering OP's question.

    1) Best source of cool air

    2) Smoothest airflow within and through the case.

    3) Balance of intake vs. exhaust

    Regarding #1, its going to depend on the outside environment that the PC is in, but most people will have the best source of cool air being near the front and top of the PC. (Think about the airflow in your room, AC ducts, etc) For sure, intake on the bottom is going to be warmer air in any case with a bottom mounted PSU, so that would not be a good idea.

    Regarding #2, without getting into a aerodynamic discussion that I am not equipped to discuss, its mostly common sense. Push and pull should be relatively, if not perfectly, symmetrical. e.g. you wouldn't have an intake and exhaust right next to each other. Also, obstructions matter. Probably the ideal scenario (an you see this on many case designs) is intake on front and exhaust on rear, in an almost straight, unobstructed line.

    Regarding #3, there are many discussions about this topic here already. More intake gives positive pressure and better dust management. More exhaust gives negative pressure, but works better with certain video card cooling designs.
Ask a new question

Read More

Zalman Cases Fan Components