Silverstone has just released a new video about the positive air pressure they are using in the previously tested Fortress FT01 case. Silverstone's engineers used smoke to show the air circulation within the chassis which looks very impressive. We have tested this feature before with turning the large upper fan around that it exhausts the air. The temperatures were worse which shows that possitive air pressure indeed helps this case with good cooling.


Wouldn't this be a nice addition to our chassis-reviews? We will see what Santa Claus is bringing this year.


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  • otherwise - Friday, December 26, 2008 - link

    This is sort of a general reply to all the filter related-comments, but this seems like a good place to dump it because it really hits the issue directly.

    I simply don't see how positive airflow inherantly solves your filtration problems.

    You have a certain volume of air that flows into your case, and a certain volume of air that flows out of your case.

    So if a positive pressure system and a negative pressure system are moving the same cfm, how is one better than the other in controlling dust? The same volume of dust particles is moving through your system!

    The only real way to argue this seems to be that a positive pressure system can have the same cooling power as a negative pressure system with less total airflow, but noone seems to be arguing this directly.
  • DominionSeraph - Sunday, January 22, 2012 - link

    The positive pressure flow will be more turbulent, keeping the dust in the air. With negative pressure, unless you have internal mixing fans, you'll likely have dead zones where air will sit and the dust in it will fall out. Reply
  • Icester - Tuesday, December 23, 2008 - link

    Why fiddle with all those fans? Just get the Chakra case (or equivalent) -- it has a nice big 250mm side-mounted fan. Then use the other "small" case fans (80, 90, 120mm) fans to exhaust over hot components. With that much cool air coming in the side, it is easy to maintain positive pressure - even when using a filter over the intake fan.

    The best filter I've found is used dryer sheets - they are cheap, disposable, conveniently available, and provide very good filtration without restricting airflow hardly at all (much better than the washable plastic mesh filters). I attach mine my affixing a bit of rough velcro to the fan grill using hot glue.
  • Ryun - Monday, December 22, 2008 - link

    As the reviews prove this, but I have a hard time believing it's merely due to the positive air pressure of the case based on this experiment alone; the experimenter is blowing the smoke directly into both fans.

    The smoke already may have sufficient velocity to blow itself through the case, regardless of whether or not the fans were on. Further, if the fans were on they may have propelled the air with a force that would have curbed the negative acceleration to allow it to move close to it's initial artificial velocity.

    On the same token, since the smoke is being blow into the case it is safe to assume the smoke machine is adding artificial positive pressure to said case that may not be attainable by the fans at all, or without a significant increase in noise generated by the fans. Both of these could have caused the dramatic effects shown in the video.

    I don't need air velocity measurements, or anything in depth to be convinced but it's clear to see Silverstone mucked the data with some bias. I would have been more impressed if Silverstone had let the smoke pass into the fans perpendicular to the fans' airflow as that could have made the result more accurate.

    ...or maybe I'm just naturally skeptical. =]
  • otherwise - Friday, December 26, 2008 - link

    I too am a bit skeptical, but instead of wall of texting people, I just wish they posted CPU/GPU/HD temps with the videos. I mean, the end result is what truly matters. Reply
  • glenster - Monday, December 22, 2008 - link

    See the thermal test results for the Silverstone Fortress FT01 at the next link:">

    It cools a CPU better than a Cooler Master HAF 932 does without the dust. Does anyone know a way to place a Noctua fan in it to cool the GPU better?
  • corsa - Monday, December 22, 2008 - link

    Look to the left.. Judging by the way the smoke is clearing soo quickly, it seems as though there is an exhaust fan drawing air from the cases rear exit.. it's out of frame of course :) Reply
  • sbuckler - Monday, December 22, 2008 - link

    Didn't look that impressive to me - mostly smoke going everywhere and no clear airflow, in particular for the cpu.

    Sure air was getting too the cpu - but the front -> back design of the heatsync it wasn't being fed properly. It was either pushing air in from above or beneath - not from the front where it needed to be pushed.
  • supremelaw - Sunday, December 21, 2008 - link

    If we compare the simple and effective designs of
    cases like the Cooler Master CM 690, it is reasonable
    to conclude all of the following:

    (1) using the natural bouyancy of warmer air
    is a good engineering principle to exploit,
    whenever possible; some vendors are implementing
    this principle e.g. by calling it the "stack effect"
    or "chimney effect";

    (2) point (1) above strongly suggests intake fans
    in the bottom panel, and exhaust fans in the top panel;
    colder air necessarily falls to the floor, and
    that is where the colder air will be found, most every time
    (unless a room heater blows heated air thru floor registers);

    (3) heat sources should be isolated in such a way that
    they intake cooler air from outside the case, and
    exhaust warmer air to the outside of the case
    without warming other components;

    (4) point (3) above therefore recommends these changes:

    (a) single high-wattage PSU should be mounted at the
    bottom rear, with an intake grill in the bottom panel,
    exhausting warmer air to the outside rear of the case;
    obviously, PSUs with higher efficiency are preferred,
    because they generate less waste heat, in general;

    (b) hot hard drives should be mounted in the upper
    5.25" drive bays, so that their warmer exhaust air
    can be exhausted immediately by fan(s) in the top panel
    again without warming other interior components;

    (c) one or more intake fans should be mounted in the
    left-side panel, to feed relatively colder air to
    video cards, CPU heatsink/fans and RAM;

    (d) hot video cards should likewise be isolated
    by taking in cooler air from those fans in the left-side panel
    and exhausting their warmer air out the rear panel --
    again without heating other interior components of the case;

    (e) a proper CPU HSF should direct its exhaust air
    directly at a 120-140mm fan mounted in the rear panel,
    or at such fan(s) mounted in the top panel;

    (f) supplementary RAM fans like Corsair's excellent design
    will help blow relatively cooler air onto the RAM DIMMs,
    as the overall air flow brings cooler air in from the
    front and bottom, and exhausts it towards the rear and top
    of the case;

    (5) supplemental fans like Antec's V-Cool should not
    be installed if they intake warmer air that is being
    exhausted by a PSU mounted at the bottom rear;
    such an arrangement violates point (3) above;
    if a PSU is mounted at the top rear, then such a
    video card cooler should work very well to take in
    cooler air from outside the rear panel and
    blow it directly onto at least one video card;

    (6) similarly, a "recycling" effect can occur
    when an exhaust fan in the upper rear panel
    emits warmer air that is, in turn, captured
    by top panel fans that blow downwards into the case;
    the latter problem is more probable if a case is
    positioned under a desk with its rear panel in
    close proximity to a wall or other solid object.

    These simple engineering principles do not cost an
    arm and a leg to implement: cf. Cooler Master's CM 690
    is an excellent example, and there are now other case
    manufacturers who are implementing these principles
    in their most recent models.

    Sincerely yours,
    /s/ Paul Andrew Mitchell, Inventor and
    Systems Development Consultant

    All Rights Reserved without Prejudice

  • mikeblas - Monday, December 22, 2008 - link

    > All Rights Reserved without Prejudice

    Wow. You're really full of yourself, aren't you?

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