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Blow in hole useful for cases?

Discussion in 'Cases, Modding & Electronics' started by tkpenalty, Jan 24, 2007.

  1. tkpenalty New Member

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    Hey guys, I have one of those generic cases and it does not have one of those intake vents (with the retractable vent... pretty good for generic) as well as a grille for the GPU. What I can do is purchase one from the store for $7 AUD. So guys, will it give better performance? If so will adding an 80mm fan to it improve the performance even more? Remember I'm using a CNPS7700CU and right now my case temps are less than satisfying. Will adding 80mm fans near the GPU (two of them) help btw?
     
  2. ex_reven New Member

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    what model is the case?

    I had a generic case with a blowhole and vent built by Nexgen
    i dont think it offered any performance increase

    Leaving the side off the case would obviously be the best way of reducing temps, but i guess you dont want to reduce the aesthetics of your case either

    Im sceptical of those cpu retractable vents, because they impede airflow within the case to your other components, particularly blocking any rear fans you may have below the PSU

    BTW - Power Colour AC is the win :)
     
  3. Namslas90 New Member

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    Pulling fresh air into your case can be a good thing. Make sure you don't disrupt the airflow inside the case though. It's easy to add a fan and end up pushing hot air from one component into another and reduce the cooling effect.
    Just by adding a northbridge fan to my mobo I shoved hot air from my CPU into my Graphics card and increased temps on the card 8 degrees. By inverting the same fan to blow away from the graphics card I reduced the card temps by 13 degrees from before adding the fan. Leaving the side off the case is not the best Idea, because is disrupts airflow. It can be at times effective; IE, in the winter with the window open.
     
  4. ex_reven New Member

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    How can having no side possibly disrupt airflow?
    Unless you have some sort of external force, eg gusts of wind blowing through your case, your airflow should remain the same. Its not like the side FORCES the air to travel over your components and pick up the heat and carry it away, its just the speed and trajectory that the air is going at, which is why other fans can destroy airflow in a poorly designed case.
     
  5. KennyT772

    KennyT772 New Member

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    wind tunnel affect. moving air against stagnant air will create drag. my temps actually go up when i remove the case panel due to fan placement and airflow. best thing to do if you think you need a blowhole is to check case temps vs ambient temps. and if there seems to be a lot of hot air coming out of the psu fan a blowhole might be a good idea.
     
  6. PVTCaboose1337

    PVTCaboose1337 Graphical Hacker

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    Blow holes in the top are 1337. Heat rises, so a fan up there does wonders.
     
  7. ex_reven New Member

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    yeah that works brilliantly, im just skeptical about side vents
     
  8. ex_reven New Member

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    wont the drag of air in that case be identical or less than the drag created by the side of the case though? I mean, the side of the case is alot more dense than air obviously, and air would be more fluid in carrying the hot air out
     
  9. Namslas90 New Member

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    Don't forget pressures also move/block air flow and tempratures affect pressures. Ambient vs. Internal. Not everyone lives outside where the wind is blowing, and if it blows against the case the wrong way it can reduce the airflow to the inside.
     
  10. ex_reven New Member

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    sigh
    if only water cooling was cheap :p
     
  11. Namslas90 New Member

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    OR

    If only fans were quiet!
     
  12. ex_reven New Member

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    having quiet fans is possible...but its alot of work
    id imagine youd need to replace bearings, clean them and oil them quite regularly

    which makes watercooling seem so much more convenient
     
  13. Namslas90 New Member

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    Fans also wear out faster than water pumps. Both cooling types take work and time; blowholes are a good shortcut.
     
  14. tkpenalty New Member

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    You sure? What if it leaks man... what if the pump fails? Thats even worse because the heatsinks inside the waterblock are tiny.
     
  15. ex_reven New Member

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    theres risks involved with everything you do in a computer system
    if you take enough due care, everything should run as advertised

    pump failure is just as prevalent as fan failure if not less common?
    and ive never had a fan die on me yet, even noname brand ones

    i guess its down to luck
     
  16. tkpenalty New Member

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    Back on topic, I've heard forced intakes actually dregrade cooling performance.... is that true?

    Btw its 80mm > 120mm Zalman.
     
  17. Carcenomy

    Carcenomy New Member

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    As far as I'm aware, the blowholes with the retractable duct were designed to meet Intel's thermal spec for LGA775s, they work okay on the stock Intel cooler, but with anything bigger and beefier, chances are it's not gonna help a great deal.

    As for the side on/off thing, the air can lose velocity as it's no longer being channeled by the solid side panel. Instead of being confined to the inside of the case, your air is buggering off out the side, diminishing the cooling effect.

    This is also why I disagree with cases that are touted as being 'great for cooling' because they're very meshy and resemble swiss cheese. IMHO it's better to seal excess holes, forcing the air to enter/exit through the appropriate fan holes rather than swirl around aimlessly entering/exiting through randomly placed holes in the case.

    TK, don't worry too much about sidepanel blowholes etc, good front intake, rear exhaust and a top blowhole will see you right. :)
     
  18. Darknova

    Darknova

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    I recently added a side intake fan over my graphics card because I had a hotspot just below it. Temp has dropped 4'C at load, 6'C at idle, and Case temp has dropped 2'C. It's located in the botton right of the side so doesn't impede flow to or from other components.
     
  19. lemonadesoda

    lemonadesoda

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    Top Tips:

    1./ Dont worry about SUCKING air into the case. Let it draw in (so long as you have sufficient openings near the bottom of the case)

    2./ BLOW air OUT of the case near the top. A good PSU fan is important... and an exit fan near the CPU is important

    3./ An exit fan near the CPU, plus a silent CPU fan IS MORE EFFECTIVE than NO exit fan, but a high performance fan on the CPU

    4./ Remember you want to make ambient temperatures (within the case) as low as possible. There is no point having super large coolers on the GPU and the CPU if the hot air is stuck in the case

    5./ I have found that standing a case upright (rather then lying in desktop) is much more effective

    6./ Take out your m/b. Get a drill with a (8mm or 10 mm) metal bit. Drill 100 holes in the BOTTOM of the case... where no one sees them... but it allows air to draw in at the bottom, and get blown out the top by PSU or CPU exit fan. Also put "feet" onto case, so case is at least 2cm off the floor/carpet.
     
  20. Carcenomy

    Carcenomy New Member

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    Cobblers - swiss cheese a good case does not make.

    Do performance car guys think 'hmmm I need better airflow, I'll just drill 100 or so 10mm holes where nobody is looking'? No. They replace the air filter with something that flows better, increase the size of the intake tubing and plenum and eventually clean up and enlarge the ports.

    All things relative. There's not much difference between air flowing through an engine's intake and air flowing through a computer case. As such I still firmly believe well placed ducting is far, far superior to this notion of hole drilling and upright cases. If top blowholes are such a great idea because heat rises, why would a desktop case NOT be a good idea (if you fitted plenty of top vent holes)?
     
  21. tkpenalty New Member

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    Um... first off,

    1. The case has a 92mm intake at the front, and a 92mm outtake in the rear, next to the CPU, these are ZM-F2 92mm (full speed) and they move HEAPS of air at full RPM

    2. 120mm Coolermaster iGreen PSU fan

    3. Um... duh, I'm not that dumb.

    4. Intake fan takes in cool air. There are some preforations on the side panel and there is some minimal suction (Not enough IMHO)

    5. Wtf does that mean? I have a mid tower not a piece of fucked up dell.

    6. Holes??? Wtf... I don't want to pwn my case with holes because I suck at drilling. Would cutting some of the base out (not under HDD) then replacing it with an aluminium honeycomb work better (It would look better LOL than drilling). I must comment though, In doing that, you would seriously damage the structural integrity of the case.

    Also I don't have a flat-lying case anyway.

    Okay man... I get it but I'm asking if a intake vent (the suck-in t
    ube, I have a CNPS7700CU, btw) Will improve performance, what I am guessing is yes because the CNPS 7700CU pulls huge amounts of air.

    I'm not making the side panel, I'm replacing it. I've heard in some cases (no pun intended) that the Suck-in vents with an 80mm fan installed actually degrades the ambient temps.

    Sometimes when people say that... I wonder, why do we need a case for a PC anyway? Why can't we just lay the parts on a piece of foam?
    Yeh... Car engines are similar to a PC's interior in terms of thermal management-except they are a step ahead. A duct fan forced intake should be called a turbocharger lol... its similar. Pump more cool air in to increase efficiency lol.
     
    Last edited: Jan 25, 2007
  22. Carcenomy

    Carcenomy New Member

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    With your 7700 you probably will see an increase in ambient temp if you run the intake tube type deal.

    The only trouble with having a pile of parts on a piece of foam is protection - there's nothing stopping your components being damaged. That's why if you wanna try things like that, get one of those snazzy frames that shop techs use on test benches. But again, no good long term, the machine can't really be moved easily as parts - imagine turning up to a LAN and having to assemble it on the spot, then what would happen if someone trips on a lead and sends the motherboard hurtling to the ground... :)

    It's all a compromise but it's one that ends up working well with some clever implementation.
     
  23. tkpenalty New Member

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    WTF? Btw, my CNPS7700 is dying from a lack of air, there is one 3000RPM 92mm Zalman fan next to it and a 120mm fan above it, I think it would improve performance, how will it decrease it anyway? Diagram?

    How about the grilles next to the GPU? I'm using an Accelero X2 and to mount the GPU fans I will have to mount them on the outside (not a problem though, it will look great with an 80mm fan grille LOL), should they be blowing in or sucking out? Theres a lot of air accumulating around the GPU area although its the only thing thats there.

    Fans/Cooling.

    92mm Zalman 3000RPM Drive bay under-bezel intake (I made the hole bigger for more air) (making a woosh, the tiny sound is being amplified by the case)

    92mm Zalman 3000RPM Rear Outtake, on silent mode it still moves so much air compared to my "best" 80mm fan, starving the CNPS7700CU of fresh air.

    120mm Coolermaster iGreen fan above the CNPS7700CU.

    Stock northbridge heatsink, with AS5... how do I burn in a northbridge? I'm using AS5 on it lol... wait... the temps dropped like 2*C over the past two days... thats good :D.

    Btw, I think Zalman's aluminium northbridges (except for the compressed aluminium version) are only replacements for the northbridges with faulty fans. Do Zalman northbridges perform better than stock northbridges of the similar size anyway? Everyone goes "Oh I got a thermaltake <insert NB cooler here> and all this shit, but never answer my question.

    Btw, um... would my cooling get affected if my X1950PRO and HDD left a small 5cm space between each other? My 92mm fan is completely under the HDD and I think the air is only going to stay low (blocked by HDD?). Should I mount the HDD lower? Like where the motor is.

    Temps so far:

    CPU:

    Load: Don't know probably 50*C... seems too hot but the AS5 right now is equivalent to some cheap generic crap which takes 3hours to settle in, need to burn in.
    Idle: 40*C

    System:

    Load: Nearly 48*C, thats why I need the vent anyway.
    Idle: 40*C to 43*C

    NB:

    Load: 45*C
    Idle: 40*C to 42*C

    GPU:

    47*C Load
    40*C Idle, pretty cool.

    It seems too hot for the rest...So what would happen if I:

    -Installed the duct+grille side panel.
    -Installed the ducting + 80mm fan
    -Installed 2x80mm fan on the grilles.
    -Both of them simulatneously.
     
    Last edited: Jan 26, 2007
  24. Carcenomy

    Carcenomy New Member

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    This blowhole you talk of, I may have it messed up. Are you wanting just a grille in the side or using the extendable P4 LGA775 style extendable duct? The reason I say your ambients may rise in such a setup, is that the airflow to your 7700 will be solely from that tube, which isn't really ideal.

    Pop in a top hole for starters, and if you want side panel fans, sure thing - although in the past they haven't really helped me.

    As for the drive and card thing... you could definitely move the drive down a few bays, give more room for airflow - the last thing you need is to partition off your intake air :)

    Quite intriguing looking at your temps versus mine... mine's ~38°C CPU at idle, raises to about 47° under heavy load with the 9500AT w/ AS5. Chipset stays at a constant 25°. GPU sits at about 36° with the VF700CU-LED w/ AS5 too. I'm running 120mm ACRyan BlackFire4 in the front, 80mm Titan cheap crap from DSE in the back. No side fan, no blow hole.

    Move that drive around a bit and report back. Feel free to gimme a bell on MSN if there's anything you wanna discuss.
     
  25. tkpenalty New Member

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    Okay... I moved the HDD down and swapped out the normal molex connector for a SATA Power connector (Behind the drivebays; from open side viewing, That part is almost EMPTY now. Then removed the rear backplates, I think I will have to use features that Ketxxx used in prowler; i.e. top expansion slot cool air duct.

    After doing all that... WOWOWOWOWOWOWOOW!!!! 36*C Idle FTW!

    But Carcenmony, isn't your motherboard a P965 Chipset motherboard the northbridge obviously runs cooler.

    What I'm trying to say is that the CNPS7700CU needs more air to cool the processor (as well as the other parts) because my 92mm fan is nearly doing more suction than my CNPS7700CU, does anyone know where I can buy a Zalman Fatal1ty replacement fan from? (Much Higher RPM).
     
    Last edited: Jan 28, 2007

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