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Any horror stories from not properly ventilating a MAME cabinet
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FrizzleFried:

--- Quote from: Donkbaca on June 29, 2011, 12:35:55 am ---The reason they exhaust is because the point of the fans is to remove heat, not intake air. The pc doesnt need air to function. If you blew air in and just let it leak out, you run the risk of heat building up as all you are doing is recirculating hot air around the case.  The heat sinks radiate heat away from the circuits, warming the air around them the fans blow this hot air out. If you had fans blowing in, you would be blowing this hot air right back on the circuits until it found a way to escape  

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Sorry Don... but you are wrong.

BTW - How many PC's have you built?  I'm up to about 80 or so.


gabe:

--- Quote from: ChadTower on June 29, 2011, 06:16:35 pm ---
--- Quote from: bkenobi on June 29, 2011, 11:41:25 am ---Interesting.  I'm a thermal analyst for a multi-billion dollar international company.  This is what I do.  I guess what I do is funny?

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NSFW

The Goodfellas - Funny how??

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This may be the only worthwhile post in this entire thread.  I LOL'd.
alfonzotan:

--- Quote from: bkenobi on June 30, 2011, 11:15:05 am ---Some fans blow some suck.  The fans at the back of your system (PSU and system fans) are typically designed as exhaust fans.  They suck air OUT of the case out into the room.  Fans on the front of a case (hard drive coolers for instance) are typically going to blow air past the HDD  INTO the case.  As far as heat transfer goes. both methods work equally.  This is convection and the primary drivers in that form of heat transfer are flow speed and delta temperature.  The equation is:

q=h*A*dT

where,
h = film coefficient (driven by flow speed, geometry, etc)
A = surface area
dT = difference in temperature between air and surface temperatures

The direction of the flow makes little difference (it's factored in with h, but a forced convection flow is really independent of what direction the flow moves).  The area is pretty important, obviously, but it's set by the hardware in the system.  The delta temperature is also critical as you get no heat transfer if the air inside the case is the same as the component being cooled.  Increasing the velocity is good, but can make for more noise which is potentially bad.

Anyway, my point is that whether the fan blows air in or sucks air out, it really doesn't make as much difference as you would think.  Now, if I were designing the flow, I'd use exhaust fans or else add fans pointing at components to make sure there was forced flow in those areas.

That'll be $50,000.  Who should I send the bill to?   :laugh2:

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These aren't the fans we're looking for.  Move along... :o
Vigo:

--- Quote from: FrizzleFried on June 30, 2011, 03:04:03 pm ---
--- Quote from: Donkbaca on June 29, 2011, 12:35:55 am ---The reason they exhaust is because the point of the fans is to remove heat, not intake air. The pc doesnt need air to function. If you blew air in and just let it leak out, you run the risk of heat building up as all you are doing is recirculating hot air around the case.  The heat sinks radiate heat away from the circuits, warming the air around them the fans blow this hot air out. If you had fans blowing in, you would be blowing this hot air right back on the circuits until it found a way to escape  

--- End quote ---

Sorry Don... but you are wrong.

BTW - How many PC's have you built?  I'm up to about 80 or so.




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Fans that blow in are generally more of a complimentary fan to increase circulation. Blowing out is generally much more efficient because it anything that blocks the path of an inward flowing fan decreases it's efficiency. A stray ribbon cable or awkward riser card can destroy the air flow of a computer with only inward fans. Fans blowing out pull more evenly from the entire space inside the computer.
Donkbaca:
Haha... Ive built my share of pcs. Just because youve done things over and over doesnt mean you are doin it right. I guess we are all just smarter than those people with the fancy degrees that manufacture and sell these things to the public.
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