Funnel Cooling Idea... good or not?

[JcFlyeR]

According to science (chemistry of gases)... If you increase pressure and then release the air... it will be cold, because when molecules are relieved of pressure they absorb heat(energy, in the form of kinetic energy) and move faster... so here is a diagram that I am proposing... Its a funnel cooling idea.... what do you guys think?

I have just been thinking about it for the last two days...

Look at diagram carefully...

DONE IN MS_PAINT! :) I GOT SKILLZZZZ!!!

[dopa]

i'm not an engineer by any stretch of the imagination but i'm pretty sure that's how most air conditioners work (with compressors).:rolleyes:
but the thing is, at some point, you'll need to dissipate that heat. if you want that cold air moving into the case, you'll have to make an outside part that gets really hot. so basically in an ideal setting, however much you cool the air going inside is how much you'll have to heat up the air outside. it's a great idea that i'm sure could be pretty cool with some tweaking. imagine that...a portable ac unit for every computer case. hah. :laugh:

[Wiggo]

Not a bad idea but something will probably miss out on some airflow. :smokin:
<center>:cheers:</center>

[Darthtanion]

Many heatsink manufacturers have attempted to make their designs with this theory in mind, but they normally fail to produce a product with any significant gains. The reason behind this failure is the turbulence that is caused when you force the airflow into a smaller pathway. This turbulence slows down the airflow rate, so you lose the added benefit of your cooler air temperatures.

It's also one of the concepts behind the small funnel-type adapters that folks use when mounting an 80mm fan on a 60mm heatsink. It's main benefit now is the quieter operating noise levels. There is usually no added gain in performance even when using a much higher CFM fan (and sometimes there is a performance drop).

[zeradul]

If you increase pressure and then release the air... it will be cold, because when molecules are relieved of pressure they absorb heat

There is one thing you are missing from that comment. When the air is compressed for the first time, heat is Created. Only then, does it cool as it is de-compressed. (and it cools exactly the same amount as it was heated to begin with) That stems from one of the fundamentals of Thermodynamics, Energy cannot be created or distroyed, and since Heat is energy, it can't just dissapear under any circumstances.

Not to mention that air (Nitrogen, Oxygen, Co2) is not a good choice for this type of discussion. The tank of an air compressor doesn't get hot when the compressor is running does it? Barely noticable increase in temp. And the nozzle doesn't get cold when you are spraying compressed air does it? Again, a very minute amount. Not even remotely enough to attempt to combat a processor's capability of producing heat.

Good thought process though.

[chisholm]

damn....and i was getting all excited about having a stream of cold air blowing in to my case :p

[JealousMidget]

You guys beat me to it :laugh: I love these kinds of questions. An essential omission is that cooling cycle AFTER the air is compressed and then allowed to expand. That is when the heat is absorbed. The real ***** in the armor is that this concept only works in a closed system. :snip: Computer cases do not qualify as closed systems by any stretch of the imagination- too many places for air to get in and out uncontrolled. Even the ones with GOOD seals would never stand up to the compression cycle. :hammer:

What the funnel concept does do is focus a given volume of air on a smaller surface area. This is commendable if all goes well, but as Darth mentioned there is the issue of turbulence which can create backpressure and potentially reduce the effectiveness of your system below that of a smaller fan that does not have a funnel. So you may want to consider that. But don't give up! It was that kind of spirit that brought us liquid nitrogen cooling :thumb:

JM :afro:

[RDR]

Similarly - an 80mm DC fan would not provide sufficient force to significantly compress the air - even in a closed system.
A funnel with a drastic reduction would just provide backpressure to the fan and reduce the volume of air being moved.

*edit* Sorry JM - I didn't read your whole post - you kind of said that already didn't you.....

[Wiggo]

Which all boils down to the reasons why fan adaptors arn't as efficient as ppl would like them to be. :smokin:
<center>:cheers:</center>

[Mr. C]

Originally Posted by chisholm

damn....and i was getting all excited about having a stream of cold air blowing in to my case :p

It is an admirable goal, so don't be discouraged.
You might be selling these guys hardware someday when you get the problem worked out:geek: