Help- making cool air intake

Hello Guys

I am trying to built a sort of ram air intake for my CPU.

What I am planning on doing is connect a pipe (or Tube) to the current CPU fan and go straight to the side of the CASE.
What I manage so far is to use a small plastic tube to the heat sink and then "taped" another fan to the end of it. the only problem so far is making the hole to the case and comming up with the proper FAN. I am using a regular 40mm Case fan, but I am wondering if it has enough "umph" to biult the presure in it.
I left the original Heatsink/fan in it so is runninng with to fans...


I have seen a kit around to take air from the fromt of the case, but that is too long of the path, and air would aclimate to temps in case.. I want a straight shoot into the CPU..

Any ideas?

Looking for the proper FAN.. I am going to Home Depot Today
to buy a PCV pipe 3" diameter/ 4" lengh... need to make a bracket
to attach to the heat sink/ and another to attach to the side of the case( has to be removable , since the side panel is remobable..

Running

Gigabyte 7N400 Pro
AMD 2700+
213 FSB X 11 Multiplier
temps at 43C with the 2 fans

Most case fans are 80mm, 40mm is just tiny. www.newegg.com has lots of fans: http://www.newegg.com/app/manufactory.asp?catalog=62&DEPA=1 thats both heatsinks and fans there. i dont know what you will find at home depot, but circtuit city will have what you need. It will just be rediculously overpriced. I only buy online.

Hello

Thanks for the link. Do you think I should look for shear CFM or for something that would give me more Pressure.

Thanks

Daniel

Usualy more cfm means more pressure. Its different with axial fans(IE blowers), they have extreme pressure and no deadspot, but low cfm. I usualy shop by noise level, nothing over 35db for me.

In order to generate a significant "ram effect" you'll need a fan capable of moving quite a bit of air.
The set up you describe will be fairly effective ( once you lose that 40mm fan and switch to 80mm or larger) at providing fresh, cool outside air to your HSF.
That should help some.

Of course, then you have to deal with the surplus of air that you have brought into the case.

Good Idea

I am already trying to convert a 40mm exhaust to a 120mm and
possibly 1-2 Intake fans in the front, hard to do so far.. only room for one 80mm...

My case is somewhat small So so far The 120mm is sitting outside the case with an adapter (80mm to 120mm). Looking to do something else....
120mm is too loud.. any recommendations on to which is a good
fan?

Thanks

Daniel

clocker2 said:

In order to generate a significant "ram effect" you'll need a fan capable of moving quite a bit of air.
The set up you describe will be fairly effective ( once you lose that 40mm fan and switch to 80mm or larger) at providing fresh, cool outside air to your HSF.
That should help some.

Of course, then you have to deal with the surplus of air that you have brought into the case.

Click to expand...

The surplus air shouldn't be to big of a deal since it is creating a positive pressure in the case. The positive pressure will push the air to the outside from every leaky spot there is.

In the fire department we use positve pressure ventilation quite a bit and it can be very effective. The only draw back is when someone opens up to many vent holes and you lose the positive pressure.

I would think having a tighter case and higher pressure inside would help here as well but the only good way to see would be to fill the case up with something like theater smoke and then fire up the fans. I also don't think it would be good for the computer componets either.

positive pressure will also help keep your case dust-free, provided all your intakes are filtered.

Hello

That sounds about right. I think I will do some comparative shopping for fans with low dba's... Will post pictures once the mess is "Organized"

Daniel

firenurse4 said:

The surplus air shouldn't be to big of a deal since it is creating a positive pressure in the case. The positive pressure will push the air to the outside from every leaky spot there is.

In the fire department we use positve pressure ventilation quite a bit and it can be very effective. The only draw back is when someone opens up to many vent holes and you lose the positive pressure.

Click to expand...

Granted, your points are all valid- as far as they go.
I would think however, that by creating a positive pressure scenario and then just counting on various and sundry case "leaks" to vent it, you have given up on any hope of controlling the airflow to achieve what you actually want it to do, namely move cool air past your heat-producing components and then out of the case.
In a typical case layout the major heat sources are all at least halfway up the height of the case, HSF, PSU and HDD. Most of the biggest and most obvious "leak" areas are lower- the PCI slots, front intake vents and the weird, illogical groupings of vent holes that case manufacturers are so fond of ( in my Xaser case, the whole area btween the PCI slot covers and the left side panel is Swiss-cheesed).
Thus, your waste, heated air rises and sits stagnant at the top of the case while the fresh cool air is pushed right out of the case before it has a chance to do much good.

Like I said, the problem arises when you have too many exits.

In theory if you sealed up the bottom of the case and had on exhaust at the top, then blowing in positve pressure at the base would give great air flow. Like you pointed out though the real world case has the bulk of its leaks at the wrong end.

All that said, I think that cooling is better with a mildly higher case pressure than to run with negative case pressure. (You really should be running with an equal number intake and exhaust vents) My reasoning behind that is that by running positve pressure, you are also moving out dust that can get into the heat sinks and help gum things up.

Yes, you are right, My case has got too many holes towards the PCI area.. I'd probably consider adding another 92mm or so fan
to the top of the case and just "plug" somehow the other holes (if possible). I do think that that would be the only way to force the air to go in a "specific" maner. You are also correct top of case is ussually hotter than the rest of the PC, bit I do not know
how much would that affect the "lower" areas such as the CPU..
Which are obviously very sensitive to temps...

Daniel

rbdaniel,Have you removed the fan grids from your case yet.These are the stampted grids infront or behind your fans.By cutting these out your reduce noise and increace air flow.A fans CFM is measured in free air.Thats with nothing around it.Take a look at the Panaflo fans,they are top notch.THE FANMAN

This may help give you some ideas!

MOD LINK

rbdaniel@bellso said:

You are also correct top of case is ussually hotter than the rest of the PC, bit I do not know
how much would that affect the "lower" areas such as the CPU..
Which are obviously very sensitive to temps...

Daniel

Click to expand...

That condition will affect the "sensitive" components to the extent that it raises the overall ambient case temp.
If you are going to take steps to bring fresh, outside air directly to the HSF area you have solved half of the battle, all that is left really is the vid card, HDD, PSU and the rest of your motherboard area.
Happy cooling.

Hello Everyone

Thanks for the feedback. I have indeed cut-off the rear "grid" and the fan sounds better. I did a crappy job, because I used sheet metal scissors.. lol . I am looking to buy a dremmel kit today if possible... any ideas where it is cheaper? When to home Depot, and their kit was from $60 to $80.

I am also going to CompUSA to check what they have for Panaflo or similar fan...

Thanks

Daniel

Hello

I forgot to mention, I just saw the link about cutting the side plexiglas and fan area.. very good link, too bad My job does not
look that good.. ;;

http://www.ocforums.com/vb/vb/showthread.php?s=&threadid=245723

Thanks

Daniel