Looking for some modding advice...

[A Guy Named Joe]

I'm been considering a mod, but not to a case.

I have a computer desk that has a computer compartment and it hides the computer nicely. However, it get's really hot in there. Really hot. I managed to garbage pick some working parts and some parts donated by friends. I got a spare PSU, 2 80 mm fans, a huge 120 mm fan, and wire grill, with some fiber material to keep the dust out.
What I'd like to do is cut a portion of the front door to the cubby hole/computer compartment out and put the two 80 mm fans in the front and the 120 mm fan in the back.

However I want to do a professional job, because one thing keeps me from doing it. My wife. She doesn't want me to do a half @$$ed job and destroy the desk, yet I know I can do a decent job if given the chance and also the help.

I want to use the PSU to power the fans, but yet I need some advice as how I would like to wire it out, and I need advice as to turn on the fans and turn them off. I'm thinking of some type of rocker switch I can flip on and off, but not sure how to go about wiring it.

I need advice!

[Frakk]

for the powersupply: you can turn on a powersupply without the motherboard and any other components by shorting out the green wire (pin 14) on the 20pin atx header by connecting it to any black wires. if the switch is on, and the pins are shorted, you should hear the fans inside the psu start spinning. now you can connect devices on the power rails

a switch for the fans: this is very easy. the yellow wire is your source of 12V on from the psu, and the two black wires are the ground. you can buy switches from radioshack for fairly cheap, they will have 2 pins, all it does is shorts the two pins/wires. just cut your 12V line, solder the pins to the two ends (doesnt matter which way) and you have a working switch.

Is the comp in a closed area like a box? because if it is, it would be just easier opening the doors or something if only the front of the case is open, maybe you should put an intake fan in the front of the case. i wouldnt bother drilling holes on the table and messing with an extra psu if not necessarry

[Matthew]

First off...I wouldn't use a psu for this job...it would just be big and in the way. Get you an old cell phone charger of some sort. Either 5volt or 12 volt for the power supply. Otherwise you would just have a Hugh hunck of metal doing nothing but powering fans and having about 200+ watts wasted. as for the fan's position (And this is only what I would do) I would put them all in the back. Have the two fans at the bottom blowing in, and the 120mm fan at the top blowing out. One as an intake and one as an exhaust. It would keep things nice an cool. Reason I would have them both at the back is it would keep things looking normal and nice on the front, and get the job done almost as well as a blow through would.

Here is a pic of how I would do it. Oh yeah...red is live wire Green is ground.

Here is a Pic on how it will work.

[Frakk]

power is not wasted, the psu wont draw the current from the outlet unless its needed lets say it wont be used up to its full potential and the other thing is you cant determin the positions of the fans before you know how the air moves inside the case (thats what matters after all). as I posted before, a front or side intake is necessary for proper airflow and to avoid negative pressure(and dust)
air enters the case from the front, exits in the back through the psu (and rear exhaust), pretty simple. now if the whole thing is in a box, you need to supply the front intake with fresh air and remove the hot air exhausted by the psu so the hot air is not circulated in the box.
If you have the front open, then there is no need for a front fan, only a fan that exhausts the hot air.

[A Guy Named Joe]

Hmmm, so I wouldn't need all of the extra fans then? I could technically then just put a front grill in the front of the door panel, and then just use one or two of the fans in the back?

[Frakk]

I'll draw you a picture tomorrow, its too late and i have to wake up tomorrow for school if you can take some photos and post it, it would be nice and a lot easier to help, or just give a detailed description of the whole thing because I dont know whats it like thanks in advance

[A Guy Named Joe]

I'll get some picts of the area tonight or tomorrow and post them on here so I can you an idea of what I'm talking about.

[Chapel]

A tip for the grill, this would cut down your airflow, but you could take the wood cut out and turn that into a grill. It would fit right in the desk and still look nice. Imagine those floor vents for wood floors, the ones that blend into the floor. Something like that would provide enough airflow to get circulation. You got to realize though, that if it gets really hot in there that your probibally not going to be making cooler air go into your case, it will just improve airflow

[A Guy Named Joe]

Hmmm...like a wood grill? Instead of cutting out one BIG piece and putting a metal wire grill, just make slits for open circulation, put the filter material in place and THEN put the metal mesh grill behind it?
That might sound like a plan.

I think I'm going to have to sit down and draw out some plans of attack before I start work on this. That way I know what I'm doing and can follow a procedure step by step.

[A Guy Named Joe]

Here are those picts I promised of the area I'll be working with...


Here's the front view of the door. I'll need to cut a hole to work with the grill area somewhere on the door.

Here's the area with the door open...

And here's a side view of the area with a open area for cables...

Now here are the measurements for the area....
19 1/2 inches...

by 11 inches...

by 20 inches deep.