My computer is inside a desk enclosure that gets pretty hot unless I leave the front door open. I was thinking of cutting a hole in the back of the desk and mounting a 140mm case fan to the desk. I was wondering if there are any 3-pin/4-pin to USB adapters out there. I'd rather not use 4-pin cabling from inside the computer out to the fan. Are there any better ways of cooling the desk?

the easiest way i can think of is power inside the computer but you refuse to use it. any DC fan will be much more expensive then PC fan. plus you will need to connect extra cable from the main outside anyway. might as well hide eveything inside your desk and get power from the computer. USB connector will only give you 5V maximum thats what USB device is required to run. and 5V any fan will not going to move much air.

your call.

I tried something similar to this once, with a desk-drawer computer. Worked ok, I think.

First thing I would do is cut two holes in the back of the desk; one to match up with the PSU, and one to match up with the intake fan (assuming you have one on the back). Then get two pieces of PVC tubing that will allow you to close up as much as possible the computer and desk holes, so you're blowing as much warm air out as possible, and sucking in as much cool air.

As the other guy said, USB is limited to 5V, and < 1A, I think (maybe even 0.5A). That's not going to drive much of a fan. Can you just remove most/all of the back area of the enclosure? Especially the top section? That may give you enough ventilation as-is, without any fans to assist. Again, I'm make sure in particular that the fans pushing hot air out of your case can blow directly out...

Clint

Thank you. I think PVC tubing would limit my ability to remove or pull out the computer from desk from time to time.

I'm thinking about using something like this to power the fan.

http://jab-tech.com/PCI-power-back-plates-c-174.html

Get a cheap drive enclosure and use its power supply to run the fan. Most have 12 and 5 volts a 1.5-2 amps each.

You should have some kind of vent on the front of the desk so the air get in.

You can also check your local electronics store(radioshack and such) for a 120volt AC fan if you do not want any power box. Many people do just this for there stereo stands too.

For me the PC powering it makes the most sense. Its easy to run a y splitter out the back and then the fan is always on with the computer. In my case my board came with a pci bracket power plug for Esata drives anyway . Those are easy and cheep to find at a local computer store that has ones laying around from systems they built.

CNeufeld, Yes, its 500ma for usb, if its asus, its as much as you feel like taking(I pulled 1.5 from it once).

I would say, don't just cut a hole, cut the whole back!

These computer hutches with computer bays can really heat up your box and shorten the lifetime of your components, so you are on the right track in seeking a way to allow for good air flow.

Many desks with computer "bays" have a back panel that can be removed. Many are attached with staples or small nails and are easy to pry out without endangering the integrity of the panel, in case you wanted to re-attach it a some point in the future.

In this particular instance, you would have to leave the "front door" to the bay open to allow for appropriate front to back air flow, at least while the computer is being used. There are many computer cases that provide interior fans, that pull air in the front and exhaust out the back to allow for good air exchange.

Try this: http://www.rackmountsolutions.net/ [...] ans_guards
(almost any rackmount fan should work, one here is 10", and connects directly to an outlet)(listed as FAN10)for $170 + S&H

Or a cheaper solution are these: http://www.frozencpu.com/products/ [...] 36c265s726

$24 + S&H (2 should do it, these are also 110v AC fans)

just buy a 120 volt fan and leave it on. or use a relay hooked to you ps to trigger the AC unit. Come on nukemaster, I woulda figured YOU'D think of the relay..I got you on this one

Thank you everybody for your suggestions. You've given me a number of avenues to look at.

This forum rocks

http://www.frozencpu.com/products/ [...] tl=g36c265


get that one it has a good cfm and is actually quiet only $20