Windows 7 - Simple question about case fan sizes...

Recently I upgraded my desktop and in return it is generating a lot more heat. The case originally came with just one fan and it is on the side and just barely under 3" from corner to corner of the screws; the screw holes in the back are exactly 4" apart. I'm going to be replacing the side fan with a better one, and adding a back fan. I realize there are 25.4mm in an inch but the spacing off my fan screw holes aren't any exact size results. I know I can't expect them to be, so what would anyone suggest I should be shopping for?

Additionally is there any specifics in a fan I should be interested in to keep my desktop cool?

First I would look up the manufacturer of the OEM fan and get the exact dimensions so that the replacement is as exact as possible, then just find a new fan that matches the same size. As for keeping your desktop as cool as can be, the more air a fan can push or pull, the more effective the cooling is. Fans are measured by size, speed (RPM), and air movement (CFM or cubic feet per minute). If you're just going for cool, high RPM and CFM are the way to go. You might have to deal with a little more noise in return though. Most fans also have a sound rating as well, if you're going for quiet computing.
Xoxide.com - Custom ATX Computer Cases, PC Mods, Computer Case mods, and Modded PC Cases is where I go for my case modding supplies.

Yeah I don't think I will be able to look up the specifics of this case any more. It's been through three motherboard replacements so it's rather old.

Is there any pertinent information on the fan itself? ie; who makes it, model number, etc.

I just realized I still had the box buried away! It doesn't say the side fan size but the front and back are both 120mm, and if the back is roughly 4" in size (1" larger than the side) I think it is safe to assume the side is 80mm.

Will give rating for attempting to help, thanks!

Not a problem. I was going to suggest that it was an 80mm. But speaking from experience, I have found some odd ball sized fans. Like 73mm, normally only in old systems though.

SO, you have a case with an intake fan on the side only? no exhaust fan above your i/o on the top rear?
If it was mine I'd upgrade the case. Changing 1 fan isn't going to make a truckload of difference so I'd upgrade the case.

This is a hi cfm fan http://www.pccasegear.com/index.php?...ducts_id=17324 or you could consider
these http://www.pccasegear.com/index.php?...oducts_id=6170
or this range http://www.pccasegear.com/index.php?...ducts_id=16687

I use Scythe fans in my case but am going to use the penetrators in my new case I think...still mulling that one over atm.
cheers

Sounds like you have spaces for both front and back fans? And currently no fans in either? You need to make sure your motherboard has extra fan headers for connections, otherwise you're looking at using a molex connector that will run the fans full speed all the time.

Based on how the fans are run, you can choose the speed. generally speaking, high speed/high CFM will bring you noise in less expensive fans. You can get some nice quiet(er) fans with decent specs for more $. Noctua, for instance makes quiet fans, and many even have the ability to slow them down using provided resistance cables.

A Guy

I have to agree that a case upgrade would be the best option here.

~Lordbob

I'll get in 3rd for the case upgrade. You could buy fans, then maybe a hole saw to add another, then end up spending fifty bucks for a Frankenrig. Or you could spend $30-$50 on a cheapo case that came with the whole works ready to go:

Newegg.com - Computer Hardware, Computer Cases, Computer Cases, $25 - $50