Secondary Case Fans

So you want more cooling, what's the first step? Sometimes you shouldn't approach your CPU as being your first priority when dealing with system cooling, in many cases (no pun intended) secondary case fans are the solution to your cooling problems.

Radio Shack...Here I come!!!

The most popular Secondary Case fan is the standard 3" or 4" Radio Shack fan, very powerful, and very effective when used properly. You have a few options with secondary case fans. Most cases allow them to be placed in a cartridge type enclosure near the front of the case to be used as an intake fan. These are most effective in AT style cases and motherboards in which the CPU is placed in the path of the intake fan which really helps cooling the system as a whole. ATX layouts benefit from secondary case fans as well, sometimes better than AT systems. If you have any peripheral cards that get extremely hot (i.e. the Monster 3D) then a secondary case intake fan is perfect for you. The fan, when left unobstructed, will not only help circulate air throughout your case, but it will also project a nice cool breeze past your peripherals. The only problem with placing a secondary case fan at the front of your case is that in many situations, the fan is blocked by cables and other such obstructions therefore limiting its capabilities.

Where do I put these thingies?

Where else can you place secondary case fans? Some cases allow you to place these quaint little fans along the sides of your drive cages, which helps a LOT if you have 7200 or 10,000RPM hard drives or other such drives spinning away in those cages. Although this is a more unorthodox method to system cooling, these unique fans can be suspended over almost any hot peripheral of yours, and in my case, the Pentium II. As you may have heard, the Pentium II (in this case, a Pentium II - 300) generates amazing amounts of heat therefore Intel supplies the end user with two options. The OEM Heatsink, weighing in at about 1.5LBS and about 1.25" tall, or the Boxed Heatsink/Fan combo which is much smaller, but very effective. For all of you Pentium II owners out there with OEM Heatsinks (like me, I just couldn't resist it) a secondary case fan suspended over the processor card which really helps cooling the titan. These fans can easily be suspended with a few rubberbands or twisty-ties, both of which should be plentiful in any tweaker's work area (can't live without twisty-ties).

Lets get technical...

Most newer Enlight cases come with these useful secondary case fans, but what happens if you don't have a 5-pin power connector (like the ones bought at Radio Shack)? Well, simple, you can use your own external power supply. Simply pick up a 12v AC adapter, which should be resting quietly in the isle next to the one where your fan came from, so swing around, grab one and head for the counter. When you get home, installing it is once again, a very simple task. Cut the proprietary power connector interface plug off of the end of the AC adapter (should look like a cylinder with an opening at one end) and viola! you have two separate wires, one for the positive terminal, one for the negative one of your new fan. Attach the wires, I suggest running them through a screwhole in your case, and plug it in. Easy huh? Well, lets make it a bit more complex, pick up a simple two-way switch and you can attach that to the connection, and that way you'll have a little desktop switch that controls your secondary case fan. If you have any of the jumperless ABIT boards and like switching clock speeds on the fly, the added option of extra cooling at a button press away is a very reassuring feature, and a great addition to any system.


Here are just a few precautions to take when installing and using secondary case fans:

  • If you are doing any of the wiring yourself, BE SURE TO USE ELECTRICAL TAPE to seal all wire connections, its common sense, but you wouldn't believe the number of people that wouldn't use it
  • Never place the secondary case fan flush against any surfaces, remember its just a fan, it requires air to expel. If you restrict one of its surfaces, well, then it has no air supply to circulate, so it simply shoots air out the sides, not very effective.
  • When positioning your fan, make sure it is at least 2" away from any surfaces, peripherals, or other components. Remember, those fan blades can cut wires if they find their way into the path of destruction, especially power supply cables. WATCH OUT!!!
  • Finally, when dealing with any type of electrical wiring, make sure you connect the correct wires together, this is mainly the cause of many fan burnouts. Bottom line, be careful =)

Secondary case fans, as I mentioned before, should be used as intake fans however you need to make sure that if you are going to use one as an intake fan, that you have a source from which to take in air (hence the name, intake). Airholes are usually punched in the front of your case, but sometimes it helps to remove that pesky Internal PC Speaker and replace it with a perfectly sized 3" fan. Once again, the decision is yours, I personally don't recommend damaging your case by punching air holes in the front of it, but that is always an option.

The Sound Side of it

Although these fans seem almost perfect, they can get quite noisy, especially if you have 2 or more in your system. Just make sure your case is well insulated, and that the fans aren't drawing power your power supply doesn't have to give out. So if noise is a big no no, then you may want to consider some of your other cooling options before selecting a Secondary Case fan.

Slot Fans

The final addition on to any perfectly cooled system would be one simple slot fan. In most cases, slot fans ease their way into a slot cutout in your case and are powered by either a 5-pin power cable or an ISA slot. Slot fans are very quiet, and can be quite effective, especially in ATX layouts. If possible, you want to get a Slot Fan powered by a power cable instead of taking up an ISA slot. Why? Well, the fan(s) on the card will vibrate, and in turn wear out the connectors on the ISA slot which isn't something I would like to do. I'm still trying to get my hands on a decent slot fan, when I do I'll post a more in-depth review of them.

Pentium II Cooling
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  • CocoMark1 - Thursday, March 17, 2022 - link

    First! Haha, this article was released a few years before i was born :O

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