An overheated system can produce errors and cause hardware to fail. Usually an overheated system will simply reboot for what appears to be no apparent reason. If you’ve determined your computer has been overheating, or if you just want to increase the airflow or decrease the noise produced by your current case fan, look to this article for instructions for augmenting or replacing your case fan and installing a fan controller (which will help regulate fan speed and noise) to go with it.

Preinstallation Considerations

Before you run to the store for the biggest and best case fan and grab your tool belt, be sure your system can accomodate a new or extra fan. For instance, you will need an unused 3-pin header on your motherboard or an available 4-pin power connector from the power supply if you’d like to add a fan to your setup. Pay attention to the cabling to ensure any extra cords won’t hinder any other components or obstruct airflow.

You will also need to figure out what kind of fan to purchase. You might be surprised by the number of options. Most fans are housed in a square casing, and the outer lengths of these cases typically measure 80mm, 92mm, or 120mm. To determine what size of fan your chassis can handle, first find out how large your current fan is and then see if there are pilot holes that allow you to place a bigger fan. If there are no pilot holes, but you’d like to install a larger size, you will need to drill the holes yourself.

As with other hardware components, case fans have a specifications list with a few key features you need to pay attention to. Airflow is measured in CFM (cubic feet per minute), and the higher this number is, the more powerful the fan. Speed, which is measured in rpm (revolutions per minute), and the airflow are directly related. Quicker fans can pump more air through the system; therefore, fans with a high rotational speed and CFM are more effective cooling devices.

You will also be able to choose between ball-bearing and sleeve-bearing fans. Ball-bearing fans have a longer life span and can tolerate greater amounts of heat for a longer period of time than sleeve-bearing case fans. Ball-bearing fans are quieter at high speeds than sleeve-bearing fans. You can also purchase double-ball-bearing fans for extended life span. Sleeve-bearing fans are less expensive, however, and are sufficient for computers that handle light computing activities, such as browsing the Internet.

Fan manufacturers design some fans to be quieter than others. As you look at the specifications, pay attention to the noise level, measured in decibels. Compare and contrast fans that meet your size requirements to find a fan with the lowest decibel number. A fan with a decibel level of 25 or less is nearly inaudible. As a general rule, the smaller your fan is, the louder it will be. Small fans have to push out the same amount of air as large fans do, but they have a smaller area to work with. The fan must spin faster to move the same amount of air, and this results in more noise.

If you’re concerned about not knowing whether your fan is going to provide the optimal amount of cooling, look for a fan with built-in temperature sensors. These fans will adjust themselves to provide a sufficient amount of cooling to your computer. For instance, Antec (www.antec.com) offers a line of SmartCool case fans that come with built-in temperature sensors.

Finally, if you are looking to add aesthetic value to your computer, there are lots of fans that have LEDs (light-emitting diodes). You can choose from colors such as red, green, and blue that will illuminate the inside of your case as the fan is running.

A good rule of thumb is to purchase the largest fan that fits your chassis and will deliver the most effective cooling with the least amount of noise.

Install The Fan

As you’re getting ready to install your case fan, remember an old high school science lesson. Hot air rises because it is less dense than cold air, which means you’ll want to position an intake fan (a fan that pulls air from the outside into the case) toward the bottom of your chassis. A good place to put such a fan is toward the bottom of the front panel of your case because there is usually a ventilation grill located there that allows the fan to suck the cool air from outside the case and blow it into the computer. A good place for an exhaust fan (a fan that pushes air out of the case) is the upper area of the case, such as under the power supply.

Before you begin the installation, shut down your computer and unplug the power cord. Then, remove the panels of your case. Each case is constructed differently, so some cases will require you to remove screws holding your case together, while others have configurations that allow you to remove your panels without unscrewing any screws.

If you already have a case fan and you are simply replacing your old one with a new one, this installation will be a cinch. All you need to do is unhook your current case fan’s power connector, unfasten the screws, and then replace it with your new fan.

Some cases will let you click your fan into place before you fasten the screws, but this isn’t always possible. When you attach the fan, check its side for an arrow that indicates the airflow direction and then position the fan according to the direction you want to push the air.

If your new fan is a different size or you are adding a fan to augment your current fan, things could get tricky. Look for the predrilled mounting holes we mentioned earlier that would allow you to easily fasten your new fan to the case. If there are no predrilled mounting holes, it’s time to get out your drill and create them. To do this, measure everything out and mark the appropriate areas where the hole will need to be drilled. Plug the fan into a 3-pin header on your motherboard or use a 4-pin adapter cable to plug your fan into the power supply’s 4-pin Molex connector. You might want to do some tidying up before you put your case back together. Try to make the cable routing as organized as possible in order to maximize airflow. Now you’re ready to close up your computer, unless you are planning to also add a fan controller.

A Few Words About Fan Controllers

Once you’ve installed your fan, it might be helpful to include a fan controller to help you manage the speed and the noise of your fans. The fan controller you purchase will determine how many fans you can connect at once, and each fan controller will have different means of controlling the fan (such as knobs, buttons, or an LCD). With a fan controller, you can minimize the noise of your fan while you’re checking your email by reducing the rpms of the fan and turn the rpms back up for computer-intensive tasks, such as gaming or working with some types of software.

You can purchase an inexpensive fan controller that just has a few knobs to adjust the rpms of your fan, but it might be more helpful to purchase something with a little more glitz. Some fan controllers will display information, such as the rpms of individual fans and the internal temperature of the computer.

Try to find a fan controller with temperature-monitoring capabilities. When your computer reaches a particular temperature internally, your fan controller will alert you with some type of alarm so you can adjust the fans accordingly. This will help ensure your computer is sufficiently cooled.

Install The Fan Controller

You will install your fan controller into an extra drive bay (where optical drives are usually located) on the front panel of your computer. Remove the front panel of your case and then slide the fan connector into the drive bay. Most fan controllers will have multiple predrilled mounting holes to accommodate 5.25-inch drive depths. Once you have the fan controller in place, fasten the screws tightly.

Next, you will need to connect the fans to the fan controller. If you are using a fan controller, you will connect the fans to it in lieu of connecting the fans to the motherboard or power supply. Most fan controllers will let you connect four different types of fans: the CPU fan, the VGA fan, and two case fans. Connecting these fans is as simple as plugging in the 3-pin connectors to each other. If your fan or your fan controller calls for a 4-pin connector, you will need an adapter cable.

Finally, your fan controller will come with a 4-pin connector cable so you can plug your fan controller into your computer’s power supply. Once you’ve got everything connected, be sure to tidy up the wiring before putting your case back together.

Keep It Clean

It’s very important to keep your fans clean because you don’t want to blow dust and dirt in and out of your computer. Every few months, blow compressed air onto your fan. You can also use a cotton swab to wipe down the fan blades and vents to ensure dirt isn’t clogging the vents and preventing air from flowing in and out.

Cooling is an important aspect of computing, so be sure your final configuration will bring sufficient cooling to your system. The difference in price between a low-quality fan and a high-quality fan isn’t much, so if you can, purchase a high-quality, quiet, efficient, ball bearing fan.

by Tessa Warner Breneman