Keeping your system cool is very important, and, therefore, one of the most important components in your power supply system can be a fan. Different iterations of the power supply fan have been cooling computers since the time PCs first came out. Modern day computers now have additional cooling methods to keep the system from overheating, such as CPU cooling fans and auxiliary fans, but fans for power supplies continue to be a critical cooling device in maintaining the overall system temperature balance. With faster and hotter processors becoming the norm, maintaining optimal temperatures is critical for the smooth running of any system, and overheating of a system often causes irreparable damage to the equipment, often leading to data loss. A fan can provide the air flow required to cool the components. In systems that require more cooling, more fans are generally used. Typically, fans are located towards the back of the power supply. There are specially designed cases with vents that allow better air flow through the system in which the power supply fan can either blow out the air from the back or draw in cooler air, depending on the design of the system. In both these instances, the flow of air should be smooth without any interruptions or blockages.
Both regular and auxiliary fans can be found in a power supply. Which type and size of fan is right for a given system depends upon that system’s specific requirements and design. The standard size of a square computer cooling fan is about 80mm; however, other sizes such as 60mm, 92mm, and 120mm can be chosen as required. Fans may be placed in various specially designed vents around a power supply.
The quality of construction is one of the most important determining factors to the quality of a fan. This involves the quality of construction that has gone into the motor and its bearings. Bearings reduce friction and allow a fan to operate at high speeds. There are typically two types of fan bearing types: ball bearings and sleeve bearings. Ball bearings have more longevity and cost more, sleeve bearings may be less expensive and their life expectancy is considered much less than a quality ball bearing
Some systems can control the speed of their fans. Power supplies may have automatic thermal control of a fan, which indicates when the power supply’s fan should turn on or off and increase or decrease its speed according to the system’s temperature. The speed of the fan is determined by the amount of airflow it can move, which is measured in cubic feet per minute or CFM. The higher the CFM, the more air the power supply’s fan is capable of distributing. Usually, around 70 CFM is a good starting point. Smaller fans with higher CFMs usually produce more noise.
One of the main reasons why fan failure occurs in power supplies is debris and dust build up. Dust can get into the motors of fans and impede the proper flow of air. The average time until predictable failure steadily increases if the computer is kept in a dusty or dirty environment, or if the computer is not cleaned at least once in six months. If the fans in the power supply stop working, then overheating can occur in the power supply as well as the rest of the components inside the computer. In an attempt to protect your system from further damage, some systems will sound an alarm if the fans stop working, or will shut down the system altogether.
Choosing Your Power Supply Fan Before choosing a fan for your power supply, check what kind of system you have first in order to determine what types of fans you should be looking at and in which direction they should circulate air. Older power supplies may need fans designed to exhaust air out from the back while newer power supply fans reverse the flow of air to draw air into the supply case, achieving better control over the air that enters the system.