When you buy a new desktop, laptop or external hard disk drive it is not unreasonable to assume that the cooling system will keep all the components with the recommended temperature range. It is alarming though, how many brand new systems, some from well-known manufacturers where the internal temperatures are at the upper edge of this temperature range. The temperature of your house or office will usually have little effect on the computer, unless it is a particularly hot day, at which point the temperatures can climb rapidly.
Data gained from centre hard disk drive usage and failure rates suggest that running a drive at too low a temperature does more harm than too hot. This is likely due to condensation building up due to temperature differentials which will occur when operating under extreme conditions. This is a situation which is unlikely to ever happen within the normal home or office environment.
Heat is the single biggest issue facing the computer industry, as it will lead to hardware failure which the nature of which is very difficult to predict due to the large number of factors which determine how the heat will be distributed inside the computer. Most failures of a hard disk drive caused due to heat do not leave any visible indication, with the rare exception of a component burning out on the controller board.
Airflow is Essential
Whether you have a desktop system with a single hard disk drive, a server with multiple drives or a RAID arrays containing a dozens of drives, the essential requirement for these is airflow. By air which is cooler than the component it is flowing across it will help to move some of the heat and dissipate it. Whether the computer is used at home, an office or in a server room, it is important that the case has enough fans to keep a constant flow of air moving. Even in an air conditioned office or server room, if the fans in a computer were stopped, it would rapidly begin to overheat at which point damage is likely to occur, even if it is not immediately apparent.
As stated before many pre-built systems can be marginal as cooling goes, often with no airflow across the hard disk drive. Most cases bought separately, in particular those bought for use as servers or gaming machines using come with multiple fans drawing air into the case directly across the cage used for housing the hard disk drives. It is worth regularly checking the temperature of your hard disk drives to ensure that they are not being slowly cooked, as the damage due to high temperatures usually builds up before it causes a failure to occur.
Reviewing the state of the fans and how many you have fitted, especially if you add any more hard disk drives is important. Any dust in the atmosphere, even with the current trend for filters used on input fans, will tend to stick to any plastic surface, which will decrease the efficiency of the cooling, especially if the speed of the fan becomes inhibited.
Cumulative Effect of Heat Damage
Running your hard drive within the state temperature range, typically from about 5 degrees Celcius to 55 degrees Celcius does not guarantee that the drive will not fail. The closer to the extremes of this temperature range the more likely that some damage will occur, although operating outside this range will not see the drive immediately fail. The hotter the drive, the higher the likelihood of some damage occurring.
Heat damage can cause a deterioration of a component, whereby it still appears to be operating correctly, such an electronic component, but once the damage has occurred it is likely to get worse, even if the temperature is maintained at a normal operating temperature. A damaged electronic component may cause unpredictable behaviour of the drive, especially as it is possible for damage to one of the microscopic connections to self heal, only for the damage to appear at another position along the track. If a hard disk drive is run at excessively high temperatures for a long period of time there are several failures which can occur, such as an electronic component fault, read/write head damage or the fluid bearing could outgas, which would lead to the spindle motor seizing up.
One Failure Can Cause More
Most people believe that an electronic component will either work correctly or fail, but as mentioned above it is possible for a fault to self heal, a process known as self annealing, a temporary condition before the fault reappears, not necessarily at the same position. This can lead to erratic behaviour of the drive, such as fluctuations in the speed of the spindle motor or could cause the read/write head to be positioned incorrectly. If the spindle motor does not spin at a constant speed, it is possible for a vibration to start which can in some cases lead to a resonance building up so that the platters move and come into contact with the read/write heads.
All drives which have suffered damage due to heat damage should be powered down and sent to a professional data recovery company such as DiskEng for data recovery. This is essential as the drive will need to be rebuilt under laboratory by a hardware data recovery specialist with the correct level of expertise.