Driving data protection forward: Peter Fox, Managing Director of AirSense Technology Ltd, considers the challenges involved in protecting computer rooms and offers some solutions

Despite our best attempts to protect them, computers are under continual attack. If it is not a virus clogging the operating system, it is dust clogging the hardware. Hackers, spare and spyware are all doing their best to get past our increasingly sophisticated firewalls and virus defences. It can seem as though every advance made by technology to protect our systems seems to be matched by a new breach of the fortifications, yet we still rely on computers to store our information, process our details, and relay our data We may employ the best antivirus precautions and install the most protective of firewalls, but our computer rooms are still vulnerable to a threat that will do more than wipe records or admit hackers. Fire, and the damage left Item putting that fire out, can cause extensive, expensive and long-term downtime. Computer rooms, intelligently protected from virtual attacks, need equally intelligent solutions to the physical possibilities of fire.

A fire in a computer room poses a number of threats to an organisation. As well as the risk to staff, there is the inevitable loss of time, money and whatever data the computers held. The impact may not be felt solely within one company. Websites may be lost, applications may not be processed, and important emails, documents and images may not reach their destinations. The effects of the potential spread of destruction may be wider than anticipated. Organisations often look to specifiers and other experts for the best possible solution to ensure computer rooms are afforded the best possible protection.

THE INTELLIGENT SOLUTION

Obviously, detecting a fire at an incipient stage oilers the best opportunity to minimise damage. Ideally, a computer room will be protected by a fire detection system that can tell the difference between a blown fuse and a blazing conflagration. It is also necessary to ensure that this sensitivity is not offered at the expense of reliability as frequent nuisance alarms can have a serious impact on downtime and productivity. Finally, we must be certain the detector is well suited to, and capable of operating flawlessly in its given environment.

There are a number of factors present in a computer room that can interfere with a detector's ability to sense a fire at an early stage, and these complications should be taken into consideration during the design process. The following factors can all have a major impact on the satisfactory operation of computer room fire detection systems: Air-conditioning, air filtration, filter efficiency, the configuration and size of the room and the direction and volume of air flowing through it.

Unlike normal 'still air' commercial applications where smoke rising from a fire at an incipient stage usually builds up rapidly as available materials combust, the situation in a computer room is different. Smoke from a fire within a computer or 'clean' room will disperse at a much faster pace because of the high rate of airflow High efficiency filtration greatly worsens the situation, as this can remove a high proportion of the smoke before it has had a chance to be detected. Moreover, it is normal that fresh-air from outside the building will be added, typically at a rate of about 10 per cent by volume, which further dilutes smoke produced within the protected environment. This combines to make computer room smoke detection a very problematic prospect unless unconventional detection methods are employed.

Considering such factors, traditional point type detectors are not the best solution to provide the required sensitivity, especially in light of the amounts of money at risk. It is not just a 'sensitivity' issue ... an aspirating incipient fire detection system operates by sampling air directly. In the case of a computer environment this usually means thai it is sampling from a high velocity air-path The positioning of point detectors on ceilings or in voids away from the airflow effectively prevents smoke from entering them until it has sufficient thermal buoyancy to rise to the detector level. This will usually require a significant source of heat, meaning that any chance to safely resolve the problem causing the fire will have been missed. To quantify the difference in sensitivity between the two smoke detection techniques, 'conventional' point type detectors typically operate at sensitivity values of between three to eight per cent obscuration per metre. Some aspirating detectors can respond to changes in smoke density as low as 0.003 per cent obs/mtr, more than 1,000 times more sensitive.

Aspirating detectors draw a continuous sample of air through a system of perforated sampling pipes, which, importantly in this situation, can be designed to draw the sample directly from an air conditioning system return flow. Aspirating detectors are available from several manufacturers and range in sensitivity from 'ordinary/normal' to 'very sensitive indeed'. Unsurprisingly, high sensitivity smoke detection is often associated with nuisance alarms, but this need not be the case. Perceptive Artificial Intelligence (PAI) algorithms can be applied, allowing them to 'think' for themselves. The detectors are programmed to condition themselves automatically to suit the protected environment. They are capable of continually modifying the sensitivity and alarm thresholds of the system so that they maximise usable performance, while preventing the system from using inappropriately high sensitivity that may cause nuisance alarms. Capable of distinguishing between day and night or working and non-working situations, this 'intelligence' system enables the suitably equipped detectors to make major and instantaneous sensitivity 'switches', based upon what the system has 'learned' about its operating environment. It should not go unmentioned that all manufacturers of high sensitivity aspirating systems employ 'automatic learning' features, but these are typically only used during initial set-up. These auto learning processes should not be confused with the vastly superior artificial intelligence process, which never stops making adjustments.

AIR CONDITIONING

'Close control' air conditioning is often used in computer rooms in order to prevent over-heating. While vital for the satisfactory operation of many core computer components, this system of air conditioning can play havoc with a traditional detector's ability to detect a conflagration before it amounts to an uncontrollable level. However, whilst being highly disruptive for conventional detectors, the high airflow rates are frequently employed to the advantage of an early warning aspirating smoke detection system.

The advantage of installing an aspirating detection system, especially in this kind of environment, is that the sampling pipe and their detection points can be placed in varying positions where the airflow is known to transport smoke. This provides a substantial advantage, as instead of carrying the smoke away from conventional ceiling mounted detectors, the high air velocity is employed to carry the smoke rapidly and directly to the sampling point of the incipient fire detection system.

It is worth discussing a few practical installation tips here, as it is often the method of installation that can help to achieve maximum efficiency, There are two main areas in which the sampling pipes should be placed:

* Underneath the raised floor; and

* In the air path returning to the A/C units, before it enters any filtration system.

In the example below, vents in the raised floor allow air to flow from the room, and the sampling pipes from the detector are strategically positioned so that the sampling boles are in the path of the air stream. This ensures that smoke will be detected very quickly as it is carried along in the air stream and flows in to the path of the sampling holes.

Most computer rooms may look The same, each will have their own unique challenges for providing the best possible protection from fire, but the importance placed on such protection is universal.

COPYRIGHT 2004 DMG World Media Ltd.
COPYRIGHT 2004 Gale Group