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Airborne Contaminants

Airborne contaminants pose another risk to computer equipment. Dust is a common problem: airborne dust particles can be drawn into computer enclosures, where they become trapped. Built-up dust can cause overheating and static buildup. CPU fans can be impeded by dust buildup, which can lead to CPU failure due to overheating. Other contaminants can cause corrosion or damaging chemical reactions.

HVAC units typically operate in a closed loop, conditioning recirculating air. Positive pressure keeps untreated air from entering the system. Any untreated air should be filtered for contaminants with filters such as HEPA (high efficiency particulate air) filters.

Heat, Flame, and Smoke Detectors

Heat detectors, flame detectors, and smoke detectors provide three methods for detecting fire. They typically alert locally, and may also be centrally monitored by a fire alarm system. In addition to creating an audible alarm, flashing lights should also be used so that both deaf and blind personnel will be aware of the alarm.

Heat Detectors

Heat detectors alert when temperature exceeds an established safe baseline. They may trigger when a specific temperature is exceeded or when temperature changes at a specific rate (such as “10°F in less than 5 minutes”).

Smoke Detectors

Smoke detectors work through two primary methods: ionization and photoelectric. Ionization-based smoke detectors contain a small radioactive source that creates a small electric charge. Photoelectric sensors work in a similar fashion, except that they contain an LED (Light Emitting Diode) and a photoelectric sensor that generates a small charge while receiving light. Both types of alarm alert when smoke interrupts the radioactivity or light, lowering or blocking the electric charge.

Dust should always be avoided in data centers. Small airborne dust particles can trigger smoke detectors just as smoke does, leading to false alarms.

Flame Detectors

Flame detectors detect infrared or ultraviolet light emitted in fire. One drawback to this type of detection is that the detector usually requires line-of-sight to detect the flame; smoke detectors do not have this limitation.