VESDA

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In firefighting a VESDA™ (Very Early Smoke Detection Apparatus) is a brand of aspirated smoke detector which is capable of detecting the microscopic particles of combustion also known as smoke. Generally aspirating smoke detectors work by drawing air in through a network of small-bore pipes laid out above or below a ceiling in parallel runs covering a protected area. Small holes are drilled into each pipe to form a matrix of holes (sampling points), providing an even distribution across the pipe network. The air sample is drawn past a sensitive optical device (usually laser) tuned to detect the extremely small particles of combustion. A VESDA detector may be used to trigger automatic fire responses, such as a gaseous fire suppression system, in high value, flame sensitive areas such as archives or computer server rooms.

VESDA is claimed to cause no false alarms, however it is so sensitive that it needs to be isolated when smoke from bonfires, barbequeues, kilns or other outdoor fires drifts near the building and when smoke machines are used in the building.