Aspirating Detection Draws Air Through Pipes to a Laser Chamber
An aspirating smoke detection system does not wait for smoke to arrive at a ceiling device. A fan continuously pulls air through a network of sampling pipes with drilled holes, and delivers it to a single, very sensitive laser scattering chamber in an accessible cabinet. Two consequences follow. Sensitivity is orders of magnitude higher than a spot detector, low enough to register smoke long before a person could smell it, which is why these systems, the Xtralis VESDA family being the best known, are used in data halls, telecom rooms, clean rooms, museums and cold stores. And the sensing point can be anywhere the pipe reaches, including inside a cabinet, at a return-air grille, or in a space too high or too cold for a spot detector to work. The trade is that the pipe network dilutes: air from one smoky hole mixes with clean air from the others, so pipe design and hole count are part of the sensitivity calculation, and transport time down a long pipe adds delay. After this Concept you can say where an aspirating system earns its cost over spot detectors and what its pipe layout does to its sensitivity.
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An aspirating smoke detection system does not wait for smoke to arrive at a ceiling device. A fan continuously pulls air through a network of sampling pipes with drilled holes, and delivers it to a single, very sensitive laser scattering chamber in an accessible cabinet. Two consequences follow. Sensitivity is orders of magnitude higher than a spot detector, low enough to register smoke long before a person could smell it, which is why these systems, the Xtralis VESDA family being the best known, are used in data halls, telecom rooms, clean rooms, museums and cold stores. And the sensing point can be anywhere the pipe reaches, including inside a cabinet, at a return-air grille, or in a space too high or too cold for a spot detector to work. The trade is that the pipe network dilutes: air from one smoky hole mixes with clean air from the others, so pipe design and hole count are part of the sensitivity calculation, and transport time down a long pipe adds delay. After this Concept you can say where an aspirating system earns its cost over spot detectors and what its pipe layout does to its sensitivity.
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