VESDA aspirating smoke detection solutions with continuous air sampling provide the earliest possible warning of an impending fire hazard. VESDA aspirating smoke detectors buy the critical time needed to investigate an alarm and initiate an appropriate response to prevent injury, property damage, or business disruption. VESDA detectors have multi-level warnings and a wide range of sensitivity that does not degrade or change over time, so even minute levels of smoke can be detected before a fire has time to escalate.

Standard smoke detectors typically operate by sensing smoke particles within a single enclosed chamber where the air is passively sampled. These detectors activate only when smoke reaches a certain concentration near the sensing element, which often results in detection occurring after a fire has already started to develop. In contrast, VESDA aspirating smoke detection systems continuously draw air samples through a network of pipes from multiple locations within the protected area. This active sampling enables detection of very low levels of smoke at the earliest stages of fire development, providing more advanced warning and increased time to respond.

The VESDA system is an Aspirating Smoke Detection (ASD) system capable of detecting smoke at low obscuration levels, enabling detection of smoke at the incipient stage. VESDA systems are successfully operating in applications ranging from ultra-clean to harsh, dirty environments. The laser detectors have a variety of alarm levels. The thresholds for each alarm level can be set to suit specific site conditions.

How VESDA Works

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Aspirating Smoke Detection Systems incorporate a network of pipes with sampling holes continuously collecting air samples from the area being protected. The sample air in the pipe network is drawn to the detector by a high-efficiency aspirator. The detector can detect minute concentrations of smoke; this is expressed as % obs per meter or foot. The success of an ASD system is dependent upon the smoke reaching the sampling holes and being efficiently transported to a detector. A well-designed pipe network considers natural and mechanically induced airflows within a customer site to ensure that air travels in the direction of the sampling holes. The length of the pipe and the number of changes in direction of the pipe will impact the efficiency of an ASD system.

The VESDA aspirating smoke detector works as follows: The annunciator/display provides four levels of alarm: Alert, Action, Fire 1, and Fire 2. Alert indicates that the smoke levels are above normal and will activate upon smoke thresholds from 0.0015 to 0.614 % obs/ft. Action will activate as the smoke levels continue to rise, and investigation of the protected area should be initiated by the facility fire protection personnel. Action is initiated by thresholds from 0.0015 to 0.614 % obs/ft. Fire 1 is a pre-alarm condition and indicates that there is a real danger of a fire condition and immediate action is required. Fire 1 is initiated at thresholds from 0.0030 to 0.614 % obs/ft. Fire 2 is an extremely serious condition. At Fire 2, automatic fire suppression systems, including preaction sprinkler or clean agent release, may be initiated, and evacuation procedures will be activated. Fire 2 is initiated at thresholds from 0.0061 to 6.575 % obs/ft.

The VESDA aspirating smoke detection system provides reliable, early warning of potential fire hazards through continuous air sampling and precise smoke detection. Its multi-level alarm thresholds enable tailored responses to different smoke levels, helping to prevent injury, property damage, and business interruption. Proper design and installation are critical to ensure optimal performance of the system in a variety of environments.

For more information on how VESDA systems can enhance your fire protection strategy, please contact Oliver Fire Protection & Security.