VESDA

VESDA air aspirating systems provide the earliest warning of a potential fire that buys time to investigate, intervene and potentially avoid business disruption in addition to the damage, downtime and cost of a suppression system discharge. The very early warning provided by a VESDA system allows early intervention to prevent suppression releases. The multiple warning levels of a VESDA system can be used to trigger different responses at different stages of a fire, from controlling air conditioning to initiating a suppression release.

VESDA systems works by continuously drawing air into a distributed pipe network via a high efficiency aspirator. The air sample then passes through a dual stage filter. The first stage removes dust and dirt from the air sample before it enters the laser detection chamber. The second, ultra fine stage provides and additional clean air supply to keep the detectors optical surface free from contamination, ensuring stable calibration and long detector life as well as minimising nuisance alarms.

From the filter, the air sample goes through the calibrated detection chamber where it is exposed to a laser light source. When smoke is present, light is scattered within the detection chamber and instantly identified by the highly sensitive receiver system. The signal is then processed and presented via a bar graph display, alarm threshold indicators and graphic display. VESDA systems are able to communicate this information to a house alarm fire panel, software management system, or a building management system via relays or high level interface.

VESDA sampling points can be placed at the return air grill or in equipment cabinets to detect smoke as it is carried by the air. In large open spaces, sampling points for VESDA detectors can be placed where smoke goes, often some distance below ceiling level. VESDA systems can be mounted in areas where access can be an inconvenience, making servicing and maintenance a lot more easier.