subject: Visual Alarm Device A Must For High Ambient Environments [print this page] Fire is a one of the many wraths that we have to face and fight despite the advancements in technology. Threat of fire is always there. Past one century has seen rapid development in terms of manufacturing and installing Fire detection systems.
Protecting homes and office spaces from the ravage fires have been on the priority list of all the policy making bodies and manufactures across the globe. But there are numerous other spaces that too require adequate evacuation warning in case of fire and most of these spaces are vast , such as Stadiums, Malls, Museums, etc.
To safeguard any area and people present from fire there is a three step process "" Detection, Warning and Protection. Visual alarm devices fall in the second segment. Mostly deployed in areas where the noise level is high, these devices help in warning people to get away from the danger zone in least possible time. There are many types of alarms depending upon the area of deployment, be it indoors, outdoors, large open spaces like stadiums etc. Devices such as strobes, beacons are part of fire detection systems that warn people of imminent fire threat. The main purpose of Visual warning systems is to warn people who are hard of hearing.
Sirens and other audio alarms have been integral part of Fire Alarm and Smoke detection systems, visual alarms have been had added at much later date. This has been done after many studies revealed that, none of the existing audio fire protection and detection equipment did not help the persons hard of hearing or those working in high noise environment to rush for safety in case a fire broke out. Visual Alarms, as part of Fire Protection system provide visual signals of an impending fire threat at all locations within the building such as Washrooms, Lobby, Stairwell etc.
Visual Alarm devices or VADs as they are known are governed by global standard EN 54 -23:2010 to which all the VADs must conform to. The standard outlines the requirements and test methods for a VAD to be accepted for installation.
At present VADs are installed on separate circuit since they consume high power. But worldwide efforts are on to include them on the same circuit as other fire detection devices so as to reduce installation costs.
Since these devices usually deploy Xenon or LED as light source it becomes difficult to measure their output. Both these elements have different characteristics "" Xenon devices have short duration whereas LED signals have long duration. But with EN 54 -23:2010 it is expected that some kind uniformity will appear in the way these devices functions.
While installing Visual Alarm devices in a building premises couple of things that must be kept in mind are: One, VADs must be installed in adequate numbers based on the size of the area that needs to be covered. Secondly, such devices should be installed in places where people can easily recognize them as warning signals and not mistake them to be part of ambient lighting. Thirdly, as part of hazard prevention and warning system, such devices should be well maintained and compliant with the Fire prevention requirements of the area to be covered.
