Either due to lack of rigorous regulations or limited resources allocated to it, there is little interest in Latin America for audio systems for evacuation for public places.
Richard Santa
In the countries of Latin America, the regulations that exist in the field of audio systems for evacuation are scarce. The few attempts on this issue are based on NFPA standards, which while they are for fire prevention, has some specific chapters for evacuation processes in case of an emergency.
Despite this situation, those in charge of the administration of public buildings understand the importance of having a good audio system that allows to guide the people who are inside the building and, obviously, the manufacturers of audio equipment have responded to these needs and in the market there is a varied offer, which comply with other international standards such as EN 54-16, ISO 7240-16 and EN 60849.
Carlos Parra, Yamaki's head of communications, explained that an audio system for evacuation must be in "any massive place where the message must arrive at any time in order to save lives in case of emergency. These scenarios are corporate buildings, shopping centers, universities, schools, transport terminals, airports, among others."
For his part, Luis Peña, training and technical support engineer at the Mexican company Representaciones de Audio, cited the NFPA standard that in its article 12.3.4 indicates that any enclosure with more than 300 occupants must be provided with an approved system of alarm and mass notification. The notification must be made by voice.
He added that "taking into account the above, we have to think about theaters, convention centers, offices, factories, theme parks, schools, temples, public transportation."
Easy to use
The two experts emphasize that the interface of current evacuation audio systems is simple, so they do not require an expert person all the time to operate them. Carlos Parra pointed out that "they are customized systems that are configured according to the number of zones or call points. The activation functions are either manual or automatic and are always working."
For Luis Peña, the systems today provide a simple interface for the control of their parameters. With practical and easy-to-use controls, you have access to change the source in each zone, audio volume in the area and whether or not you want to receive conventional voices.
He added that "the inclusion of an internet connection to the evacuation system, allows the administrator or operators to be aware of any problem in the system, allowing a very fast response time."
Noise and dispersion
To have a good evacuation system, two factors that directly influence its operation must be taken into account: the noise level at the site of the installation and the dispersion.
"These two factors can give us a very good idea of the type of speaker suitable for the application, as well as the optimal placement of the speakers. The systems must basically have good intelligibility, a good sound pressure level (SPL) according to the application and a uniform coverage in the area where there is a flow of people, "said Luis Peña.
The representative of Yamaki indicated other features that the systems should have:
- The transmission lines between the central equipment, speakers and microphones must be continuously monitored and in case one of these lines presents failure the system must report it for repair.
- The system must be redundant, it means that in case the amplifier or speaker fails it must have backup equipment that guarantees the operation of the system.
- The voice alarm system must be able to activate automatically.
- You must have a backup power supply system as in the case of a UPS.
- When the system detects an alarm, it must deactivate all calls, music and / or announcements that are taking place in the affected areas, in order to make emergency calls.
- All messages should be clear, short and unambiguous, ensuring that they can be reproduced in case of emergency.
- The system must ensure a progressive and staggered evacuation.
- Calls should be allowed from different points to deliver evacuation directions if necessary.
The latest
The latest developments that are on the market for these systems have pre-recorded messages, which can be activated by the fire detector system and alarm system or also directly by the firefighter from a call station.
They can work for ambient sound while allowing periphoning. Also, as a redundant system allowing to have a backup amplifier that would act automatically in case of failure of the main.
In addition, these must be completely decentralized systems to facilitate the installation and growth of the system, as well as the total use of the network infrastructure using digital audio protocols.
Likewise, they must facilitate the internal operation of the building where it is installed, minimizing the number of audio systems incorporating conventional voice and the distribution of ambient music.
To avoid
One of the most common mistakes made during the installation of evacuation systems is to skimp on the quality of the materials used, for example cables, connectors, among others. If the previous point is taken into account, these elements will transmit the information of the system, so a failure could have fatal consequences.
Therefore, a very good structured project from the design is required. It is not the same to use an ambient music system to make calls and evacuation messages, as well as to use systems specialized in emergency and evacuation but poorly configured.
For Carlos Parra, one of the main mistakes is that the volume level of an emergency call must be higher than the volume of the ambient sound and the latter must be suspended during the call, things like this type are the ones that are not taken into account, as is also the case of volume controls that affect the entire system, including the emergency.
"The use of network-based systems without the inclusion of a redundant network also implies a significant lack in the system, since operators do not keep in mind that accidents happen and that anything that happens to the main line of communication with the system will leave it completely, or partially in some more advanced systems, Disabled. Thinking of a second path for the communication of the elements, you can foresee these details and take the functionality of the system to the maximum, "said the Audio Representations engineer.
It concluded that in the case of Mexico, not all facilities have adequate evacuation systems. In several cases the economic situation influences the budget allocated to them, but with the simple fact that the system allows to save one or several lives, it justifies its implementation.
