to 75%. T is helps ensure occupants who are unfamiliar with the building's egress routes or emergency plans can quickly escape the building safely — even in smoke-fi lled or darkened buildings with little or no visibility.
WHAT'S CONSIDERED NORMAL? Although a fi re and life-safety contractor usually commands a good understanding of the occupancy and structural type, it's also wise to evaluate all possible uses. T is would include current and future, as well as the conditions under which the fi re/life- safety systems will operate. While reaching an idea of what constitutes normal, everyday use for a large building is fairly simple, it's also easy to overlook unusual circumstances or application changes that can aff ect the environment. T ese out-of-the-ordinary instances could be seasonal in nature, related to special occasions such as concerts and other performances within the facility that impact noise and foot traffi c, or physical additions such as a waterfall in a hotel lobby that could muffl e notifi cation devices or create problems due to high humidity. When designing for intelligibility, it is important to consider worst-case scenarios for
ambient noise, and to provide a voice evacuation system that would meet those requirements (see "Code Speaks Louder About Intelligibility" sidebar). Planning for the ordinary and the
extraordinary within the framework of what's normal in fi re and life-safety system design is just part of the picture. Engineers and contractors also have to
balance cost effi ciencies, environmental applicability and suitability, and the business interests of all involved parties, among many other factors. When it comes to life safety, large venues require big thinking.
Roopa Shortt (roopa.shortt@systemsensor.com) is Audible Visible Marketing Manager for System Sensor.
When designing for intelligibility, it is important to consider worst-case scenarios for ambient noise, and to provide a voice evacuation system that would meet those requirements.
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