Reliable detection of smoke in high ceiling spaces has been considered to be a challenge and most practitioners default to using detection technologies - such as Optical Beam Smoke Detectors (OBSD) or Aspirating Smoke Detectors (ASD) - which derive their smoke measurements over a line or an area rather than at a single location. Such "integrating" technologies are used because they are inherently more sensitive to smoke that is diluted or distributed as it rises to higher levels than point type smoke detectors. Evidence to support this has recently been gathered from a 3 phase project undertaken by BRE Global, which included; a review of existing evidence of applications and of the recommendations for the protection of spaces with high ceilings, an investigation of the value of computational methods for predicting detection performance in such spaces, and culminating in some full scale fire tests for verification and validation of performance in a 43m high space. This paper summarizes the key results from the research project and the major recommendations which have led to changes to current Design and Installation Codes for ASD in UK, specifically extending height limits and providing guidelines on the use of cumulative sampling in high ceiling spaces.
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