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Fire risk and warehousing

From aircraft hangars to agricultural storehouses, industrial commodities to retail merchandise, large volume buildings and storage properties such as warehouses and ‘superstores’ serve a variety of purposes.
 
Consumer and commercial goods ranging from fresh, frozen and packaged foods through to industrial products such as automotive parts, paint, paper, textiles and fertilizer are some examples of the high-value, and often highly flammable stock that occupy warehouse facilities.
 
To allow for the demands of maximum storage utilisation and a diverse range of contents, a typical warehouse configuration exists as a large volume area with high-bay racking, automated picking systems, and general and mezzanine storage sections.
 
Factors to consider
 
In warehouse environments, primary factors such as size and height, number of entry points, storage racks, and product flammability increase the fire risk, and subsequent detection of a fire event.
 
While conventional smoke detection may be adequate for general commercial applications, the unique characteristics of a warehouse facility highlight the fundamental disadvantages that conventional ‘passive’ smoke detection such as point and beam detectors have in application-specific environments.
 
Due to the height and volume configurations of a warehouse facility, the incidence of smoke
stratification is a major challenge to detecting a potential fire event.
 
As initial smouldering smoke does not have adequate buoyancy to reach the ceiling section of a warehouse, the design, detector location and level of response of point-type and beam detectors do not provide reliable or proactive smoke detection.
 
Not only can the positioning of stock and storage racks impede access and maintenance of conventional detectors, but the size, shape and positioning of stock may either obstruct or cause a beam detector to false alarm.
 
Other challenges to beam detection include structural movement caused by external climatic changes, increasing the incidence of a beam detector activating a false alarm. Plus there is the significant cost factor associated with the number of point-type or beam detectors that are required to protect a warehouse facility.
 
Installing an aspirating ‘active’ smoke detection system is the best way to avoid a warehouse fire.
 
Very early warning aspirating smoke detection
 
Very early warning aspirating smoke detection systems provide the optimum protection against fire by reliably detecting the presence of smoke at the earliest possible stage. Despite the key environmental challenges of a warehouse environment, aspirating smoke detection technology overcomes the difficulties associated with conventional detection systems.
 
Aspirating smoke detection cumulatively samples air via multiple sampling holes in a pipe network and transports the air sample to a centrally located detector for accurate analysis. By positioning the detector in an easily accessible location, programming and maintenance of the detector can be performed without disrupting routine warehouse operations.
 
A sampling pipe network can achieve a coverage of up to 2,000 m2 per detector, providing cost effective smoke detection, regardless of the size, configuration and warehouse storage requirement. With programmable sensitivity levels, each detector can be customised to address the unique environmental characteristics of a warehouse facility, such as external pollution and airflow from the dispatch and delivery areas.
 
In addition to advanced smoke detection capabilities and programmable alarm thresholds, staged levels of response to an escalating fire condition provides the earliest opportunity for incident investigation and management, reducing the requirement for fire brigade intervention.
 
Performance-based design
 
Performance-based design determines the best fire protection system by assessing the environmental risks at the concept design stage, such as the internal and external environment, smoke source, smoke movement, heat transfer and smoke detection within the structure.
 
Leading aspirating smoke detection system such as VESDA offer performance-based technology, providing optimum protection of a warehouse facility by addressing the unique characteristics of size and height, high bay racking and storage, and automated picking systems.
 
Warehouse installation scenarios
 
For complete fire protection, the smoke detection system is flexible to allow pipe work to be mounted on the ceiling or roof, and also within the storage racking.
 
Many industry standards specify height considerations when installing a smoke detection system. The system addresses the issue of warehouse height and the occurrence of smoke stratification with multiple-level sampling. By positioning either drop pipe or sampling holes at specific levels of the warehouse ceiling and walls, the incidence of smoke stratification does not impede the ability to detect smoke at the earliest possible stage.
 
For warehouses that contain high-bay racking, sampling pipe/s can be located within the racking with sampling points located along the pipe work.
 
In large volume warehouse storage facilities, advanced aspirating smoke detection technology and flexible system design provides cost effective, low maintenance, early warning smoke detection.
 

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