High-sensitivity aspirating smoke detectors (ASDs) excel at providing very early warning of fires. Because of their high sensitivity chamber, their ability to cover large areas, and their ability to detect smoke in high-airflow environments, ASDs are ideal solutions for many common smoke detection applications. New ASD technology is enabling fire system designers to solve a much broader range of fire detection challenges, enabling them to take aspiration anywhere. In this article, Stephen Lederer, Sr. Product Marketing Manager, Aspiration Business Unit at System Sensor, explains that the latest innovations in aspirating smoke detection technologies increase their effectiveness in traditional high-sensitivity applications, while also enabling them to meet a much wider range of fire detection challenges.
Smoke Detection in Data Centres
One of the most common applications for ASDs has been data facilities. Server rooms are home to expensive equipment and valuable business processes and data. In these facilities, every second of downtime accrued, transaction missed and byte of data destroyed due to smoke or fire can mean significant financial losses. In fact, according to a recent study by Emerson Network Power, downtime in a data centre has an average cost of about $500,000 per event.
The potential for smoke and fire is heightened in data facilities as the electrical equipment they contain creates a high-heat-density environment. At the same time, air conditioning devices used to control the temperature create a high air flow and air filters used by the AC units can remove smoke particulate, making detecting smoke in data centres extremely challenging.
ASDs overcome the challenges of protecting data centres by actively sampling air through a network of pipes. These pipes can be run above the ceiling, under the floor, in-between, in, and above server racks and cabinets, and in the return air duct of an air handling unit – anywhere smoke might travel.
These detectors are capable of providing Very Early Warning Smoke Detection. This level of sensitivity, combined with multiple levels of alerts, enable facilities to implement a strategic response plan to address incipient fire conditions before costly damage and downtime can occur.
|Recent developments have enabled ASDs to potentially eliminate costs related false alarms|
A newer innovation that can enhance data centre smoke detection is increased nuisance immunity. Traditionally, nuisance alarms have been accepted as the cost of using a high-sensitivity aspirating detector. However, more advanced detection and filtering technology has greatly enhanced the nuisance immunity of some ASDs, enabling the detector to potentially eliminate costs-related false alarms.
Smoke Detection in Warehouse Spaces
A fire in a warehouse can potentially cost millions in lost inventory and downtime. Fires can also escalate quickly due to the amount of stored goods and the presence of combustible materials. But because of their size, these spaces present unique challenges to traditional detection devices. Large, open areas with high ceilings can cause smoke to dilute and not reach ceiling-mounted spot detectors in detectable quantities, and differences in temperature can cause stratification that prevents smoke from even reaching the ceiling.
Aspirating smoke detectors can overcome many of the challenges typically present in warehouses. An ASD’s pipe system may be run vertically up racks and across the ceiling, taking samples along its pipe network to overcome the challenges of stratification. To further protect stored goods, pipes may also be run intra-rack to ensure complete coverage of a warehouse facility. If the warehouse is very large, a single ASD unit can cover several thousands of square metres of space, reducing the number of devices required.
One common warehouse application challenge that has been difficult for ASDs to overcome is that the constant movement of inventory, forklifts, and air currents can release an unusual amount of dust and dirt into the air. This makes nuisance rejection a must in many warehouse environments.
Again, recent developments in the filtering and detection of particulate have made it possible for some ASDs to provide the high-sensitivity required to detect very small levels of smoke while rejecting nuisance particulate from the detection equation. This mitigates the effects of dilution and enables a response before costly inventory damage can occur.
Recent developments in the filtering and detection of particulate have made it possible for some ASDs to provide the high-sensitivity required to detect very small levels of smoke while rejecting nuisance particulate from the detection equation
Another recent advance beneficial to these spaces is integral communications capabilities in the ASD that enable it to actively notify facility managers at the first instance of trouble. For example, there are devices that can communicate directly to the many major fire alarm panels without the need for any extra hardware. There are also devices that use an onboard Ethernet port to send e-mails to up to six individuals when set alarm thresholds are reached. The integral Ethernet capabilities also allow the device to be monitored anywhere in the facility via the Local Area Network (LAN), or anywhere in the world using a Web browser and a VPN-capable device.
Smoke Detection in Cold Storage Spaces
Costly loss of product and productivity are just two ways a fire can do a great deal of damage to cold storage facilities. However, due to low temperatures, normal UL listings for many traditional passive detection devices preclude their use in refrigerated storage applications. Furthermore, because cold storage environments have extremely dry atmospheres, high airflows, and the presence of highly combustible materials, fires can often spread very quickly.
An ASD can be mounted outside the extreme environment in an easily accessible location. It then draws air through a pipe network that is run into the cold storage space, so the device is not exposed to the cold temperatures that prevent the use of many traditional devices. Temperatures within a cold storage facility can vary between –40°C and 18°C. There are systems, for example, listed to sample air as cold as -20°C. But if the air sample is colder than the listed ratings, it can be warmed before entering the device.
Cold storage typically exists in a warehouse-style setting, so these facilities present many of the same challenges as warehouse applications. It is essential to protect freezers/chiller rooms, coolers, shipping bay areas, ceilings and ceiling voids. In addition to these areas, it is recommended to sample air from the return air path in the protected area. Samples may also be drawn from within the racks.