The correct application of fire detection in industrial environments is no less important than that of any commercial or residential application. However, many people seem to find challenging the fundamental issue of the selection of equipment. What is the most appropriate fire detection equipment for the job? Communication is the key.
Over the past 25 years the development of fire detection products has progressed considerably from earlier times, when the choice of equipment was limited and somewhat basic in performance. Today the industry has a myriad of equipment available from which to choose. Equipment manufacturers inevitably come up with new ideas, introduce innovative techniques and develop specific equipment with the aim of satisfying new needs and capture greater percentages of the available market. The industrial market sector in particular however has always been one area where traditional detection equipment struggles with performance for a variety of reasons.
Technology or new equipment development brings with it certain questions, with one in particular being: “what is the best technology or type of equipment available to serve the particular risk?” This is not an easy question to answer, since each application and environment is so individual, and each has its own idiosyncrasies and needs that lend it to specific types of equipment. As a result we are challenged with how to make the right choice. Determining the most suitable equipment puts pressure on those that are involved directly with the installation of fire detection systems, those that specify systems, cover risks, attend to system alarm call-outs and certainly the end user who lives with the life cycle cost of any system installed.
Cost too plays a very important role in system equipment selection. One could even be forgiven if, on occasion, we become lost in the “smoke cloud” surrounding equipment preference. Nevertheless, having an ever increasing number and choice of detectors available to us and with the wide variety of applications in which they can be installed, there is no doubt that in many applications equipment is being misapplied.
Reasons for this include an often limited knowledge of the equipment and technology available, a lack of understanding of the application and environment, a lack of understanding of design around sustainable maintenance for the life of the equipment and budget constraints. The need to simply win projects by installing the least expensive equipment is also a known industry concern.
In order to achieve the best outcomes, the key stakeholders must communicate openly and collaboratively to identify the variables that a detection system will be required to perform against. Figure 1 includes these key stakeholders: the end user, the product developer, system designer and approval agency (where required).
It can be unclear to the different parties what the system objects are without this communication, and the incorrect selection, installation and approval of an appropriate detection system to mitigate the known risk can have very negative and costly consequences.
This article focuses on key issues that should be considered in the selection of appropriate detection systems and provides some useful processes for evaluating the available detection options in the industrial market sector. Any of the suggestions provided here though are only as successful as the communication between key stakeholders to consider them.
The Industrial Market Sector
The term “industrial” generally refers to that market sector involved primarily with manufacturing, processing and other similar operations.
Industrial applications present many challenges for effective and reliable fire detection. Not only does the fire detection system need to detect fires at the earliest possible stage it must also be able to withstand the various environmental conditions without generating nuisance alarms.
Conditions can vary from mildly contaminated to that of high background pollution. While many of the cleaner areas, for example, control rooms, switch rooms, and the like can be easily catered for by the use of ‘standard’ forms of smoke detection, there are areas that require careful thought with regard to the selection of equipment. In high background pollution environments or where constant dust exists, or even where smoke and fumes need to be tolerated as part of “normal” operation, the challenges in applying effective fire detection in these situations becomes even more difficult.
Equipment must perform when dust, dirt, and high levels of background pollution exist, contend with varying airflow conditions and finally offer the best possible benefits for the total cost of ownership over the life of the detector.
Site Characteristic & Fire System Objectives
Industrial site characteristics are generally wide and varied. Large fuel loads, high temperatures, toxic, flammable and /or corrosive gases and liquids, wash downs, variable air movement, high ceilings … the list goes on; significantly different to the commercial office or shopping centre. Many sites can be slow to evacuate creating a real need for the earliest fire detection notification possible.
The fire protection objectives may vary but are also no less important than those in the commercial world, generally set down by insurers, owners and site managers applicable to the individual site and risks. These for example may include:
- Minimise the potential for fires and explosions through an effective fire prevention plan.
- Provide an effective means of limiting the size and consequence of fire incidents through early detection, effective emergency equipment and procedures.
- Avoid high insurance deductibles.
- Lower insurance premiums.
- Ensure compliance with local codes and standards.
- Provide ease of maintenance at minimal cost.
The fire risks may not be significantly different to those in other market sectors either. There are still electrical equipment faults, ignition risks due to external factors, lighting faults, bad housekeeping and human factor risks; all can contribute to real losses. Of course there are specific risks that exist, such as mechanical equipment faults, overheating due to excessive friction or equipment malfunction, open flames and hot surfaces and process upset. Regardless of whatever fire risk exits, these must be carefully assessed and the appropriate fire detection equipment selected.
The overwhelming challenge relating to fire detection equipment however is that of its ability to withstand the conditions of the application for its life expectancy, which must include a cost consideration for maintenance.
The environmental conditions that exist in industrial facilities can present huge challenges. High levels of dust and dirt can cause malfunctions and nuisance alarms, smoke dilution in large volumetric enclosures influenced by air movement and stratification make it difficult to detect the early signs of fire. Normally-occurring background levels of smoke cannot easily be distinguished from real fire conditions and un-heated or un-cooled spaces cause temperature extremes outside of the operating range of some smoke detectors.
Onsite activities such as wash downs can damage or destroy smoke detectors. In all, the many challenges a detector must face in these facilities limits the type available and their suitability to withstand these challenges.
The correct equipment selection is the first step in ensuring a fit for purpose solution.
Selecting the Most Appropriate Fire Detection
Although regulatory requirements typically stipulate where and when fire detection should be installed, ultimately the choice of detection equipment is left those who quote and are involved in the installation process. The question is: “what are the criteria for selection”?
Figure 2 outlines some of the key points to consider in order determine system suitability and the appropriate fire detection product for the job.
In relation to individual product choice, many manufactures claim their equipment is up to the task. So how then do we prioritise our choice?
Perhaps the first step is to conduct a simple evaluation? The two key points that should not be over looked and essentially form the basis for the selection of appropriate equipment, are the consequence of loss to fire and the cleanliness of the environment in which the detection equipment is to operate.
The consequence of loss to fire can equate to how well the detection system can detect a fire, that is, if the sensitivity is poor then the risk and loss will increase. In terms of the cleanliness of the environment to be protected, if the equipment chosen is unable to cope with the conditions (environment cleanliness) and operate with minimal service and maintenance then it can be deemed inappropriate for the risk.
In addition, there is the aspect of longevity. What is the likely life cycle of the product? The more difficult the environment the more robust the equipment must be. Also, the harsher the environment the more intelligent the fire detection system must be. And do not overlook the ability to maintain the system in terms of access and cost.
To best illustrate this we can look at a simple selection matrix that has been developed and can aid in the evaluation. The chart (Figure 3, next page) has been termed the “2 x 2 Fire Detection Selection Matrix”. It provides a basic concept in which to view the selection of fire detection equipment for a number of market sectors and environments.
The “X” axis considers the environment, “Clean to Dirty”; the “Y” axis depicts the “Fire Risk” from low to high with consideration to detector sensitivity. There are four quadrants that represent the main fire market sectors.
The following is a brief explanation of each quadrant:
• Quadrant 1: Generic
The Generic Solution or Quadrant 1 can be defined as the sector where the fire industry conducts the bulk of its business, that is, the cleaner environments that are more or less considered low risk.
Typical applications include residential, commercial applications, office blocks, health care facilities, shopping centres and the like. The fire industry in general services this sector very well. Structures and applications are assessed and detection systems installed in line with codes and standards.
A variety of equipment is available from manufacturers to service this particular sector, for example, point detectors of various types, thermal detectors and beam detectors. Aspirating Smoke Detection (ASD) systems are very capable of addressing this segment and have indeed been used, although point detectors (addressable) are the most popular choice. Cost is certainly a significant factor here since compliance to minimum codes and standards is all that is required for the client. Fire contractors make their bread and butter from this sector which is very competitive.
• Quadrant 2: High Risk
The second quadrant the “High Risk” is the area that represents those clean environments but with high risk. Failure to respond at the early stages of a fire in these risks threatens business continuity and/or life safety. These high risk applications require suitable high capability detection with sound performance where any fire incident experienced could incur huge losses.
Depending on the application, specialist fire consultants and contractors and, in some cases, insurance will assess the risk and determine how the application is to be protected. Minimum requirements here are often above those suggested by codes and standards and ‘performance based’ solutions are often considered in larger facilities. Applications comprise mainly telecommunications facilities, computer and data centre facilities, semi-conductor and clean rooms and so on. Many electrical switch/substations and control rooms also fall into this category. It is also not uncommon for large open spaces and warehouses where critical equipment or goods are stored to be considered in this quadrant.
While point detection is certainly installed in these facilities ASD is still the chosen detection solution frequently used in these high risk high sensitivity areas and where very early warning detection is paramount.
• Quadrant 3: Set and Forget
The term “Set and Forget” has been used here since equipment often deemed appropriate for the application by manufacturers is installed with the confidence and the impression that it will perform with minimal issues and maintenance… in essence, install it and forget it.
This solution sits in the low risk/dirty quadrant, typically the industrial sector where the challenge in these types of environments is to select a product that will provide a level of fire detection without false alarm activity. The effort expended at the concept and design stage ensures the effectiveness of the detection system.
Unfortunately, the fire industry often places too much reliance on the products used in Quadrant 3 without understanding the environmental challenges. Owners and developers may even take a ‘let it burn’ approach to these sites. They just want to get everybody out and pass the responsibility to the fire services and their insurers.
A wide and diverse range of industrial applications and environments can fit within this sector and this tends to be where many of the issues occur. Products considered for this sector include thermal detection, CO, beams, linear heat cable and ASD; even specially designed detectors such as multi-criteria or multi-sensors have been developed to specifically try and minimise nuisance alarms. However, since industrial working environments can be very hostile the conditions can render many of these forms of detection ineffective.
On the other hand, and contrary to the belief of many in the fire industry, a realistic and viable option for smoke detection in hostile environments is ASD. A system can be specifically engineered and designed for the application and environment with an appropriate on-going maintenance plan that can perform as intended.
• Quadrant 4: Difficult and Special
Perhaps the most involved sector of all in this matrix is the “Difficult and Special”. The solutions in this sector are purely industrial and must be considered in line with the risk present and the environment to be protected. Any high value processes/assets contained within industries require special attention. Examples can include:
- Dusty/Dirty – flour mills, grain silos, fertiliser plants, mining, potentially explosive environments.
- Freezer/Cold rooms – damp areas – food processing.
- Corrosive – processing wash-down, battery manufacturing, chemical storage and processing.
The solution in most situations is not cheap to implement, will likely require some system engineering and will come with a maintenance requirement needed to ensure continued operation. Specifiers and end users in this segment usually educate themselves well with regard to the options available before making a decision. Once again ASD has been used quite successfully in this sector.
As previously suggested, all too frequently we see detection equipment suitable for the “Generic Solution” being misapplied and used, for one reason or another, in the other ‘quadrants’. The equipment selected is installed without due thought to the application or environment or the costs associated with maintenance. Communication between the key stakeholders expressed in Figure 1 can help to avoid this misapplication.
Nevertheless, regardless of the type of detection chosen, the two key factors that should not be ignored are the consequences of loss to fire and the cleanliness of the environment to be protected. If these two factors are not considered then:
- A “Generic Solution” into “Set and Forget” results in poor detection and continued nuisance alarms.
- A “Generic Solution” into “High Sensitivity” exposes the client to increased loss through delayed detection.
- A “Set and Forget” into “High Sensitivity” results in high exposure to loss.
The “Difficult and Special” usually does not go too far wrong as the client, engineer or plant manager has a high level of involvement in the solution.
The matrix is offered as a simple means of proving some food for thought in terms of detection equipment selection and is by no means a total answer to evaluating all applications. Nonetheless, having consideration to the industrial market sector and conditions, aspirating smoke detection is a very real option and a well designed and engineered system using purpose built equipment will certainly offer a solution.
With this in mind, the next step would be to become familiar with the site, risk application and environment with the view to installing and ASD system. In the next issue of International Fire Protection, I plan to provide some advice with regard to the installation of ASD systems in industrial applications.
For further information, go to www.xtralis.com