Active fire protection
From Wikipedia, the free encyclopedia
Active fire protection (AFP) is one of three components of structural fire protection.
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General Active fire protection Fire suppression Fire extinguishers Fire detection/alarm Fire alarm control panel Practices |
[edit] Definition and role
Active means that items or systems are 'activated', mechanically or electronically and require a certain amount of motion, activity, electricity and/or heat in order to function. Typically this refers to systems such as sprinklers, where the sprinkler bulb which holds back the water breaks and the water moves, as an example; or fire or smoke detection systems, where smoke or heat are sensed and the detector or connected alarm system is activated.
Within AFP, there are two branches: Detection of fire (manual or automatic), and suppression of fire (manual or automatic).
[edit] Lobbying
Industry lobby groups are typically divided into these two camps, active and passive fire protection. Each try to garner more business for themselves through code hearings etc. At present, AFP appears to be winning this fight.
The omniscient point of view would certainly favour a balanced approach between all three parts, Education, AFP and PFP. Engineers who actually design the products upon which everything is based, who actually conduct fire testing and know that some tests pass and some test fail (both in AFP and PFP) and know how much field conditions can influence matters, ordinarily realise that no one side has all the answers. This very small group of people, however, who engage in product design, testing and certification, does not have a recognisable voice in shaping the course of the battle that continues to rage between AFP and PFP. It is not even an identifiable trade per se. You cannot learn it in school and the majority of information is proprietary in nature.
While PFP is the basis of most older codes, it is losing ground to AFP, in part because of the allure of being able to quantify matters better. Water flow and electricity are the cornerstones of AFP and they are easily quantifiable and fit neatly into tables and standards. Moreover, the trend towards performance based or objective based codes tends to favour anything that supports less substantial construction. A wall with a 1 hour fire-resistance rating can be safely presumed to cost less money to build than a 3 hour rated wall, as fewer materials are required for the lesser rating. For instance, a 1 hour rating may only require 1 double layer of Type X drywall, whereas a 2 hour rating needs four layers, 2 on each side of the stud, respectively. One may look this up in Underwriters Laboratories directories or the Canadian National Building Code (NBC). The use of automatic suppression with "risk informed" codes, often favours the savings of less solid structures, which are elaborately sprinklered. At times it works the other way around, as firewalls that protrude through the roof structure are used to "sub-divide" buildings such that the separated parts do not require sprinklers.
