Room Integrity is often an overlooked aspect of a clean agent installation whereby it is required that the concentration of the clean agent meets the sufficient “Hold Time” when discharged in a room in order to properly extinguish fires. Achieving this “Hold Time” is largely dependent on the overall leakage in the room otherwise referred to as the “Equivalent Leakage Area” or ELA in the industry. The most common and widely accepted way of determining whether the enclosure achieves the sufficient “Hold Time” for the agent is by carrying a Door Fan Test (DFT). This involves pressurising and depressurising the enclosure to check if it achieves the pass rate and if the enclosure fails the test, the presence of leaks are the common contributors to this failure. The industry introduces various methods to identify these leaks which are then patched up before the DFT is being conducted again. What is an often-neglected fact is that as a buildings age or their internal use is changed, leak sites will begin to develop. If the gas cannot be held in the confined space on discharge during a fire event, the probability of its suppression diminishes in proportion to the size of the leak sites. Clean agents are designed to operate in limited spaces where there is a need for speed of suppression given the asset risk and where the space is occupied by people. They must be easily maintained in-situ, non-flammable and non-toxic. They must comply with ISO 14520 and NFPA 2001 standards demanding fast discharge in 10 seconds and fire extinguishing within 30 seconds, delivering confidence to the operator that it delivers “best fire safety practise”.
Despite DFT being a reliable method to determine the “hold time”, methods to locate the leak sites themselves are inaccurate such as the use of smoke pencils or draught testing using the back of a hand. The limitations of the DFT often lie in the fact that the leakage areas are only identified during installation of the clean agent system and make no acknowledgement to the fact that additional leak sites may develop throughout the lifetime of a building.
In the event of fire, a pencil sized hole between compartments size 6m x 6m x 3m would take just 4 minutes before a person would not be able to see their hand due to smoke. If this compartment was a fire escape, there could be a severe threat to life if people cannot escape. Thus it is clear to see why the maintenance of the integrity of the compartments is essential to genuinely aid the safety to human life. As building age or their internal use is changed leak sites develop and the threat to people becomes high.
APPROVED DOCUMENT B (ADB)
The regulations demand that compartmentation is upheld for the safety of the individuals, who entrust their lives into its integrity. Approved document B, Fire Safety, Volume 2, Buildings other than dwelling house states that: 8.0 Every compartment wall should form a complete barrier to fire between the compartments they separate. 8.35 – any stairway or other shaft passing directly from one compartment to another should be enclosed in a protected shaft so as to delay or prevent the spread of fire between compartments. However, despite regulations best effort to promote the implementation of compartmentation and room integrity, the last review of the Building Regulations Approved Document B was made in 2006 (12 years ago) and its next review was not due to be completed until 2022 (which would then be a gap of 17 years), meaning that the attention that is deserved is often disregarded.
Coltraco Ultrasonics have provided a smart solution for quick and easy assurance of compartmentation and leak detection. The proprietary device known as the Portascanner® 520 ultrasonic leak detector uses ultrasonic technology to not only pinpoint precise leak locations, but to determine their leak apertures as small as 0.06mm with a tolerance of +/-0.02mm, and is by far the most mathematically proven accurate device for this function.