What is Room Integrity Test – Door Fan Test?
When making engineering designs for rooms where clean gas fire extinguishing systems will be installed, it is taken as a basis that the room is completely leak-proof. For this reason, in order to determine and report whether the fire extinguishing system designed for the room adequately protects the room against fire in the event of a fire, performing the gas discharge test (live test) instead is a recommended test method according to all national and international standards.
Clean gas fire extinguishing system, upon detection of fire, compressed clean gas (can be halocarbon or inert gas) is used in the room is released into it. Once the enclosure is fully flooded with gas, gas will begin to leak out at a rate that depends primarily on the leakage area at the bottom of the enclosure. This is because most gaseous substances (except nitrogen) are heavier than air. If there is a leak in the room, gas begins to leak out of the room and air replaces the gas.
A clean gas extinguishing system is designed to protect critical systems within the room for a specified period of time after the gas is released, called the ‘hold time’. This can usually be 10 minutes or in some cases 20 minutes or any other time period depending on the exact situation and the standard used. To keep the gas inside the chamber, the chamber must be sufficiently airtight to prevent the gas from leaking out too quickly: the less leakage, the greater the retention time of the chamber.
Besides gas loss due to leakage, another important factor to consider when designing rooms with clean gas extinguishing systems is Peak pressure. When the substance is released into a chamber, the pressure in the chamber will increase and a peak pressure will be reached (before the required retention time begins).
For inert substances (such as nitrogen and argon), a positive peak pressure is reached due to the large amount of the substance released from a high-pressure cylinder. For halocarbons (such as HFC-227), both negative and a positive peak pressure will occur. A peak pressure will occur due to the cooling effect caused by the phase change of the gas (negative pressure) and also due to the explosion of nitrogen (pressurization agent) at the end of the process (positive pressure).
Both positive and negative peak pressures can be high enough to cause serious damage to the enclosure. Damage can range from cracks in structures to completely burst walls, door frames and ceilings. When damage occurs, the substance will leak out of the enclosure and the fire will not be suppressed as desired.
The room integrity test is evaluated by the door fan test. This air tightness test is used to measure the leakage of a room. Based on leakage, the software estimates the retention time and peak pressure performance of rooms equipped with clean gas extinguishing systems.
The door fan test will calculate the results taking into account the worst case scenario; It draws air through leaks present at the top and bottom of the enclosure to anticipate the descending interface of the suppressant. The time required for the gas to drop to the minimum maintained height defines the retention time of the concentration.
How to Perform Room Integrity Test – Door Fan Test?
Room Integrity Test or Door Fan Test is a test performed to report the concentration of the gas in the room after gas discharge and how long it remains at the specified protection height, in the light of the values obtained by pressurizing and depressurizing the spaces where clean gas fire extinguishing systems are installed with the help of a fan. Based on the leak, the software estimates the retention time and peak pressure performance of rooms equipped with a clean gas extinguishing system. The time required for the extinguishing agent to drop to the minimum protected height defines the concentration retention time.
Points to be Considered?
*Care should be taken to ensure that the room is fully sealed against fire as much as possible. All openings in the rooms created during manufacturing must be closed with fire-resistant materials.
*When choosing a testing company for the test, care should be taken to ensure that the company’s test applicator has a valid-up-to-date certificate and that the people coming for the test are the people whose names appear on this certificate.
*It should be ensured that the test devices are calibrated within the periods specified by the manufacturer and have valid calibration documents. (Retrotec company provides checking of calibration documents on the site)
*Different unloading scenarios can be applied on the program during testing. Incorrect reporting should not be made using methods that are not compatible with the design of the extinguishing system and room in the room, just because it meets the retention period. Otherwise, in case of a possible fire, insurance companies may exclude insurance coverage due to incorrect reporting.
Why FSS?
Our company uses RETROTEC brand test equipment, which is world-renowned and proficient in room tightness tests. In addition, the tests are carried out by our engineers certified by Retrotec (Level 1-2-3). The calibration of our devices and the certificates of the practicing engineers are updated according to the periods recommended by the company.
In case the test results are negative, our customers are provided with reports on the scenarios in which the test may be valid or how it can be compliant.
As FSS, in addition to performing room tightness tests of newly installed systems, we also carry out retests or accuracy/compliance checks of already performed tests and report them.
CONTACT US to get a quote or information about room tightness testing.