Room Integrity Test (Door Fan Test)
Facts!!
Fire suppressing agents are designed to protect rooms in addition to using traditional sprinkler methods.
59% of Clean Agent systems FAILED to keep out fire and smoke.*
Agents MUST remain in the room for a specified time for proper suppression to occur.
Room Integrity Testing is the only National Fire Protection Association (NFPA) recognised test to determine agent retention time and room leakage.
NFPA Requirement On Room Integrity Test
Compliance with NFPA 2001 (2008 ED.) requires :
Clause 7.4 The enclosure protected by the clean agent shall be thoroughly inspected at least every 12 months to determine if penetrations or other changes have occurred that could adversely affect agent leakage or change volume of hazard, or both. Where the inspection indicates conditions that could result in the inability to maintain the clean agent concentration, the conditions shall be corrected.
Clause 7.2.3 Where external visual inspection indicates the container is damaged, additional strength tests shall be required.
Clause 7.6.1 All persons who could be expected to inspect, test, maintain or operate fire systems must be highly trained.
Clause 7.7.2.3 All total flooding systems shall have the enclosure examined and tested to locate and effectively seal any significant air leaks that could fail in the enclosure to hold the specified agent concentration level for the specified holding period. The current preferred method is using a blower door fan unit and smoke pencil.
“Experience has shown that the primary cause of discharge test failure is the inability to hold the specified concentration for the entire holding period. “
Room Integrity Test. What Is It?
An Integrity test predicts how long fire suppressant agents take to descend to a given level in the room without having to release the agent itself.
The Integrity test is carried out using:
Modular adjustable panels for the door frame which adjusts to fit a wide variety of door sizes.
Calibrated Fan(s) and range configuration
Calibrated gauge(s)
Laptop Computer
Enclosure Integrity Software
The system is set up in an available doorway. The protected area gradually pressurised, and the fan flow readings are recorded, then to check those measurements the room is depressurised to take measurements to compare. The predicted retention time is calculated from the leakage characteristics and the enclosure and extinguishing system data.
A retention time of 10 minutes is the standard minimum period the suppressant agents except for Co2 that requires a 20 min retention Time. Ten minutes is long enough for most deep-seated fires to be cooled so that reignition is unlikely. Gaseous fire suppression systems should provide adequate time for the emergency services to attend and in most cases, prevent the fire from taking hold.
When An Integrity Test Is Required?
When you have a gaseous suppression system installed, your protected area requires testing to ensure that the suppressant is maintained within the area and works in case of fire. It is a requirement of most insurance policies and British standards that your suppression system is tested at least annually.
An Integrity retest is also required if any modifications are made to the area.
So moving a partition, fitting a new door, installing new cables or pipes or in any way modifying the structural perimeter of an enclosure will almost certainly affect gaseous fire suppression retention. Any changes to the room (no matter how small or inconsequential they may seem) requires a retest to be carried out.
How Is A Room Integrity Test Carried Out?
1. Background
Successful extinguishant of a fire by a gaseous extinguishing system is critically dependent upon the extinguishing concentration being maintained for a specified period after discharge. A retention time of ten minutes applies in most cases. Failure to do so may result in reignition and fire spread.
Integrity testing using door fan methodology provides a means of predicting the retention time without the need to release the extinguishing gas. It is a requirement of all relevant British, European and International Standards that integrity tests be conducted on initial installation and after that at annual intervals.
2. Methodology
The test methodology is per the general requirements specified in the relevant parts of BS 5306, BS: ISO 14520, NFPA 12A, NFPA 2001 and the BFPSA Code of Practice for Gaseous Extinguishing Systems. It applies to all extinguishing gases (e.g. Halon1301, FM200, Argonite, Inergen) and can be used for descending interface, mechanical mixing and extended discharge applications.
3. Principle
The door fan equipment is located in a doorway to create small pressure differentials between the enclosure and surrounding areas. Pressure and airflow measurements are made, from which the leakage characteristics of the enclosure are established. The predicted retention time is calculated from these leakage characteristics and the enclosure and extinguishing system data.
4. Apparatus
Calibrated 240V/110V AC variable speed fan(s)
a frame which fits into the door opening
pressure gauges
chemical smoke pencils
portable computer and sundries.
5. Procedure
The enclosure is measured, a sketch plan made and the type and quantity of extinguishant recorded. The height of the highest hazard in the enclosure (risk height) is noted.
Where relevant, doors within the enclosure are opened, and a number of false floors and ceiling tiles are removed so that the protected enclosure is tested as one space. False ceiling tiles are not removed where the ceiling void is not protected. A return air path is established outside the enclosure by opening doors/windows as appropriate.
The door fan equipment is set up in a suitable door opening. The door does not need to be removed. Personnel may continue to work within the enclosure during the test and may enter and leave, subject to access, except when pressure readings are being taken. Access restrictions are less than a few minutes at a time and can be discontinued at once if necessary.
Any air handling equipment involving supply into, or extract from, the enclosure requires to be set by the client or end-user into the same condition as would occur on system discharge (usually dampers closed and fans off). This need occur only while pressure readings are taken. Recirculation and a/c units without fresh air make-up may be left operating throughout the test to prevent temperature build-up in the enclosure. Details of the arrangements are noted.
The extinguishing system and enclosure data obtained earlier are entered on to the computer. The computer calculates the design concentration and the column pressure (typically between 4 and 20Pa) that would be exerted by the gas after discharge.
The door fan(s) is used to pressurise and depressurise the enclosure to the column pressure and the fan pressure required in each case is recorded. For specific system design, a series of pressure readings are taken. The pressures used are shallow and present no risk to the enclosure or the equipment.
The pressure data is entered on to the computer, which calculates the airflow, equivalent leakage area and the retention time.
If the result satisfies the specified retention time (usually 10 minutes), the enclosure is deemed to have passed the test.
If the retention time is less than that required, a detailed inspection is undertaken to establish the main leakage paths. This includes floor and ceiling voids as relevant. On occasions, chemical smoke pencils may be used in conjunction with the door fan equipment to assist leakage identification. These produce only minimal quantities of smoke at the perimeter of the enclosure and are not used in the vicinity of any sensitive electronic equipment.
In the event that the leakage path distribution is found to be other than the worst-case situation assumed in the initial computer calculation, the retention time is recalculated accordingly. Also, if practicable, significant leaks may be temporarily sealed, new pressure readings taken and a revised retention time calculated. Retention times meeting requirements are recorded as passes, subject to any necessary corrective actions; those not doing so are reported to have failed.
The duration of the test is approximately two hours per enclosure.
A written test report is submitted to the client within a specified period (usually 24 hours). If required (by prior arrangement) a summary report can be prepared on-site. The report contains details of the enclosure, extinguishing system parameters, pressurisation results and predicted retention time graph. Recommendations are given advising the sponsor of any leakage areas or other features requiring remedial action.
