Level 1 Manual

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Level 1 Training

for

Fire Enclosure Integrity Design, Testing,

and Witnessing

For complying with • NFPA 2001 - Appendix C

• NFPA 12A - Appendix B • ISO 14520 – Annex E

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Date Person Rev Notes

May 2, 2003 TL 0.00 Initial Copy

Aug 14, 2003 TL 0.01 Major additions from Old Level 1 manual Sept 03, 2003 TL More Major Additions

Added Copyright Oct, 2003 TL 0.03 Added design section

Added Retention Time Section Changed E2001 to CA2001 in disclaimer

Added Appendix C – Enclosure Design Specification Nov 2003 TL 0.04 Added witness chapter

Nov 2003 TL 0.05 Finished witness chapter

Added Enclosure Verification Form Nov 2003 TL 0.06 Added Glossary or Terms

Nov 19 2003 CG Reviewed entire document Sept 20, 2004 JG 0.10 Modified NFPA excerpts

9/22/2004 9:59 AM

M:\Projects\Training\Fire\Level 1\Manual\Level 1 Manual (rev 0.10).doc

This document contains materials protected under International Copyright Laws. All rights reserved. No part of this document may be copied or reproduced in any form or by any means without the prior written consent of Retrotec Energy Innovations Ltd.

Retrotec makes no warranties with respect to this documentation and disclaims any implied warranties of merchantability, quality, or fitness for any particular purpose. The information in this document is subject to change without notice. Retrotec reserves the right to make revisions to this publication without obligation to notify any person or entity of any such changes.

CleanAgent 2001 and CA2001 are Trademarks of Retrotec Energy Innovations Ltd. Other trademarks or brand

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1 WHAT IS ENCLOSURE INTEGRITY TESTING... 6

1.1 Why Clean Agent Systems?...6

1.2 The Discharge Test ...6

1.3 The Door-Fan Test ...7

What is a Door-Fan test?...8

Static Pressures...8

Total Room (Whole Room) Leakage ...8

Measuring Lower Leaks...9

Predicting the Retention Time...9

1.4 Other Door-Fan Applications...9

Pressure Relief Vents ...9

Smoke and Contaminant Movement ...10

2 AGENT LOSS MECHANISMS... 11

2.1 Pressures Across Holes: How Agent is Lost...11

2.2 Pressures That Cause Agent Loss ...13

Dynamic Discharge Pressure ...13

Gravity...13

Convection ...14

Forced Air Circulation ...15

Static Pressures...15

Wind Pressures...15

2.3 Enclosure Behavior during Retention ...16

The Descending Interface...16

Continual Mixing ...18

3 CALCULATING RETENTION TIME... 19

3.1 What is Retention Time?...19

3.2 Retention Time in the Descending Interface Case ...20

3.3 Retention Time in the Continual Mixing Case...20

3.4 Retention Time in the Extended Discharge Case ...20

3.5 Retention Time Dependencies...21

Leakage Area (ELA) ...21

Agent Initial Concentration and Final Concentration ...21

Equipment Height and Enclosure Height...22

3.6 Measuring Maximum Agent Height?...22

3.7 Measuring Minimum Protected Height? ...22

4 RECURRING DESIGN PROBLEMS... 24

4.1 Cascading Pressures ...24

4.2 Common Sub-floor...25

4.3 Pressurized Sub-floor ...26

4.4 Common Above-ceiling Spaces: Discharge will pull smoke in ...26

4.5 Common Above-ceiling Spaces: HVAC Leakage ...27

4.6 Suspended Ceilings Too Low ...27

5 GOOD ENCLOSURE DESIGN PRACTICES... 28

5.1 Superior Protection for Less Money! Interested? ...28

5.2 Run walls slab to slab...28

5.3 Eliminate T-bar suspended ceilings ...29

5.4 Maximize the room height and volume...29

5.5 Select an appropriate retention time...30

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6.1 How a Single Door-fan “Sees” a Room ...31

6.2 The Lower Leaks Test...32

7 WITNESSING AN ENCLOSURE INTEGRITY TEST... 33

7.1 Technician Training ...33

7.2 Software Conformance...33

7.3 Room Pressure Gauge Calibration Certificate ...33

7.4 System calibration ...34

7.5 Field Calibration check procedure ...34

7.6 Return Path...34

7.7 Room and Equipment Set-up ...35

7.8 Static Pressure Check ...35

7.9 Gauge Set-up...35

7.10 Flow and Room Pressures Entered Correctly...36

7.11 Range Selection...36

7.12 Testing in Both Directions ...36

7.13 Determining the Leakage Split – The BCLA Test ...36

7.14 Technical Judgment...37

7.15 Yearly Retests ...37

7.16 Commonly Needed Inert Gas Clarifications ...37

7.17 Enclosure Integrity Test Verification Form ...38

7.18 Standards and How They Apply ...43

7.19 Range List for Door Fans...44

Flow Range Pictures for 2000 Series Door-fans...44

Flow Range Pictures for 900 series Door-fans...47

7.20 Small Room Retention Times ...48

Selecting an Appropriate Retention Time ...48

Recommended Times for Small Rooms...48

8 APPENDIX A–AGENT COMPARISON... 50

8.1 Standards...50

8.2 Agents ...51

8.3 Specific volume and density constants for agents...52

8.4 Concentration Ranges ... from an enclosure leakage perspective ...53

8.5 Comparing Retention Times ... descending interface case...55

8.6 Comparing retention times ... continual mixing case ...56

8.7 Conclusions ...57

8.8 Agent Comments...58

9 APPENDIX B–NFPASTANDARD EXCERPTS... 59

9.1 NFPA 2001 Standard (Year 2004 Edition) ...59

9.4 NFPA 12A Halon...68

9.5 NFPA 12 for CO2...69

10 APPENDIX C–SAMPLE ENCLOSURE INTEGRITY TEST SPECIFICATION... 70

10.1 General Enclosure Design Guidelines...70

Slab To Slab Walls or Solid Ceiling ...71

Avoidance of Attached Volumes ...72

Penetration Planning ...72

Document Passageways ...73

HVAC Dampers ...73

"Un-closeable" Openings ...73

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10.2 Enclosure Integrity Specifications...75

Enclosure Integrity Performance Specification...76

Enclosure Integrity Prescriptive Specifications...76

10.3 Clean Agent System Specifications ...78

10.4 HVAC Specifications...79

Ductwork...79

10.5 Approval/Acceptance of Clean Agent System...80

10.6 Approval/Acceptance of Enclosure Integrity ...80

10.7 Warranty...82

11 APPENDIX D–ENCLOSURE INTEGRITY VERIFICATION FORM... 84

12 APPENDIX E–GLOSSARY OF TERMS... 88

13 APPENDIX E–CA2001DEMO EXAMPLE ... 95

13.1 Home tab ...95

13.2 Building/Room tab ...96

13.3 Agent/Test tab ...96

13.4 Total Leaks tab...97

13.5 Retention tab ...97

13.6 Total Leaks tab...98

13.7 Field Cal tab ...99

13.8 Wind Losses tab ...100

13.9 Venting tab ...101

13.10 Saved Tests tab...102

13.11 Calibrations and Reports ...104

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Section 01 – Introduction to Door-Fan Testing

1 What is Enclosure Integrity Testing

1.1 Why Clean Agent Systems?

Water-based suppression systems provide only a minimum amount of fire protection. For critical company information systems, data centers, paper archives, museums and other enclosures whose contents are susceptible to water damage, sprinkler systems will indeed protect the building from fire damage, but at the expense of the contents being protected! It was due to this necessity to provide sufficient fire protection for the building and also to mitigate or eliminate damage to the contents that non-water-based suppression systems were introduced. Halon was one for the first of these fire suppressants. Halon (and other gaseous systems) presented a new problem to the designer however; to extinguish a fire and to keep it suppressed, the gas needed to be present in the enclosure for many minutes. Enclosures now had to be “tight” enough to retain the Halon in sufficient concentration and for sufficient time to ensure that re-ignition did not occur.

1.2 The Discharge Test

Prior to 1988, the capability of an enclosure to retain its fire suppressant was assessed by a Discharge Test. Sensors that detected fire suppressant concentration were installed at various points of interest around the room and then the fire suppressant system was discharged. During the discharge, these sensors where monitored, usually with strip-chart recorders. A room would pass or fail the test by examining the agent concentration at the top of the equipment over time. The room passed the test if sufficient agent

concentration was present after the required hold time at the top of the equipment. In the event that the room failed, usually the only recourse was for a sealing job to be

undertaken and then, for the discharge test to be repeated.

Aside from the cost of repeated discharge tests, Halon, the predominant agent at the time, was also known to be an ozone depleter. In 1989 the EPA mandated the industry to

eliminate all future Halon discharges for the purpose of enclosure integrity verification. Even today, the discharge test is of limited use due to:

1) High Cost: Costs of labor and product to repeatedly recharge system is high. 2) Disruption: Discharge test is very disruptive to occupied enclosures.

3) Failure Identification: In the event of failure, the discharge test offers no opportunity to identify leak locations.

4) Repeat Testing: Although the Standards encourage annual retest, the above factors virtually preclude any retesting

FM200 Discharge

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Section 01 – Introduction to Door-Fan Testing 1.3 The Door-Fan Test

Towards the end of the discharge era, several progressive installers found a unique way to ensure that they would always pass the discharge test. They used a fan mounted in a doorway to create pressure which in turn allowed them to locate hidden leaks using chemical smoke. When the leaks were sealed, the room would always pass the discharge test. It worked so well that the discharge test has now been replaced by the Door-Fan Test.

NFPA 2001, NFPA 12A, and ISO 14520 now all require

an enclosure integrity test as part of the acceptance procedure for all clean agent systems, including all halocarbon and inert gas agents. This comprehensive test and calculation procedure predicts how long the agent will stay in the room if it were ever discharged.

The Enclosure Integrity Test’s primary goal is to predict the enclosure’s retention time in the event that the Clean Agent Fire Suppression System is discharged.

The discharge test typically only verified agent distribution in one location, usually the most favorable. This often led to assuming that other approval steps for the enclosure could be overlooked. To make matters worse, the discharge test was never repeated. The room leakage would increase steadily, compromising the system from day one.

The Enclosure Integrity Test’s simplicity and accuracy, encourages trouble-shooting of problem rooms and retesting either periodically or after enclosure modification.

In the past, enclosures were often designed merely to pass the discharge test. This often left rooms with fire barriers on only 5 sides and with the top completely open. Often only ceiling tiles stood between the protected enclosure and an adjacent unprotected area! Smoke or fire could readily enter from above.

The Enclosure Integrity Test is also the best way to ensure that the enclosure is protected from smoke events occurring OUTSIDE of the protected room!

Now, the EPA, Industrial Risk Insurers, Factory Mutual, other insurers, Fire suppression equipment manufacturers, and the FSSA all encourage Door-Fan tests on every installation. Both NFPA (Sec 4-4) and ISO (Annex E) require Door-Fan tests to be repeated every 12 months, or whenever new holes are made in the enclosure.

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Section 01 – Introduction to Door-Fan Testing What is a Door-Fan test?

The Door-Fan Test measures the size of holes in the enclosure using a door-fan to pressurize the room to the same pressure it would experience during discharge. Knowing the pressure inside the enclosure, the pressures across each wall, and the flow through the door-fan to maintain the enclosure pressure, a computer calculates the retention time.

Static Pressures

When conducting a door-fan test it is very important to be aware of, and to measure any static pressures in an enclosure. There are two static pressures to be aware of; the static pressure at the time of the door-fan test and the static pressure that will exist during discharge. These static pressures can be created due to damper or duct leakage, wind loading on the enclosure and many other reasons. This static pressure will act to push or pull the agent out faster than normal, reducing the retention time and must be taken care of in any calculation of retention time. State-of-the-art software, such as Retrotec’s CA2001 Windows Software, takes this calculation into account. Refer to C-2.5.2.3 & C-1.3.21 in NFPA2001 for additional information on this concept.

Total Room (Whole Room) Leakage

Using a single door fan to pressurize the room will measure the total leakage area of the entire room; floor, walls, and ceiling. This result is called the Whole Room or Total Room Leakage. Because this measurement includes the leakage in upper area of the room, where the agent would not normally leak out, it often results in

unrealistically large leakage and unrealistically short retention times. A room which passes a Whole room test would most certainly pass a discharge test. A room which fails the Whole Room Test however, might very-well pass a discharge test if the majority of leaks were at ceiling level.

When conducting a Total Leaks Test, a single door-fan is temporarily installed in a doorway leading from the protected room to a large open area or outdoors. The fan speed is adjusted to obtain a pressure difference between the test room and the volume surrounding the room. This pressure (usually 10 to 15 Pa) is similar to the steady state pressure (column pressure) exerted by the agent at floor level immediately after discharge. The computer converts flow and pressure readings into an Equivalent Leakage Area (EqLA), the total area of all the cracks, gaps, and holes in the room.

Door-fan pressurizes room

Air flows out through leaks in floors, walls and ceiling

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The measurement is done by first blowing air out of the room (depressurization) and then into the room (pressurization). The two readings are averaged to reduce errors due to static pressure, HVAC operation, wind and faulty gauge zeroing.

Measuring Lower Leaks

A room that fails the Total Leak Test can easily pass a discharge test if all of its leaks are located at the ceiling level. In this extreme case, the heavier-than-air agent settles to the floor and, with nowhere to leak to, remains there indefinitely.

Since the leakage area of the above-ceiling space is generally far greater than the below-ceiling leakage area (BCLA), measurement of the BCLA can dramatically increase the

calculated retention time. The BCLA can be measured separately using a flex-duct or plastic on the ceiling to neutralize any leaks in the above-ceiling space. These techniques eliminate the upper leaks for the purpose of measuring the more important lower leaks. Both leakage measurements are then used to make a more accurate prediction of retention time. Predicting the Retention Time

After discharge, the heavier-than-air agent creates a small positive pressure within the enclosure. Flow develops whenever holes have pressure across them. The greater the pressure and the larger the hole, the greater the amount of agent lost. As the agent leaks out the bottom, a small negative pressure develops at the top. This pulls air in through the higher level leaks. Each agent creates a slightly different pressure as indicated by the densities as shown in NFPA 2001.

The door-fan test measures the size of the holes within the enclosure. The quantity of agent and height of the room determine the pressure difference across holes in the enclosure. Knowing the size of the holes, the pressure difference, and the minimum equipment height or agent concentration, Retrotec’s CA2001 software predicts how many minutes will pass until the equipment is no longer protected. This time, from discharge until the equipment is no longer protected is called the Retention Time.

1.4 Other Door-Fan Applications

In addition to the enclosure integrity test, the door-fan equipment can be used for a number of other applications.

Pressure Relief Vents

Of interest to the clean agent installer is the testing of rooms for adequate pressure relief. In all cases, if a room is too tight, potentially damaging pressure can develop after agent discharge. Using Retrotec’s CA2001 software, the door-fan test equipment can be used to predict the maximum expected pressure in the room during discharge and calculate the amount of venting required.

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If pressure-relief vents are installed in the enclosure, the door-fan test equipment can be used to pressurize the enclosure and test correct design and functioning of the vents. Retrotec’s experience having tested 100’s of enclosures and supported 1000’s of testers world-wide is that pressure relief vents rarely open at the prescribed pressures and if they do, rarely open fully as required.

The door-fan equipment can also be used to test for blockages in venting capacity not apparent to visual inspection. Crushed duct-work, debris in duct-work, blocked weather covers and malfunctioning dampers are all easily tested using the door-fan.

Smoke and Contaminant Movement

An emerging industry is the evaluation and prediction smoke and other contaminant movement through multi-floor building. Conventional predictions have been based on guessed or “typical” leakage areas in floors, walls and ceiling. The door-fan test however can be used to isolate and measure leakage areas of individual walls, ceilings, shafts and floors.

New techniques have been developed using three specially designed door fans that allow the tester to measure the leakage of each floor slab separately. Floor to elevator shaft and floor to stairwell leakage can also be measured. Individual shafts can be measured in their

entirety.

The preliminary results of this testing indicates that most buildings leak ten to 100 times more than they should in order to be safe from smoke moving through the building. Check the Retrotec website at www.retrotec.com or e mail [email protected] for the latest paper on this topic.

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Section 02 – Agent Loss Mechanisms

2 Agent Loss Mechanisms

2.1 Pressures Across Holes: How Agent is Lost

Consider the case of a bucket; regardless how large an opening at the top, fluid will not leak out.

The same is true for an enclosure full of agent. Shortly after the discharge, once the agent settles out, a room with large openings at the ceiling level will contain the agent

indefinitely.

With a hole at the top and a hole at the bottom, water will leak out at a rate dictated by the ratio of upper and lower leak areas. If the upper leak is reduced enough, water leakage out the bottom will be reduced. Generally, even if the upper leaks are entirely sealed, water will still slowly leak out as air bubbles into the bucket.

The same is true in the enclosure full of agent. Sealing the upper leaks will eventually slow the flow of agent out of the room, but will not stop it. Agent leakage is primarily governed by the lower leaks.

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Given an unlimited capacity for replacement air to enter the bucket, leakage is directly related to the total area of the lower leaks. Double the size of the holes and the leakage doubles. Triple the size of the holes and the leakage triples.

2x holes

=

2x leakage

3x holes

=

3x leakage

Depending on the density/concentration of the fluid in the bucket; for the same sized hole, as the concentration increases, so does the flow out of the bucket increase. It is not directly proportional however, doubling the leakage area only adds 50-60% leakage.

0% Agent

5% Agent

10% Agent

This is of significant importance in enclosures that fail. A very common misconception is to simply add more agent to increase the retention time. This is, in fact, wrong. Adding more agent increases the concentration and will actually reduce the retention time!

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2.2 Pressures That Cause Agent Loss

There are a number of influences that will act on the agent/air mixture as the agent enters the enclosure and during the time it remains within the enclosure. These influences will play a key role in how agent is lost from the enclosure.

Dynamic Discharge Pressure

In the seconds during and immediately following discharge the agent mixes violently with the air in the enclosure. Swirls and eddies due to various combinations of warming, cooling and expansion lead to a homogeneous concentration of agent throughout every corner of the flooded enclosure.

Pressures created in the first few seconds of discharge (dynamic discharge pressures) are ignored in the retention time prediction model. While these pressures can be very large, they often swing wildly between positive and negative values, making them difficult to predict. In addition, their duration is very short making their contribution small when compared to steady state losses. Non-the-less, a small amount of initial agent loss is assumed to occur and the equations used to calculate the required concentration per NFPA have a loss factor built in.

What happens next, during the remaining minutes of the retention time however is virtually impossible to model. It is useful however to understand the mechanisms at work within the enclosure and how they affect the distribution of the agent.

Gravity

Gravity acts on the heavier-than-air clean agent/air mixture within the enclosure and, in the absence of any other influence, will cause the agent/air mixture to leak out the bottom of the enclosure. Air is then pulled into through the leaks in the top of the enclosure. A short period of time after the discharge a well-defined agent-air interface may form, much like the interface between water and air in a bucket, or the way fresh water flows on top of salt water.

Agents that are significantly denser than air (such as Novec which is 10x the density of air, and most of the other halocarbons) will be more influenced by gravity than agents that have densities similar to air (such as Argon and the other inert gases). The more dense agents tend to merely run out faster than the less dense. For example, 40% CO2 runs out about

twice as fast as 40% Argon.

N2, which is actually less dense than air, should theoretically rise to the ceiling, though

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1. Agent/Air Mixture Leaks Out

2. To be replaced be air

If there were no leaks in the floor, a pressure would be created at the floor due to the column of heavier-than-air agent pressing upon the floor. This pressure is referred to as the column pressure. If floor leaks exist, as they always do, the column pressure is dropped partially across the floor and partially across the ceiling depending on the ratio of leaks, much like how voltages are dropped across two resistors. It the holes are the same size, then about half the Column Pressure is dropped across the ceiling and half across the floor. The absolute sum being the column pressure. A positive value will be felt at the lowest portions of the enclosure, near zero in the middle of the column and a negative pressure at the top of the air-to agent interface.

Convection

“Hot air rises” and this is no exception in an enclosure. Even though computer and other electronic equipment may be shut down at the time of discharge, 100’s or 1000’s of watts of heat are still contained in their chassis. This heat will cause localized “plumes” to form around the equipment, drawing in gases from the floor level, transporting them up the equipment towers, to be released above the equipment and cycled back to the floor.

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Even in the absence of hot equipment, upward convective currents will form along locally warm walls and downward currents will form along locally cooler walls.

Lighter gases will be more significantly affected by convection than heavier gases.

Forced Air Circulation

Self-contained air conditioning units, circulating fans, HVAC systems, and even equipment cooling-fans all act to

mechanically circulate air around the room. If these fans are running during discharge and during the retention time, they will act to continually churn the agent and air within the enclosure.

Static Pressures

Leaky ductwork, HVAC systems with a fresh air supply, and stack effects are just a few of the things that can cause a higher pressure to exist in the enclosure relative to neighboring rooms or outside. This higher pressure, not due to the column pressure of the agent itself is called a Static Pressure.

Due to conditions beyond the control of the tester, a static pressure may be present during the Door-Fan Test. By sealing up the blower with a cover or a piece of cardboard, this static pressure can be measured and by opening up a small hole in the blower (for example, by removing a single plug in the low-flow plate) and using the smoke puffer, the direction of the static pressure can be observed. A static pressure that is present during the Door-Fan Test, is called the Static Pressure During Test and must be measured in both magnitude and direction for the test to be accurate.

A static pressure within the enclosure during the retention time will act to significantly increase the flow of agent out of the room. In extreme cases, with very leaky HVAC systems or extreme wind conditions, the agent is literally “blown” out of the room. This Static Pressure During Retention must also be assessed and entered into the retention time calculation.

Wind Pressures

Wind blowing onto the wall of an enclosure can cause huge pressure fluctuations within the enclosure will literally blow the agent out of the enclosure. Add to this the vacuum effect in

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the lea of the building and we get a recipe for rapid failure of enclosures that are exposed to frequent windy conditions. Neither NFPA nor ISO standards address this issue.

2.3 Enclosure Behavior during Retention

After the initial effects of the discharge have concluded, the enclosure will revert to some form of stead-state behavior. This behavior will be a result of the combined influences of gravity, convection, and forced air circulation as discussed above. The combined behavior in any enclosure will be different based on which of the above influences are present, which are predominant, and which agent is used.

The resultant steady-state behavior will lead to one of two modes of retention within the enclosure, Descending Interface and Continual Mixing.

The Descending Interface

In enclosures with little heat-generating equipment and no forced-air circulation (such as museums and paper archival rooms) the over-riding influence will be gravity. The heavier-than-air agent-air mixture will settle to the floor of the room and a layer of any displaced air will migrate to the ceiling.

Due to the column pressure of the mixture, a pressure difference will develop between the area within the enclosure and the rooms outside the enclosure. This pressure difference will cause agent to flow outwards through any holes in the enclosure. The greater the pressure difference, the faster the flow of agent. Agent will flow out of holes at floor level faster than similar sized holes mid-wall.

As agent flows out of the holes near the bottom of the enclosure, air will rush into the

enclosure at the ceiling level to replace it. As this happens, the agent-air interface will slow drop. This is called a Descending Interface.

Equipment will be protected so long as the descending interface is above it. Once the descending interface touches, or drops below the equipment, it is no longer considered to be protected. This protected equipment height should be specified by the enclosure designer, physically measured, or can be taken to be 75% of the room height, as agreed upon by the AHJ.

The following three graphs depict the results from an actual Halon discharge with a

descending interface. During the test, three probes measuring Halon concentration were set up, each at a different height. Time is given on the horizontal (X) axis and Halon

concentration is given on the vertical (Y) axis. In all three cases, the concentration rises rapidly to the approximately 6.5% design concentration.

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At the 173” (14.5’) level, concentration is held for about a minute, and then slowly drops as agent drains from the room. By 4 minutes, the concentration reaches 1% and equipment at that level would no longer be protected.

Probe at 173" from floor slab

0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 Time (minutes) %Halon.

At the 146” (12’) level, concentration is held for about 4 minutes, and then rapidly drops over the next 2 minutes to 1%, at which time equipment at this height is no longer

protected.

0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 Time (minutes) %Halon

At the 86” (7’) level, the initial concentration is held for almost 12 minutes and then slow drops to 1% concentration at 17 minutes.

0 1 2 3 4 5 6 7 8 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Time (minutes) %Halon

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Section 02 – Agent Loss Mechanisms Continual Mixing

In enclosures containing hot and massive equipment, or circulating fans, chillers and HVAC systems that remain running during the retention time, the agent will be continually circulated. As a result, there will be a uniform concentration of agent throughout the enclosure at any point in time. As the mixture leaks out of the enclosure, concentration at the floor will decay at the same rate as the concentration near the ceiling. This is called Continual Mixing.

The agent concentration throughout the room will begin at the initial design concentration and over time, decrease. Equipment in the room will be protected so long as the agent concentration is greater than some minimum concentration. This minimum concentration should be stipulated by the enclosure designer or with the agreement of the AHJ or witness, may be based upon the manufacturers’ suggested minimum concentration to prevent re-ignition.

The minimum concentration is often confused with initial concentration, which it is not. For example, the typical starting concentration for FM-200 is 7.5% but according to some

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Section 03 – Calculating Retention Time

3 Calculating Retention Time

3.1 What is Retention Time?

Retention time is the amount of time it takes until the first piece of protected equipment is no longer protected.

Retention time begins the moment that agent begins to be released into the enclosure. The actual discharge itself takes only seconds to complete. This discharge time is considered to be part of the retention time.

The retention time ends when the first piece of equipment is no longer protected. This can happen in one of two ways, depending on the mode of retention in the enclosure; either the descending interface reaches the highest piece of equipment; or the agent concentration drops below the specified minimum concentration to prevent re-ignition.

Contrary to popular belief, there is no specification in the NFPA standards for a 10 minute retention time. What NFPA 2001 does say is:

A.5.6 In establishing hold time, designers and authorities having jurisdiction should consider the following or other unique factors that can influence the performance of the suppression system:

1) Response time of trained personnel 2) Sources of persistent ignition

3) Excessive enclosure leakage

4) System enclosure venting requirements 5) Inertion and re-flash hazards

6) Wind down of rotating equipment

The hold time for the duration of protection should be sufficient to control the initial event and allow for support should resurgence occur once the agent has dissipated.

Under the NFPA standard, it is up to the designer or AHJ to specify the retention time, and they should as a minimum, take into consideration the time it will take for trained personnel to respond to the situation. A remote cell-site may warrant a hold time of significantly more than the commonly used 10 minutes, while the server room in a fire hall might get away with less than 10 minutes.

ISO 14520 Section 4 of Annex E does specify a minimum 10 minute retention time and refers to the guidelines set out in section 7.8.2 to determine potentially longer retention times.

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3.2 Retention Time in the Descending Interface Case

In the absence of any circulation, a defined interface will form between the agent-air

mixture and the air as the agent-air mixture flows out of the lower leaks and the external air rushes in through the upper leaks.

As the agent leaks out of the enclosure, this interface will slowly descend in height.

Initially all equipment in the enclosure will be bathed in agent, but over time, as the agent escapes, the higher equipment will slowly begin to be exposed to the air as the interface drops.

3.3 Retention Time in the Continual Mixing Case

In enclosures with circulating fans, self-contained cooling or heating systems, racks of computer equipment with cooling fans, or large heat generating equipment, there will be significant circulation and mixing of the agent and the air. In these cases, no descending interface will form. Instead, the concentration of the agent will remain the same

throughout the enclosure and will slowly drop, throughout the enclosure, as the agent leaks out.

The concentration will begin at the design concentration immediately after discharge. As the agent leaks out of the enclosure, the concentration will slowly fall. The equipment throughout the enclosure will lose protection when the concentration falls to the minimum concentration. This minimum concentration is usually taken to be the manufacturer’s minimum concentration to prevent re-ignition but must ultimately be specified by the designer, engineer, or AHJ.

3.4 Retention Time in the Extended Discharge Case

After the initial discharge, some systems may continue their discharge for many minutes to maintain the agent concentration. This is especially true in enclosures that are extremely leaky.

In these cases, the retention time begins at the start of the initial discharge, continues through the extended discharge and then continues through the normal retention time after the extended discharge finishes.

The extended discharge is an excellent way to obtain an indefinite retention time without conducting significant room sealing. The flow from the extended discharge need only be enough to account for the leakage from the enclosure, which is usually relatively low. Software such as Retrotec’s CA2001 will calculate the required extended discharge flow rate based on the door-fan test.

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Section 03 – Calculating Retention Time 3.5 Retention Time Dependencies

There are a number of factor and enclosure characteristics that affect the retention time. Knowledge of these dependencies up front, before the enclosure is designed can save time, money and aggravation in the long run.

Leakage Area (ELA)

It may seem obvious, but for the record, leakage area affects retention time. The larger the leakage area is - the shorter the retention time will be. Reducing the leakage area will increase the retention time

If only a whole-room test is performed, the worst case 50% upper leaks – 50% lower leaks leakage split must be assumed.

If leakage split between upper and lower leaks can be determined, the retention time may be able to be lengthened to compensate for reduced lower leakage.

Agent Initial Concentration and Final Concentration

When there is no mixing, a descending interface will form. Below the descending interface, the agent concentration will remain constant at the original, design concentration. It is important to understand that, without mixing, increasing the initial agent concentration will increase the column pressure, increase the speed at which the agent escapes from the enclosure and hence DECREASE retention time.

A common misconception with a failed room is that adding more agent will fix the problem. With a descending interface, the opposite will occur.

1. With a descending interface, adding more agent will decrease the retention time. When there is mixing, the agent concentration remains homogeneous throughout the enclosure and slowly decreases, throughout the enclosure, as agent leaks out. The

concentration begins at the initial design concentration and immediately begins to decrease. The retention time ends when the concentration reaches some specified minimum

concentration. This minimum concentration must be lower than the initial concentration. A common misconception is that the enclosure fails when the concentration drops below the initial concentration. This happens almost instantly as agent begins to leak from the room.

1. Retention time is dependent on the difference between the starting concentration and the final concentration. The larger the difference, the longer the retention time. 2. With mixing, adding more agent to a failed enclosure will usually increase the

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Section 03 – Calculating Retention Time Equipment Height and Enclosure Height

When there is no mixing, a descending interface will form. Immediately after discharge, the interface will be located at the highest flooded point in the room which is usually at the upper slab, or at the suspended ceiling if present. This is called the Maximum Agent Height. As agent begins to leak out of the room, the descending interface begins to drop in height, to be replaced with fresh air from above. When the descending interface reaches the highest piece of protected equipment, protection is assumed to be lost. When there is no mixing, retention time is the time from discharge until the descending interface reaches the protected equipment. When there is no mixing, retention time is dependent on the

difference between the maximum agent height (the height of total flooding) and the minimum protected height (equipment height).

1. With a descending interface, increasing the ceiling height (increasing the maximum agent height) will increase the retention time.

2. With a descending interface, decreasing the height of the protected equipment will increase the retention time.

When there is mixing, retention time does not depend on equipment or enclosure height.

3.6 Measuring Maximum Agent Height?

The Maximum Agent Height is measured from the lowest point in the room, to the highest intentionally flooded spot in the room. When the enclosure has a suspended floor, the Minimum Protected Height is measured from the lower slab.

Do not measure above suspended ceilings if there is NO agent discharged there. Do NOT measure to the bottom of trenches if there is very little leakage there.

Minimum Protected (Equipment) Height Maximum Protected (Agent) Height Maximum Protected (Agent) Height Minimum Protected (Equipment) Height

3.7 Measuring Minimum Protected Height?

The Minimum Protected (Equipment) Height is measured from the lowest point in the room to the highest piece of equipment being protected. In cases where there is no equipment in the room, 75% of the overall room height is chosen.

When the enclosure has a suspended floor, the Minimum Protected Height is measured from the lower slab.

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Section 04 – Recurring Design Problems

4 Recurring Design Problems

At Retrotec we’ve tested hundreds of enclosures and provided technical support and consulting on thousands more. Here are some of the most common design problems. Problems we see again and again and again. Most of these problems have simple fixes that are inexpensive and simple to implement during the design phase of the enclosure and are typically expensive and difficult to implant upon discovery during the door-fan test.

4.1 Cascading Pressures Pressure +25 Pa Pressure +10 Pa Pressure 0 Pa Flow Flow

Protection lost in seconds!

Cascading room pressures will create a horizontal flow through the enclosures which will add to normal agent losses. In the above example, the center room is protected with clean agent. After the discharge, the agent will effectively “pile up” on the low pressure side of the room, and be blown out of the room far quicker than predicted. In one case, with a leaking cable tray, protection would have been lost in seconds!

This room pressurization system must be shut down at discharge to prevent these

uncertainties, or if not possible, the clean agent enclosure must be specifically engineered to resist these pressures.

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Section 04 – Recurring Design Problems 4.2 Common Sub-floor

Sub-floors always seem to present many opportunities for mistakes. One of the most significant problems is when the protected zone is connected to an adjacent room by common sub-floor. This could be due to some (poor) design, or because sections of the partition wall have been mistaken uninstalled (a common occurrence under doorways). Agent is discharged into the protected room and sub-floor but will quickly flow up through the sub-floor into the next room as if it were water finding its level.

The Solution to this problem is that either both rooms need to be discharged at the same item or that the walls must be continued to the lower slab.

All too often we observe partition walls that, for some reason, do not continue to the lower slab in the sub-floor

This wall rests on a false floor. We are looking from the protected zone into the adjacent unprotected space. Agent will flow under the wall causing the protected enclosure to lose concentration immediately. Flooding the entire sub-floor is often used in an attempt to address the problem. This doesn’t work however, because the agent just forces its way up through the floor from the underside, unintentionally flooding the adjacent room.

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Section 04 – Recurring Design Problems 4.3 Pressurized Sub-floor

Wall cavities that connect the sub-floor space to the above-ceiling space will cause agent to be forced above the false ceiling if the sub-floor is pressurized during the retention period.

Pressurized sub-floor pushes agent into the above-ceiling space

4.4 Common Above-ceiling Spaces: Discharge will pull smoke in

Common above-ceiling space

Protected Zone Smoke event in

neighbouring room

Walls that only extend up to the T-bar suspended-ceiling rely on flimsy tiles and clips to hold in the gas at discharge and to protect the enclosure from fire and smoke events outside the protected zone. The result is inadequate protection.

Agent can be lost at discharge when the tiles get blown away, reducing agent concentration. Worse however is that smoke from an external event (smoldering trash bin or neighbouring event) can cause the clean agent system to discharge. As the agent naturally leaks out, smoke will be “pistoned” into the enclosure, causing unnecessary damage to the equipment and unnecessary costs for clean-up, service, and recharge of the system.

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Section 04 – Recurring Design Problems

4.5 Common Above-ceiling Spaces: HVAC Leakage

HVAC pressures arising from either leaky supply or leaky returns will act to push or pull agent out of the enclosure faster than expected.

HVAC Leaky Supply Dampers Passive Return Leaks Increased Pressure Forces Agent out

Faster

4.6 Suspended Ceilings Too Low

Equipment

Worst possible design. Leaky T-bar, suspended ceiling connects enclosure to events in other parts of the building. No reserve over the equipment. Short retention time.

Better design using slightly more agent to act as reserve over the equipment. No connection to rest of building. Fire barrier

on all sides. _Equipment

Ceiling void

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Section 05 – Good Enclosure Design Practices

5 Good Enclosure Design Practices

5.1 Superior Protection for Less Money! Interested?

Consider the case of a 500 ft2 room where $10,000 and two weeks were spent to seal it tight enough to pass the enclosure integrity test. If a few $100 more had been spent on more agent, and the ceiling raised several feet, this could have been avoided.

Often the general contractor finds himself rebuilding a room that was not designed to be tight enough to hold agent.

There are 4 guidelines that will: • Ease passing the door fan test

• Dramatically improve fire and smoke protection

• Solve 90 % of the design problems that have to be solved at the last minute just prior to occupancy

5.2 Run walls slab to slab

Include construction details that would allow for sealing of the wall to the upper slab. extending walls to the upper slab and sealing them airtight is often the only defense from fire and smoke entering the enclosure from the outside. This sealing is the MOST important thing that can be done to improve protection in the enclosure. Refer to C-1.2.1 (b) in NFPA2001.

This is the easiest way to get slab to slab walls sealed. This spray on flexible rubber is available from 3M and Grace and it has a fire rating! Better yet, it is flexible and will not crack and fall out as many other treatments will. Loaded floors can move ½ an inch, but this sealant will remain flexible over that range. Just stuff Rockwool backing in any size gap and start building up layers of this rubber sealant. And we don’t even get any commission for saying this.

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Section 05 – Good Enclosure Design Practices 5.3 Eliminate T-bar suspended ceilings

Eliminate T-bar suspended ceilings in enclosures where the walls do not go slab to slab. Use a solid sheetrock ceiling with access hatches and walkways above it.

a. Clipping tiles is often used but is ineffective. Clips are lost almost immediately. As soon as the tiles are opened the clips go flying and

are never replaced. This is an example of a practice that was commonly used to keep tiles in place during a discharge but has no practical application for long-term protection. This recommendation is in spite of its mention in NFPA2001 section C-1.2.3.10

b. Discharge agent above the false ceiling. Often for a few added pounds of agent, an immense improvement in protection can be gained. For starters, ceiling tiles will usually go flying during a discharge, causing agent to get lost above the suspended ceiling. This agent will mix with the above-ceiling air to provide a concentration that is lower than the initial concentration. Some of this agent may come down to replace losses below, but at a decreased concentration. Discharging agent above the false ceiling solves the displaced ceiling-tile problem and in most cases will triple the retention time. Good value.

c. Use Fire Rated ceiling tiles. This would be an option for existing installations.

The positive view of T-bar

ceilings On the negative side

T-bar suspended ceilings are low cost, do conceal

ductwork and wiring, and tiles can be removed to gain access.

T-bar suspended ceilings usually begin to look tattered even before the construction job is complete. The tiles often go flying when the system is discharged. Fire and smoke events occurring outside the protected zone are far more likely to cause damage in the enclosure than events that occur within it.

The sheetrock ceiling option

The sheetrock ceiling provides a complete enclosure to protect the contents of the room from externally generated smoke damage. This increased protection or

compartmentalization shows up when the leakage of the room is measured using the door fan. Instead, install a sheetrock ceiling with access hatches; cover it with plywood, then sheetrock above so it can be walked on while servicing the equipment above.

5.4 Maximize the room height and volume

Place the ceiling as high as possible. More clean agent = more protection. In small rooms, run pipe and supply nozzles to fill the above-suspended-ceiling space.

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Section 05 – Good Enclosure Design Practices

The greater volume of clean agent in the enclosure, the greater the protection. Merely putting a higher concentration in the room will only ensure the agent will run out of the room faster (this is not true in the less common case where the agent is continually mixed after discharge).

5.5 Select an appropriate retention time

NFPA 2001 states “... the design concentration ... shall be maintained for a sufficient period of time to allow effective emergency action by trained personnel.” The following

guidelines are suggested for small enclosures.

For example, a remote site where re-ignition was possible, and where it would take 30 minutes for trained personnel to arrive, should be specified as 30 minutes. On the other hand, a small room with little or no potential for a deep-seated fire and where personnel would respond within 5 minutes would need a retention time of 5 minutes. NFPA 2001 does not recommend any specific time. The AHJ must ultimately decide what time is

appropriate. ISO however, does specify 10 minutes.

All rooms typically have at least one door that will generally leak about 5 to 20 in2. A 350 ft3 room with a 10 minute hold time requires a leakage of 7 in2_{or less to pass. Since that is not}

really practical, reducing the specified hold time or adding an extended discharge is the only option.

Alternatively, make the room bigger or discharge agent above false ceilings.

5.6 Fit automatic door closers

Doors often get wedged or propped open when the room is in use. This practice must be discouraged because the clean agent system will not work properly with perimeter doors open. A better solution is automatic door release mechanisms that will close the doors whenever the first alarm sounds. Choose a door opener that will close the door when it is de-energized so on power failure the doors close.

For room volumes of: 2,500 1,250 625 350 ft3

Minimum achievable leakage area is: 62 42 32 23 in2

Suggesting a retention times for inerts: 10 10 8 6 minutes And suggesting retention times for halocarbons: 8 6 4 3 minutes

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Section 06 – The Door Fan Test

6 The Door-fan Test

6.1 How a Single Door-fan “Sees” a Room

3 units

1.5 units

1 unit

Each of the above four enclosures has 3 units of leakage area. The first one has its three units located at the ceiling level, the second at the floor level, the third equally split between the ceiling and floor and the fourth equally split between the floor, ceiling and mid-way up the wall.

Each enclosure, however, has a significantly different retention time as indicated below.

3 units

1.5 units

1 unit

Infinite retention

time Longest retention time Shortest retention time Middle retention time

A single door-fan will measure the size of the leakage area in each room at 3 units.

Both the NFPA and ISO standards make the assumption that a 50-50 split of leakage between ceiling and floor exists (the third room in the example). This assumption leads to the most conservative calculation of retention time.

This calculation is called the Whole Room Test or the Total Leaks Test and is always the first step in the enclosure integrity procedure. Retrotec’s CA2001 software automatically

performs this calculation and generates the retention time based on the 50-50 leakage distribution.

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Section 06 – The Door Fan Test 6.2 The Lower Leaks Test

As stated above, the whole room test will produce the most conservative calculation of retention time. If the total leakage of the enclosure is small enough compared to the volume of the enclosure, it is possible that the enclosure will pass with sufficient retention time.

The vast majority of rooms however have significantly more total leakage than the retention time calculation permits. Rooms with suspended ceilings are the most problematic, as the areas above the suspended ceiling are rarely sealed sufficiently to pass the Whole Room Enclosure Test. In this case, the standards dictate that the leakage distribution must be measured. This is done by measuring the lower leaks.

To accurately measure the Lower Leaks (those leaks below the ceiling), one of two test techniques may be employed – The Plastic-on-the-Ceiling-Test or The Flex Duct Test. Both of these tests attempt to isolate the Above-Ceiling Leaks from the Below-Ceiling Leaks. In doing so, a more accurate calculation of retention time can be made.

If only considering agent retention rooms with excessive above-ceiling leaks will hold agent just fine. However, this is a poor design practice as they will not prevent smoke ingress from adjacent rooms, nor will they prevent external events from triggering the suppression system.

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Section 07 – Witnessing a Test

7 Witnessing an Enclosure Integrity Test

The witness plays a key role in ensuring that the test is completed correctly. Many witnesses are unaware however, of exactly what they need to look for and what factors affect the test results. What follow is a short explanation of each of the points that the witness should be aware of during the test.

The 4-page Enclosure Integrity verification Form that follows is a comprehensive check-list showing each and every point that must be inspected to complete an approval according to NFPA 2001.

7.1 Technician Training

6.6.1 All persons who could be expected to inspect, test, maintain, or operate fire extinguishing systems shall be thoroughly trained and kept thoroughly trained in the functions they are expected to perform.

NFPA 6.6.1 requires that testers be appropriately trained. The testing technician should be certified to at least Level 2 for conducting a single door-fan test and at least Level 3 when conducting a dual door-fan test. Testers who have completed any part of Retrotec’s training program are listed on our website at www.retrotec.com, with complete details of their level of certification.

Technician certification is stored within the CA2001 software, is displayed prominently in the software and on reports, and is easily viewable by the authority upon request.

7.2 Software Conformance

Analysis tools in use by the technician to produce ELA and retention time calculations must conform to the standard being tested to (either NFPA or ISO).

Retrotec’s HA6 DOS software and CA2001 Windows software conform to the NFPA 12A and 2001 standards exactly.

CA2001 conforms to the ISO 14520 standard exactly.

7.3 Room Pressure Gauge Calibration Certificate

The NFPA standard requires that the pressure gauge used to measure the room pressure be calibrated annually. Experience shows however that unless the gauge has been damaged or moves unevenly it is generally within 10%.

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Calibration certificates for each piece of equipment are stored within CA2001. The witness should ensure that the gauge being used by the technician has a current calibration

certificate within CA2001 and that the serial number on the gauge matches the serial number in the software.

The ISO standard recommends calibration but does not suggest the interval. It does require +/- 1% accuracy. Retrotec recommends annual calibration of all pressure gauges.

7.4 System calibration

C.2.2.1.6 Door fan systems should be checked for calibration every 5 years under controlled conditions, and a certificate should be available for inspection at all integrity tests. The calibration should be performed according to manufacture’s specifications.

The certificate should include the following:

1) Description of calibration facility and responsible technician. 2) Date of calibration and serial number of door fan.

3) Room pressure gauge error estimates at 8, 10, 12, 15, 20 and 40 Pa measured by both ascending and descending pressures (minimum).

4) Fan calibration at a minimum of 3 leakage areas (approximate): 0.5 m², 0.25 m², and 0.05 m² measured at a pressure of 10 Pa.

7.5 Field Calibration check procedure

A field calibration check can be requested by the witness to see if the equipment and operator can actually measure a hole of a known size. This test takes very little time to perform and is the perfect way to gain confidence in the tester, test equipment, and test technique.

It is preferable to inform the operator beforehand of the expectation to perform a field calibration check so the operator can bring the requisite equipment.

7.6 Return Path

There must be a complete and unobstructed flow path from every leak in the enclosure back to the Door-fan otherwise some leaks may not be measured. This may entail opening

stairwell or elevator doors to floors above and below, neighboring room doors, and perhaps windows and doors leading outside (if the enclosure under test borders an external wall). The witness should ensure that the operator has examined and accounted for the return paths from all leaks.

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7.7 Room and Equipment Set-up

All doors within the zone must be open. The HVAC system and all dampers must be set as they would be at or during a discharge.

A doorway must be selected that opens into the largest and most open space. Applying tape to seal up the Door-fan panels is OK as long as the doorway is tighter than the panels.

The volume of the room should be calculated on-site using a tape measure or by counting tiles. Taking volume measurements from blue-prints or site-staff as gospel, without confirmation, should not be permitted.

Maximum agent height and minimum protected height must be physically (and correctly) measured on-site.

Similarly, the operator must confirm the weight or volume of agent through actual inspection of the bottles, not by consulting design documents or talking to site staff.

7.8 Static Pressure Check

Before beginning the test, the operator should accurately determine the static pressure. With the doorway completely sealed and the door-fan completely sealed, the magnitude of the static pressure must be measured. By opening a small hole (perhaps a single low-flow plug) and using smoke, direction of the static pressure should be determined.

Relying on the positive/negative sign as read from a digital gauge is very error-prone and should be discouraged.

The origin of pressures above 3 or 4 Pa should be determined and rectified if possible.

7.9 Gauge Set-up

In the case of analog gauges, gauge leveling and zeroing must be completed before any tubes are hooked up. Most analog gauges are meant to be mounted vertically (usually on door-frame or in a pre-designed rack or console). Once mounted, the gauges should be carefully zeroed using small screw-driver and tapped gently to ensure stability. Once zeroed, analog gauges should be quite stable over the course of the test and need only be spot-checked occasionally or tapped prior to each measurement.

In the case of digital gauges, zeroing is usually done through a pneumatic switch, either manually or automatically. Many digital gauges are susceptible to position and once zeroed, should not be moved. Digital gauges also tend to drift slightly over time as they warm up. Digital gauges should be zeroed prior to each test measurement.

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7.10 Flow and Room Pressures Entered Correctly

In addition to ensuring that the gauges are correctly reading the pressures, the witness should also confirm that the operator actually records the pressure correctly and enters it correctly into the software.

7.11 Range Selection

The “Ranges” on a Retrotec door-fan refers to the selection of flow-restrictor-plates or orifices that change the airflow through the blower. Testing on the correct Range is extremely critical for good results for two reasons.

Often the same room-pressure can be achieved with a number different Ranges (just like a manual transmission car can achieve the same speed in a number of different gears). For the best results, the door-fan should be running above ½-speed and the flow-pressure through the door-fan must be greater than the room-pressure and should be at least double the room pressure. If these conditions aren’t met, the operator should change to the next smaller flow range.

If the operator does not input the correct flow-range that the test was conducted on into the software, the results can be significantly affected. Retrotec’s CA2001 Windows software displays a picture of the selected Range, which must be acknowledged, before the results of each test are entered. On older versions of software, the ranges can only be identified by consulting a pictorial table.

The witness must confirm that the range on the printout or shown in software during the test matches the range that is actually used by the operator.

7.12 Testing in Both Directions

Rooms must be tested positively and negatively to eliminate bias due to duct leaks and other static pressures. Testing in both directions is not done due to positive pressures after

discharge.

7.13 Determining the Leakage Split – The BCLA Test

To measure leaks in the lower part of the room is not the same as taping up leaks to pass a discharge test. The leakage of the whole room, including the ceiling is measured in the first test, the Total Leaks Test. The lower leaks can be measured separately to get a more

accurate prediction of retention time. The Total leaks test MUST be performed first and then, and only then, can the BCLA test be performed.

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During a ceiling-neutralization/flex-duct test, the witness should ensure that the operator has indeed neutralized smoke flow across the ceiling. Smoke must be used in this test as equalizing pressures using a gauge is not adequate.

7.14 Technical Judgment

As a last resort to other BCLA techniques, Retrotec software has a spreadsheet method of determining leak location. For enclosures with extremely large overhead leaks they may be passed using “technical judgment” as per the following section:

Section C-1.2.2 (e) of NFPA 2001 App C version 2000 states:

“Enclosures with large overhead leaks but no significant leaks in the floor slab and walls will yield unrealistically short retention time predictions. Experience has shown that enclosures of this type can be capable of retaining clean agent for prolonged periods. However, in such cases the AHJ might waive the quantitative results in favor of a detailed witnessed leak inspection of all floors and wall with a door fan and smoke pencil.”

It must be understood that, although this test will show the enclosure’s ability to hold agent in a discharge test, a large measure of the passive fire protection has been eliminated due to the absence of an upper sealed smoke and fire barrier.

7.15 Yearly Retests

All enclosures must be re-tested yearly if any doubt exists as to whether the room has had any more holes put in it in the last year.

7.16 Commonly Needed Inert Gas Clarifications

Inert gases are all heavier than air (with the exception of Nitrogen) and will, according to NFPA 2001, run out of room leaks.

They are not as heavy as halocarbons and usually only run out at half the rate. They do run out though.

Inert agent enclosures have a very narrow window where they must be tight enough to hold the agent but loose enough to vent peak discharge pressures.

All inert clean agents need relief vent areas according to their manufacturers. Inert agents still must pass the door-fan tests.

If the enclosure has a vent, its area can be checked with the door fan and some vents can be tested for their ability to open under pressure.

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7.17 Enclosure Integrity Test Verification Form

Because there are so many aspects for the witness to keep track of during the enclosure integrity test, Retrotec has developed an easy-to-follow check-off sheet. You can also find this form in the appendices at the end of this document.

Please feel free to copy this form and customize it for your own organization as you require.

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Enclosure Integrity verification form

Building Room Test # Testing technician Witness Date and time of test

Check

off Screen tab

Name on Computer

Screen What to look for

__ yes

__ no Home

“View” button will display the current certificate

Is the One Year Calibration Certificate up to date?

__ yes

__ no Home

Is the Five Year Calibration Certificate up to date?

__ yes

__ no Home

Does the technician have the correct level of training? See Level 1-A, page 15

__ yes

__ no Building/Room Elevation

Is it correct within 1000 ft.? See Level 1-A, page 12 __ yes

__ no Building/Room

Net protected room volume

This is used to re-calculate the design

concentration. It must be re-measured, was it? See Level 1-A, page 12

__ yes

__ no Building/Room

Room operating temperature

Was the temperature expected during a discharge within 10F or 5 C? It may differ from the

temperature at the time of test. See Level 1-A, page 12

__ yes

__ no Building/Room

Maximum agent height

Was it re-measured from floor slab to highest combustible? Enter the maximum agent height from lower slab to highest point that is flooded with agent. See Level 1-A, page 13

__ yes

__ no Building/Room

Minimum agent retention

Do you agree with the time shown? See Level 1-A, page 13

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Check

off Screen tab

Name on Computer

Screen What to look for

__ yes

__ no Agent/Test Agent weight

Were you able to confirm the agent weight or volume? See Level 1-A, page 14

__ yes

__ no Agent/Test Agent volume Only used for INERGEN in North America __ yes

__ no Agent/Test Initial Concentration

Does the concentration meet the specification? See Level 1-A, page 14

__ yes __none

Remove all temporary tape or get sufficient assurance it will be replaced with a permanent seal.

__ yes __ no __ n/a

Total Leaks Enter untested values

If untested values were entered, do you agree with their validity? See Level 1-A, page 16. It would be unusual to have untested values. __ yes

__ no Total Leaks Smoke

Did you see the smoke movement test at the doorway? See Level 1-A, page 17

__ yes

__ no Total Leaks

Test both

directions: Was the enclosure tested in both directions? __ yes

__ no Total Leaks Static pressure

Did you observe the static pressure measurement at the time of the door fan test?

Temperature during test(0_F) __ yes __ no Total Leaks Temperature during test(0_C)

Was the temperature within 100_{F or 5}0_{C of that}

recorded? The NFPA Procedure requires a

measurement if the difference is greater than 18

0_{F or10}0_C

__ yes

__ no Total Leaks Range for room pressures:

Was the room pressure reading within the range specified?