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Proper Sealing of Clean Agent Rooms and Enclosures

If the room leaks, the system fails. Clean agent and inert gas systems depend on a tight enclosure so agent concentration stays in place long enough to suppress the fire and help prevent re ignition. Poor sealing is one of the most common reasons rooms fail door fan tests and cannot be commissioned.

This guide is written for facility managers, EHS teams, engineers, general contractors, and electrical and mechanical trades supporting special hazard rooms across Pennsylvania, New Jersey, New York, Delaware, and Maryland. If you are in a 12 hour drive radius of Breinigsville, PA and commissioning is approaching, this page is meant to help you avoid rework and delays.

Need help with a failing door fan test or an upcoming clean agent commissioning? Call 1-800-360-0687 or (610) 709-5000, or use our Contact Us page.

Fastest triage: share room dimensions, ceiling height, whether the ceiling plenum and raised floor are part of the protected volume, and how HVAC shutdown and dampers are tied into release.

Properly sealed computer room protected by clean agent fire suppression

A sealed computer room is the first line of defense in clean agent and inert gas fire suppression performance.

At a Glance

  • What this solves: commissioning failures, short hold times, and rework caused by predictable leakage paths.
  • Where it matters most: data centers, server rooms, UPS and battery rooms, control rooms, telecom, electrical rooms, archives, museums, and other high value assets.
  • What fails rooms most often: above ceiling leakage, unsealed penetrations, poor door gasketing, plenum pathways, and uncontrolled HVAC openings.
  • What to plan for: door fan testing (room integrity test) and whatever hold time your design, AHJ, and specifications require.
  • Bottom line: sealing details are just as important as cylinder sizing, nozzle layout, and releasing logic.

Jump to:

What a Sealed Enclosure Means

A sealed enclosure is a defined protected volume where clean agent or inert gas can discharge, mix, and remain effective for the required period. In practical terms, it means you have controlled air leakage paths and you know exactly what is inside the protected volume.

Think of the room as a bathtub and the agent as the water. A single hidden opening can drain performance fast. Most failures are not dramatic gaps, they are cumulative small leaks that add up.

What should be defined before sealing work begins

  • Protected volume boundaries: slab to deck walls or equivalent sealed barrier, door openings, and any shafts or plenums that are included or isolated.
  • Ceiling and raised floor approach: whether the ceiling void and raised floor are part of the protected volume, or isolated from it.
  • HVAC interaction: what opens, what closes, what shuts down, and how it is interlocked with the releasing sequence.
  • Penetration ownership: who seals electrical, low voltage, and mechanical penetrations, including future moves, adds, and changes.

Why Sealing Matters for Clean Agent and Inert Gas Systems

Total flooding systems are engineered around concentration. If concentration drops too quickly because the enclosure leaks, suppression becomes less predictable and the risk of re ignition rises.

  • Clean agents such as ECARO-25, FM-200, and FK-5-1-12 (SF-1230) are engineered to reach a design concentration by volume.
  • Inert gas systems such as ProInert2 (including IG-55 and IG-541 options) reduce oxygen below the level needed for combustion while staying within accepted exposure guidance for the space.
  • NFPA guidance ties performance to enclosure integrity and a minimum hold time, often around 10 minutes for many clean agent applications, depending on the hazard, design basis, and AHJ expectations.

For broader engineering guidance on special hazard system design, see Design Considerations for Special Hazard Fire Suppression.

Common Leakage Points That Cause Door Fan Test Failures

Most failed room integrity tests come down to a short list of predictable issues. Fixing these during construction is dramatically easier than correcting them after finishes, ceilings, and cable infrastructure are installed.

Leakage map, what to look for first

Area Why it matters Typical fixes
Top of wall, above ceiling When walls stop at a suspended ceiling, gas can leak over the top into adjacent spaces and destroy hold time. Extend walls slab to deck where feasible, or create a continuous sealed barrier above the ceiling. Seal joints and transitions.
Cable trays, ladder racks, conduit sleeves Penetrations add up fast, and frequent cable changes reopen previously sealed points. Seal penetrations properly, including both sides where applicable. Use appropriate listed firestop systems when required by wall rating.
Doors, frames, and undercuts Doors are common low level leakage paths, especially at jambs and under the leaf. Door sweeps, gasketing, proper latching, and automatic closing where appropriate. Avoid propping doors open.
Windows and vision panels Perimeter gaps leak and glazing must handle pressure changes during discharge. Seal perimeter joints and verify glazing and framing details align with room construction and project requirements.
HVAC ducts, plenums, shafts Uncontrolled openings act like permanent vents. Ceiling plenums used as return air paths can drain hold time. Coordinate dampers that close on release, confirm shutdown and sealing approach, and define whether plenums are included or isolated.

Wall construction and above ceiling leaks

  • Walls should extend from floor slab to structural deck or the next solid barrier.
  • If walls stop at a suspended ceiling, gas can leak over the top into adjacent spaces.
  • Seal joints between walls, floors, and ceilings using appropriate materials, and use fire rated systems where required by code.

Cable and conduit penetrations

  • Openings for cable trays, ladder racks, and conduit are major sources of leakage.
  • Seal penetrations properly, and firestop where required to maintain ratings.
  • Moves, adds, and changes can reopen previously sealed points, especially in data centers and control rooms.

Doors, frames, and windows

  • Doors should fit tightly and close reliably.
  • Weather stripping and door sweeps reduce leakage at jambs and under the door.
  • Vision panels and interior windows should be sealed at the perimeter and use glazing suitable for discharge pressure changes.

HVAC systems and plenums

  • Supply and return ducts that penetrate the room often require dampers that close on clean agent release.
  • Ceiling plenums used as return air paths must be addressed as part of the enclosure or isolated from the protected volume.
  • Uncontrolled openings to adjacent plenums or shafts can significantly reduce hold time.

Understanding the Door Fan Test and Hold Time Requirements

Room integrity testing is the proof that sealing work is effective. Many AHJs and insurance stakeholders expect an enclosure integrity test for total flooding clean agent systems as part of commissioning documentation.

How a door fan test works

  • A calibrated fan is temporarily installed in a doorway or other suitable opening.
  • The fan pressurizes and depressurizes the room while measuring airflow and pressure differences.
  • Software calculates equivalent leakage area and estimates how long the agent will remain effective based on the room and design assumptions.

What happens if the room fails

  • Test results show whether leakage is primarily high level, low level, or both.
  • Technicians often use smoke tools to locate leaks at walls, ceilings, doors, and penetrations.
  • Contractors seal the identified points and testing is repeated until the enclosure meets the project requirement.

Design and Construction Checklist to Build a Tight Clean Agent Room

Planning ahead saves time and money. Use this checklist to reduce the odds of a last minute door fan failure.

Project planning and scope coordination

  • Coordinate clean agent protection early so wall types, slab to deck construction, and ceiling design support room integrity.
  • Include sealing requirements in bid documents and subcontractor scopes for electrical, low voltage, and mechanical trades.
  • Use appropriate fire stopping systems where a wall has a required rating and penetrations must maintain that rating.

Field checks before finishes are closed

  • Inspect top of wall conditions and above ceiling pathways before ceiling grid and tiles hide the leakage paths.
  • Inspect around large penetrations, cable trays, and sleeves, including behind cabinets and wall mounted equipment.
  • Install door hardware, sweeps, and gasketing that support life safety egress and reduce leakage.
  • Confirm HVAC paths and damper behavior align with the suppression sequence and the defined protected volume.

If the room protects high value assets such as servers, control systems, or archival materials, pair these construction practices with engineering guidance on Design Considerations for Special Hazards.

Renovations, Retrofits, and Changes After Commissioning

Clean agent rooms rarely stay static. Over time, new cables are pulled, equipment is added, and walls or ceilings are modified. Each change can affect room integrity.

  • Seal any new cable tray, conduit, or mechanical penetration immediately after work is complete.
  • Include room integrity considerations in construction projects near or within the protected enclosure.
  • Consider re testing room integrity as a best practice after significant envelope, HVAC, plenum, or cable infrastructure changes.

SSI supports owners with design, installation, integrity testing coordination, and ongoing service for clean agent systems and inert gas systems.

Codes, Standards, and Industry Guidance

Room integrity is tied directly to codes, standards, project specifications, and AHJ expectations. Use these resources as a baseline, then confirm what applies to your specific hazard and jurisdiction.

For information on how federal regulation affects some HFC agents over time, see SSI guidance on the AIM Act and HFC phasedown.

Service Area and How SSI Supports Room Integrity Projects

Suppression Systems, Inc. provides clean agent and inert gas system design, installation, and project support throughout Pennsylvania, New Jersey, New York, Delaware, and Maryland, including commissioning support where room integrity is a schedule critical factor.

  • Support for new construction, tenant fit outs, and facility upgrades.
  • Practical guidance for contractors on identifying and sealing predictable leakage paths.
  • Lifecycle support for installed systems where integrity can change over time due to building modifications.

Why SSI

  • Over 40 years of providing great service to customers, with special hazard focus.
  • Support across clean agents and inert gas, including FK-5-1-12, ECARO-25, FM-200, and ProInert2.
  • Code driven approach that aligns design, installation, and commissioning expectations.
  • Local responsiveness across the Mid Atlantic and Northeast corridor for projects that cannot slip.

See more: 10 Reasons to Choose SSI

FAQs

Do clean agent rooms need to be sealed?

For most total flooding applications, enclosure integrity strongly influences performance. Sealing reduces leakage, improves predicted hold time, and supports more reliable commissioning results.

What is the most common reason rooms fail door fan tests?

Above ceiling leakage and unsealed penetrations are frequent root causes, especially when walls stop at a suspended ceiling or when cable infrastructure changes over time.

If the room fails, can we just add more agent?

Adding agent does not fix uncontrolled leakage paths. The practical approach is to identify leakage points, seal them properly, then re test until the enclosure meets the required performance.

What changes should trigger a re review of room integrity?

Major cable additions, new penetrations, ceiling or wall modifications, HVAC path changes, and construction work adjacent to the room can all affect integrity and should trigger a review of the enclosure.

Next Steps

If you are preparing for a door fan test or correcting a failed test, send SSI:

  • Room drawings or rough dimensions, ceiling height, and what is included in the protected volume.
  • Agent type and system type (clean agent or inert gas) and commissioning schedule.
  • HVAC notes: dampers, shutdown sequence, plenums, and any shafts connected to the room.
  • Known problem areas: above ceiling pathways, door gaps, high penetration walls, or recent construction work.

Call 1-800-360-0687 or (610) 709-5000, or use our Contact Us page.

Related SSI Pages

Suppression Systems Inc.

155 Nestle Way, Suite 104, Breinigsville, PA 18031

Toll Free: 1-800-360-0687, Phone: (610) 709-5000, Fax: (610) 709-5001

Email: info@suppressionsystems.com