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Aug 23 2009

Louvers in Fire-Rated Doors

Category: Fire DoorsLori @ 11:07 pm Comments (6)

Fusible Link LouverWhen I started working in the door and hardware industry, we regularly installed fusible link louvers in fire-rated doors, as allowed by various door manufacturers’ listings.  Although fusible link louvers are still available, their use is limited by current codes:

The IBC – 2009 does not allow louvers in smoke barrier doors in I-2 occupancies (710.5, Exception 1), smoke partitions (711.5.1), or door assemblies in corridors or smoke barriers (715.4.3.1). [Previous editions of the IBC contain the same requirements but the reference numbers are slightly different.]

NFPA 101 – 2009 does not allow louvers in smoke partitions ( or smoke barriers (8.5.4), and various occupancy chapters contain further limitations on their use.

Fusible link louvers rely on a fusible link which melts at elevated temperatures, allowing the blades of the louver to close.  These louvers have been tested and certified to maintain the fire resistance of the door assembly, but smoke may pass through the louver before the link melts.

There are two additional types of louvers available for use on fire-rated doors, but they would require a variance from the local code official since they are not specifically allowed by the codes.  One type is the Advantage Intumescent Louver by Zero International (Zero also offers the FB Intumescent Block).  This louver design incorporates intumescent material which expands when heated to seal the openings in the louver.  Smoke would also be a concern with this type of louver.

The second type is a smoke-actuated damper/shutter assembly by the Lorient Group.  Although I have seen a sample of this system, I have not seen it in use in the U.S.  If it reliably prevents the passage of smoke through the louver, we could eventually see the use of this type of product allowed by the codes.

If you have any information to add about the use of louvers in fire-rated doors, please leave a comment (click and scroll down).

Graphic courtesy of National Guard Products, Inc.

6 Responses to “Louvers in Fire-Rated Doors”

  1. John Mickiewicz says:

    Hi Lori,
    My question is: can you install a fusible link louver in a 90min. fire rated door located at Elevator Machine room? Are there any codes or stipulations that would not allow this?

    • Lori says:

      Hi John –

      I haven’t seen anything in the elevator standards about this, but I’m not intimately familiar with all of them. But in the IBC there are several locations where louvers are prohibited. One of those locations is “Door Assemblies in Corridors and Smoke Barriers.” So the question is whether this elevator machine room is considered a door in a corridor or smoke barrier. Louvers are also prohibited in smoke partitions.

      In the Opening Protectives section of NFPA 101 it says, “ Doors shall not include louvers,” so that would apply to any fire door assembly unless there was a specific exception.

      – Lori

  2. Ross says:

    I have an unusual situation – a fusible-link louver (24″ x 24″) in a 60M hollow-metal door which the architect wants to cover with a larger louver on the outside of the door for cosmetic purposes. He originally scheduled a 30″ x 60″ louver in these doors and wants to keep the “look”. I know there used to be restrictions on plant-ons for fire rated doors, but this is a bit different. Thanks for all your help!

    • Lori says:

      Hi Ross –

      Louvers are not allowed by the model codes in most locations where a fire door would be required – for example, smoke partitions, smoke barriers, and corridor doors with a fire rating. If this fire door is in one of the rare locations where louvers are not prohibited, it would be up to the door manufacturer’s listings whether installing the larger louver is acceptable.

      – Lori

  3. Chris says:

    Is there any issue with fire rating a door that has a half-lite with a louver below?

    • Lori says:

      Hi Chris –

      That would be up to the listings of the door manufacturer, but as I said in the article there are very few locations where the codes allow louvers.

      – Lori

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