When 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 (7126.96.36.199). [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 (188.8.131.52) 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.
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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?
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, “184.108.40.206 Doors shall not include louvers,” so that would apply to any fire door assembly unless there was a specific exception.
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!
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.
Is there any issue with fire rating a door that has a half-lite with a louver below?
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.
I am currently working on a building that needs to use fire-resistant louvers up to 120 minutes. Can you provide me?
I am in Vietnam, if you have an agent in Vietnam please introduce me.
if not, of course I think I will need to import.
Thank you & best regards,
Hi Hieu –
Your contact in Vietnam would be Raymond Lim – Raymond.Lim@allegion.com.
We need to install a door louver that could potentially work backwards in case of smoke or fire; open the blades instead of closing them, to allow smoke to purge.
Is there such a product in the market ? Thank you !
Hi Panos –
I have not seen a door louver like that, but I think there may be wall louvers that work that way.
A fully louvered can be fire rated?
Kindly specify the limitations of the fire-rated door with louvers.
Hi Mirza –
Louvers are not allowed in fire doors in most locations because even fusible link louvers could allow a lot of smoke to pass through the louver before it closes. There is more information in this post: https://idighardware.com/2017/11/qq-louvers-in-fire-doors/.
Hi, Cal-Royal Products (DKS), makes a 90Min louvered door insert #VLV1812 that is NOT fusible link.
I was wanting to know how this can be used in a fire door?
Can a fusible link louver be utilized in the upper portion of the door instead of the bottom like the typical installation?
Hi Dave –
The model codes prohibit louvers in almost all fire door locations. Even fusible link louvers could let a lot of smoke pass through before the link melts. I think having the louver in the top half of the door would be even worse, because a larger volume of smoke would pass through because of where the neutral pressure plane is located.
Can I get 3′ x 0.5′ louver to be fix in 8mm thk Bison Board for covering Elc Duct ?