Smoke or Heat Vent with ESFR Sprinkler System?

6/10/2021

NFPA 13 Section 20.6.6.3:
"Early suppression fast-response (ESFR) sprinklers shall not be used in buildings with automatic heat or smoke vents unless the vents use a high-temperature rated, standard-response operating mechanism."

ESFR sprinklers are designed to act fast and suppress the fire, the inclusion of a roof vent that opens up before the sprinkler activates could severely impact sprinkler activation both in terms of timing and location (as the moving smoke could activate a more remote sprinkler). If automatic roof vents are present, they should have a high-temperature rated standard-response operating mechanism to ensure that the sprinkler activates before the vent opens up.

Based on the above, am I correct to interpret smoke venting is not required with ESFR systems?

How do I go about handling smoke or heat vents with ESFR, or are they not necessary to begin with?

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6 Comments

Franck

6/10/2021 08:13:46 am

The value of automatic vents in unsprinklered buildings is not questionable.

For sprinklered building, on the other hand...
Sprinkler protection systems are not designed to operate with open heat and smoke systems at the roof level which would generate air flows and might have a cooling effect at the sprinkler head location, this could result in a critical delay in sprinkler operation.
Sprinkler protection criteria are based on the assumption that roof vents and draft curtains are not being used.
When operating too early (before the sprinkler activation) it may open more heads.
On the control mode, this is an adverse situation, but not always critical.
With ESFR, it becomes critical because of the limited number of heads, the quick operation of the sprinklers and the purpose that is extinguishment, not control.
For that reason, "we" don't want heat/smoke vents to operate before the ESFR.
This the requirements for "no vents" or manually operated vents with a high temperature fusible link.

On the other hand, firefighters need smoke/heat vents for some operations.
This is when sometimes standards may come in conflict.

Venting in a sprinklered fire does not remove heat and smoke for manual access as effectively as in an unsprinklered fire because sprinkler water entrains smoke and absorbs much of the heat. With sprinklers preventing air temperatures from reaching very high levels, the temperature differential between the inside and outside air is fairly small, so the rate of smoke passage through the vents is minimized. Therefore, in most cases, venting a sprinklered storage fire is neither effective nor desirable. During the initial stages of the fire, it is usually best to keep the building closed to limit the supply of air while sprinklers gain control.

You will find interesting information in NFPA 13E– Recommended Practice for Fire Department Operations in Properties Protected by Sprinkler and Standpipe Systems – Annex B

6/10/2021 08:16:23 am

But at the end (as it is normally the case), the AHJ will have the last word on whether you need to put smoke vents or not in your building.

If you need to, with ESFR, just be sure to have manually operated vents only, and with a fusible link with a temperaute rating well above the operating temperature of the sprinklers (high temperature fusible links for smoke vents are better when using ordinary temperature ESFR).

CJ Bonczyk

6/10/2021 08:17:49 am

If a smoke and heat removal system is installed along with a sprinkler system, the automatic roof vents are required to have an operating element with a temperature classification higher than the sprinklers per NFPA 13. This is in hopes to minimize the potential effect the smoke and heat removal system can have on sprinkler activation. For automatic heat or smoke vents used with ESFR sprinklers by requiring automatic heat or smoke vents to use a high-temperature rated, standard-response operating mechanism. However if allowed by the AHJ depending on the use of local codes adopted, you can eliminate the use of smoke and heat vents with the use of ESFR sprinklers in high piled storage occupancies.

Jay

6/10/2021 09:08:24 am

See International Fire Code chapter 32 for the table that specifies when smoke and heat vents are required.
Pay attention to table note J, which states that the smoke/heat vents are not required when the building is protected with ESFR installed in accordance with NFPA 13.

Chong Y K link

6/11/2021 03:53:51 pm

Based on the above response please confirm on the following :-

We are doing a FEED for a Copper Foil Plant and would like find out whether any one of you have any experienced on the Copper Foil Factory for the production of electro-deposited copper foils used in Lithium-Ion Batteries for electric vehicle.

I would like to know whether any fire compartmentation and smoke fill system required as the Ground Floor occupies 7 acres of floor space.

From the Basement the copper materials are transported to the First Floor where 14% sulfuric is added to dissolve the copper scrap. Due to the array of piping in the production process, it would be difficult to do have an oversize compartment as they requires this free space for the production flow from Basement to the First Floor.

Appreciate your confirmation on the above as we intend to use ESFR sprinkler system as per NFPA 13 and all production floor shall be sprinklered.
Appreciate your comments and advice.

sean

6/12/2021 08:13:30 am

See 910.2 of the IFC or IBC they have an exception for ESFR sprinkler systems

Smoke or Heat Vent with ESFR Sprinkler System?

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