Draft Curtains and Deluge systems

[Stanovby]

at my current job, we do commercial work in restaurants. We've had a discussion at my office concerning the requirements of draft curtains. I was told that they are only required in NYC. This is usually behind the front counter and are used to mount the menuboard on. Sometimes in a remodel of the store we have to modify this. In NYC we have to make sure it matches the existing construction which in NYC is usually onw or 2 layers of gyp board. We had a discussion about if this is required only in NYC to have a fire rated draft curtain system. Also a lot of times there are sprinklers directly behind the soffit. Some people refer to this as a deluge system. Isn't there two things going on here? A deluge system is different from a draft curtain?

 

[steveray]

The draft curtain is usually between 2 different sprinkler systems such as ESFR and standard response........

 

[Yankee Chronicler]

A deluge system is an automatic sprinkler system in which when activated ALL the heads go off simultaneously. In a standard NFPA 13 system, each head is activated separately by a fuse located in that head. What you are describing does not sound like a deluge system -- unless NYC uses non-industry-standard terminology.

 

[Jay Smith]

In searching online for these terms, I found the term water curtain (rather than draft curtain) used for closely spaced sprinklers. Maybe that’s the source of the confusion. Here’s an example:

https://www.ladbs.org/docs/default-source/publications/information-bulletins/building-code/water-curtain-in-lieu-of-protected-exterior-openings-ib-p-bc2014-106.pdf

 

[Tim Mailloux]

Water curtain & deluge system in my experience are the same thing.

 

[Stanovby]

Yes this issue comes up in NYC. Our client which is typically a McDonald's restaurant usually calls it a draft curtain. My understanding of a draft curtain is that it keeps smoke from traveling throughout the space when there is a fire, which is a different issue than what the the sprinklers are for, if I'm understanding it correctly. They usually have sprinklers directly behind the draft curtain / Menuboard soffit. When we modify the area behind the counter we usually say to match existing construction as far as the soffit goes. Usually we make it one or two layers of gyp board going all the way to the deck. A lot of the times we dont know what the existing construction is.

 

[Stanovby]

I was under the impression this was a draft curtain used to keep smoke from spreading throughout the restaurant. There are usually sprinklers right behind it, spaced 4'-0" apart. There is some cooking equipment in the kitchen, but these are usually fire rated in NYC


508.1General.
Each portion of a building shall be individually classified in accordance with Section 302.1. Where a building contains more than one occupancy group, the building or portion thereof shall comply with the applicable provisions of Section 508.2, 508.3 or 508.4, or a combination of these sections.

Exceptions:

1.Occupancies separated in accordance with Section 510.

2.Where required by Table 415.6.2, areas of Group H-1, H-2 and H-3 occupancies shall be located in a detached building or structure.

3.Where identified in Table 509, rooms or spaces shall be treated as incidental uses.

4.Where not identified in Table 509, mechanical and/or electrical equipment rooms shall be permitted to be classified as the occupancy within which they are located, or at the option of the applicant, classified as Group F-2 occupancy in accordance with Section 306.3.

5.Commercial kitchens classified as Group F-2 need not be separated by fire separations from adjoining dining spaces, provided that the conditions of Items 5.1, 5.2, and 5.3 are met:

5.1.The cooking equipment is vented directly to the outdoors;

5.2.A draft curtain of noncombustible material, at least 24 inches (609 mm) down from the ceiling, is provided to separate the opening between the cooking facilities and the dining spaces; and

5.3.A fire protection system is installed and located as set forth in Item 5.3.1 or 5.3.2.

5.3.1.A fire protection system in accordance with Sections 903 and 904 is installed within the cooking facilities. Additionally, sprinkler heads protecting the opening between the cooking facilities and the dining spaces shall be located within 24 inches (609 mm) of the curtain on the cooking facilities side; or

5.3.2.A fire protection system in accordance with Section 903 is located along any opening between the cooking facilities and the dining space on the cooking facilities side, with sprinkler heads located within 24 inches (609 mm) of the opening and, if the opening is more than 60 inches (1524 mm) wide, the sprinkler heads are spaced not more than 48 inches (1219 mm) on center.

 

[Yankee Chronicler]

Water curtain & deluge system in my experience are the same thing.

No, they are not. A water curtain is a line of closely-spaced heads protecting a specific surface or opening. A deluge system is a dry pipe system in which ALL the heads are open and the entire system is dry. Rather than the system being pressurized as in a dry pipe system (which still only sees one or more heads open when fused by heat from the fire), a deluge system holds the water back with a deluge valve. When that valve is opened by the detection system, the system is flooded and ALL heads immediately discharge water.

What Is a Deluge Sprinkler System? How Does It Work?

What Is a Deluge Sprinkler System, and How Does It Work? - Mill Brook Fire Protection

millbrookfireprotection.com

Deluge System: Definition, Working, Applications, and Advantages | What is Piping

A deluge system is a fixed fire protection system designed to protect against severe fuel hazards. A large number of sprinklers simultaneously act to bring any undesirable fire event under control.

whatispiping.com

How does a Deluge Fire Suppression System Work? - Fire Systems, Inc.

A Deluge Fire Suppression System is a system wherein sprinkler heads are always in an open position to allow for a larger flow of water.

firesystems.net

 

[Stanovby]

No, they are not. A water curtain is a line of closely-spaced heads protecting a specific surface or opening. A deluge system is a dry pipe system in which ALL the heads are open and the entire system is dry. Rather than the system being pressurized as in a dry pipe system (which still only sees one or more heads open when fused by heat from the fire), a deluge system holds the water back with a deluge valve. When that valve is opened by the detection system, the system is flooded and ALL heads immediately discharge water.

What Is a Deluge Sprinkler System? How Does It Work?

What Is a Deluge Sprinkler System, and How Does It Work? - Mill Brook Fire Protection

millbrookfireprotection.com

Deluge System: Definition, Working, Applications, and Advantages | What is Piping

A deluge system is a fixed fire protection system designed to protect against severe fuel hazards. A large number of sprinklers simultaneously act to bring any undesirable fire event under control.

whatispiping.com

How does a Deluge Fire Suppression System Work? - Fire Systems, Inc.

A Deluge Fire Suppression System is a system wherein sprinkler heads are always in an open position to allow for a larger flow of water.

firesystems.net

Is a deluge system typically a fully sprinklered space? You wouldn't have just some sprinklers around the menuboard soffit as in my photo. that would not be a deluge system?

 

[tmurray]

No, they are not. A water curtain is a line of closely-spaced heads protecting a specific surface or opening. A deluge system is a dry pipe system in which ALL the heads are open and the entire system is dry. Rather than the system being pressurized as in a dry pipe system (which still only sees one or more heads open when fused by heat from the fire), a deluge system holds the water back with a deluge valve. When that valve is opened by the detection system, the system is flooded and ALL heads immediately discharge water.

I think the confusion is that a lot of water curtains are also deluge systems, so people conflate the two.

 

[tmurray]

Is a deluge system typically a fully sprinklered space? You wouldn't have just some sprinklers around the menuboard soffit as in my photo. that would not be a deluge system?

Not necessarily. We see deluge systems a lot in Canada to create a water curtain for stages. The rest of the building might be sprinklered, it might not.

The selection of sprinkler system is based on both the code requirements and NFPA 13 requirements.

You will typically only see deluge systems in buildings that have a crazy high hazard of fire or where the risk of damage to fire spread is high, but damage from water would be negligible. It is relatively rare to see full deluge systems and when you do the water demand and pressure requirements get crazy very fast. Sprinkler systems are rarely designed so that all heads can operate at once, with deluge being one of the exceptions.

 

[Yankee Chronicler]

Is a deluge system typically a fully sprinklered space? You wouldn't have just some sprinklers around the menuboard soffit as in my photo. that would not be a deluge system?

A water curtain is not a deluge system.

 

[bill1952]

A water curtain is not a deluge system.

I agree, but will point out that deluge systems as used for proscenium open protection (stage and auditorium) are very frequently referred to as water curtains, however incorrectly. But people refer to "sprinklers" as "heads" and I know from code committee and hearings the correct term is "sprinkler".

I "think" water curtains use a different type of sprinkler, one that is fan shaped, and I have mostly seen them on large glass areas in lieu of protected exterior openings and draft stops.