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2003 IBC 716.5 and maybe the IFC

steveray

steveray

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I have a team of architects and engineers that are of the understanding that believe that fire dampers are not required where a fully 26GA ducted system crosses a 1 hr fire barrier but has openings on both sides.....We have always interpreted (and been taught)this section to mean the ductwork is continuous through side "A" and only has openings on side "B", not both sides....Upon further reading, I can see how this can be interpreted both ways....Any input?

717.5.2 in 2012 codes

716.5.2 Fire barriers.

Duct and air transfer openings of fire barriers shall be protected with approved fire dampers installed in accordance with their listing.

Exception: Fire dampers are not required at penetrations of fire barriers where any of the following apply:

1. Penetrations are tested in accordance with ASTM E 119 as part of the fire-resistance-rated assembly.

2. Ducts are used as part of an approved smoke control system in accordance with Section 909.

3. Such walls are penetrated by ducted HVAC systems, have a required fire-resistance rating of 1 hour or less, are in areas of other than Group H and are in buildings equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 or 903.3.1.2. For the purposes of this exception, a ducted HVAC system shall be a duct system for conveying supply, return or exhaust air as part of the structure’s HVAC system. Such a duct system shall be constructed of sheet steel not less than 26 gage thickness and shall be continuous from the air-handling appliance or equipment to the air outlet and inlet terminals.
 
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steveray said:
I have a team of architects and engineers that are of the understanding that believe that fire dampers are not required where a fully 26GA ducted system crosses a 1 hr fire barrier but has openings on both sides.....We have always interpreted (and been taught)this section to mean the ductwork is continuous through side "A" and only has openings on side "B", not both sides....Upon further reading, I can see how this can be interpreted both ways....Any input?716.5.2 Fire barriers.

Duct and air transfer openings of fire barriers shall be protected with approved fire dampers installed in accordance with their listing.

Exception: Fire dampers are not required at penetrations of fire barriers where any of the following apply:

1. Penetrations are tested in accordance with ASTM E 119 as part of the fire-resistance-rated assembly.

2. Ducts are used as part of an approved smoke control system in accordance with Section 909.

3. Such walls are penetrated by ducted HVAC systems, have a required fire-resistance rating of 1 hour or less, are in areas of other than Group H and are in buildings equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 or 903.3.1.2. For the purposes of this exception, a ducted HVAC system shall be a duct system for conveying supply, return or exhaust air as part of the structure’s HVAC system. Such a duct system shall be constructed of sheet steel not less than 26 gage thickness and shall be continuous from the air-handling appliance or equipment to the air outlet and inlet terminals.
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26 gauge metal penetrating the wall with opening on both sides, would be a transfer duct and would require a damper.

Such a duct system shall be constructed of sheet steel not less than 26 gauge thickness and "shall be continuous from the air-handling appliance or equipment to the air outlet and inlet terminals."

Shall be continuous from air handling appliance or equipment would fit the exception for no damper.
 
Thanks Gregg.....what I am talking about is a typical duct system (fully metallic) with supplies or returns on both sides of a rated fire barrier...the duct is continuous to the terminals, they just happen to be on both sides of the wall.....not just a stub to exchange air (which is what we call a transfer duct....

My common sense (and plan review) says dampers....they are arguing the contrary....
 
My take is that it allows for the air handler to be on the other side of the fire barrier, but only if it exclusively serves one side. If the duct system has openings between the air-handler and the fire barrier, it is not continuous.
 
Thanks Brudgers......"shall be continuous from the air-handling appliance or equipment to the air outlet and inlet terminals." is worded poorly IMHO....it doesn't say anything about terminals on either side of the wall....
 
steveray,

You listed the 2003 Section in your topic title, but also listed the 2012 Section

in your topic discussion. Please clarify which codes you are using. Thanks! :)

.
 
It's in my sig.....2003 based.....thought I would throw in the newer stuff for those of you that are not as impaired as we, or did not have access to the older stuff....Thanks!
 
steveray said:
Thanks Brudgers......"shall be continuous from the air-handling appliance or equipment to the air outlet and inlet terminals." is worded poorly IMHO....it doesn't say anything about terminals on either side of the wall....
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Ok, give me an example of an HVAC system that is not continuous.
 
mtlogcabin said:
But a return plenum isn't constructed of 26 guage metal ductwork
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But for the continuity requirement, one could use a plenum as part of the return, and comply by connecting it to a fire damperless 26 gauge duct near the fire barrier. I.e. "continuous" means that jumpers aren't allowed without fire dampers.
 
I'm not following your concept for return plenums in regards to this fire barrier penetration. FWIW IMC 602.1 plenums are restricted to a single fire area.

The IMC commentary figure for exception #3

Barrier_zpsd92850b3.jpg


Francis
 
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Thanks Francis!...I was only looking in the IBC.....I don't know why that figure is not in that commentary.....I guess it is allowable by that figure, I don't really understand how that is really any less dangerous than a transfer duct....are they just giving that much credit for the sprinklers? I will have to read that IMC commentary when I get a chance....
 
Francis Vineyard said:
I'm not following your concept for return plenums in regards to this fire barrier penetration. FWIW IMC 602.1 plenums are restricted to a single fire area. The IMC commentary figure for exception #3 Francis
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Assume the ducts are returns. Picture the ducts on each side ending before they turn down, and the addition of a grille at the ceiling level...i.e. two plenums in the picture with a metal ducts drawing air from each.
 
brudgers said:
Assume the ducts are returns. Picture the ducts on each side ending before they turn down, and the addition of a grille at the ceiling level...i.e. two plenums in the picture with a metal ducts drawing air from each.
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That wouldn't be continuous from the air-handling appliance or equipment. Nice try though.
 
kilitact said:
That wouldn't be continuous from the air-handling appliance or equipment. Nice try though.
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Yes, "continuous" rules out using a plenum without a damper. But allows both sides of the fire barrier to be supplied by a single air-handler.

Both my original interpretation and that of the OP (in so far as I understand it) were incorrect.

If you want to argue, you'll have to find something else.

Nice try though.
 
brudgers said:
Assume the ducts are returns. Picture the ducts on each side ending before they turn down, and the addition of a grille at the ceiling level...i.e. two plenums in the picture with a metal ducts drawing air from each.
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Thanks for clarification. Guess the logic of this code section will go in my file of unsolved mysteries of how this makes sense.

This is not an unusual situation but it's difficult to run large system without a vibration isolation (flexible) duct for temperature; it seems though it could be possible to have one of the 3 fire areas depicted in the figure above to be plenum and the other 2 ducted but I suspect it would be a nightmare to balance and maintain.

Francis
 
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brudgers said:
Yes, "continuous" rules out using a plenum without a damper. But allows both sides of the fire barrier to be supplied by a single air-handler.

Both my original interpretation and that of the OP (in so far as I understand it) were incorrect.

If you want to argue, you'll have to find something else.

Nice try though.
Click to expand...
Wasn't looking to argue, just paying you a compliment. perhaps I shoulda just said atta boy.
 
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