# Air Transfer Opening



## mtlogcabin (Oct 29, 2012)

Is there a definition in the code (any code) as to what is an "Air Transfer Opening"

I know what I was taught in the trade but not sure it is the same intent in the code.


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## north star (Oct 29, 2012)

*= =*

From *the NFPA 90A, 2012 Edition, Section 3.3.12* - Air Transfer

Opening: "An opening designed to allow the movement of environmental air

between two contiguous spaces."

*$ $*


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## fatboy (Oct 29, 2012)

From an NFPA document here;http://www.nfpa.org/assets/files/pdf/glossarya2004.pdf''>http://www.nfpa.org/assets/files/pdf/glossarya2004.pdf' rel="external nofollow">

http://www.nfpa.org/assets/files/pdf/glossarya2004.pdf 

Air Transfer Opening - An opening designed to allow the movement of environmental air between two
​contiguous spaces.

From The 2009 IBC - Chapter 7 definitions;

*FIRE DAMPER.* A _listed_ device installed in ducts and _*air transfer openings *_designed to close automatically upon detection of heat and resist the passage of flame. _Fire_ _dampers_ are classified for use in either static systems that will automatically shut down in the event of a fire, or in dynamic systems that continue to operate during a fire. A dynamic _fire_ _damper_ is tested and rated for closure under elevated temperature airflow. EDIT: Dang north star, beat me to it.


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## north star (Oct 29, 2012)

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fatboy,  ... 

FWIW, ...contiguous is defined as "near", or "touching"!



*= =*


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## fatboy (Oct 29, 2012)

aaaaaaaa, I know?


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## north star (Oct 29, 2012)

*$ $ $*

I know that you know, ...others may not!.....Just trying to help!

*# # #*


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## Gregg Harris (Oct 29, 2012)

fatboy said:
			
		

> From an NFPA document here;http://www.nfpa.org/assets/files/pdf/glossarya2004.pdfhttp://www.nfpa.org/assets/files/pdf/glossarya2004.pdf
> 
> http://www.nfpa.org/assets/files/pdf/glossarya2004.pdf' rel="external nofollow"> Air Transfer Opening - An opening designed to allow the movement of environmental air between two
> ​contiguous spaces.
> ...


NFPA

Environmental Air.

 Air that is supplied, returned, recirculated, or exhausted from spaces for the purpose

of modifying the existing atmosphere within the building.

2012 IMC Environmental Air

Air that is conveyed to or from occupied areas through ducts which are not part of the heating or air conditioning system, such as ventilation for human usage, domestic kitchen range exhaust, bathroom exhaust, domestic cloths dryer exhaust and parking garage exhaust.

 Two conflicting definitions of Environmental Air


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## fatboy (Oct 29, 2012)

OK, gotcha......didn't know if I was missing something.


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## Francis Vineyard (Oct 29, 2012)

mtlogcabin said:
			
		

> Is there a definition in the code (any code) as to what is an "Air Transfer Opening" I know what I was taught in the trade but not sure it is the same intent in the code.


*201.4 Terms not defined. *Where terms are not defined through the methods authorized by this section, such terms shall have ordinarily accepted meanings such as the context implies.

An opening (not ducted) that allows air to be exchange or move from one place to another.

For example: Mixed Use and Occupancy, Construction: 508.2.2.1 “…Doors shall not have air transfer openings and shall not be undercut in excess of the clearances permitted in accordance with NFPA 80.”



Hope this helps adds clarity.



Francis


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## mtlogcabin (Oct 29, 2012)

> An opening (not ducted) that allows air to be exchange or move from one place to another


That was my understanding

Now my delemia

104 unit hotel 4 stories

The hotel has an ERV sytyme supplying MUA to all the units

The 1st floor is ducted to each room with a ceiling diffusser and a smoke damper for each room

The 2nd, 3rd and 4th floors ERV is supplied through a plenum and each ceiling opening has a smoke damper.

716.5.7 Smoke partitions.

A listed smoke damper designed to resist the passage of smoke shall be provided at each point that an air transfer opening penetrates a smoke partition. 

The first floor are clearly not air transfer openings. The remaining floors supplied by a plenum probably are.

The fire plans examiner is worried  about getting a lot of false alarms with this system and I see his concern but I believe they are required.

Any suggestions? Alternate smoke detection in lieu of the duct detectors?


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## Francis Vineyard (Oct 31, 2012)

Crickets; anyone there?

Francis


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## klarenbeek (Oct 31, 2012)

Check IMC 607.3.3.2 (2009) #3 Where a smoke damper is installed within an unducted opening in a wall, a spot-type detector listed for releasing service shall be installed within 5 feet horizontally from the damper.

Duct detectors would not work well in unducted openings because they usually require a certain amount of air velocity to work properly.

The only other option would be #5 of the same section: Where a total-coverage smoke detector system is provided within (all) areas served by the HVAC system, smoke dampers shall be permitted to be controlled by the smoke detection system.


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## klarenbeek (Oct 31, 2012)

Just reread the dilema and saw that the smoke partition is the ceiling, is that correct? If that's the case, I would require the spot detector to be immediately above the opening, probably in the direction the air would get drawn with the equipment running.


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## Dr. J (Nov 6, 2012)

If I understand correctly, there are no openings from the ERV system in the corridor itself, the ERV system is ducted directly to each dwelling unit on the first floor, and on the upper floors, it dumps into the above ceiling space of the corridor and then somehow transfers through openings above the ceiling to each dwelling unit

Section 711 Smoke Partitions have nothing to do with this.  Smoke partitions are only in I-2 occupancies.  What you have are Fire Partitions.

Here is the section of interest:

*716.5.4.1 Corridors. *A_listed smoke damper _designed to resistthe passage of smoke shall be provided at each point a duct orair transfer opening penetrates a _corridor _enclosure required tohave smoke and draft control doors in accordance with Section715.4.3.
​*Exceptions:*
​1. _Smoke dampers _are not required where the building isequipped throughout with an _approved _smoke controlsystem in accordance with Section 909, and _smokedampers _are not necessary for the operation and controlof the system.2. _Smoke dampers _are not required in _corridor _penetrationswhere the duct is constructed of steel not lessthan 0.019 inch (0.48 mm) in thickness and there are
​no openings serving the _corridor._

The first floor does need dampers at all since there are no openings to the corridor.

On the upper floors, we need to know how the Fire Partitions terminate (see the options in IBC 709.4).  If it is a tunnel construction, (exception 3), then there are no penetrations of the Fire Partition, and therefore no dampers are required.   If the walls terminate at the deck (basic requirement), or with a one-sided membrane (exception 2), then the penetration of the Fire Partition occurs at the corridor wall, and this is where the smoke damper is required.  In no case should a damper be at the ceiling of the dwelling unit, since the ceiling is NOT the Fire Partition.

Note that where the Fire Partition does extend to the deck, smoke dampers could still be avoided simply by ducting the ERV air to each dwelling unit.  I have to believe a bit of duct work is much cheaper (and less susceptible to false alarms) than some ductwork.

Another issue - If the air is just being dumped above the ceiling of the corridor, how is it assured that the correct amount of OA is delivered to the breathing zone of each dwelling unit (IMC 403.2).


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## Dr. J (Nov 6, 2012)

The first floor does NOT need dampers at all since there are no openings to the corridor.

(what happened to the edit button?)


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## north star (Nov 6, 2012)

*$ $ $*







> "(what happened to the edit button?)"


Dr. J,



The Edit Button is now for Sawhorsies only!......If you were

a Paid Subscriber before, that subscription may have lapsed.

Send a PM to Jeff or RJJ and inquire, ...or possibly consider

becoming a Sawhorsie! :agree





*% % %*


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## Dr. J (Nov 6, 2012)

thanks NS.


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## Dr. J (Nov 6, 2012)

Wait a minute, the upper floors are screwed up in the first place, UNLESS the corridor is a tunnel construction.

IBC:

*1018.5.1 Corridor ceiling. *Use of the space between the
​_corridor _ceiling and the floor or roof structure above as areturn air plenum is permitted for one or more of the following
​conditions:

The corridor above ceiling space can be used as a RETURN plenum, not a supply or make-up plenum.  

If the plenum arrangement is to be used, the corridor MUST be a tunnel construction, and therefore there are no Fire Partition penetrations and therefore no smoke dampers;  if the walls extend to the deck, then the above ceiling space CAN NOT be used as a plenum, the make up air must be ducted, and therefore no smoke dampers are required.


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