2018 IMC Definition of Corridor?

[redbird11]

The 2018 IBC defines a corridor as: An enclosed exit access component that defines and provides a path of egress travel. IMC does not contain a definition.

My project is not required to have rated corridors. However, IMC 601.2 says -

Corridors shall not serve as supply, return, exhaust, relief or ventilation air ducts.

Exceptions:

1. Use of a corridor as a source of makeup air for exhaust systems in rooms that open directly onto such corridors, including toilet rooms, bathrooms, dressing rooms, smoking lounges and janitor closets, shall be permitted, provided that each such corridor is directly supplied with outdoor air at a rate greater than the rate of makeup air taken from the corridor.
2. Where located within a dwelling unit, the use of corridors for conveying return air shall not be prohibited.
3. Where located within tenant spaces of 1,000 square feet (93 m2) or less in area, use of corridors for conveying return air is permitted.
4. Incidental air movement from pressurized rooms within health care facilities, provided that the corridor is not the primary source of supply or return to the room.

So if I don't call them corridors and call them hallways or "unrated corridors" can I use them for return air?

 

[north star]

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What will your Hallways be used for ?

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[steveray]

If it is a "enclosed exit access component/ path of travel" it is a corridor... the definition is what qualifies it, not the label....The intent is to preserve the MOE....

 

[klarenbeek]

If not directly defined in the mechanical code but it is in the IBC, go with the IBC definition. It can still be an exit path of travel and not be rated.

 

[redbird11]

"Corridors shall not serve as supply, return, exhaust, relief or ventilation air ducts."

So if I'm not required to have a "corridor" and my condition is partial height non-rated walls bounding a path that people do use as exit access with no ceiling.... Can I return air through the space?

 

[steveray]

You are never "required" to have a corridor....But if you have something that meets the definition, then it is....Rated or not....

 

[Genduct]

"Corridors shall not serve as supply, return, exhaust, relief or ventilation air ducts."

So if I'm not required to have a "corridor" and my condition is partial height non-rated walls bounding a path that people do use as exit access with no ceiling.... Can I return air through the space?

YES because the defined area you describe is used to define designated paths within the space for safe travel and is NOT constructed with rate partitions or barriers
IMHO

 

[rgrace]

"Corridors shall not serve as supply, return, exhaust, relief or ventilation air ducts."

So if I'm not required to have a "corridor" and my condition is partial height non-rated walls bounding a path that people do use as exit access with no ceiling.... Can I return air through the space?

Well that's a slippery slope. "Partial height" can be three feet tall or nine feet tall with a 6" to 8" opening between the top of the wall and the ceiling. Rated or non-rated is not significant and is moot. The intent of this section is to prevent smoke from being pulled from another area of the structure that is in a fire condition, into a space (corridor) being used as a means of escape by the occupants. If you use the air distribution system to smoke up this space (corridor), you guarantee casualties. Still want to use it as a return?