dwelling units sharing air

[Torqued 2 Spec]

it came to my attention yesterday through a discussion with a fire stopping specialist that I am apparently not aware of where code standards require that air not be shared or communicated between dwelling units contained in an R occupancy.
While I was certain that portions of the intent contained within chap 4, specifically- 420 would address this more specifically than does chaper 7, I was not able to lay a finger on a substantive answer to such a prohibition.
As a newbie I guess I shouldn't be surprised, not to be able to find something, but honestly, I sure thought it would be as plain as my nose.

 

[BN4537]

Shared how?

IBC 420.2 requires walls to be constructed as fire partitions, and 708.6, .7, .8, .9. deals with penetrations and openings.

IMC 601.5, number 5 says you can't pull return air from another dwelling unit.

 

[Torqued 2 Spec]

Beniah,
Great points. Super citations for reference!

I think that’s what surprises me the most. While fire separation is explicit and noise attenuation is specified, if an assembly were sound tested post construction and passed at or better than 45 (see 1206.2), and through and membrane service piping penetrations between units were to utilize , for example, fire collars instead of fire stop sealants it’s possible that if Duane the rock Johnson lived next door, you might just about certainly smell what the Rock is cooking.