# Intake / Exhaust Separation Questions



## Mech (Apr 14, 2021)

2015 IMC

1. Clothes dryer discharge air is considered _environmental air_ and can be 3 ft from operable openings into the building.  If the dryer utilizes gas, is the discharge air still considered _environmental air_ or is it upgraded to hazardous or noxious with an increased distance requirement to operable building openings and mechanical air intakes?  I am thinking the discharge air is now considered noxious.

2. When measuring the distance between exhaust and intake or operable openings, should I measure around the corner as shown or only measure on one wall face?  I am thinking measuring around the corner is required.

3. I assume I must maintain distances between exhaust ducts and openings into mechanical rooms for when exhaust air is discharged and someone is in the mechanical room.  Correct?


__
		https://flic.kr/p/2kSWN9d


Thanks!


*Code excerpts:*

Section 401.4 Intake opening location. Air intake openings shall comply with all of the following:

1. Intake openings shall be located not less than 10 feet from lot lines or buildings on the same lot.

2. Mechanical and gravity outdoor air intake openings shall be located not less than 10 feet horizontally from any hazardous or noxious contaminant source, such as vents, streets, alleys, parking lots, and loading docks, except as specified in Item 3 or Section 501.3.1. Outdoor air intake openings shall be permitted to be located less than 10 feet horizontally from streets, alleys, parking lots and loading docks provided that the openings are located not less than 25 feet vertically above such locations. Where openings front on a street or public way, the distance shall be measured from the closest edge of the street or public way.

3. Intake openings shall be located not less than 3 feet below contaminant sources where such sources are located within 10 feet of the opening.

4. Intake openings on structures in flood hazard areas shall be at or above the elevation required by Section 1612 of the International Building Code for utilities and attendant equipment.



Section 501.3.1 Location of exhaust outlets. The termination point of exhaust outlets and ducts discharging to the outdoors shall be located with the following minimum distances:

1. For ducts conveying explosive or flammable vapors, fumes or dusts . . .  N/A

2. For other product-conveying outlets: 10 feet from the property lines; 3 feet from exterior walls and roofs; 10 feet from operable openings into buildings; 10 feet above adjoining grade.

3. For all environmental air exhaust (includes bathroom and dryer exhaust): 3 ft from operable openings into buildings and 10 ft from mechanical air intakes. Such exhaust shall not be considered hazardous or noxious.

4. N/A

5. For Specific systems see the following sections:
    5.1 Clothes dryer exhaust - [Nothing regarding separation distance in this section.]
    5.2 N/A
    5.3 N/A
    5.4 N/A
    5.5 N/A


----------



## SH225 (Apr 15, 2021)

Moist air discharged from a gas dryer would be the same as moist air discharged from an electric dryer.


----------



## Chrisjoneill (Apr 19, 2021)

curious on the thoughts about around the corner question too...just got this comment on my plan review...running out of places to run exhausts!


----------



## Mech (Apr 19, 2021)

I am going to play it safe and measure around the corner.


----------

