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Bathroom Fans through the soffit??

2012 IRC

M1501.1 Outdoor discharge.
The air removed by every mechanical exhaust system shall be discharged to the outdoors in accordance with Section M1506.2. Air shall not be exhausted into an attic, soffit, ridge vent or crawl space.
 
2006 IRC, in a different section, M1507.2, Does not list soffit or ridge vent.
 
2006 IRC
M1501.1 Outdoor discharge.
The air removed by every mechanical exhaust system shall be discharged to the outdoors. Air shall not be exhausted into an attic, soffit, ridge vent or crawl space.
Exception: Whole-house ventilation-type attic fans that discharge into the attic space of dwelling units having private attics shall be permitted.
 
Pfall52 said:
From the residential code.
R303.5.2 Exhaust openings. Outside exhaust openings
shall be located as not to create a nuisance. Exhaust openings
shall not be directed onto walkways. Exhaust openings
shall not terminate within 3 feet of a ventilated
section in a soffit.
Click to expand...
Which version of IRC is this quote from?
 
2018 IRC section 1504.3 says:
"Air exhaust openings shall terminate as follows:
  1. Not less than 3 feet (914 mm) from property lines.
  2. Not less than 3 feet (914 mm) from gravity air intake openings, operable windows and doors.
  3. Not less than 10 feet (3048 mm) from mechanical air intake openings except where the exhaust opening is located not less than 3 feet (914 mm) above the air intake opening. Openings shall comply with Sections R303.5.2 and R303.6."
An eave cap discharges below the soffit, not in the soffit. The 3 foot distance from a ventilated portion of a soffit might be good practice, but it isn't in the current IRC.
 
2018 IRC
M1501.1 Outdoor discharge.
The air removed by every mechanical exhaust system shall be discharged to the outdoors in accordance with Section M1504.3. Air shall not be exhausted into an attic, soffit, ridge vent or crawl space.

Exception: Whole-house ventilation-type attic fans that discharge into the attic space of dwelling units having private attics shall be permitted.
 
mtlogcabin said:
Air shall not be exhausted into an attic, soffit, ridge vent or crawl space.
Click to expand...
I'd argue that it is not exhausted into the soffit. It is exhausted to the exterior, with a duct that extends through the soffit.

So long as there are not openings within 3-ft of the discharge location, what's the issue? Approve it and move on.
 
mtlogcabin said:
2018 IRC
M1501.1 Outdoor discharge.
The air removed by every mechanical exhaust system shall be discharged to the outdoors in accordance with Section M1504.3. Air shall not be exhausted into an attic, soffit, ridge vent or crawl space.

Exception: Whole-house ventilation-type attic fans that discharge into the attic space of dwelling units having private attics shall be permitted.
Click to expand...
"Into" signals the code intent, as in "into" a space. Soffit has a "space" on the inside, not the exterior. And we've all seen bath fan exhaust ducts just dropped "into" the soffit area, as if the installer was hoping the exhausted air would somehow find a way through the soffit vents.

For example, here is a letter from a NC DOI official regarding related question:
 
classicT said:
I'd argue that it is not exhausted into the soffit. It is exhausted to the exterior, with a duct that extends through the soffit.
Click to expand...
Perhaps Jar can shed some light on this one since he took the picture (when he worked on the dark side) if it vented to the exterior or just to the soffit. Either way it is easy to see that the moist air came right up the insulation baffle and that is why there should be no soffit vent openings within 3 ft either side of the exhaust opening.
1643130904665.jpeg
 
mtlogcabin said:
Perhaps Jar can shed some light on this one since he took the picture (when he worked on the dark side) if it vented to the exterior or just to the soffit. Either way it is easy to see that the moist air came right up the insulation baffle and that is why there should be no soffit vent openings within 3 ft either side of the exhaust opening.
View attachment 8523
Click to expand...
That looks like it was exhausted to the exterior but right above the outlet was a soffit vent. That is obviously non-compliant and one should cite R303.5.2 or M1504.3 because there is a soffit vent opening within 3-ft of the exhaust termination.
 
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