Bathroom Fan Venting — New Diagram Now Shows Soffit Termination as Acceptable?

[rbleich (Richard Bleich)]

@lunderwood

Why does the first photo (older photo) show ‘discharging through the soffit to the exterior’ as wrong and the second photo (updated photo) shows ‘discharging through the soffit to the exterior’ as correct? (did standards change?)

The standard didn’t change, the interpretation did.

@rbleich

That still doesn’t explain why you’re teaching your students to call out soffit vents. Discharging into soffits is disallowed. Discharging into a soffit vent is not best practice, but it’s not disallowed.

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.