/ Field knowledge · IMC 501.3
Exhaust that re-enters the building is not exhausted.
IMC 501.3: exhaust goes outdoors where it will not bother people and cannot be pulled back in. Never into attics or crawl spaces. Keep it off walkways. Kitchen grease uses 506.3.13 — this page is the rest of the exhaust.
Educational 2024 IMC 501.3–501.3.1. Confirm the adopted edition. This is not an outlet design.
- Environmental air (model-code 501.3.1 item 3): 3 ft to property lines; 3 ft to operable openings (not Group U); 10 ft to mechanical air intakes. Listed intake/exhaust combo fittings have a dwelling-unit path when installed per instructions.
- Other product-conveying: 10 ft to property lines; 3 ft from exterior walls/roofs; 10 ft to operable openings; 10 ft above grade.
- Explosive / flammable product-conveying: larger separations (30 ft class). Do not guess this from a bathroom fan detail.
- Ductless range hood is not outdoor exhaust. If used, Chapter 4 ventilation still has to be provided.
Re-entrainment
The outlet next to the OA intake is the comment. Dimension lot line, openings, intakes, and grade. Aim the throw. Flood elevation is an early coordination item in Miami-Dade.
Related: DCT 501 Part 2 · grease 506.3.13 · discharge check.
What to send
What is being exhausted (toilet, dryer, kitchen, lab, garage), roof/wall photos or elevations, and nearby OA intakes.
If the outlet is next to an intake or a sidewalk
Send what is being exhausted and the elevation. Masterbuild will say whether this is 501.3, 504, or 506.3.13.
Send Project Background+1 (786) 398-6940 · osmany.portal@masterbuildconsulting.com
Masterbuild provides engineering services under a written scope. Nothing on this page is project-specific engineering advice, a code interpretation for your project, or a representation about permit approval.