Daily Code Talk #31 — IMC 401 (Part 2): Outdoor-Air Intake Location (401.4)

🧠 Plain English Highlights• 401.4(1): Intakes not less than 10 feet from lot lines and from other buildings on the same lot.• 401.4(2): Keep not less than 10 feet horizontally from contaminant sources (vents, streets, alleys, parking, loading). You may be closer to streets/alleys/parking/loading only when the intake is not less than 25 feet above those surfaces. If fronting a street/public way, measure from the nearest edge.• 401.4(3): If a source is within 10 feet horizontally, place the intake not less than 3 feet below that source. Exception: no separation needed for an individual dwelling unit using a listed combo intake–exhaust fitting installed per the fan manufacturer.• 401.4(4): In flood hazard areas, set intakes at or above the elevation required for utilities and attendant equipment by IBC 1612.🏗️ Why It MattersRedlines here are siting errors: measured from the wrong street edge, missed the 25-foot vertical relief, intake set level with nearby exhausts, or intake below flood elevation. Resolve on the site plan before louvers are released.🧾 Where To Show It (sheet map)• M-001: “OUTDOOR-AIR INTAKES PER IMC 401.4. SHOW OFFSETS TO LOT LINES, BUILDINGS, STREETS, ALLEYS, PARKING, LOADING, AND EXHAUSTS. WHEN FRONTING A STREET/PUBLIC WAY, MEASURE FROM THE NEAREST EDGE. IN FLOOD HAZARD AREAS, SET ABOVE IBC 1612.”• M-101+: Dimension strings from each intake to lot line, on-site buildings, street/public way, parking/loading, and to nearest exhaust/plumbing vent; show vertical offsets where using the 25-foot allowance; draw flood design elevation.• M-501/502: OA louver detail (drainable section, screen, flashing continuity) with MI page; note vertical-offset logic and street-front measurement; cut a flood line through the wall section.• M-601 (Schedule adds): Intake ID | Serving System | Dist. to Lot Line | Dist. to Building | Dist. to Street/Public Way | Dist. to Parking/Loading | Nearest Exhaust/Plumbing Vent (H/V) | Intake Elev. & Flood Check | Louver Model + AMCA ref | MI Page.🔧 Quick Field Tip• If you cannot keep 10 feet horizontally from streets/parking, raise the intake to not less than 25 feet above that surface and show the dimension.• When facing a street/public way, pull distance from the closest edge, not the centerline.• Keep the intake at least 3 feet below any exhaust located within 10 feet; avoid level terminations.• In mapped flood zones, set the intake above the required elevation or detail an approved protection method.Comment “IMC401” for the Intake and Protection Kit. DM “ADVISORY” for a preliminary plan review before you file.