Daily Code Talk #63: IMC 506 Part 6 (506.5 Exhaust Equipment)

🧠 Plain-English Highlights• 506.5 equipment must be approved or listed and comply with 506.5.1 through 506.5.6.• 506.5.1 Type I exhaust fans: Fan housing must be built like a grease duct (see 506.3.1) unless the fan is listed to UL 705.• 506.5.1.1 motor location: Motor must be outside the exhaust airstream.• 506.5.1.2 in line fan indoors: If an enclosed grease duct connects to an in line fan not outdoors, the fan must be in a room or space with the same fire resistance rating as the grease duct enclosure, with service access and ventilation per the manufacturer.• 506.5.2 pollution control units (PCU) Key checks:- UL 8782 listed PCU, UL 705 listed fan, noncombustible supports, indoor units listed for indoor use, clearances per listing.- If indoors with enclosed grease duct: dedicated rated enclosure space equal to duct enclosure rating, with access and ventilation per manufacturer.- Other must haves: roof mounted units at least 18 in above roof, discharge location per 506.3.13, pressure drop monitoring with a visual alarm in the cooking area when airflow drops below design, factory fire suppression, service clearances, and wash down drains to a grease interceptor with trapped or sealed drain.• 506.5.3 discharge and drainage: Discharge cannot impinge on roof, equipment, or structure. Vertical discharge fans need a drain outlet at the low point to an approved grease reservoir.• 506.5.4 upblast fan mounting: Hinged fan, flexible weatherproof electrical cable, and a restraint. Grease duct extends at least 18 in above roof.• 506.5.5 clearances: 18" to combustibles unless listed for less.• 506.5.6 termination: Must meet 506.3.13. - Parapet exception: 2 ft minimum if parapet is not higher than the top of discharge opening.🏗️ Why it mattersRedlines usually come from missing hinge and service access, no grease drain to reservoir, motor shown in the airstream, discharge blasting the roof, or PCU alarms and drains not detailed.🗺️ Where to show it• M-001: Type I exhaust equipment note for UL listings, motor out of airstream, hinge and cable, grease drain, clearances, and PCU requirements if used.• Roof plan: fan tag with hinge and restraint, duct height, drain routing, discharge direction, and clearance bubble.• Schedule: PCU enclosure rating, access, ventilation, and drain to grease interceptor.🔧 Field tipOn the roof plan, add a “TYPE I FAN CHECK” line next to each fan: UL 705 listed, motor out of airstream, hinged with flex cable and restraint, duct 18" above roof, drain to grease reservoir, discharge not impinging, 18" clearance. Comment “IMC506-P6” if you want a paste ready M-001 note and roof fan tag.