IMC 507 is the hood chapter. If IMC 506 was the "grease duct life-safety system," 507 is the front end: hood type selection, geometry, airflow, construction, and verification that it actually captures and contains.
Plain English: Plain English Highlights
Start with the hood type (507.1 + 507.2 + 507.3)
Hoods are Type I or Type II and must capture and confine cooking vapors/residues.
If ANY appliance under a hood requires Type I, the entire hood is Type I.
Domestic appliances used commercially must still meet Type I/II requirements (not IMC 505).
Hood type rules (507.1)
Type I or Type II, designed to capture and confine vapors and residues.
If ANY appliance under a hood requires Type I, the entire hood is Type I.
Operation and interlocks (507.1.1)
Operate during cooking.
Exhaust rate per hood listing or code sizing (Type I 507.2.10, Type II 507.3.4).
Type I appliances cannot operate unless exhaust is on.
Sensor start must activate within 15 minutes.
Interlocks cannot extinguish standing pilots or rely on suppression components.
Hood geometry (507.1.6)
Canopy: 6 in overhang, max 4 ft lip to cooking surface.
Noncanopy: max 3 ft above surface, max 1 ft setback.
Testing (507.1.7)
Performance test before final approval.
Verify exhaust airflow, makeup air per IMC 508, and capture and containment.
Type I key checks (507.2)
Label minimum cfm per linear foot.
Extra heavy duty requires independent exhaust and cannot cover lighter duty.
Construction, welds, clearances, UL 1046 filters, and required suppression.
Type II key checks (507.3)
Light duty, dishwashers, heat or moisture only.
Minimum net exhaust per 507.3.4 tables.
Code Path: Where to show it
M-001: "IMC 507 HOOD COMPLIANCE" note set:
Type I vs Type II basis
Interlock / controls sequence language
Exhaust basis (hood listing or 507.2.10 / 507.3.4)
Performance test + capture/containment test requirement
M-101: hood type tags, duty classification basis, hood mounting heights/overhangs, and exhaust CFM callouts.
Details: hood support, clearance protection (when using exceptions), filter angle + drip tray concept, grease gutter/receptacle notes.
Controls narrative: Type I interlock logic, sensor access where used, and "no reliance on suppression components."
Check: Do
Treat the hood like equipment with geometry + airflow + controls, not a symbol.
Put the performance test requirement on the drawings so it doesn't get missed.
Review Risk: Don't
Don't size airflow by "rule of thumb" when 507.2.10 / 507.3.4 drives minimum net exhaust.
Don't skip the interlock sequence on Type I hoods.
Field Tip: Field tip
HOOD QA sweep: TYPE + DUTY + GEOMETRY + NET EXHAUST + INTERLOCK + FILTERS (Type I) + TEST.
Comment "IMC507" if you want a paste ready M001 hood note set plus a one-page hood QA checklist.
Masterbuild QA Lens
Exhaust systems need a source-to-discharge story. Identify what is being captured, how it is captured, how it is routed, where it terminates, and what interlocks or separations protect the building.
Drawing / Submittal Check
Verify source classification, hood or pickup point, duct material, route, cleanouts or access, fan selection, discharge location, make-up air, controls, and required coordination with fire protection or alarms.
Common Review Risk
The expensive miss is treating all exhaust the same. Grease, dryer, dust, hazardous, smoke control, battery, and specialty exhaust systems carry different proof requirements.
When To Escalate
Escalate when exhaust involves grease, hazardous materials, combustible dust, battery charging, smoke control, rated shafts, energy recovery, or any discharge that can re-enter the building.
Kitchen Exhaust Coordination
For kitchen exhaust, tie the hood schedule, appliance lineup, grease duct route, cleanouts, fan discharge, fire suppression interface, and make-up air strategy into one reviewable story.
Duct System Coordination
For duct and plenum items, check material limits, insulation continuity, vapor control, access, listed products, and whether the surrounding space changes the requirement.