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:
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:
HOOD QA sweep: TYPE + DUTY + GEOMETRY + NET EXHAUST + INTERLOCK + FILTERS (Type I) + TEST.
Masterbuild QA Lens
For the Section 507 hood summary close-out, the three most common pre-occupancy failures are: (1) installed hood dimensions do not match the permit drawings (different cooking equipment added late); (2) listed grease filters are not in place at inspection; (3) the fire suppression system is not listed for the specific hood model installed. Coordinate the final equipment list with the hood manufacturer before inspection - not after.
Drawing / Submittal Check
The kitchen hood summary on M-001 must cross-reference the exhaust system (IMC 506) drawing sheet, the fire suppression drawing, and the gas piping drawing. The fire suppression system requires a separate permit in most jurisdictions - confirm who is pulling that permit and note it on M-001.
Common Review Risk
Commercial kitchen mechanical sets that arrive without a coordinated fire suppression drawing cross-reference are routinely held until the suppression contractor's drawings are submitted. In most jurisdictions, the kitchen hood fire suppression is a separate permit - but the mechanical reviewer wants to see the coordination note. Confirm on M-001 who is pulling the suppression permit and when the suppression drawings will be submitted.
When To Escalate
Escalate when the commercial kitchen is in a shared-tenancy building where the kitchen exhaust, fire suppression, and gas permits are being pulled by different contractors reporting to different stakeholders. Multi-contractor kitchen projects without a single mechanical coordinator generate conflicts between the hood exhaust design, the fire suppression design, and the gas valve sequence that are discovered at commissioning, not during design.
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
Commercial kitchen hood exhaust duct specifications must reflect the listed hood, design CFM, minimum CFM, grease duct construction class, and access panel locations. All of these belong on the exhaust duct schedule.