Daily Code Talk #67: IMC 507 Part 6 (507.1 General + Exceptions)

🧠 Plain-English Highlights• 507.1 hood type rules- Commercial hoods must be Type I or Type II.- They must capture and confine cooking vapors and residues.- If ANY appliance under one hood requires Type I, the entire hood must be Type I.- If Type II is required, you may install Type II OR Type I (Type I is always the “safe upgrade,” but it triggers Type I installation rules when applicable).• 507.1 key exceptions and “no hood required” cases (where listed/approved)- A lot of plan review pain comes from missing the listings.1. Listed recirculating systems (UL 710B)• If the kitchen uses a factory-built recirculating system listed/labeled to UL 710B (installed per IMC 304.1), several IMC 507 hood rules don’t apply (ex: hood outlet placement, hood size/location rules, certain Type I construction/filter/airflow provisions, and Type II hood material rules).• The space is still treated as a kitchen and must be ventilated per Table 403.3.1.1.• For ventilation floor area calc: each appliance counts as at least 100 sf.2. No hood required (specific cases)- A hood is not required at/above:• UL 710B listed recirculating systems (again).• Listed integral downdraft systems (listed for the application per NFPA 96).• Smoker ovens with integral exhaust listed/tested for the application.• UL 2162 listed wood-fuel ovens (vented per manufacturer).• UL 197 listed electric cooking appliances for reduced grease emissions.• UL 921 listed electric dishwashers with self-contained condensing.• Certain “heat/moisture only” appliances when the HVAC/separate removal system accounts for the load: Provide space exhaust at 0.70 cfm/sf, and for floor area calcs count each non-Type-II appliance as at least 100 sf (plus that extra area exhausted at 0.70 cfm/sf).🏗️ Why it mattersCommon redlines: “recirc hood” shown with no UL 710B listing, downdraft called out with no listing basis, and designers skipping hood exhaust but also skipping the required space exhaust/ventilation logic.🗺️ Where to show it• M-001: “IMC 507 HOOD TYPE BASIS” note + a dedicated “EXCEPTIONS” note listing UL 710B / UL 197 / UL 921 / UL 2162 / NFPA 96 downdraft (as applicable).• Hood/appliance schedule: include LISTING STANDARD + MODEL for any exception-driven design.• Ventilation schedule noting Kitchen spaces: when using the heat/moisture-only option, show the 0.70 cfm/sf and the “100 sf minimum per appliance” basis.🔧 Field tipRun a quick “LISTING CHECK” on every kitchen plan: If you’re claiming an exception, put the UL/NFPA standard + model number on the drawings. If it’s not on the sheet, it’s not defensible.Comment “IMC507-P6” if you want a paste-ready M-001 exception note + schedule fields.