Commercial Kitchen Hood Exhaust (IMC 507)
Type I (grease) and Type II (vapor-only) commercial-kitchen hood exhaust airflow per IMC 2021 §507.13 / §507.20 duty multipliers. Makeup air, duct area, grease-duct slope reminder. NFPA 96 governs grease-handling exhaust system design.
Formula and source
Type I: Q = duty_multiplier * L. Wall-canopy duty multipliers (light 200, medium 300, heavy 400, extra-heavy 550 cfm/ft) per IMC 2021 §507.13. Single-island canopy (400 / 500 / 600 / 700). Double-island (250 / 300 / 400 / 550). Backshelf / proximity / pass-over (250 / 300 / 400; extra-heavy not allowed). Type II: Q = 100 * L (IMC 507.20). Makeup = 0.80 * Q (IMC 508 balance check). Duct area (in^2) = Q / V * 144.
IMC 2021 §507.13 (Type I) and §507.20 (Type II). NFPA 96-2024 governs grease-handling exhaust system design.
Audience
This tile is built for hvac and the adjacent professions in the HVAC group. The interactive calculator runs entirely in your browser. No account, no fee, no advertising, no tracking.
Related tools
Posture
Rough Logic answers the math question the working professional asks on the job. The site is a calm, fast, ad-free, account-free, ever-free reference. It does not interpret code. It does not replace the licensed professional. It does not store your inputs. The Authority Having Jurisdiction governs all installations and inspections.