HVAC & Ventilation

Hood Extract Calculations

Classifies the hood style and the appliance duty, calculates the extract flow, splits out the make-up air, and sizes the duct and collar to a design velocity. Type I (grease) and Type II (heat and condensate) hoods, all styles. Two methods are kept deliberately separate: an ASHRAE preliminary route for early design and a detailed DW/172 route for the issued calculation. An ASHRAE 90.1 energy advisory flags where the kitchen exhaust rate would breach the energy limits.

Pinned to

Last reviewed against the printed text · 24 August 2026

Sample report

2.09 m³/s exhaustKitchen Hood Extract, KH01View the issued report

Walkthrough

1:52Hood Extract Calculations

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