Principal Exhaust Duct Size Table 9.32.3.4.B. Forming Part of Sentences 9.32.3.4.(9) and (10) [mm]: Inche(s): = Table 9.32.3.4B Ontario Regulation 332/12 Building Code, Information published by oncodes.ca for educational purposes only. Similar articles Protection Against Depressurization Minimum Outdoor Air Supply and Main Trunk Duct Sizes Structural Movement Wiring in ducts and plenum chambers