Field glossaryin. w.c. / in. wgInches of water column, the unit for building and duct pressure; about 249 Pa per inchUsed across 2 Anvilfield field guides, most in HVAC. Where this shows upHVACBuilding pressurization field guideHVACMakeup air unit field guide Related termscfmDOASESPMakeup airStack effectType I hoodType II hood Back to the full field glossary