Field glossaryMakeup airAir brought in to replace what is exhausted, by ducted outside air, transfer air, or surplus supplyUsed across 2 Anvilfield field guides, most in HVAC. Where this shows upHVACBuilding pressurization field guideHVACCommercial exhaust ventilation guide Related termsBackdraft damperDOASin. w.c. / in. wgStack effectUpblast fan Back to the full field glossary