Vapor Barrier 4 : The term applied to an impervious layer of material superimposed upon a layer of insulation. Vapor barriers are always applied on the warm side of the insulation layer
EESiFlo North America, Terminology and Glossary: HVAC Terms, Pennsylvania, USA 2002. flowmeterdirectory.com/flowmeter_terminology, (Heat, Vent and Air Cond - Amer) {553}