What does “pressure equalized system” mean?
The term “pressure equalized system” is part of the rainscreen system principle that employs two separate cladding “layers” in the construction of a building’s exterior wall. These layers act together as the final moisture barrier, the air/vapor barrier, an insulating layer and a building structural wall. The outer layer allows water penetration through open wall joints, yet it is in the action of how water penetration occurs and how it is handled that the rainscreen principle diverges into two types of systems: drained/back-ventilated and pressure-equalized/compartmented. Briefly, the drained/back-ventilated approach minimizes water penetration via joint design, channeling water that does enter down through vertical channels and out the bottom exterior of the wall. The pressure-equalized/compartmented approach relies on a carefully designed system of vented openings, which act to equalize the air pressure between the exterior and interior of a building wall. Sections of the wall are “
