Air leakage and vapor diffusion, although related, are not the same. They are two different processes that occur in the building envelope, especially in a commercial building, and they have different impacts on the energy efficiency and indoor air quality of a building. …
In hot climates, the placement of a vapor barrier in a commercial building is critical to manage the interior vapor pressure and maintain the building's structural integrity. It's an essential part of the moisture control strategy that safeguards the building from potential damages due to condensation. …
In a cold climate, the primary reason for using an interior vapour barrier is to manage the interior vapor pressure and reduce the risk of condensation within the wall assembly. This is especially important in commercial buildings where the control of indoor humidity levels can be challenging due to the high occupancy levels and diverse activities taking place within the …
