Why Use an Air Barrier?
Air Barrier Systems are used to make the building perform better. The primary purpose of an air barrier system is to stop the air from leaking into and out of the building enclosure.
The first impact on the building will work as intended. The occupants are more comfortable, are provided draft free space, and are protected from pollutants from entering the building. These pollutants can range from pollens, suspended particulates and odors to biological contaminates on the other side.
Mechanical systems can be properly sized rather than having to compensate for the air leakage by over-sizing the equipment. In addition to the equipment not having to condition the air that leaked in, the equipment will work more efficiently.
Moisture laden air leaking in from either the inside or the outside are barred from entering the building enclosure. If this is not done this moisture laden air can migrate far enough into the building assembly that they can be cooled down to their dew point and at this point the water vapor turns to liquid water. This liquid water can corrode metals in the building assembly, provide one of the ingredients needed for mold growth, saturate building materials such as fibrous insulations, gypsum wall board, and wood. Air leakage has the ability to transport exponentially more moisture into and through the building enclosure than occurs through vapor diffusion alone.
Determination of building materials and the growth of mold is detrimental to indoor air quality.
Air barriers, especially when used to separate two different environments within a building can protect one occupant from another occupant’s pollutants (such as second hand cigarette smoke), odors (such as cooking odors) and noise (sound delivered by air transport).