Commercial Air Barrier Systems
As a key part of the building envelope, commercial air barrier systems perform several jobs at once. All of them help protect the building and its occupants, but an air barrier’s ability to boost building energy efficiency promises substantial environmental benefits. According to the National Institute of Standards and Technology (NIST), air barriers cut building heating and cooling energy consumption by an average of 30% across all climates.
Protecting structures and spaces
Air barriers guard against several forces that diminish long-term building performance. That’s because uncontrolled air leakage doesn’t just drive heating and cooling costs. Air leakage can lead to several scenarios that will negatively impact the building lifecycle and the quality of the conditioned space. That’s because over time, uncontrolled airflow can lead to an unhealthy environment within the building. For example, condensation in the insulation and/or other building materials decreases thermal resistance and become wet, freeze and thaw, compromising building integrity and durability.
To avoid trapping moisture in the wall assembly, air barriers may also have to handle vapor drive. The wall assembly design, climate and local dew point will all help architects decide if the building needs a vapor permeable or non-permeable air barrier.
Proper installation and selection matters
All air barrier system components – the membrane, flashing, sealants and accessories – must be compatible chemically and installed properly. The choice of air barrier system type – self-adhered sheet, or fluid-applied – must be considered carefully according to the building’s architectural details, its climate, application temperatures and more.
Air barrier performance testing
Once installed, air barriers can be subject to several post-application performance tests. Here are the highlights of the most common evaluations:
- Substrate Acceptability – Primarily a visual inspection completed by the consultants, verifying that wall materials are in place and free of gaps, voids, damage and possibly moisture.
- Pull Adhesion Testing (ASTM D 4541) – This destructive test features a portable adhesion tester that pulls a disc glued to the wall membrane away from the wall.
- Detection of Air Leakage Sites (ASTM E 1186) – Soap film or smoke locate air leakage sites under pressure. Often called the “bubble gun” or “smoke pencil” test, this one looks for the “big holes”.
- Notes on Assembly Air and Water Leakage Testing (ASTM E 783 and ASTM E 1105) – These tests are for wall assembly mockups or actual construction to help establish components, assembly sequence, workmanship and detailing.
- Air Leakage through Assembly (ASTM E 783) – An area of the wall is fitted with a de-pressurization chamber, and air leakage is measured at a specified static pressure difference.
- Water Leakage through Assembly (ASTM E 1105) – An area of the wall is covered with a constant film of water and a static pressure difference is induced from the interior or exterior side.
- The Whole Building Air Leakage Test (ASTM E 779) – A blower door, or multiple blower doors de-pressurize the building to a specified level. The fan flow rate needed to maintain the pressure difference is the total building air leakage.
Henry can help you optimize building envelope and commercial air barrier system performance by helping you find optimal solution for your project. Questions about air barrier systems? Schedule a meeting with one of our reps today.