Whole Building Air Leakage Testing Is Changing Energy Code Requirements

Energy codes for metal buildings undergo periodic updates, with these codes setting the mandatory minimum standards to which designers, builders and contractors must comply when fabricating and erecting metal buildings. The most current and widely used documents that set energy efficiency and energy code guidelines for metal buildings are ASHRAE 90.1-2019 and IECC 2021.

Among the more notable changes made to these documents include new requirements for air leakage testing for metal buildings. Before, these requirements, which seek to improve the performance of a building’s thermal envelope, were only in place in a few states. Prior editions of ASHRAE 90.1-2019 and IECC 2021 left them optional in most other areas.

Testing for and Reducing Air Leakage

Metal buildings, in general, are resistant to air leakage. Many pass air leakage tests with relative ease. Most air leakage tests involve the use of certain diagnostic tools, such as synthetic smoke, to identify where leaks exist, and they usually take about a day to complete.

There are certain areas within a steel building that may be more prone to air leakage than others. Doors and windows are common sources of air leaks. Seams and gaps along the building envelope may also allow air to escape, particularly if proper care isn’t taken during erection.

Insulating metal buildings is a highly effective way to reduce air leakage. However, extra care is necessary when installing the insulation, as gaps or tears in the insulation system also have the potential to let air escape.