The purpose of this test procedure is to measure the air leakage rate through a building envelope.
1. This enclosure leakage procedure is applicable to nonresidential buildings.
a. Buildings that have less than 10,000 ft2 of conditioned floor area may perform the whole-building air leakage test in accordance with Residential Energy Services Network (RESNET)/ANSI/ICC3 380-2019 Guidelines and RA3.8 rather than those in NA5.2-7.
b. Buildings that have more than 50,000 ft2 of conditioned floor area, a sectional test method of co-pressurizing representative test floors and taking data from the specific floors is permitted when following the procedures in Sections NA5.2-7. Representative test floors must meet the following conditions as adopted from ASHRAE 90.1-2019 Exceptions to 5.4.3.1.1:
i. The entire floor area of all stories that have any spaces directly under a roof.
ii. The entire floor area of all stories that have a building entrance or loading dock.
iii. Representative above-grade wall sections of the building totaling at least 25% of the wall area enclosing the remaining conditioned space. Floor areas in parts a) and b) shall not be included in the 25%.
iv. When interpreting the data and determining the final air leakage rate, the measured air leakage is area-weighted by the surface areas of the building envelope.
The measurement procedure shall be based on the specifications of ASTM E3158 by blower door fan assembly (architectural only) and multi-point regression testing as further specified in Sections NA5.2, NA5.3, NA5.4, NA5.5, NA5.6, NA5.7 below.