1.1 This test method covers the airflow measurement calibration techniques for fan pressurization systems used for measuring air leakage rates through building envelopes.

1.2 This test method is applicable to systems used for air leakage measurement as described in Practice E779.

1.3 This test method involves the installation of the fan pressurization system in a calibration chamber. Use of the fan pressurization system in an actual building may introduce additional errors in the airflow measurement due to operator influence, interference of internal partitions and furnishings, weather effects, and other factors.

1.4 The proper use of this test method requires a knowledge of the principles of airflow and pressure measurement.

1.5 This standard includes two basic procedures, a preferred procedure, based on ASHRAE Standard 51/AMCA Standard 210, and an optional procedure based on a nonstandard airflow measurement technique, commonly used by manufacturers of fan pressurization devices, but which has not been compared with standard airflow measurement techniques.

1.6 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.