ASTM E779 - 10

    Standard Test Method for Determining Air Leakage Rate by Fan Pressurization

    Active Standard ASTM E779 | Developed by Subcommittee: E06.41

    Book of Standards Volume: 04.11


      Format Pages Price  
    PDF 10 $42.00   ADD TO CART
    Hardcopy (shipping and handling) 10 $42.00   ADD TO CART
    Standard + Redline PDF Bundle 20 $50.40   ADD TO CART


    Significance and Use

    Air leakage accounts for a significant portion of the thermal space conditioning load. In addition, it affects occupant comfort and indoor air quality.

    In most commercial or industrial buildings, outdoor air is often introduced by design; however, air leakage is a significant addition to the designed outdoor airflow. In most residential buildings, indoor-outdoor air exchange is attributable primarily to air leakage through cracks and construction joints and is induced by pressure differences due to temperature differences, wind, operation of auxiliary fans (for example, kitchen and bathroom exhausts), and the operation of combustion equipment in the building.

    The fan-pressurization method is simpler than tracer gas measurements and is intended to characterize the air tightness of the building envelope. It is used to compare the relative air tightness of several similar buildings to identify the leakage sources and rates of leakage from different components of the same building envelope, and to determine the air leakage reduction for individual retrofit measures applied incrementally to an existing building, and to determine ventilation rates when combined with weather and leak location information.

    1. Scope

    1.1 This test method measures air-leakage rates through a building envelope under controlled pressurization and de-pressurization.

    1.2 This test method is applicable to small temperature differentials and low-wind pressure differential, therefore strong winds and large indoor-outdoor temperature differentials shall be avoided.

    1.3 This test method is intended to quantify the air tightness of a building envelope. This test method does not measure air change rate or air leakage rate under normal weather conditions and building operation.

    Note 1—See Test Method E741 to directly measure air-change rates using the tracer gas dilution method

    1.4 This test method is intended to be used for measuring the air tightness of building envelopes of single-zone buildings. For the purpose of this test method, many multi-zone buildings can be treated as single-zone buildings by opening interior doors or by inducing equal pressures in adjacent zones.

    1.5 Only metric SI units of measurement are used in this standard. If a value for measurement is followed by a value in other units in parentheses, the second value may be approximate. The first stated value is the requirement.

    1.6 This standard does not purport to address all of the safety concerns, 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. For specific hazard statements see Section 7.


    2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

    ASTM Standards

    E631 Terminology of Building Constructions

    E741 Test Method for Determining Air Change in a Single Zone by Means of a Tracer Gas Dilution

    E1258 Test Method for Airflow Calibration of Fan Pressurization Devices


    ICS Code

    ICS Number Code 91.140.30 (Ventilation and air-conditioning systems)

    UNSPSC Code

    UNSPSC Code 40101500(Ventilation)


    DOI: 10.1520/E0779-10

    ASTM International is a member of CrossRef.

    ASTM E779

    Citing ASTM Standards
    Back to Top