5.1 The exterior building envelope and its components (for example, windows and doors) separate the interior conditioned spaces from exterior environmental factors such as heat, cold, rain, wind, noise dust, etc. Building materials and components can expand or contract to varying degrees, depending on seasonal and diurnal exterior ambient air temperatures. Fluctuations in the ambient air temperatures can alter the sealing characteristics of windows, curtain walls, and doors by changing weather seal compression ratios. Thermal expansion or contraction of framing materials coupled with thermal blowing due to temperature gradients through the product, and alterations in the effective leakage areas due to weather seal shrinkage and compression set, can also significantly alter the air leakage rates of these products in field service applications. Air leakage tests performed using Test Method E283 (a laboratory air leakage test performed at ambient temperature conditions) will not account accurately for changes in air leakage rates that may occur from dimensional changes in fenestration systems, materials, and components.

5.2 It is recommended that test specifiers consult the manufacturer for recommended test temperature extremes.

5.3 This procedure provides a means for evaluating air leakage rates of fenestration systems under various temperature and pressure conditions and air flow directions. It is also applicable for use in evaluating the efficiency of weather sealing products in fenestration systems. All air flow rates are converted to standard conditions to provide a means of comparison between measurements made at different ambient air temperature and pressure conditions.

5.4 Air leakage rates are sometimes used for comparison purposes. Such comparisons may not be valid unless the components being tested and compared are of essentially the same size, configuration, and design.

1.1 This test method provides a standard laboratory procedure for determining the air leakage rates of exterior windows, curtain walls, and doors under specified differential air temperature and pressure conditions across the specimen.

1.2 Specified temperature and pressure conditions are representative of those that may be encountered at the exterior thermal envelope of buildings, excluding the effects of heat buildup due to solar radiation.

1.3 This laboratory procedure is applicable to exterior windows, curtain walls, and doors and is intended to measure only such leakage associated with the assembly and not the installation; however, the test method can be adapted for the latter purpose.

1.4 This is a laboratory procedure for testing at differential temperature conditions. Persons interested in a laboratory test at ambient conditions should reference Test Method E283. Persons interested in a field test on installed windows and doors should reference Test Method E783.

1.5 Persons using this procedure should be knowledgeable in the areas of heat transfer, fluid mechanics, and instrumentation practices, and shall have a general understanding of fenestration products and components.

1.6 The values stated in SI units are to be regarded as standard. The inch-pound units given in parenthesis are provided for information only.

1.7 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.