【国外标准】 Standard Test Method for Evaluating the Ability of Exterior Vents to Resist the Entry of Embers and Direct Flame Impingement

5.1 This test method evaluates the ability of exterior vents that mount vertically or horizontally to resist the entry of embers and flame penetration through the vent.NOTE 3: A comparison study between the vertical air flow apparatus and a horizontal air flow apparatus, developed at the National Institute of Standards and Technology (NIST), has been conducted. A summary of the results of that comparison study are presented in Section X1.3 of the Appendix.5.2 Flame Intrusion Test—Refer to the Significant and Use Section in Test Method E2912 for information related to the direct flame impingement on the vent.1.1 This fire-test-response standard prescribes two individual methods to evaluate the ability of a gable end, crawl space (foundation) and other vents that mount on a vertical wall or in the under-eave area to resist the entry through the vent opening of embers and flame. The ability of such vents to completely exclude entry of flames or embers is not evaluated. Roof ridge and off-ridge (field) vents are excluded from this standard. Acceptance criteria are not provided in this standard.NOTE 1: Test Method E2912 records information relevant to evaluate completely excluding the entry of flames through the venting device.1.2 Ember entry and flame penetration are evaluated separately using different test procedures. A commentary and summary of the development of the ember test apparatus are given in Appendix X1.1.3 These laboratory tests are used to evaluate the response of vents when subjected to ember and flame exposures under controlled conditions.1.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.1.5 Unless otherwise specified, the tolerance for dimensions in figures and text in this document shall be ±5 %.1.6 This test method does not address interior fire spread.1.7 The standard is used to measure and describe the response of materials, products or assemblies to heat and flame under controlled conditions, but does not by itself incorporate all factors required for fire hazard or fire risk assessments of the materials, products or assemblies and other cladding materials under actual fire conditions.1.8 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.9 Fire testing is inherently hazardous. Adequate safeguards for personnel and property shall be employed in conducting these tests.1.10 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.