1.1 本标准中的试验方法适用于低层住宅和商业建筑中的空气分配系统。 1.2 这些测试方法涵盖了测量空气分配系统空气泄漏的四种技术。该技术使用空气流量和压力测量来确定泄漏特性。 1.3 其中两种技术的测试方法还规定了在正常运行期间表征分配系统空气泄漏量所需的辅助测量。 1.4 包括系统鼓风机引起的总再循环空气流量的测试方法，以便空气分配系统的泄漏可以标准化，这是能量计算经常需要的。 1.5 正确使用这些测试方法需要了解空气流量和压力测量的原理。 1.6 其中三种测试方法旨在测量从空气分配系统到外部的空气泄漏。另一种测试方法测量总的空气泄漏，包括空调空间内部的空气泄漏。 1.7 以国际单位制或英寸磅单位表示的数值应单独视为标准。每个系统中规定的值可能不是完全相等的；因此，每个系统应独立使用。 将两个系统的值合并可能导致不符合标准。 1.8 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的使用者有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 有关具体危险说明，请参阅第节 7. 。 1.9 本国际标准是根据世界贸易组织技术性贸易壁垒委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认的标准化原则制定的。 ===意义和用途====== 5.1 空气分配系统和非空调空间之间的空气泄漏会影响分配系统的能量损失、建筑物的通风率和空气污染物的进入率。 5.2 住宅和小型商业建筑的渗透能量负荷和通风率的确定通常基于这样的假设，即渗透和通风的主要驱动力是风和室内/室外温差。对于具有穿过无条件空间的配电系统的建筑来说，这可能是一个不合适的假设，因为该系统存在相对适度的泄漏对整体通风率有相对较大的影响。 需要这些外部分配系统的空气泄漏特性来确定其通风、能量和污染物进入的影响。 5.3 只要系统未运行，通过外部空气分配封套的空气泄漏可以按照与建筑封套中的空气泄漏相同的方式进行处理（见试验方法 E779 )。然而，当系统鼓风机打开时，空气分配系统泄漏的压力通常明显大于驱动自然渗透的压力。根据泄漏的大小，这些压力可能导致比自然渗透大得多的流量。 因此，能够将这些泄漏与建筑围护结构泄漏隔离开来是很重要的。空气分配系统的泄漏必须在现场进行测量，因为在确定这些系统的泄漏时，工艺和安装细节比设计更重要。 5.4 对于规范、标准和其他合规性或质量控制应用，满足指定目标（例如，参考压力下的空气流量）的精度和可重复性比操作条件下的空气泄漏流量更重要。一些现有的规范、标准和自愿项目要求使用更简单的测试方法（测试方法D），该方法不会将供应与回流泄漏、内部泄漏与外部泄漏分开，也不会估计操作条件下的泄漏压力。 5.5 测试方法A、B和C可用于能源使用计算以及合规性和质量控制应用。试验方法D仅用于合规性和质量控制。

1.1 The test methods included in this standard are applicable to the air distribution systems in low-rise residential and commercial buildings. 1.2 These test methods cover four techniques for measuring the air leakage of air distribution systems. The techniques use air flow and pressure measurements to determine the leakage characteristics. 1.3 The test methods for two of the techniques also specify the auxiliary measurements needed to characterize the magnitude of the distribution system air leakage during normal operation. 1.4 A test method for the total recirculating air flow induced by the system blower is included so that the air distribution system leakage can be normalized as is often required for energy calculations. 1.5 The proper use of these test methods requires knowledge of the principles of air flow and pressure measurements. 1.6 Three of these test methods are intended to produce a measure of the air leakage from the air distribution system to outside. The other test method measures total air leakage including air leaks to inside conditioned space. 1.7 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard. 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. For specific hazard statements, see Section 7 . 1.9 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. ====== Significance And Use ====== 5.1 Air leakage between an air distribution system and unconditioned spaces affects the energy losses from the distribution system, the ventilation rate of the building, and the entry rate of air pollutants. 5.2 The determination of infiltration energy loads and ventilation rates of residences and small commercial buildings are typically based on the assumption that the principal driving forces for infiltration and ventilation are the wind and indoor/outdoor temperature differences. This can be an inappropriate assumption for buildings that have distribution systems that pass through unconditioned spaces, because the existence of relatively modest leakage from that system has a relatively large impact on overall ventilation rates. The air leakage characteristics of these exterior distribution systems are needed to determine their ventilation, energy, and pollutant-entry implications. 5.3 Air leakage through the exterior air distribution envelope may be treated in the same manner as air leakage in the building envelope as long as the system is not operating (see Test Method E779 ). However, when the system blower is on, the pressures across the air distribution system leaks are usually significantly larger than those driving natural infiltration. Depending on the size of the leaks, these pressures can induce much larger flows than natural infiltration. Thus, it is important to be able to isolate these leaks from building envelope leaks. The leakage of air distribution systems must be measured in the field, because it has been shown that workmanship and installation details are more important than design in determining the leakage of these systems. 5.4 For codes, standards, and other compliance or quality control applications, the precision and repeatability at meeting a specified target (for example, air flow at reference pressure) is more important than air leakage flows at operating conditions. Some existing codes, standards, and voluntary programs require the use of a simpler test method (Test Method D) that does not separate supply from return leakage, leakage to inside from leakage to outside, or estimate leakage pressures at operating conditions. 5.5 Test Methods A, B, and C can be used for energy use calculations and compliance and quality control applications. Test Method D is intended for use in compliance and quality control only.