1.1本指南描述并比较了不同的方法，用于评估泄压引起的反冲和泄漏的可能性或存在性。 1.2在减压或自然条件下，对减压引起的回吸和溢出进行评估。 1.3本指南中涉及的家用通风燃烧设备包括热水器和加热炉。本指南也适用于锅炉。 1.4本指南中给出的方法适用于I类（配备通风罩和引风机）熔炉。本指南不适用于第三类（配备动力通风口）或第四类（直接通风口）熔炉。 1.5本指南中的方法不用于识别由于通风孔堵塞或热交换器泄漏导致的回吸或溢出。 1.6本指南无意为确定是否符合器具和通风装置的规范要求提供依据，但确实包括对装置的目视评估。该评估可能表明需要由合格的技术人员进行彻底检查。 1.7本指南中方法的用户应熟悉燃烧装置的操作以及使用鼓风机门进行室内气密性测量。本指南中描述的一些方法需要熟悉差压测量和基于计算机的数据记录设备的使用。 本指南并非旨在解决与其使用相关的所有安全问题（如有）。用户有责任制定适当的安全和健康实践，并在使用前确定监管限制的适用性。 在执行本指南中给出的某些程序时，可能会发生一氧化碳（CO）暴露或火焰熄灭。有关在执行此类程序时必须采取的预防措施，请参阅第节。

1.1 This guide describes and compares different methods for assessing the potential for, or existence of, depressurization-induced backdrafting and spillage from vented residential combustion appliances. 1.2 Assessment of depressurization-induced backdrafting and spillage is conducted under either induced depressurization or natural conditions. 1.3 Residential vented combustion appliances addressed in this guide include hot water heaters and furnace. The guide also is applicable to boilers. 1.4 The methods given in this guide are applicable to Category I (draft-hood- and induced-fan-equipped) furnaces. The guide does not apply to Category III (power-vent-equipped) or Category IV (direct-vent) furnaces. 1.5 The methods in this guide are not intended to identify backdrafting or spillage due to vent blockage or heat-exchanger leakage. 1.6 This guide is not intended to provide a basis for determining compliance with code requirements on appliance and venting installation, but does include a visual assessment of the installation. This assessment may indicate the need for a thorough inspection by a qualified technician. 1.7 Users of the methods in this guide should be familiar with combustion appliance operation and with making house-tightness measurements using a blower door. Some methods described in this guide require familiarity with differential-pressure measurements and use of computer-based data-logging equipment. This guide does not purport to address all safety concerns, if any, associated with its use. It is the responsibility of the user to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to use. Carbon monoxide (CO) exposure or flame roll-out may occur when performing certain procedures given in this guide. See Section, for precautions that must be taken in conducting such procedures.